SOLID ELECTROLYTE MATERIAL FOR LITHIUM SECONDARY BATTERY, ELECTRODE, AND BATTERY

Abstract

A solid electrolyte material for a lithium secondary battery, an electrode, and a battery, relating in particular to an additive material capable of improving rapid transmission of ions in lithium secondary battery electrodes, a preparation method therefor and application thereof, and a solid electrolyte material for a secondary battery, a preparation method therefor and application thereof, as well as an electrode, an electrolyte thin layer, and a preparation method therefor.

Claims

1. A lithium secondary battery additive represented by the following formula:
Li.sub.bM.sub.aX.sub.c, wherein M is one or more selected from B, Al, Ga, In, Y, Sc, Sb, Bi, Nb, Ta, Ti, Zr, V, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Cu, Ag, Zn, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; X is one or more selected from F, Cl, Br and I; 0.2≤b≤6; 0.1≤a≤3; and 1≤c≤9.

2. The lithium secondary battery additive according to claim 1, wherein, 1≤b≤3; and/or, 0.2≤a≤1; and/or, 3≤c≤6; preferably, the lithium secondary battery additive is represented by any one of the following formulas, Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6, wherein 0≤d≤1; further, d is selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0; Li.sub.3InCl.sub.6, or Li.sub.3NbCl.sub.8, or Li.sub.3YCl.sub.6.

3. The lithium secondary battery additive according to claim 1, wherein the lithium secondary battery additive is in a form of a glass phase, a glass-ceramic phase or a crystalline phase.

4. A method for preparing the lithium secondary battery additive according to claim 1, wherein, the lithium secondary battery additive is obtained by mixing the required raw materials or precursors according to the proportion and then grinding; or further prepared into a corresponding phase state by adopting an organic solvent co-dissolution recrystallization method, a heating eutectic method and a method of contacting raw material particles in an insoluble hydrocarbon organic solvent.

5. The preparation method according to claim 4, wherein, the raw materials or precursors include LiX and MX.sub.y precursors, wherein M is one or more selected from B, Al, Ga, In, Y, Sc, Sb, Bi, Nb, Ta, Ti, Zr, V, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Cu, Ag, Zn, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; X is one or more selected from F, Cl, Br and I; 0.2≤b≤6; 0.1≤a≤3; and 1≤c≤9; 1≤y≤6, and preferably, 2≤y≤5.

6. The preparation method according to claim 4 or 5, wherein, during the mixing process of the required raw materials or precursors, a proper amount of cosolvent, fluxing agent or ligand of complex is further added, specifically further added with NH.sub.4Cl, I.sub.2, LiI or S.

7. The preparation method according to claim 4, wherein, the obtained glass phase or glass-ceramic phase intermediate product is transformed into glass-ceramic phase or crystalline phase by a heating annealing method; wherein, the temperature for heating annealing is preferably 100 to 600° C., more preferably 150 to 350° C.; the time for heating annealing is preferably 10 minutes to 24 hours, more preferably 1 to 10 hours; further preferably, NH.sub.4Cl, I.sub.2, LiI, S, P or ferrocene is added during the heating annealing to adjust and control the phase and morphology.

8. (canceled)

9. (canceled)

10. A lithium secondary battery, wherein, at least one of the cathode layer, the electrolyte layer and the anode layer of the battery contains one or more of a lithium secondary battery additives represented by the following formula:
Li.sub.bM.sub.aX.sub.c, wherein M is one or more selected from B, Al, Ga, In, Y, Sc, Sb, Bi, Nb, Ta, Ti, Zr, V, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Cu, Ag, Zn, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; X is one or more selected from F, Cl, Br and I; 0.2≤b≤6; 0.1≤a≤3; and 1≤c≤9; wherein, the lithium secondary battery preferably includes a liquid-phase lithium secondary battery, a half-solid-state lithium secondary battery and an all-solid-state lithium secondary battery.

11. A solid electrolyte material for a secondary battery represented by the following formula:
A.sub.1-3.sub.zIn.sub.zX; wherein, A is one or more selected from Li, Na, K and Cs; X is one or more selected from F, Cl, Br and I; and 0<z≤0.33.

12. The solid electrolyte material according to claim 11, wherein, 0.1≤z≤0.25; preferably, the solid electrolyte material is represented by any one of the following formulas:
Li.sub.4InCl.sub.7;
Li.sub.3InCl.sub.5F;
Li.sub.1-3.sub.zIn.sub.zCl, z is 0.25, 0.2, 0.167, 0.143 or 0.1; or,
Na.sub.3InCl.sub.4Br.sub.2.

13. The solid electrolyte material according to claim 11, wherein, wherein In is partially or completely replaced by one or more of the following elements: Al, Ga, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Bi, Sb, Cr, Co, Zr, Zn, Cd, and Mg; preferably, the solid electrolyte material is represented by any of the following formulas: Li.sub.3In.sub.0.8Y.sub.0.2Cl.sub.6, or Li.sub.zIn.sub.0.1Zn.sub.0.9Cl.sub.4.1, or LiGaCl.sub.4, or Li.sub.6FeCl.sub.8, or Li.sub.3YCl.sub.6, or Li.sub.3BiCl.sub.6.

14. The solid electrolyte material according to claim 11, wherein, the solid electrolyte material may be in a form of a glass phase, a glass-ceramic phase or a crystalline phase; or, the solid electrolyte material comprises a principal crystalline phase, and the crystalline phase has a distorted rock salt phase structure; or, the solid electrolyte material may contain a heterogeneous crystalline phase, which has a different crystal structure arrangement from the principal crystalline phase; or, the solid electrolyte material may contain an amorphous phase.

15. A preparation method of a solid electrolyte material for a secondary battery represented by the following formula:
A.sub.1-3.sub.zIn.sub.zX; wherein, A is one or more selected from Li, Na, K and Cs; X is one or more selected from F, Cl, Br and I; and 0<z≤0.33, wherein the preparation is carried out by a liquid phase method; the raw materials or precursors used include but are not limited to AX, InX.sub.3 and MX.sub.a; wherein the definitions of A and X are the same as those of claim 11; M is one or more of Al, Ga, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Bi, Sb, Cr, Co, Zr, Zn, Cd and Mg; and 2≤a≤4; preferably, the raw materials or precursors used are hydrates or solutions of the AX, InX.sub.3 or MX.sub.a; or, preferably, the raw materials or precursors used are precursors of the AX, InX.sub.3 or MX.sub.a that can dissociate or react in liquid phase with equivalent ionic effects, and the precursors include but are not limited to carbonates and bicarbonates; or, preferably, HCl and NH.sub.4Cl are appropriately added as hydrolysis inhibitors or complexing agents in the preparation process of the liquid phase method.

16. The preparation method according to claim 15, characterized by comprising: dissolving the required raw materials or precursors in a certain proportion in the liquid phase, wherein the mass ratio of the required raw materials or precursors to the liquid phase is 1:0.5 to 1:15, preferably 1:2 to 1:5; further preferably, the liquid phase is deionized water or an organic solvent or a mixed solvent of organic solvent/water; more preferably, the organic solvent is ethanol.

17. The preparation method according to claim 15, wherein an annealing treatment may be carried out after drying in the liquid phase method, and the temperature for annealing is 100 to 600° C., preferably 120 to 500° C.; preferably, the annealing is performed in an air atmosphere, an inert gas atmosphere or a vacuum atmosphere.

18. (canceled)

19. (canceled)

20. A secondary battery comprising a cathode (layer), an anode (layer), and an electrolyte layer between the cathode (layer) and the anode (layer); at least one of the cathode (layer), the anode (layer) and the electrolyte layer includes one or more of a solid electrolyte materials for a secondary battery represented by the following formula:
A.sub.1-3.sub.zIn.sub.zX; wherein, A is one or more selected from Li, Na, K and Cs; X is one or more selected from F, Cl, Br and L and 0<z≤0.33; wherein the secondary battery comprises a lithium secondary battery and a sodium secondary battery.

21. A solid electrolyte material, wherein, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase which has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays.

22. The solid electrolyte material according to claim 21, wherein, in the first crystalline phase, the X-ray intensity of the (001) plane in the crystal structure is set to I.sub.(001), and the X-ray intensity of the (131) plane in the crystal structure is set to I.sub.(130), wherein, I.sub.(001)/I.sub.(131)>0.6 is satisfied, preferably, I.sub.(001)/I.sub.(131)>0.8.

23. The solid electrolyte material according to claim 21, wherein, in the first crystalline phase, the X-ray intensity of the (001) plane in the crystal structure is set to I.sub.(001), and the X-ray intensity of the (110) plane in the crystal structure is set to I.sub.(110), wherein, I.sub.(110)/I.sub.(001)<0.85 is satisfied, preferably, I.sub.(110)/I.sub.(001)<0.65.

24. The solid electrolyte material according to claim 21, characterized by further comprising a heterogeneous crystalline phase having a peak at a position of 2θ=10.8°±0.2° in X-ray diffraction measurement using copper Kα rays; preferably, the heterogeneous crystalline phase has a different crystal structure from the first crystalline phase, and the heterogeneous crystalline phase is interposed between the first crystalline phase.

25. The solid electrolyte material according to claim 21, characterized by further comprising an amorphous phase; preferably, the amorphous phase is interposed between the first crystalline phase.

26. The solid electrolyte material according to claim 21, wherein, 0.3≤a≤0.7, and 0.95≤b≤1.10; preferably, a is 0.53 and b is 1.03.

27. The solid electrolyte material according to claim 21, characterized by having an ionic conductivity of more than 10.sup.−3 S/cm; preferably, an ionic conductivity of 0.7 to 2.5 mS/cm, or an ionic conductivity of 1.0 to 2.0 mS/cm; preferably, the solid electrolyte material has a composition represented by Li.sub.1.5In.sub.0.53Cl.sub.3; preferably, the ionic conductivity of the material under the condition of room temperature is 2 mS/cm.

28. (canceled)

29. The solid electrolyte material according to claim 21, wherein, the X-ray diffraction pattern of the solid electrolyte material is shown in FIG. 24.

30. An all-solid-state lithium battery, characterized by having a cathode active material layer, an anode active material layer and a solid electrolyte layer formed between the above cathode active material layer and the above anode active material layer, wherein at least one of the cathode active material layer, the anode active material layer and the solid electrolyte layer includes a solid electrolyte material wherein, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase which has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays.

31. An electrode, characterized by comprising a solid electrolyte material, an electrode material, a conductive agent and a binder; wherein, the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6; or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03.

32. The electrode according to claim 31, wherein, the solid electrolyte material is represented by Li.sub.3b-3aIn.sub.aCl.sub.3, in the first crystalline phase, the X-ray intensity of the (001) plane in the crystal structure is set to I.sub.(001), and the X-ray intensity of the (131) plane in the crystal structure is set to I.sub.(131), wherein, I.sub.(001)/I.sub.(131)>0.6 is satisfied; preferably, I.sub.(001)/I.sub.(131)>0.8; and/or, in the first crystalline phase, the X-ray intensity of the (001) plane in the crystal structure is set to I.sub.(001), and the X-ray intensity of the (110) plane in the crystal structure is set to I.sub.(110), wherein, I.sub.(110)/I.sub.(001)<0.85 is satisfied; preferably, I.sub.(110)/I.sub.(001)<0.65.

33. The electrode according to claim 31, wherein, the solid electrolyte material represented by Li.sub.3b-3aIn.sub.aCl.sub.3 further comprises a heterogeneous crystalline phase, and the heterogeneous crystalline phase has a peak at a position of 2θ=10.8°±0.2° in X-ray diffraction measurement using copper Kα rays; preferably, the heterogeneous crystalline phase has a different crystal structure from the first crystalline phase, and the heterogeneous crystalline phase is interposed between the first crystalline phase.

34. The electrode according to claim 31, wherein, the solid electrolyte material represented by Li.sub.3b-3aIn.sub.aCl.sub.3 further comprises an amorphous phase; and preferably, the amorphous phase is interposed between the first crystalline phase.

35. The electrode according to claim 31, wherein, the X-ray diffraction pattern of the solid electrolyte material represented by Li.sub.3b-3aIn.sub.aCl.sub.3 is shown in FIG. 24.

36. The electrode according to claim 31, wherein, the electrode material is wrapped in the solid electrolyte material; wherein the weight ratio of the electrode material to the solid electrolyte material is preferably (95:5) to (70:30), more preferably 85:15.

37. The electrode according to claim 31, wherein, the content of electrode material in the electrode is 50 wt % to 98 wt %, and/or the content of solid electrolyte material is 2 wt % to 50 wt %, and/or the content of conductive agent is 1 wt % to 10 wt %, and/or the content of binder is 1 wt % to 10 wt %.

38. A preparation method of an electrode, characterized by comprising a solid electrolyte material, an electrode material, a conductive agent and a binder; wherein, the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6; or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03, characterized by comprising dissolving the solid electrolyte material or the precursor thereof in water, then adding the electrode material, uniformly mixing, drying, and further vacuum dewatering and drying; or the preparation method comprises dissolving the solid electrolyte material or the precursor thereof and the electrode material in an organic solvent, ultrasonically dispersing, drying, and then further vacuum desolventizing and drying.

39. An electrolyte thin layer, characterized by comprising a solid electrolyte material and a binder; wherein the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6 or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03; preferably, the content of the solid electrolyte material is 20 wt % to 100 wt %, more preferably 45 wt % to 99 wt %; the content of the binder is 0 to 80 wt %, more preferably 1 wt % to 55 wt %.

40. A preparation method of an electrolyte thin layer, characterized by comprising a solid electrolyte material and a binder; wherein the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6; or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03, characterized by comprising dissolving the binder in a solvent, then adding a solid electrolyte material or the precursor thereof and a conductive agent to prepare a slurry, coating the slurry on a current collector or a flexible substrate, drying, and then peeling off from the current collector or the flexible substrate.

41. A secondary battery, characterized by comprising an electrode, characterized by comprising a solid electrolyte material, an electrode material, a conductive agent and a binder; wherein, the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6; or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03; the secondary battery is preferably a lithium/lithium ion secondary battery.

42. A secondary battery, characterized by comprising an electrolyte thin layer, characterized by comprising a solid electrolyte material and a binder; wherein the solid electrolyte material is Li.sub.aMX.sub.b, M is one or more of Al, Ga, In, Sc, Y and La element, X is one or more of F, Cl and Br, 0≤a≤10, and 1≤b≤13; preferably, the solid electrolyte material is one or more selected from Li.sub.3InCl.sub.6, Li.sub.3YCl.sub.6, Li.sub.3YBr.sub.6, Li.sub.3HoCl.sub.6 and Li.sub.3ScCl.sub.6; or, the solid electrolyte material has the composition represented by Li.sub.3b-3aIn.sub.aCl.sub.3, wherein 0.2≤a≤0.8, and 0.9≤b≤1.15; the solid electrolyte material further has a first crystalline phase, the first crystalline phase has peaks at positions of 2θ=14.6°±0.15°, 16.7°±0.15° and 34.3°±0.15° in X-ray diffraction measurement using copper Kα rays; preferably, 0.3≤a≤0.7, and 0.95≤b≤1.10; and more preferably, a is 0.53, and b is 1.03; the secondary battery is preferably a lithium/lithium ion secondary battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0139] FIG. 1 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6 (d=0.2) additive in Example 1.1;

[0140] FIG. 2 is a temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6 (d=0.2) additive in Example 1.1;

[0141] FIG. 3 shows the change curve of the value of d in glass-ceramic phase Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6 additive in Example 1.1 and the ionic conductivity of corresponding products.

[0142] FIG. 4 is an X-ray diffraction pattern of crystalline phase Li.sub.3InCl.sub.6 in Example 1.2;

[0143] FIG. 5 is a temperature-dependent ionic conductivity diagram of crystalline phase Li.sub.3InCl.sub.6 in Example 1.2;

[0144] FIG. 6 is a charge and discharge curve of the all-solid-state LiIn—LiCoO.sub.2 secondary battery in Application Example 1.1.

[0145] FIG. 7 is a charge and discharge curve of the all-solid-state LiIn-NMC811 secondary battery in Application Example 1.1.

[0146] FIG. 8 is a charge and discharge curve of the liquid-phase Li-LCO secondary battery in Application Example 1.2;

[0147] FIG. 9 is an X-ray diffraction pattern of z=1/7 (Li.sub.4InCl.sub.7) obtained in aqueous solution in Example 2.1;

[0148] FIG. 10 is a temperature-dependent ionic conductivity diagram of Li.sub.4InCl.sub.7 obtained in aqueous solution in Example 2.1;

[0149] FIG. 11 is a temperature-dependent ionic conductivity diagram of Li.sub.3InCl.sub.5F obtained in aqueous solution in Example 2.2;

[0150] FIG. 12 is a graph showing the relationship between ionic conductivity at room temperature and z of Li.sub.1-3.sub.zIn.sub.zCl (0.1≤z≤0.25) obtained in Example 2.3;

[0151] FIG. 13 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.3In.sub.0.8Y.sub.0.2Cl.sub.6 solid electrolyte material obtained in Example 2.5;

[0152] FIG. 14 is a temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.3In.sub.0.8Y.sub.0.2Cl.sub.6 solid electrolyte material obtained in Example 2.5;

[0153] FIG. 15 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.2In.sub.0.1Zn.sub.0.9Cl.sub.4.1 solid electrolyte material obtained in Example 2.6;

[0154] FIG. 16 is an X-ray diffraction pattern of glass-ceramic phase LiGaCl.sub.4 solid electrolyte material obtained in Example 2.7;

[0155] FIG. 17 is an impedance curve of glass-ceramic phase LiGaCl.sub.4 solid electrolyte material obtained in Example 2.7 at room temperature;

[0156] FIG. 18 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.6FeCl.sub.8 solid electrolyte material obtained in Example 2.8;

[0157] FIG. 19 is an impedance curve of glass-ceramic phase Li.sub.6FeCl.sub.8 solid electrolyte material obtained in Example 2.8 at room temperature;

[0158] FIG. 20 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.3YCl.sub.6 solid electrolyte material obtained in Example 2.9;

[0159] FIG. 21 is a temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.3YCl.sub.6 solid electrolyte material obtained in Example 2.9;

[0160] FIG. 22 is a charge and discharge curve of the all-solid-state LiIn—LiCoO.sub.2 secondary battery in Application Example 2.1.

[0161] FIG. 23 is a charge and discharge curve of the all-solid-state LiIn-NMC811 secondary battery in Application Example 2.1;

[0162] FIG. 24 is an X-ray diffraction pattern of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1 and the corresponding structural refinement diagram thereof;

[0163] FIG. 25 is a synchrotron radiation X-ray absorption spectrogram of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1 and the fitting structure model thereof;

[0164] FIG. 26 is a diagram showing the crystal structure and atomic distribution of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1;

[0165] FIG. 27 is an electrochemical characterization of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1. Fig. a is the temperature-dependent impedance curve of the material and the corresponding ionic conductivity thereof, and Fig. b is the voltage window test curve of the material;

[0166] FIG. 28 is a charge and discharge curve of the all-solid-state LiIn—LiCoO.sub.2 secondary battery in Application Example 3.1;

[0167] FIG. 29 is a charge and discharge curve of the all-solid-state LiIn-NMC811 secondary battery in Application Example 3.1;

[0168] FIG. 30 shows the process of forming LiCoO.sub.2 cathode material coated by Li.sub.3InCl.sub.6 in liquid phase of Example 4.1 and the prepared material;

[0169] FIG. 31 shows the process of in-situ formation of LiCoO.sub.2 cathode material coated by Li.sub.3InCl.sub.6 in liquid phase of Example 4.2 and the prepared material;

[0170] FIG. 32 shows the process of forming NMC532 cathode material coated by Li.sub.3InCl.sub.6 in the organic phase of Example 4.3 and the prepared material;

[0171] FIG. 33 shows the process of in-situ formation of NMC532 cathode material coated by Li.sub.3InCl.sub.6 in the organic phase of Example 4.4 and the prepared material;

[0172] FIG. 34 shows the process of preparing the organic phase coated electrode material in Example 4.5 and the prepared material;

[0173] FIG. 35 shows the process of preparing the organic phase coated electrolyte layer in Example 4.6 and the prepared material.

SPECIFIC MODES FOR CARRYING OUT THE EMBODIMENTS

[0174] The following Examples are intended to illustrate the present invention, but are not intended to limit the scope of the present invention. If the specific technology or conditions are not indicated in the Examples, it shall be carried out according to the technology or conditions described in the literature in the art, or according to the product manual. Those reagents or instruments that do not indicate the manufacturer are all conventional products that can be purchased through formal channels.

[0175] In the following Examples, the grinding is carried out in a glove box, either manual grinding or machine grinding; the ball milling operation may be carried out in a zirconia ball mill tank, usually a sealed ball mill.

Example 1.1: Glass-Ceramic Phase Li.SUB.3.Y.SUB.1-d.In.SUB.d.Cl.SUB.6 .Additive and the Preparation Thereof

[0176] 30 mmol of LiCl (1.29 g), 10-10a mmol of InCl.sub.3 and 10a mmol of YCl.sub.3 were ground, then placed into a zirconia ball milling tank with a ball-to-material ratio of 30:1, and then the ball mill was sealed for 30 hours with a ball milling speed of 550 rpm. The sample obtained after ball milling was the glass-ceramic phase Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6 additive. In which d is 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0.

[0177] FIGS. 1 and 2 are respectively the X-ray diffraction pattern and temperature-dependent ionic conductivity diagram of the glass-ceramic phase Li.sub.3Y.sub.1-dIn.sub.dCl.sub.6 (d=0.2) prepared in the present Example. FIG. 3 shows the change curve of the above value of d and the ionic conductivity of corresponding products.

Example 1.2: Crystalline Phase Li.SUB.3.InCl.SUB.6 .Additive and the Preparation Thereof

[0178] 30 mmol of LiCl (1.29 g) and 10 mmol of InCl.sub.3 (2.21 g) were ground, then placed into a zirconia ball milling tank with a ball-to-material ratio of 20:1, and then the ball mill was sealed for 20 hours with a ball milling speed of 550 rpm. The intermediate product obtained after ball milling was reacted in a sealed quartz tube at 450° C. for 10 hours. The resulting product was the crystalline phase Li.sub.3InCl.sub.6 additive.

[0179] FIGS. 4 and 5 are respectively the X-ray diffraction pattern and temperature-dependent ionic conductivity diagram of the crystalline phase Li.sub.3InCl.sub.6 prepared in the present Example.

Example 1.3 Glass Phase Li.SUB.3.NbCl.SUB.8 .Additive and the Preparation Thereof

[0180] The preparation method is similar to that in Example 1.1, except that the raw materials used were as follows: 30 mmol of LiCl (1.29 g) and 2.7 g of NbCl.sub.5; the ball milling speed was changed to 450 rpm, and the time for ball milling was 10 hours. After the precursor was subjected to ball milling, the glass phase Li.sub.3NbCl.sub.8 additive can be obtained.

Example 1.4 Glass-Ceramic Phase Li.SUB.3.YCl.SUB.6 .Electrode Additive Material and the Preparation Thereof

[0181] 30 mmol of LiCl (1.29 g), 10 mmol of YCl.sub.3 (1.95 g) and 20 mmol of ammonium chloride (1.08 g) were ground and mixed, and then dissolved in tetrahydrofuran solvent. Subsequently, the obtained solution was dried in a vacuum drying oven at 150° C. The obtained intermediate product was calcined at 500° C. for 5 hours in argon atmosphere to obtain the glass-ceramic phase Li.sub.3YCl.sub.6 electrode additive material.

Application Example 1.1: Application of the Crystalline Phase Li.SUB.3.InCl.SUB.6 .Electrode Additive Material Prepared in Example 1.2 in all-Solid-State LiIn—LiCoO.SUB.2., LiIn—LiNi.SUB.0.8.Mn.SUB.0.1.Co.SUB.0.1.O.SUB.2 .(LiIn-NMC811)

[0182] Unmodified LiCoO.sub.2 and NMC811 were used as cathode materials. The cathode material and the crystalline phase Li.sub.3InCl.sub.6 electrode additive material were mixed at a ratio of 70:30 (mass ratio) in a glove box by using a mortar to grind for 20 minutes. The ground material was used as a cathode powder. A thin metal indium sheet was used as anode, and commercial Li.sub.10GeP.sub.2S.sub.12 electrolyte material was used as electrolyte. 100 mg of Li.sub.10GeP.sub.2S.sub.12 electrolyte material was put into a mold battery liner with a cross-sectional area of 0.785 square centimeters, and subjected to tableting at a pressure of 200 MPa to obtain the electrolyte layer.

[0183] Then, 10 mg of cathode powder was added to one side of the electrolyte layer, and spread evenly, and then subjected to the second tableting at a pressure of 350 MPa to laminate the cathode layer and the electrolyte layer together. Subsequently, an indium sheet was placed on the other side as an anode layer. After the whole process was completed, the liner was put into the mold battery, pressed and sealed by tightening the screws. After sealing, all-solid-state LiIn—LiCoO.sub.2 and LiIn-NMC811 secondary batteries can be obtained. Among them, the all-solid-state LiIn—LiCoO.sub.2 battery was measured for charging and discharging at a current density of 100 mA, and a cutoff voltage of 1.9 to 3.6 volts. FIG. 6 is a charge and discharge curve of the battery for 1 to 5 cycles. The charge capacity for the first cycle was 142 mAh/g lithium cobaltate, the discharge capacity for the first cycle was 131 mAh/g lithium cobaltate, and the corresponding coulombic efficiency for the first cycle was 91.7%. After that, the capacity of the battery was stabilized at about 130 mAh/g lithium cobaltate, and the reversibility of the battery cycle was good. Among them, the all-solid LiIn-NMC811 battery was charged and discharged with a current density of 100 μA, and a cutoff voltage of 1.9 to 3.9 volts. FIG. 7 is the charge and discharge curve of the battery in the first cycle, the charge capacity for the first cycle was 231 mAh/g NMC811, the discharge capacity for the first cycle was 192 mAh/g NMC811, and the corresponding t coulombic efficiency for the first cycle was 83.1%.

Application Example 1.2: Application of Crystalline Phase Li.SUB.3.InCl.SUB.6 .Electrode Additive Material Prepared in Example 1.2 in Liquid Phase Li—LiCoO.SUB.2

[0184] Unmodified LiCoO.sub.2 was used as cathode material. The cathode material and the crystalline phase Li.sub.3InCl.sub.6 electrode additive material were mixed at a ratio of 90:10 (mass ratio) in a glove box by using a mortar to grind for 20 minutes. The ground material was used as cathode powder. 85 wt % cathode powder, 10 wt % PVDF binder and 5 wt % conductive carbon black were used for stirring and slurrying, and NMP was used as the solvent for slurrying. The obtained slurry was coated on a metal aluminum foil, then dried at 100° C. in vacuum to obtain the cathode plate. The thickness of the plate was greater than 400 μm, and the load of single-sided LCO was higher than 20 mg/cm.sup.2. With lithium sheet as the counter electrode, polyolefin porous membrane (Celgard 2500) as the separator, and the mixed solution of ethylene carbonate (EC) and dimethyl carbonate (DMC) (a volume ratio of 1:1) of LiPF.sub.6 as the electrolyte, the CR2016 battery was assembled in a glove box in argon atmosphere. The electrical performance was tested at a test temperature of 25° C. FIG. 8 is the charge and discharge curve of the battery for the first cycle. The charge capacity for the first cycle was 139 mAh/g LCO, the discharge capacity for the first cycle was 129 mAh/g LCO, and the corresponding coulombic efficiency for the first cycle was 92.8%.

[0185] The above experimental result shows that that the lithium secondary battery additive provided by the present invention may improve the electrode ion transmission speed and is compatible with the exist lithium secondary battery electrode materials. The material has high ionic conductivity at room temperature, stable in air and simple in preparation method, and is compatible with the existing electrode materials of a lithium secondary battery. It is expected to solve the problems of slow ion transmission of electrode materials, low load of electrode materials, difficulty in further improving electrode thickness and the like in a lithium secondary battery, so that it is expected to realize the preparation of electrode plate with high energy density and low electrode polarization, and further improve the energy density of the lithium secondary battery.

Example 2.1: Preparation of Li.SUB.4.InCl.SUB.7 .Solid Electrolyte Material in Aqueous Solution

[0186] 40 mmol LiCl (1.7 g) and 10 mmol InCl.sub.3 (2.21 g) were weighed in air atmosphere and transferred into a 20 ml glass bottle, subsequently 10 ml deionized water was added for dissolution and mixing. After all the materials were completely dissolved, the glass bottle was placed in an oven at 90° C. for drying, and the sample obtained after drying was further placed in a muffle furnace at 260° C. for annealing for 5 hours. Samples obtained after annealing were glass-ceramic phase Li.sub.4InCl.sub.7 solid electrolyte materials.

[0187] FIGS. 9 and 10 are the X-ray diffraction pattern and temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.4InCl.sub.7 solid electrolyte material prepared in the present Example, respectively.

Example 2.2: Preparation of Li.SUB.3.InCl.SUB.5.F Solid Electrolyte Material in Aqueous Solution

[0188] The preparation method is similar to that in Example 2.1, except that 40 mmol of LiCl (1.7 g) precursor was replaced with a mixture of 20 mmol of lithium chloride (0.85 g) and 10 mmol of lithium fluoride (0.26 g). The temperature for annealing was changed to 400° C. The sample obtained after annealing was glass-ceramic phase Li.sub.3InCl.sub.5F solid electrolyte material.

[0189] FIG. 11 is a temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.3InCl.sub.5F solid electrolyte material prepared in the present Example.

Example 2.3: Preparation of Various Li.SUB.1-3..SUB.zIn.SUB.z.Cl (z=0.25, 0.2, 0.167, 0.143, 0.1) Solid Electrolyte Materials in Liquid Phase Environment

[0190] LiCl and InCl.sub.3 were mixed according to a ratio of 1-3z:z (z=0.25, 0.2, 0.167, 0.143, 0.1), at the same time, ensure that the feeding of LiCl and InCl.sub.3 was 40 mmol. Then 5 ml of deionized water was added for dissolving. After all the precursors were completely dissolved, the resultant was placed in a drying oven at 100° C. for drying. The sample obtained after drying was the glass-ceramic phase Li.sub.1-3.sub.zIn.sub.zCl (0.1≤z≤0.25) solid electrolyte material.

[0191] FIG. 12 is a graph showing the relationship between ionic conductivity at room temperature and z of the glass-ceramic phase Li.sub.1-3.sub.zIn.sub.zCl (0.1≤z≤0.25) solid electrolyte material prepared in the present Example.

Example 2.4: Preparation of the Glass-Ceramic Phase Na.SUB.3.InCl.SUB.4.Br.SUB.2 .Solid Electrolyte Material

[0192] 10 mmol of NaCl (0.58 g), 10 mmol of NaBr (1.03 g) and 10 mmol of InCl.sub.3 (2.21 g) were weighed under an air atmosphere and transferred into a 20 ml glass bottle, and then 7 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed in an oven at 90° C. for drying, and the sample obtained after drying was further placed in a muffle furnace at 350° C. for annealing for 5 hours under a vacuum environment. The sample obtained after annealing was glass-ceramic phase Na.sub.3InCl.sub.4Br.sub.2 solid electrolyte material.

Example 2.5: Preparation of Glass-Ceramic Phase Li.SUB.3.In.SUB.0.8.Y.SUB.0.2.O.SUB.6 .Solid Electrolyte Material

[0193] 30 mmol of LiCl (1.272 g), 8 mmol of InCl.sub.3 (1.768 g) and 2 mmol of YCl.sub.3 (0.39 g) was weighed under argon atmosphere and transferred into a 20 ml glass bottle, and then 10 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed in an oven at 90° C. for drying, and the sample obtained after drying was further placed in a vacuum drying oven at 200° C. for reaction. After the reaction, the product obtained was sealed in a quartz glass tube and placed into a muffle furnace for annealing at a temperature of 500° C., for 8 hours. The sample obtained after annealing was glass-ceramic phase Li.sub.3In.sub.0.8Y.sub.0.2Cl.sub.6 solid electrolyte material.

[0194] FIGS. 13 and 14 are the X-ray diffraction pattern and temperature-dependent ionic conductivity diagram of the glass-ceramic phase Li.sub.3In.sub.0.8Y.sub.0.2Cl.sub.6 solid electrolyte material prepared in the present Example, respectively.

Example 2.6: Preparation of Glass-Ceramic Phase Li.SUB.2.In.SUB.0.1.Zn.SUB.0.9.Cl.SUB.4.1 .Solid Electrolyte Material

[0195] 20 mmol of LiCl (0.848 g), 9 mmol of ZnCl.sub.2 (1.224 g) and 1 mmol of InCl.sub.3 (0.221 g) were weighed under argon atmosphere and transferred into a 20 ml glass bottle, and then 5 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed on a heating plate in a fume hood at 90° C. for drying, and the obtained sample after drying was further placed in a vacuum drying oven at 200° C. for reaction for 5 hours. Subsequently, the resultant was subjected to annealing at 300° C. in vacuum atmosphere for 60 minutes, and the obtained sample was a glass-ceramic phase Li.sub.2In.sub.0.1Zn.sub.0.9Cl.sub.4.1 solid electrolyte material.

[0196] FIG. 15 is an X-ray diffraction pattern of glass-ceramic phase Li.sub.zIn.sub.0.1Zn.sub.0.9Cl.sub.4.1 solid electrolyte material prepared in the present Example.

Example 2.7: Preparation of Glass-Ceramic Phase LiGaCl.SUB.4 .Solid Electrolyte Material

[0197] 10 mmol of LiCl (0.424 g) and 10 mmol of GaCl.sub.3 (1.76 g) were weighed under argon atmosphere and transferred into a 20 ml glass bottle, and then 3 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed on a heating plate in a fume hood at 90° C. for drying, and the sample obtained after drying was further placed in a vacuum drying oven at 200° C. for reaction for 5 hours. And the obtained sample was the glass-ceramic phase LiGaCl.sub.4 solid electrolyte material.

[0198] FIGS. 16 and 17 are the X-ray diffraction pattern and impedance curve at room temperature of the glass-ceramic phase LiGaCl.sub.4 solid electrolyte material prepared in the present Example, respectively. It can be calculated from FIG. 17 that the ionic conductivity of the material at room temperature is 9*10.sup.−5 S/cm.

Example 2.8: Preparation of Glass-Ceramic Phase Li.SUB.6.FeCl.SUB.8 .Solid Electrolyte Material

[0199] 30 mmol of LiCl (1.272 g) and 5 mmol of FeCl.sub.2 (0.634 g) were weighed under argon atmosphere and transferred into a 20 ml glass bottle, and then 5 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed in a vacuum box at 90° C. for vacuum drying, and the sample obtained after drying was further dehydrated at 200° C. for 5 hours. The obtained sample was a glass-ceramic phase Li.sub.6FeCl.sub.8 solid electrolyte material.

[0200] FIGS. 18 and 19 are the X-ray diffraction pattern and impedance curve at room temperature of glass-ceramic phase Li.sub.6FeCl.sub.8 solid electrolyte material prepared in the present Example. It can be calculated from FIG. 19 that the ionic conductivity of this material at room temperature is 5*10.sup.−6 S/cm.

Example 2.9: Preparation of Glass-Ceramic Phase Li.SUB.3.YCl.SUB.6 .Solid Electrolyte Material

[0201] 30 mmol of LiCl (1.272 g) and 10 mmol of YCl.sub.3 (1.953 g) were mixed under argon atmosphere and transferred into a 20 ml glass bottle, and then 5 ml of absolute ethanol was added for dissolving and mixing. After all materials were completely dissolved, the glass bottle was dried in argon at 90° C., and the sample obtained after drying was further dehydrated at 200° C. for 5 hours, and then the resultant was subject to annealing at 500° C. for 2 hours. The obtained sample was a glass-ceramic phase Li.sub.3YCl.sub.6 solid electrolyte material.

[0202] FIGS. 20 and 21 are the X-ray diffraction pattern and temperature-dependent ionic conductivity diagram of glass-ceramic phase Li.sub.3YCl.sub.6 solid electrolyte material prepared in the present Example, respectively.

Example 2.10: Preparation of Glass-Ceramic Phase Li.SUB.3.BiCl.SUB.6 .Solid Electrolyte Material

[0203] 30 mmol of LiCl (1.272 g) and 10 mmol of BiCl.sub.3 (3.15 g) were mixed under argon atmosphere and transferred into a 20 ml glass bottle, and then 10 ml of concentrated hydrochloric acid was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed on a heating plate in a fume hood at 90° C. for drying, and the sample obtained after drying was further placed in a vacuum drying oven at 200° C. for reaction for 5 hours. The obtained sample was a glass-ceramic phase Li.sub.3BiCl.sub.6 solid electrolyte material.

Application Example 2.1: Application of the Glass-Ceramic Phase Li.SUB.4.InCl.SUB.7 .Solid Electrolyte Material Prepared in Example 2.1 in all-Solid-State LiIn—LiCoO.SUB.2., LiIn—LiNi.SUB.0.8.Mn.SUB.0.1.Co.SUB.0.1.O.SUB.2 .(LiIn-NMC811)

[0204] Unmodified LiCoO.sub.2 and NMC811 were used as cathode materials. The cathode material and the glass-ceramic phase Li.sub.4InCl.sub.7 solid electrolyte material obtained in Example 2.1 were mixed at a ratio of 90:10 (mass ratio) in a manner of manual grinding for 5 minutes under an air atmosphere. The ground sample was placed into a 20 ml glassware bottle, and deionized water of five times the mass of the sample was added for dispersion, and then placed into an ultrasonic instrument for ultrasonic treatment for 5 minutes. After the ultrasonic treatment, the glassware bottle was placed into a vacuum drying oven and dried at 80° C. for 12 hours under a vacuum environment. The sample obtained after drying was the cathode powder of the secondary battery. A thin metal indium sheet was used as the anode, and the glass-ceramic phase Li.sub.4InCl.sub.7 solid electrolyte material and the commercial Li.sub.10GeP.sub.2S.sub.12 electrolyte material were also used as the electrolyte. 50 mg of Li.sub.4InCl.sub.7 solid electrolyte material was put into a mold battery liner with a cross-sectional area of 0.785 square centimeters, and subjected to tabletting at a pressure of 100 MPa to obtain the first electrolyte layer. Subsequently, 50 mg of Li.sub.10GeP.sub.2S.sub.12 electrolyte material was placed at one end of the first electrolyte layer, and subjected to tabletting at a pressure of 200 Mpa to obtain a double-layer electrolyte layer. Subsequently, 10 mg of cathode powder was added to the end of Li.sub.4InCl.sub.7 electrolyte layer, and after being spread evenly, the resultant was subjected to a third tabletting at a pressure of 350 Mpa to laminate the cathode layer and the electrolyte layer together. Subsequently, an indium sheet was placed at the end of Li.sub.10GeP.sub.2S.sub.12 electrolyte material as an anode layer. After the whole process was completed, the liner was put into the mold battery, pressed and sealed by tightening the screws. After sealing, all-solid-state LiIn—LiCoO.sub.2 and LiIn-NMC811 secondary batteries can be obtained. Among them, the all-solid-state LiIn—LiCoO.sub.2 battery was measured for charging and discharging at a current density of 100 mA, and a cutoff voltage of 1.9 to 3.6 volts. FIG. 22 is a charge and discharge curve of the battery. Among them, the all-solid-state LiIn-NMC811 battery was charged and discharged with a current density of 100 mA, and a cutoff voltage of 1.9 to 3.9 volts. FIG. 23 is a charge and discharge curve for the first cycle of the battery.

Application Example 2.2: Application of the Glass-Ceramic Phase Na.SUB.3.InCl.SUB.4.Br.SUB.2 .Solid Electrolyte Material Prepared in Example 2.4 in an all-Solid-State Sodium Secondary Battery

[0205] Unmodified NaCrO.sub.2 was used as cathode material. The cathode material, the glass-ceramic phase Na.sub.3InCl.sub.4Br.sub.2 solid electrolyte material and the conductive carbon black were mixed at a ratio of 80:15:5 (mass ratio) in a glove box by using a mortar to grind for 20 minutes. The ground material was used as cathode powder. A tin sheet was used as an anode, and a glass-ceramic phase Na.sub.3InCl.sub.4Br.sub.2 solid electrolyte material was used as an electrolyte. 100 mg of Na.sub.3InCl.sub.4Br.sub.2 solid electrolyte material was put into a mold battery liner with a cross-sectional area of 0.785 square centimeters, and subjected to tableting at a pressure of 100 MPa to obtain the electrolyte layer. Subsequently, 10 mg of cathode powder was added to one end of the electrolyte layer, and spread evenly, and then subjected to a second tableting at a pressure of 350 MPa to laminate the cathode layer and the electrolyte layer together. Subsequently, a tin sheet is placed at the other end of the electrolyte layer as an anode layer. After the whole process was completed, the liner was put into the mold battery, pressed and sealed by tightening the screws. After sealing, an all-solid-state NaCrO.sub.2/Sn secondary battery can be obtained. The electrical performance was measured at a temperature of 25° C.

[0206] The following X-ray diffraction is all measured using copper Kα rays.

[0207] The following methods of ionic conductivity were tested by AC impedance, which is as follows: 150 mg of electrolyte material were weighed in the glove box, then subjected to tableting in the mold battery at a pressure of 350 MPa, then the thickness of electrolyte layer was measured and recorded as L, then the resultant was directly assembled into a carbon/electrolyte/carbon symmetrical cell in mold battery, the AC impedance of the battery under open circuit condition was measured, and the obtained impedance value was recorded as R, calculation was performed using the formula of σ=L/(R.Math.A), wherein a is the ionic conductivity, L is the thickness of the electrolyte layer, R is the impedance value, and A is the electrode area of the electrolyte sheet.

Example 3.1: Preparation of the Li.SUB.3b-3a.In.SUB.a.Cl.SUB.3 .(a=0.53, b=1.03) Solid Electrolyte Material

[0208] 30 mmol of LiCl (1.275 g) and 10 mmol of InCl.sub.3.4H.sub.2O (2.93 g) were weighed in air atmosphere and transferred into a 100 ml glass bottle, subsequently, 20 ml of deionized water was added for dissolving and mixing. After all the materials were completely dissolved, the glass bottle was placed in an oven at 80° C. for vacuum drying, and the sample obtained after drying was further dehydrated in a vacuum oven at 200° C. for 5 hours. The sample obtained after dehydration was glass-ceramic phase Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material.

[0209] FIG. 24 is an X-ray diffraction pattern of the glass-ceramic phase Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example and the corresponding structural refinement diagram thereof.

[0210] FIG. 25 is a synchrotron radiation X-ray absorption spectrogram of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example and the fitting structure model thereof.

[0211] According to the above X-ray diffraction and the corresponding structural refinement diagram and synchrotron radiation X-ray absorption spectrogram analysis thereof, it shows that the indium ions in the crystal structure of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in the present Example have a different arrangement from that reported in literature and database.

[0212] According to the crystal structure of Li.sub.3InCl.sub.6 in the Inorganic Crystal Structure Database (Card No. 04-009-9027), the indium ions are arranged at 2 positions of In.sub.1 (0, 0.333, 0) and In.sub.2 (0, 0, 0), with indium ions accounting for 7% at In.sub.1 and 87.5% at In.sub.2, as shown in Table 1 below.

TABLE-US-00001 TABLE 1 Atomic arrangement of Li.sub.3InCl.sub.6 crystal structure Site Atom x y z occupation Position Cl1 0.2421 0.1622 0.2388 1.000 8j Cl2 0.2450 0.0000 −0.2338 1.000 4i In1 0.0000 0.3333 0.0000 0.07 4g In2 0.0000 0.0000 0.0000 0.875 2a Li1 0.5000 0.0000 0.5000 1.000 2d Li2 0.0000 0.1683 0.5000 1.000 4h

[0213] In the Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example, all indium ions are arranged at In.sub.1 (0, 0.333, 0) position, accounting for 53%, as shown in Table 2 below.

TABLE-US-00002 TABLE 2 Crystal structure and atomic distribution of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in Example 3.1 Site Atom x y z occupation Position Cl1 0.2421 0.1622 0.2388 1.000 8j Cl2 0.2450 0.0000 −0.2338 1.000 4i In1 0.0000 0.3333 0.0000 0.530 4g Li1 0.5000 0.0000 0.5000 1.000 2d Li2 0.0000 0.1683 0.5000 1.000 4h

[0214] FIG. 26 shows the diagram of crystal structure and atomic distribution of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example.

[0215] FIG. 27a is a temperature-dependent impedance curve of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example and the corresponding ionic conductivity thereof. The ionic conductivity of the material at room temperature is 2 mS/cm. FIG. 27b is the voltage window test curve of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in the present Example. the test method is carried out by using cyclic voltammetry with Li/electrolyte/Au battery.

Application Example 3.1: Application of the Glass-Ceramic Phase Li.SUB.1.5.In.SUB.0.53.Cl.SUB.3 .Solid Electrolyte Material Prepared in Example 3.1 in all-Solid LiIn—LiCoO.SUB.2 .and LiIn—LiNi.SUB.0.8.Mn.SUB.0.1.Co.SUB.0.1.O.SUB.2 .(LiIn-NMC811)

[0216] Unmodified LiCoO.sub.2 and NMC811 were used as cathode materials. The cathode material and the glass-ceramic phase Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1 were mixed at a ratio of 70:30 (mass ratio) in a manner of manual grinding for 5 minutes in a glove box, and the obtained sample was the cathode powder of the secondary battery. A metal thin indium sheet was used as anode, and the glass-ceramic phase Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material obtained in Example 3.1 and the commercial Li.sub.10GeP.sub.2S.sub.12 electrolyte material were also used as electrolytes, respectively. 50 mg of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material was put into a mold battery liner with a cross-sectional area of 0.785 square centimeters, and subjected to tabletting at a pressure of 100 MPa to obtain the first electrolyte layer. Subsequently, 50 mg of Li.sub.10GeP.sub.2S.sub.12 electrolyte material was placed at one end of the first electrolyte layer, and subjected to tabletting at a pressure of 200 Mpa to obtain a double-layer electrolyte layer. Subsequently, 10 mg of cathode powder was added to the end of the Li.sub.1.5In.sub.0.53Cl.sub.3 electrolyte layer, and after being spread evenly, it was pressed for a third time at a pressure of 350 MPa, and the cathode layer and the electrolyte layer were laminated together. Subsequently, an indium sheet was placed at the end of Li.sub.10GeP.sub.2S.sub.12 electrolyte material as an anode layer. After the whole process was completed, the liner was put into the mold battery, pressed and sealed by tightening the screws. After sealing, all-solid LiIn—LiCoO.sub.2 and LiIn-NMC811 secondary batteries can be obtained. Among them, the all-solid LiIn—LiCoO.sub.2 battery was charged and discharged at a current density of 100 μA, and a cutoff voltage of 1.9 to 3.6 volts. FIG. 28 is a charge and discharge graph of the all-solid-state LiIn—LiCoO.sub.2 battery. Among them, the all-solid-state LiIn-NMC811 battery was charged and discharged with a current density of 100 μA, and a cut-off voltage of 1.9 to 3.8 volts. FIG. 29 is a charge and discharge graph of the all-solid-state LiIn-NMC811 battery for the first cycle.

[0217] The results show that the ion arrangement position of Li.sub.1.5In.sub.0.53Cl.sub.3 solid electrolyte material prepared in Example 3.1 is different from that of Li.sub.3InCl.sub.6 crystal structure in inorganic crystal structure database (Card No. 04-009-9027), and the electrolyte material has higher ionic conductivity, thus realizing the application of the material in solid-state batteries.

[0218] See table 3 for the specific explanation of terms and abbreviations involved in the drawings

TABLE-US-00003 Term/abbreviation Explanation ExpData Experimental Data Normalized Normalized Data Photon Energy Energy of the Photon Modeling Model fitting Normalized Absorption Normalized absorption intensity arb unit Absorbed energy Current Electric current Voltage Potential difference Solid electrolyte Solid state electrolyte Capacity Battery capacity

Example 4.1: Li.SUB.3.InCl.SUB.6 .Coated LiCoO.SUB.2 .Cathode Material Formed in Liquid Phase

[0219] 75 mg of Li.sub.3InCl.sub.6 was dissolved in 2 g of water, then 425 mg of LiCoO.sub.2 was added, dried at 100° C., and then transferred to a vacuum oven at 200° C. for further dehydration and drying to obtain Li.sub.3InCl.sub.6 coated LiCoO.sub.2. No inert atmosphere protection is required in the whole experiment process.

[0220] In FIG. 30, (a) indicates the specific synthesis process; Heating means the condition of heating, and Vacuum means the condition of vacuum; (b) and (c) show SEM photos of LiCoO.sub.2 before coating; (d) and (e) show SEM photos of LiCoO.sub.2 after coating.

Example 4.2: Li.SUB.3.InCl.SUB.6 .Coated LiCoO.SUB.2 .Cathode Material Formed In Situ in Liquid Phase

[0221] 27.4 mg of LiCl and 47.6 mg of InCl.sub.3 was dissolved in water, and then 425 mg of LiCoO.sub.2 was added, the resultant was evaporated to dryness in a 100° C. oven and then transferred to a 200° C. vacuum oven to react for 5 hours. The LiCoO.sub.2 coated with Li.sub.3InCl.sub.6 was obtained (the mass ratio of Li.sub.3InCl.sub.6 to LiCoO.sub.2 was 15:85). No inert atmosphere protection is required in the whole experiment process.

[0222] In FIG. 31, (a) indicates the specific synthesis process; Heating means the condition of heating, and Vacuum means the condition of vacuum; (b) is SEM photo of LiCoO.sub.2 before coating; (c) and (d) are SEM photos of coated LiCoO.sub.2; (e) indicates the first charge and discharge curves of LiCoO.sub.2 coated with different contents of Li.sub.3InCl.sub.6; and (f) shows the cyclic stability of LiCoO.sub.2 coated with different contents of Li.sub.3InCl.sub.6. The abscissa in (e) represents the specific discharge capacity, and the ordinate represents the voltage corresponding to the anode of lithium metal; the current density for constant current charge and discharge is 0.13 mA/cm.sup.2. The abscissa in (f) indicates the number of cycles, the left ordinate indicates the specific discharge capacity, and the right ordinate indicates the coulombic efficiency, the current density of the cycle test is 0.13 mA/cm.sup.2. The experimental samples in (e) and (f) were Li.sub.3InCl.sub.6 coated LiCoO.sub.2 electrodes with different mass ratios (05:95, 10:10, 15:85) controlled by the above method. Electrochemical test results show that, the first discharge specific capacity of LiCoO.sub.2 electrode containing 15% Li.sub.3InCl.sub.6 is 131 mAh/g. After 60 cycles, it remains at 106.4 mAh/g. The first discharge specific capacity of LiCoO.sub.2 electrode containing 10% Li.sub.3InCl.sub.6 is 91.6 mAh/g. After 60 cycles, it remains at 64.7 mAh/g. The first discharge specific capacity of the LiCoO.sub.2 electrode containing 5% Li.sub.3InCl.sub.6 is 40.1 mAh/g. After 60 cycles, it remains at 12.9 mAh/g.

Example 4.3: Li.SUB.3.InCl.SUB.6 .Coated NMC532 Cathode Material Formed in Organic Phase

[0223] 75 mg of Li.sub.3InCl.sub.6 and 425 mg of NMC532 were added into 2 g of ethanol, and dispersed ultrasonically for 5 min, then transferred to an oven at 100° C. for drying, and then transferred to a vacuum oven at 200° C. for further desolvation and drying to obtain NMC532 coated with Li.sub.3InCl.sub.6 (the mass ratio of NMC532 to Li.sub.3InCl.sub.6 was 85:15), and no inert atmosphere protection is required in the whole experiment process.

[0224] NMC532 coated with different contents of Li.sub.3InCl.sub.6 was prepared by controlling the mass ratios of NMC532 and Li.sub.3InCl.sub.6 to 80:20 and 90:10, respectively.

[0225] In FIG. 32, (a) indicates the specific synthesis process; Ethanol means ethyl alcohol, Heating means the condition of heating, and Vacuum means the condition of vacuum; (b) indicates the electron micrographs of NMC532 coated with different contents of Li.sub.3InCl.sub.6.

Example 4.4: Li.SUB.3.InCl.SUB.6 .Coated NMC532 Cathode Material Formed In Situ in Organic Phase

[0226] 3 mol of LiCl and 1 mol of InCl.sub.3 (total mass: 150 mg) was dissolved in 2 g of ethanol, then 850 mg of SC-NMC532 (single crystal NMC532) was added, and placed in a 100° C. oven for drying by evaporation, then transferred to a 200° C. vacuum oven to react for 5 hours to obtain the SC-NMC532 coated with Li.sub.3InCl.sub.6 (the mass ratio of Li.sub.3InCl.sub.6 to SC-NMC532 was 15:85). No inert atmosphere protection is required during the whole experiment process. SC indicates single crystal.

[0227] In FIG. 33, (a) shows the specific synthesis process; Ethanol means ethyl alcohol, Heating means the condition of heating, and Vacuum means the condition of vacuum; (b) is SEM photo of SC-NMC532 before coating; (c) and (d) are SEM photos of coated SC-NMC532; (e) indicates the first charge and discharge curves of LiCoO.sub.2 coated with different contents of Li.sub.3InCl.sub.6; (f) shows the cyclic stability of LiCoO.sub.2 coated with different contents of Li.sub.3InCl.sub.6. The abscissa in (e) represents the specific discharge capacity, and the ordinate represents the voltage vs. the anode of lithium metal. The current density of constant current charge and discharge is 0.13 mA/cm.sup.2. The abscissa in (f) indicates the number of cycles, the left ordinate indicates the specific discharge capacity, and the right ordinate indicates the coulombic efficiency. The current density of the cycle test is 0.13 mA/cm.sup.2. The experimental samples in (e) and (f) are synthesized Li.sub.3InCl.sub.6 coated SC-NMC532 electrodes controlled according to the above method, wherein the mass ratio of Li.sub.3InCl.sub.6 to SC-NMC532 is 15 wt %:85 wt %, wherein SC indicates single crystal. Electrochemical test results show that SC-NMC532 has a first discharge specific capacity of up to 159 mAh/g in Li.sub.3InCl.sub.6 electrolyte, and the capacity remains at 137.6 mAh/g after 10 cycles.

Example 4.5: Organic Phase Coated Electrode Material

[0228] 100 mg of PVDF was dissolved in a certain mass of NMP first, then 150 mg of Li.sub.3InCl.sub.6, 850 mg of LiCoO.sub.2 and 100 mg of acetylene black were weighed and added into the PVDF-NMP solution, and the content of NMP was adjusted to prepare the slurry, then the obtained slurry was blade coated on the carbon-coated aluminum foil current collector, and then transferred to a vacuum oven at 110° C. for drying to obtain the cathode plate.

[0229] In FIG. 34, (a) shows the process of preparing slurry and the process of coating slurry; (b) represents the plate obtained after drying; (c) shows the comparison of electrochemical performance with blade coating of the slurry prepared in the present Example on the carbon-coated aluminum foil and the electrochemical performance with blade coating of the slurry on the conventional aluminum foil. The abscissa of (c) represents the specific discharge capacity, and the ordinate represents the voltage corresponding to the anode of lithium metal. The current density of constant current charge and discharge is 0.13 mA/cm.sup.2. The experimental samples are aluminum foil (Al) and carbon-coated aluminum foil current collector (C-coated Al), and CC represents current collector. The test results indicate that the coated electrode of carbon-coated aluminum foil exhibits less polarization.

Example 4.6: Organic Phase Coated Electrolyte Layer

[0230] 200 mg of polymer binder (SEBR) was weighed and dissolved in a certain amount of n-heptane (heptane), and then 1.8 g of Li.sub.3InCl.sub.6 was added, the slurry was prepared by controlling the content of heptane, and then the slurry was blade coated on the copper current collector, and dried in vacuum at 100° C. After drying, the electrolyte layer was peeled off to obtain a thin layer of solid state electrolyte material.

[0231] In FIG. 35, (a) shows the prepared ultrathin electrolyte layer; (b) shows the comparison of the XRD results of Li.sub.3InCl.sub.6 before and after heptane dispersion; the results show that there is no phase change before and after the Li.sub.3InCl.sub.6 dispersed by heptane solvent, which proves that there is no chemical reaction and physical dissolution of Li.sub.3InCl.sub.6 in heptane.

INDUSTRIAL APPLICABILITY

[0232] The present invention discloses a lithium secondary battery additive, a battery and an electrode. The lithium secondary battery additive provided by the present invention has high ionic conductivity and air stability, and is capable of improving the rapid transmission of electrode ions, increasing the electrode load and thickness, and improving the energy density of the battery. The solid electrolyte material provided by the present invention has high lithium ion conductivity. The electrode and electrolyte thin layer provided by the present invention may significantly improve the ionic conductivity, chemical/electrochemical stability and plasticity. The present invention has wide application prospect and good industrial practicability in the technical field of a secondary battery.