Prussian blue positive electrode material, preparation method therefor, and electrochemical energy storage device

Abstract

The present disclosure provides a prussian blue analogue positive electrode material, a preparation method therefor and an electrochemical energy storage device. A molecular formula of the prussian blue analogue positive electrode material is A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d.□.sub.y.(i-H.sub.2O).sub.z, where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; □ is a M′(CN).sub.6 cavity; L is a neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; i-H.sub.2O is an interstitial water; 0<x≤2; 0<c≤1; 0<y<1; 0<d≤6y; 0≤z≤16. In the prussian blue analogue positive electrode material of the present disclosure, the neutral ligand L participates in the coordination with a transition metal and substitutes the coordinated water partly or wholly, so that a content of the coordinated water is decreased or even eliminated, therefore, the water absorption performance of the prussian blue analogue positive electrode material will be decreased significantly, in turn the performance of the electrochemical energy storage device is significantly improved.

Claims

1. A prussian blue analogue positive electrode material, wherein a molecular formula of the prussian blue analogue positive electrode material is A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d.Math.(i-H.sub.2O).sub.z; where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; L is a neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; i-H.sub.2O is an interstitial water; 0<x≤2; 0<c≤1; 0<y<1; 0<d≤6y; 0≤z≤16.

2. The prussian blue analogue positive electrode material according to claim 1, wherein A is one or more selected from a group consisting of Li.sup.+, Na.sup.+, K.sup.+, Ca.sup.2+, Mg.sup.2+, Zn.sup.2+ and Al.sup.3+.

3. The prussian blue analogue positive electrode material according to claim 1, wherein M is a transition metal.

4. The prussian blue analogue positive electrode material according to claim 3, wherein M is one or more selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ru, Sn, In and Cd.

5. The prussian blue analogue positive electrode material according to claim 1, wherein M′ is a transition metal.

6. The prussian blue analogue positive electrode material according to claim 5, wherein M′ is one or more selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ru, Sn, In and Cd.

7. A preparation method of a prussian blue analogue positive electrode material for preparing the prussian blue analogue positive electrode material according to claim 1, comprising steps of: placing a positive electrode material with a molecular formula of A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-d(i-H.sub.2O).sub.z which is prepared in advance into an environment of a neutral ligand L, then making ligand exchange performed to obtain a prussian blue analogue positive electrode material with a molecular formula of A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d(i-H.sub.2O) .sub.z; where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; L is the neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; i-H.sub.2O is an interstitial water; 0<x≤2; 0<c≤1; 0<y<1; 0<d≤6y; 0≤z≤16.

8. The preparation method of the prussian blue analogue positive electrode material according to claim 7, wherein the environment of the neutral ligand L is a solution containing the neutral ligand L or a gas containing the neutral ligand L.

9. The preparation method of the prussian blue analogue positive electrode material according to claim 8, wherein the solution containing the neutral ligand L is a liquid formed by the neutral ligand L itself, an aqueous solution containing the neutral ligand L or a mixed solution of water and an organic solvent containing the neutral ligand L.

10. The preparation method of the prussian blue analogue positive electrode material according to claim 9, wherein the organic solvent is one or more selected from a group consisting of methanol, ethanol, acetone, DMF, DMSO, tetrahydrofuran, n-propanol, isopropanol, ethylene glycol and propylene glycol.

11. The preparation method of the prussian blue analogue positive electrode material according to claim 8, wherein the gas containing neutral ligand L is a gas formed just by the neutral ligand L itself or a mixed gas formed by the neutral ligand L and an inert gas.

12. The preparation method of the prussian blue analogue positive electrode material according to claim 11, wherein the inert gas is one or more selected from a group consisting of N.sub.2, CO.sub.2, Ar and He.

13. A electrochemical energy storage device, comprising: a positive electrode plate comprising a positive electrode current collector and a positive electrode film which is provided to the positive electrode current collector and contains a positive electrode material; a negative electrode plate; and a separator; wherein, the positive electrode material comprises the prussian blue analogue positive electrode material according to claim 1.

14. The electrochemical energy storage device according to claim 13, wherein the electrochemical energy storage device is a lithium-ion battery, a sodium-ion battery, a potassium-ion battery, a zinc-ion battery or an aluminum-ion battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view illustrating a crystal structure of a prussian blue analogue positive electrode material.

(2) FIG. 2 is a schematic view illustrating an exchange of ligands of a prussian blue analogue positive electrode material.

(3) In FIG. 1 and FIG. 2, a gray larger globe represents a metal M, a black larger globe represent a metal M′, a gray smaller globe represents a carbon atom, a black smaller globe represents a nitrogen atom.

DETAILED DESCRIPTION

(4) Hereinafter a prussian blue analogue positive electrode material, a preparation method therefor and an electrochemical energy storage device according to the present disclosure will be described in detail.

(5) Firstly, a prussian blue analogue positive electrode material according to a first aspect of the present disclosure is described. A molecular formula of the prussian blue analogue positive electrode material is A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d.□.sub.y.(i-H.sub.2O).sub.z; where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; □ is a M′(CN).sub.6 cavity; L is a neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; i-H.sub.2O is an interstitial water; 0<x≤2; 0<c≤1; 0<y<1; 0<d≤6y; 0≤z≤16.

(6) In the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, the neutral ligand L participates in the coordination with a transition metal and substitutes the coordinated water b-H.sub.2O partly or wholly, so that a content of the coordinated water b-H.sub.2O is decreased or even eliminated, therefore, the water absorption performance of the prussian blue analogue positive electrode material will be decreased significantly. The interstitial water i-H.sub.2O in the prussian blue analogue positive electrode material is more easily to be removed through a heating process (for example, the interstitial water i-H.sub.2O in the prussian blue analogue positive electrode material is removed together in a drying process of a positive electrode slurry), and will not influence the transmission of A-ion (A-ion is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+), meanwhile will reduce the negative effect brought by the existence of the interstitial water i-H.sub.2O, for example, the interstitial water i-H.sub.2O will dissociate into an electrolyte and influence the performance of the electrochemical energy storage device.

(7) In the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, preferably, A may be one or more selected from a group consisting of Li.sup.+, Na.sup.+, K.sup.+, Ca.sup.2+, Mg.sup.2+, Zn.sup.2+ and Al.sup.3+.

(8) In the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, preferably, M may be a transition metal, further preferably, M may be one or more selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ru, Sn, In and Cd.

(9) In the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, preferably, M′ may be a transition metal, further preferably, M′ may be one or more selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ru, Sn, In and Cd.

(10) Secondly, a preparation method of a prussian blue analogue positive electrode material according to a second aspect of the present disclosure is described, is for preparing the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, and comprises steps of: placing a positive electrode material with a molecular formula of A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y.□.sub.y.(i-H.sub.2O), which is prepared in advance into an environment of a neutral ligand L, then making ligand exchange performed to obtain a prussian blue analogue positive electrode material with a molecular formula of A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d.□.sub.y.(i-H.sub.2O).sub.z; where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; □ is a M′(CN).sub.6 cavity; L is a neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; i-H.sub.2O is an interstitial water; 0<x≤2; 0<c<1; 0<y<1; 0<d≤6y; 0≤z≤16. Referring to FIG. 2, after the ligand exchange, the coordinated water b-H.sub.2O is partly or wholly substituted by the neutral ligand L.

(11) In the preparation method of the prussian blue analogue positive electrode material according to the second aspect of the present disclosure, the environment of the neutral ligand L may be a solution containing the neutral ligand L or a gas containing the neutral ligand L. The solution containing the neutral ligand L may be a liquid formed by neutral ligand L itself, an aqueous solution containing the neutral ligand L or a mixed solution of water and an organic solvent containing the neutral ligand L. The organic solvent may be one or more selected from a group consisting of methanol, ethanol, acetone, DMF, DMSO, tetrahydrofuran, n-propanol, isopropanol, ethylene glycol and propylene glycol. The gas containing the neutral ligand L may be a gas formed just by the neutral ligand L itself or a mixed gas formed by the neutral ligand L and an inert gas. The inert gas may be one or more selected from a group consisting of N.sub.2, CO.sub.2, Ar and He.

(12) In the preparation method of the prussian blue analogue positive electrode material according to the second aspect of the present disclosure, A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y.□.sub.y (i-H.sub.2O), may be prepared by a conventional co-precipitation reaction.

(13) Thirdly, a preparation method of a prussian blue analogue positive electrode material according to a third aspect of the present disclosure is described, is for preparing the prussian blue analogue positive electrode material according to the first aspect of the present disclosure, and comprises steps of: making a cyanide anion of the transition metal M′ and a cation of the transition metal M in an environment of the neutral ligand L perform co-precipitation reaction to obtain a prussian blue analogue positive electrode material with a molecular formula of A.sub.xM.sub.c[M′(CN).sub.6].sub.1-y(b-H.sub.2O).sub.6y-dL.sub.d.□.sub.y (i-H.sub.2O).sub.z; where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+; M is a metal with the valence of 2+ or 3+; M′ is a metal with the valence of 2+ or 3+; b-H.sub.2O is a coordinated water; □ is a M′(CN).sub.6 cavity; L is a neutral ligand, the neutral ligand is one or more selected from a group consisting of CH.sub.3CN, NH.sub.3, CO and C.sub.5H.sub.5N; H.sub.2O is an interstitial water; 0<x≤2; 0<c≤1; 0<y<1; 0<d≤6y; 0≤z≤16. Referring to FIG. 2, after co-precipitating in a solution containing neutral ligand L, the coordinated water b-H.sub.2O is partly or wholly substituted by the neutral ligand L.

(14) In the preparation method of the prussian blue analogue positive electrode material according to the third aspect of the present disclosure, the environment of the neutral ligand L may be a solution containing the neutral ligand L or a gas containing the neutral ligand L. The solution containing neutral ligand L may be a liquid formed by the neutral ligand L itself, an aqueous solution containing the neutral ligand L and a mixed solution of water and an organic solvent containing the neutral ligand L. The organic solvent may be one or more selected from a group consisting of methanol, ethanol, acetone, DMF, DMSO, tetrahydrofuran, n-propanol, isopropanol, ethylene glycol and propylene glycol. The gas containing neutral ligand L may be a gas formed just by the neutral ligand L itself or a mixed gas formed by the neutral ligand L and an inert gas. The inert gas may be one or more selected from a group consisting of N.sub.2, CO.sub.2, Ar and He.

(15) Finally, an electrochemical energy storage device according to a fourth aspect of the present disclosure is described, and comprises a positive electrode plate, a negative electrode plate and a separator. The positive electrode plate comprises a positive electrode current collector and a positive electrode film which is provided to the positive electrode current collector and contains a positive electrode material. The positive electrode material comprises the prussian blue analogue positive electrode material according to the first aspect of the present disclosure.

(16) In the electrochemical energy storage device according to the fourth aspect of the present disclosure, the electrochemical energy storage device may be a lithium-ion battery, a sodium-ion battery, a potassium-ion battery, zinc-ion battery or an aluminum-ion battery. The prussian blue analogue positive electrode material according to the first aspect of the present disclosure is a prussian blue analogue positive electrode material containing a A-ion which is used to improve the performance of the corresponding electrochemical energy storage device containing the A-ion, where, the A-ion is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn.sup.2+ and Al.sup.3+.

(17) In the electrochemical energy storage device according to the fourth aspect of the present disclosure, the negative electrode plate may comprise a negative electrode current collector and a negative electrode film which is provided to the negative electrode current collector and contains a negative electrode material, and the negative electrode material is one or more selected from a group consisting of carbon based material and silicon based material.

(18) In the electrochemical energy storage device according to the fourth aspect of the present disclosure, the negative electrode plate may also be an A metal or an A metal alloy, where, A is one or more selected from a group consisting of alkali metal, alkaline-earth metal, Zn and Al.

(19) Hereinafter the present disclosure will be described in detail in combination with examples. It should be noted that, the examples described in the present disclosure are only used for explaining the present disclosure, and are not intended to limit the scope of the present disclosure.

Comparative Example 1

(20) A solution (1) was obtained by dissolving appropriate amount of Na.sub.4Fe(CN).sub.4 into appropriate amount of deionized water, a solution (2) was obtained by dissolving appropriate amount of MnCl.sub.2 into appropriate amount of deionized water, then the solution (2) was slowly added into the solution (1) under mixing operation, mixing was then performed for 24 h, then after filtering and drying, a sample needed was obtained. The test results of ICP and TG indicated that the molecular formula of the sample was Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24.□.sub.0.04 (i-H.sub.2O).sub.1.61.

Comparative Example 2

(21) A solution (1) was obtained by dissolving appropriate amount of Na.sub.4Fe(CN).sub.4 into appropriate amount of deionized water, a solution (2) was obtained by dissolving appropriate amount of FeCl.sub.2 into appropriate amount of deionized water, then the solution (2) was slowly added into the solution (1) under mixing operation, mixing was then performed for 24 h, then after filtering and drying, a sample needed was obtained, where, an inert gas was used for protection in the synthetic process, so that Fe.sup.2+ was prevented from being oxidized. The test results of ICP and TG indicated that the molecular formula of the sample was Na.sub.1.58Fe[Fe(CN).sub.6].sub.0.09(b-H.sub.2O).sub.0.60.□.sub.0.10.(i-H.sub.2O).sub.1.34.

Comparative Example 3

(22) A solution (1) was obtained by dissolving appropriate amount of K.sub.4Fe(CN).sub.4 into appropriate amount of deionized water, a solution (2) was obtained by dissolving appropriate amount of MnCl.sub.2 into appropriate amount of deionized water, then the solution (2) was slowly added into the solution (1) under mixing operation, mixing was then performed for 24 h, then after filtering and drying, a sample needed was obtained. The test results of ICP and TG indicated that the molecular formula of the sample was K.sub.1.33Mn[Fe(CN).sub.6].sub.0.82(b-H.sub.2O).sub.1.08.□.sub.0.18 (i-H.sub.2O).sub.2.58.

Example 1

(23) Appropriate amount of the sample obtained in comparative example 1 was taken and uniformly mixed with appropriate amount of solution of acetonitrile (CH.sub.3CN), mixing was then performed under room temperature for 12 h for ligand exchange, then after filtering and drying which were performed after exchange, an acetonitrile-exchanged sample was obtained, of which the molecular formula was Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24-d1 (CH.sub.3CN).sub.d1.□.sub.0.04.(i-H.sub.2O).sub.1.61, 0<d1<0.24.

Example 2

(24) A solution (1) was obtained by dissolving appropriate amount of Na.sub.4Fe(CN).sub.4 into 20% ammonium hydroxide, a solution (2) was obtained by dissolving MnCl.sub.2 which had an equal ratio into appropriate amount of deionized water, then the solution (2) was slowly added into the solution (1) under mixing operation, mixing was then performed for 24 h, then after filtering and drying, a sample whose molecular formula was Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24-d2(NH.sub.3).sub.d2.□.sub.0.04.(i-H.sub.2O).sub.1.61, 0<d2<0 0.24 was obtained, where, the sample was obtained by co-precipitating in an solution of ammonium hydroxide and exchanging with NH.sub.3.

Example 3

(25) Appropriate amount of the sample obtained in comparative example 2 was taken and uniformly mixed with appropriate amount of solution of acetonitrile, mixing was then performed under room temperature for 12 h for ligand exchange, then after filtering and drying which were performed after exchange, an acetonitrile-exchanged sample was obtained, of which the molecular formula was Na.sub.1.58Fe[Fe(CN).sub.6].sub.0.90(b-H.sub.2O).sub.0.60-d3(CH.sub.3CN).sub.d3.□.sub.0.10.(i-H.sub.2O).sub.1.34, 0<d3<0.60.

Example 4

(26) Appropriate amount of the sample obtained in comparative example 3 was taken and uniformly mixed with appropriate amount of solution of acetonitrile, mixing was then performed under room temperature for 12 h for ligand exchange, then after filtering and drying which were performed after exchange, an acetonitrile-exchanged sample was obtained, of which the molecular formula was K.sub.1.33Mn[Fe(CN).sub.6].sub.0.82(b-H.sub.2O).sub.1.08-d4(CH.sub.3CN).sub.d4.□.sub.0.18 (i-H.sub.2O).sub.2.58, 0<d4<1.08.

(27) In order to test the water absorption performance of the prussian blue analogue positive electrode material, the sample in all examples and comparative examples were dried for 12 h at 120° C., then the dried sample was divided into two groups (a first group and a second group), the water content of the first group was tested using Karl Fischer Moisture Titrator immediately, and the water content of the second group was tested using Karl Fischer Moisture Titrator after placed in the air for 1 h. The test cut-off temperature of the water content is 170° C.

(28) TABLE-US-00002 TABLE 2 Test results of the water content of examples 1-4 and comparative examples 1-3 water content of the water content of the sample first group/ppm second group/ppm Example 1 1044 3157 Example 2 1287 3573 Example 3 2252 6100 Example 4 2309 6901 Comparative example 1 2311 8091 Comparative example 2 3296 10372 Comparative example 3 3583 15928

(29) It could be seen from a comparison between the test results of the water content of examples 1-2 and comparative example 1, Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24.□.sub.0.04 (i-H.sub.2O).sub.1.61 still contained 2311 ppm water after drying at 120° C. for 12 h, and had particularly strong water absorption performance, the water content thereof increased to 8091 ppm after placed in the air for 1 h; however, in example 1, after exchanged by acetonitrile, a part of the coordinated water of the sample was substituted by acetonitrile, then the sample became Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24-d1(CH.sub.3CN).sub.d1.□.sub.0.04.(i-H.sub.2O).sub.1.61, of which the water content decreased from 2311 ppm to 1044 ppm after drying at 120° C. for 12 h, and of which the water content was just 3157 ppm after placed in the air for 1 h, therefore, it indicated that the water absorption performance of the prussian blue analogue positive electrode material which contained sodium and was obtained in example 1 was greatly decreased; however, in example 2, when co-precipitating in an solution of ammonium hydroxide and synthesizing, a part of the coordinated water of the sample was substituted by NH.sub.3 which entered into the crystal structure of the prussian blue analogue positive electrode material, then the sample became Na.sub.1.85Mn[Fe(CN).sub.6].sub.0.96(b-H.sub.2O).sub.0.24-d2(NH.sub.3).sub.d2.□.sub.0.04.(i-H.sub.2O).sub.1.61, of which the water content decreased from 2311 ppm to 1287 ppm after drying at 120° C. for 12 h, and of which the water content was just 3573 ppm after placed in air for 1 h, therefore, it indicated that the water absorption performance of the prussian blue analogue positive electrode material which contained sodium and was obtained in example 2 was greatly decreased.

(30) It could be seen from a comparison between the test results of the water content of example 3 and comparative example 2, Na.sub.1.58Fe[Fe(CN).sub.6].sub.0.90(b-H.sub.2O).sub.0.60.□.sub.0.10.(i-H.sub.2O).sub.1.34 still contained 3296 ppm water after drying at 120° C. for 12 h, and had particularly strong water absorption performance, the water content thereof increased to 10372 ppm after placed in air for 1 h; however, in example 3, after exchanged by acetonitrile, a part of the coordinated water of the sample was substituted by acetonitrile, then the sample became Na.sub.1.58Fe[Fe(CN).sub.6].sub.0.90(b-H.sub.2O).sub.0.60-d3(CH.sub.3CN).sub.d3.□.sub.0.10.(i-H.sub.2O).sub.1.34, of which the water content decreased from 3296 ppm to 2252 ppm after drying at 120° C. for 12 h, and of which the water content was just 6100 ppm after placed in the air for 1 h, therefore, it indicated that the water absorption performance of the prussian blue analogue positive electrode material which contained sodium and was obtained in example 3 was greatly decreased.

(31) It could be seen from a comparison between the test results of the water content of examples 4 and comparative examples 3, K.sub.1.33Mn[Fe(CN).sub.6].sub.0.82(b-H.sub.2O).sub.1.08.□.sub.0.18 (i-H.sub.2O).sub.2.58 still contained 3583 ppm water after drying at 120° C. for 12 h, and had particularly strong water absorption performance, the water content thereof increased to 15928 ppm after placed in air for 1 h; however, in example 4, after exchanged by acetonitrile, a part of the coordinated water of the sample was substituted by acetonitrile, then the sample became K.sub.1.33Mn[Fe(CN).sub.6].sub.0.82(b-H.sub.2O).sub.1.08-d4(CH.sub.3CN).sub.d4.□.sub.0.18.(i-H.sub.2O).sub.2.58, of which the water content decreased from 3583 ppm to 2309 ppm after drying at 120° C. for 12 h, and of which the water content was just 6901 ppm after placed in the air for 1 h, therefore, it indicated that the water absorption performance of the prussian blue analogue positive electrode material which contained potassium and was obtained in example 4 was greatly decreased.

(32) In conclusion, the neutral ligand L was introduced into the prussian blue analogue positive electrode material of the present disclosure, then the coordinated water b-H.sub.2O was substituted partly or wholly by the neutral ligand L, so that a content of the coordinated water b-H.sub.2O in a prussian blue analogue positive electrode material was decreased or even eliminated, and the water absorption performance of the prussian blue analogue positive electrode material was decreased significantly.