Preparation method of battery composite material and precursor thereof

Abstract

A preparation method of a battery composite material includes steps of providing phosphoric acid, a first metal source, a second metal source and water, processing a reaction of the first metal source, the second metal source, the phosphoric acid and the water to produce a first product, calcining the first product to produce a first precursor or a second precursor, among which each of the first precursor and the second precursor is a solid-solution containing first metal and second metal, and processing a reaction of the first precursor or the second precursor, and a first reactant to obtain a reaction mixture, and then calcining the reaction mixture to produce the battery composite material. As a result, the battery product has two stable charging and discharging platforms, such that the present invention achieves the advantages of enhancing the stability and the electric performance.

Claims

1. A preparation method of a battery composite material, comprising steps of: (a) providing phosphoric acid, a first metal source, a second metal source and water, wherein the formula of the phosphoric acid is written by H.sub.3PO.sub.4, the first metal source is a ferric source, the second metal source is a manganese source, and the formula of the ferric source is written by Fe.sub.7(PO.sub.4).sub.6; (b) processing a reaction of the first metal source, the second metal source, the phosphoric acid and the water to produce a first product; (c) calcining the first product to produce a first precursor or a second precursor, wherein each of the first precursor and the second precursor is a solid-solution containing first metal and second metal, and the formula of the first precursor and the second precursor is written by (Mn.sub.xFe.sub.1-x).sub.2P.sub.2O.sub.7, and wherein x is greater than or equal to 0.5, and is less than or equal to 0.95; and (d) processing a reaction of the first precursor or the second precursor, and at least a first reactant to obtain a reaction mixture, and then calcining the reaction mixture to produce the battery composite material, wherein the formula of the battery composite material is written by LiMn.sub.xFe.sub.1-xPO.sub.4.

2. The preparation method according to claim 1, wherein the first reactant is lithium hydroxide, and the formula of which is written by LiOH.

3. The preparation method according to claim 1, wherein the step (b) further comprises sub-steps of: (b1) allowing a first quantity of the water to dissolve a second quantity of the first metal source and a third quantity of the phosphoric acid to produce a first solution; and (b2) processing a reaction of the first solution and the second metal source and waiting for at least a first time period to produce the first product.

4. The preparation method according to claim 3, wherein the weight ratio of the first metal of the second quantity to phosphoric acid of the third quantity is 1:1.

5. The preparation method according to claim 3, wherein the first quantity is 5 liters, the second quantity is 904.9 grams, the third quantity is 2772.7 grams, and the first time period is 8 hours.

6. The preparation method according to claim 1, wherein the step (c) further comprises a sub-step of: (c1) calcining the first product in air atmosphere to produce the first precursor; or (c2) calcining the first product in a protective atmosphere to produce the second precursor.

7. The preparation method according to claim 6, wherein the protective atmosphere is a nitrogen atmosphere or an argon atmosphere.

8. The preparation method according to claim 6, wherein the first precursor and the second precursor are ferric manganese pyrophosphate.

9. The preparation method according to claim 1, wherein the step (d) further comprises sub-steps of: (d1) mixing at least the first reactant, and the first precursor or the second precursor; (d2) performing a high-temperature calcination; and (d3) producing the battery composite material.

10. The preparation method according to claim 9, wherein the high-temperature calcination is processed in an environment with temperature greater than 500 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates the flow chart of a preparation method of a battery composite material according to an embodiment of the present invention;

(2) FIG. 2 schematically illustrates a detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention;

(3) FIG. 3 schematically illustrates another detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention;

(4) FIG. 4 schematically illustrates another detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention;

(5) FIG. 5A schematically illustrates the X-ray diffraction analysis diagram of a precursor prepared in air atmosphere by the preparation method of the battery composite material of the present invention;

(6) FIG. 5B schematically illustrates the X-ray diffraction analysis diagram of a precursor prepared in a protective atmosphere by the preparation method of the battery composite material of the present invention;

(7) FIG. 6A schematically illustrates the X-ray diffraction analysis diagram of a battery composite material prepared by the preparation method of the battery composite material of the present invention with the first precursor;

(8) FIG. 6B schematically illustrates the X-ray diffraction analysis diagram of a battery composite material prepared by the preparation method of the battery composite material of the present invention with the second precursor;

(9) FIG. 7A schematically illustrates a charging and discharging characteristic diagram of a cell battery made of a battery composite material prepared by the preparation method of the battery composite material of the present invention;

(10) FIG. 7B schematically illustrates a charging and discharging characteristic diagram of a cell battery made of another battery composite material prepared by the preparation method of the battery composite material of the present invention;

(11) FIG. 7C schematically illustrates a charging and discharging characteristic diagram of a cell battery made of another battery composite material prepared by the preparation method of the battery composite material of the present invention;

(12) FIG. 7D schematically illustrates a charging and discharging characteristic diagram of a cell battery made of another battery composite material prepared by the preparation method of the battery composite material of the present invention;

(13) FIG. 8 schematically illustrates the TEM analysis diagram of the precursor prepared by the preparation method of the precursor of the battery composite material of the present invention;

(14) FIG. 9 schematically illustrates the EDS (stands for energy dispersive spectroscopy) analysis diagram of the precursor prepared by the preparation method of the precursor of the battery composite material of the present invention;

(15) FIG. 10A and FIG. 10B schematically illustrate the TEM analysis diagram of the battery composite material prepared by further steps of the preparation method of the battery composite material of the present invention with the first precursor; and

(16) FIG. 11A and FIG. 11B schematically illustrate the TEM analysis diagram of the battery composite material prepared by further steps of the preparation method of the battery composite material of the present invention with the second precursor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(17) The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.

(18) Please refer to FIG. 1. FIG. 1 schematically illustrates the flow chart of a preparation method of a battery composite material according to an embodiment of the present invention. A preparation method of a batter composite material of the present invention includes steps as follows. At first, providing phosphoric acid, a first metal source, a second metal source and water as shown in step S100, among which the formula of the phosphoric acid is written by H.sub.3PO.sub.4. In some embodiments, the first metal source and the second metal source are respectively selected from at least one of ferric source, manganese source, cobalt source and nickel source, and are preferred to be ferric source and manganese source, respectively.

(19) Next, processing a reaction of the first metal source, the second metal source, the phosphoric acid and the water to produce a first product as shown in step S200. In some embodiments, the step S200 is preferred to include two sub-steps. Please refer to FIG. 2 simultaneously. FIG. 2 schematically illustrates a detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 2, the detailed flow chart of the step S200 includes a first sub-step of allowing a first quantity of the water to dissolve a second quantity of the first metal source and a third quantity of the phosphoric acid to produce a first solution as shown in step S201, and a second sub-step processing a reaction of the first solution and the second metal source and waiting for at least a first time period to produce the first product as shown in step S202. In this embodiment, the first time period is for example 8 hours, but not limited thereto. Additionally, the weight ratio of first metal of the second quantity to phosphor of the third quantity is 1:1. That is, by adjusting the ratio of the second quantity to the third quantity, the first metal and the phosphor may have the same quantity for fully reacted in the coming steps to completely produce the first product. Moreover, according to the conception of the present invention, the first product can be produced by a reaction of first metal and second metal and a compound releasing phosphate ions in a solution, but not limited herein.

(20) Then, calcining the first product obtained in the step S200 to produce a first precursor or a second precursor as shown in step S300, among which each of the first precursor and the second precursor is a solid-solution containing first metal and second metal, and is preferred to be applied to prepare the lithium-ion anode battery composite material with olivine crystalline structure. For example, the second precursor is ferric manganese pyrophosphate, and the formula of ferric manganese pyrophosphate is written by (Mn.sub.xFe.sub.1-x).sub.2P.sub.2O.sub.7, but not limited thereto. In addition, in some embodiments, the step S300 further includes sub-steps. Please refer to FIG. 1 and FIG. 3 simultaneously. FIG. 3 schematically illustrates another detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 3, the step S300 of the preparation method of the battery composite material of the present invention further includes sub-steps S301 and S302. The step S300 is practically implemented by selectively performing one of the sub-steps S301 and S302. The step S301 is a step of calcining the first product in air atmosphere to produce the first precursor, and the step S302 is a step of calcining the first product in a protective atmosphere to produce the second precursor. In other words, the difference between the step S301 and the step S302 is that the thermal treatment of the first product is implemented in air atmosphere in step S301, and the thermal treatment of the first product is implemented in a protective atmosphere, such as a nitrogen atmosphere or an argon atmosphere, in step S302.

(21) Finally, as shown in step S400, processing a reaction of the first precursor or the second precursor, and a first reactant to obtain a reaction mixture, and then calcining the reaction mixture to produce the battery composite material. The battery composite material is for example lithium ferric manganese phosphate or lithium ferric manganese phosphate nano-co-crystalline olivine, the formula of lithium ferric manganese phosphate is written by LiMn.sub.xFe.sub.1-xPO.sub.4, x>0. Preferably, x is greater than or equal to 0.5, and is less than or equal to 0.95, such that the battery composite material has a better electric performance. It should be noted that the first precursor or the second precursor is reacted with at least the first reactant in the step S400. Certainly, the first precursor or the second precursor is not limited to be reacted only with the first reactant, or be reacted with the first reactant and other reactants.

(22) Please refer to FIG. 1 and FIG. 4. FIG. 4 schematically illustrates another detailed flow chart of the preparation method of a battery composite material according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 4, the step S400 of the preparation method of the battery composite material of the present invention further includes sub-steps as following. At first, as shown in step S401, mixing at least a first reactant, and the first precursor or the second precursor, among which the first reactant is lithium carbonate, a compound containing lithium, or a mixture of several compounds containing lithium. Next, as shown in step S402, performing a high-temperature calcination (e.g. greater than 500 C.). Finally, as shown in step S403, producing the battery composite material, such as lithium ferric manganese phosphate or lithium ferric manganese phosphate nano-co-crystalline olivine.

(23) In the step S200 or the step S400, metal oxide, such as V.sub.2O.sub.5, TiO.sub.2 or MgO, can be added into the reaction, so that a LiMn.sub.xFe.sub.1-xPO.sub.4-like material containing the metal oxide, which can be called or named lithium ferric manganese phosphate nano-co-crystalline olivine (LFMP-NCO), is produced.

(24) Under this circumstance, the present invention provides a preparation method of a battery composite material for reducing the number of times of reduction-oxidation reactions in manner of preparing the battery composite material through the precursor produced via reactions, so that the stability of the manufacturing processes is enhanced, and the difficulty of the manufacturing processes is reduced.

(25) The following embodiments are presented herein for purpose of illustration and description of the preparation method of the battery composite material of the present disclosure.

1st Embodiment

(26) At first, providing 904.9 grams of Fe.sub.7(PO.sub.4).sub.6, 2772.7 grams of phosphoric acid (Purity>85%), 5.0 liters of deionized water and manganese source, mixing Fe.sub.7(PO.sub.4).sub.6 and the deionized water as a first metal source or a secondary metal source, and then adding the phosphoric acid to process a reaction and stirring. Next, adding the manganese source as a second metal source or a primary metal source and waiting for at least 8 hours to fully process a reaction to produce a precursor solution. Then, calcining the precursor solution in air atmosphere or a protective atmosphere (e.g. nitrogen atmosphere or argon atmosphere) with temperature greater than 400 C. The calcined compounds in air atmosphere and in the protective atmosphere are analyzed in manner of X-ray diffraction, and the analysis diagrams are respectively shown as FIG. 5A and FIG. 5B. After comparing the diagrams with JCPDS card, the first precursor is confirmed to be a solid-solution containing Mn and Fe, the structure of the first precursor is similar with Mn.sub.2P.sub.2O.sub.7, and the structure of a second precursor is also similar with Mn.sub.2P.sub.2O.sub.7. However, in the first precursor and the second precursor, Mn is replaced by Fe. The first precursor and the second precursor can be written by (Mn.sub.x,Fe.sub.1-x).sub.2P.sub.2O.sub.7. The ratio of Mn to Fe can be obtained through stoichiometry. The precursors are (Mn.sub.0.73Fe.sub.0.27).sub.2P.sub.2O.sub.7.

(27) Next, take the preparation of 18 molecules of lithium ferric manganese phosphate for example. Adding 2059.6 grams of the first precursor or the second precursor obtained in the above-mentioned steps and 755 to 792.7 grams of lithium hydroxide (i.e. LiOH) into 10 liters of pure water to process a reaction, and then adding the appropriate carbon source. Performing a high-temperature calcination with temperature greater than 500 C. to the product of reaction. The calcined compounds are analyzed in manner of X-ray diffraction, and the analysis diagrams are respectively shown as FIG. 6A and FIG. 6B. After comparing the diagrams with JCPDS card, the compounds are confirmed to be lithium ferric manganese phosphate (i.e. LiMn.sub.xFe.sub.1-xPO.sub.4). The ratio of Mn to Fe can be obtained through stoichiometry. The compounds are LiMn.sub.0.73Fe.sub.0.27PO.sub.4.

(28) Next, mixing LiMn.sub.0.73Fe.sub.0.27PO.sub.4 obtained in the above-mentioned steps, conductive material Super P and 4 weight percent of binder (PVDF+NMP) in a ratio of 8.5:0.5:1. First, mixing 0.5 grams of conductive carbon black (Super P) and 25 grams of binder (PVDF:NMP=40:960) for 10 minutes. The rotational speed is 1200 rpm. Then, adding 8.5 grams of LiMn.sub.0.73Fe.sub.0.27PO.sub.4 and mixing for another 10 minutes. Next, coating the dispersed slurry on an aluminum substrate with a blade coater, among which the coating thickness is 0.3 millimeters. Then, putting the coated aluminum substrate into an oven and baking the coated aluminum substrate at 110 C. for 1 hour. Finally, forming the aluminum substrate as a circular plate, among which the diameter of the circular plate is 1.3 centimeters, and making a coin-cell battery with this circular plate, lithium metal (as the negative electrode), 1 molar concentration of LiPF.sub.6 and a mixed electrolyte of EC and DMC (volume ratio=3:7). The electric characteristics of charging and discharging of the coin-cell battery are tested and analyzed through a charging and discharging machine. The test and the analysis are performed at 0.1 coulombs for two cycles and 2 coulombs for two cycles. The charging and discharging characteristic diagram is shown as FIG. 7A. The cutoff voltages of charging and discharging of the coin-cell battery are respectively 2.5 and 4.5 volts.

2nd Embodiment

(29) Adjusting the ratio of the ferric source to the manganese source of the first embodiment for finally obtaining the battery composite material with the ratio of Mn to Fe equal to 8:2. In other words, the battery composite material is adjusted as LiMn.sub.0.8Fe.sub.0.2PO.sub.4. The electric characteristics of charging and discharging are tested under the same environment, and the charging and discharging characteristic diagram is shown as FIG. 7B. The rest portion of this embodiment is similar with the first embodiment, and is not redundantly described herein.

3rd Embodiment

(30) Adjusting the ratio of the ferric source to the manganese source of the first embodiment for finally obtaining the battery composite material with the ratio of Mn to Fe equal to 85:15. In other words, the battery composite material is adjusted as LiMn.sub.0.85Fe.sub.0.15PO.sub.4. The electric characteristics of charging and discharging are tested under the same environment, and the charging and discharging characteristic diagram is shown as FIG. 7C. The rest portion of this embodiment is similar with the first embodiment, and is not redundantly described herein.

4th Embodiment

(31) Adjusting the ratio of the ferric source to the manganese source of the first embodiment for finally obtaining the battery composite material with the ratio of Mn to Fe equal to 9:1. In other words, the battery composite material is adjusted as LiMn.sub.0.9Fe.sub.0.1PO.sub.4. The electric characteristics of charging and discharging are tested under the same environment, and the charging and discharging characteristic diagram is shown as FIG. 7D. The rest portion of this embodiment is similar with the first embodiment, and is not redundantly described herein.

5th Embodiment

(32) Adding metal oxide, such as V.sub.2O.sub.5, TiO.sub.2 or MgO, in the step S200 or the step S400 of the first embodiment, so that lithium ferric manganese phosphate nano-co-crystalline olivine is produced. The rest portion of this embodiment is similar with the first embodiment, and is not redundantly described herein.

6th Embodiment

(33) At first, providing 2445.6 grams of Fe.sub.2(C.sub.2O.sub.4).sub.3.5H.sub.2O, 3947.1 grams of phosphoric acid (Purity>85%), 5.0 liters of deionized water and manganese source, mixing Fe.sub.2(C.sub.2O.sub.4).sub.3.5H.sub.2O and the deionized water as a first metal source or a secondary metal source, and then adding the phosphoric acid to process a reaction and stirring. Next, adding the manganese source as a second metal source or a primary metal source and waiting for at least 8 hours to fully process a reaction to produce a precursor solution. Then, calcining the precursor solution in air atmosphere or a protective atmosphere (e.g. nitrogen atmosphere or argon atmosphere) with temperature greater than 400 C. to produce the first precursor or the second precursor.

(34) Next, take the preparation of 18 molecules of lithium ferric manganese phosphate for example. Adding 2059.6 grams of the first precursor or the second precursor obtained in the above-mentioned steps and 755 to 792.7 grams of lithium hydroxide (i.e. LiOH) into 10 liters of pure water to process a reaction, and then adding the appropriate carbon source. Performing a high-temperature calcination with temperature greater than 500 C. to the product of reaction. The calcined compounds are analyzed in manner of X-ray diffraction and are confirmed to be lithium ferric manganese phosphate LiMn.sub.0.73Fe.sub.0.27PO.sub.4.

7th Embodiment

(35) At first, providing 1789 grams of Fe(C.sub.2H.sub.3O.sub.2).sub.2, 3947.1 grams of phosphoric acid (Purity>85%), 5.0 liters of deionized water and manganese source, mixing Fe(C.sub.2H.sub.3O.sub.2).sub.2 and the deionized water as a first metal source or a secondary metal source, and then adding the phosphoric acid to process a reaction and stirring. Next, adding the manganese source as a second metal source or a primary metal source and waiting for at least 8 hours to fully process a reaction to produce a precursor solution. Then, calcining the precursor solution in air atmosphere or a protective atmosphere (e.g. nitrogen atmosphere or argon atmosphere) with temperature greater than 400 C. to produce the first precursor or the second precursor.

(36) Next, take the preparation of 18 molecules of lithium ferric manganese phosphate for example. Adding 2059.6 grams of the first precursor or the second precursor obtained in the above-mentioned steps and 755 to 792.7 grams of lithium hydroxide (i.e. LiOH) into 10 liters of pure water to process a reaction, and then adding the appropriate carbon source. Performing a high-temperature calcination with temperature greater than 500 C. to the product of reaction. The calcined compounds are analyzed in manner of X-ray diffraction and are confirmed to be lithium ferric manganese phosphate LiMn.sub.0.73Fe.sub.0.27PO.sub.4.

8th Embodiment

(37) At first, providing 821.3 grams of Fe.sub.2O.sub.3, 3947.1 grams of phosphoric acid (Purity>85%), 5.0 liters of deionized water and manganese source, mixing Fe.sub.2O.sub.3 and the deionized water as a first metal source or a secondary metal source, and then adding the phosphoric acid to process a reaction and stirring. Next, adding the manganese source as a second metal source or a primary metal source and waiting for at least 8 hours to fully process a reaction to produce a precursor solution. Then, calcining the precursor solution in air atmosphere or a protective atmosphere (e.g. nitrogen atmosphere or argon atmosphere) with temperature greater than 400 C. to produce the first precursor or the second precursor.

(38) Next, take the preparation of 18 molecules of lithium ferric manganese phosphate for example. Adding 2059.6 grams of the first precursor or the second precursor obtained in the above-mentioned steps and 755 to 792.7 grams of lithium hydroxide (i.e. LiOH) into 10 liters of pure water to process a reaction, and then adding the appropriate carbon source. Performing a high-temperature calcination with temperature greater than 500 C. to the product of reaction. The calcined compounds are analyzed in manner of X-ray diffraction and are confirmed to be lithium ferric manganese phosphate LiMn.sub.0.73Fe.sub.0.27PO.sub.4.

(39) Please refer to FIG. 8 and FIG. 9. FIG. 8 schematically illustrates the TEM analysis diagram of the precursor prepared by the preparation method of the precursor of the battery composite material of the present invention. FIG. 9 schematically illustrates the EDS (stands for energy dispersive spectroscopy) analysis diagram of the precursor prepared by the preparation method of the precursor of the battery composite material of the present invention. As shown in FIG. 8 and FIG. 9, in the TEM analysis diagram and the EDS analysis diagram, it is shown that the precursor prepared by the preparation method of a precursor of a battery composite material of the present invention contains phosphor, ferrite and manganese (i.e. P, Fe, Mn). The formula of the precursor is verified and matched with (Mn.sub.xFe.sub.1-x).sub.2P.sub.2O.sub.7. In addition, the ratio of Mn to Fe is analyzed in manner of EDS. The verified result illustrates that the formula of the precursor is written by (Mn.sub.0.7Fe.sub.0.3).sub.2P.sub.2O.sub.7.

(40) Please refer to FIG. 10A and FIG. 10B. FIG. 10A and FIG. 10B schematically illustrate the TEM analysis diagram of the battery composite material prepared by further steps of the preparation method of the battery composite material of the present invention with the first precursor. As shown in FIG. 10A and FIG. 10B, through the embodiments mentioned above, the lithium ferric manganese phosphate prepared by further steps of the preparation method of the battery composite material of the present invention with the first precursor is analyzed through TEM, and the TEM diagrams captured under magnifications of 150000 and 300000 are respectively shown as FIG. 10A and FIG. 10B.

(41) Please refer to FIG. 11A and FIG. 11B. FIG. 11A and FIG. 11B schematically illustrate the TEM analysis diagram of the battery composite material prepared by further steps of the preparation method of the battery composite material of the present invention with the second precursor. As shown in FIG. 11A and FIG. 11B, through the embodiments mentioned above, the lithium ferric manganese phosphate prepared by further steps of the preparation method of the battery composite material of the present invention with the second precursor is analyzed through TEM, and the TEM diagrams captured under magnifications of 150000 and 300000 are respectively shown as FIG. 11A and FIG. 11B.

(42) From the above description, the present invention provides a preparation method of a battery composite material and a precursor thereof for reducing the number of times of reduction-oxidation reactions in manner of preparing the battery composite material through the precursor produced via reactions, so that the stability of the manufacturing processes is enhanced, and the difficulty of the manufacturing processes is reduced. Furthermore, by preparing a solid-solution including first metal and second metal as a precursor for finally producing a battery composite material, the battery composite material and the battery product have two stable charging and discharging platforms, such that the advantages of enhancing the stability and the electric performance are achieved.

(43) While the disclosure has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.