Method for regenerating waste lithium iron phosphate battery by combining spontaneous reaction

Abstract

The invention belongs to the technical field of secondary battery material regeneration. The invention relates to lithium iron phosphate batteries, in particular to a method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction. The regeneration method comprises the following specific regeneration steps: carrying out ball milling on the recycled lithium iron phosphate positive electrode material to obtain powder with the sphericity degree of 0.8-0.9 and D50 of 1-2.5 [mu] m; ultrasonically dispersing the powder in a dopamine solution, adding a lithium sulfate solution, carrying out microwave ultrasonic reaction, adjusting the pH value to 7.6-7.8, continuing the microwave ultrasonic reaction, filtering, washing and drying to obtain a dried filter cake; and placing the dried filter cake in an inert atmosphere, carrying out heat preservation calcination for 3-5 hours at the temperature of 600-800 DEG C, cooling, discharging, and scattering to obtain the regenerated lithium iron phosphate positive electrode material. Wherein the dopamine solution further comprises a water-soluble aluminum salt accounting for 3-5% of the mass of the dopamine solution and microcrystalline cellulose accounting for 3-5% of the mass of the dopamine solution.

Description

Technical Field

[0001] The present invention belongs to the technical field of secondary battery material regeneration. More specifically, it relates to a method for regenerating waste lithium iron phosphate batteries by combining spontaneous reactions. Background Art

[0002] For waste lithium-ion batteries, recycling and regenerating the batteries after disassembly is a common method. At present, there are many drawbacks to this approach. For example, the high cost. Due to the complex internal structure of the battery, disassembly requires a large amount of manpower and equipment, and the design of automated disassembly equipment is complex and expensive. In addition, there are many potential safety hazards during the disassembly process. Since the battery contains electrolyte and harmful substances, they may leak during disassembly, causing harm to the environment and human health. Moreover, during the disassembly process, there may be a short circuit or mechanical damage, which may cause the battery to catch fire and explode. Furthermore, during the disassembly process, some active materials may not be recyclable due to mechanical damage or contamination, resulting in a low material recovery rate.

[0003] Based on this, if the battery can be regenerated without disassembly through a spontaneous reaction, the above problems can be effectively solved. However, during the use of the battery, the decomposition of the electrolyte and the formation of the solid electrolyte interface (SEI) film consume active lithium, resulting in a decrease in capacity, and the change in the structure of the positive electrode material caused by long-term cycling, such as particle fragmentation, and the negative electrode material is damaged due to lithium dendrites or volume expansion, etc. A series of changes, the impact is very complex. At present, for this field, if a feasible spontaneous reaction is used to solve many problems, it is still a technical problem that needs to be overcome. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: during the recovery and regeneration of the positive active material of lithium iron phosphate batteries, how to reduce the difficulty of recovery and regeneration and achieve effective and uniform repair of the positive electrode material. The present invention provides a method for regenerating waste lithium iron phosphate batteries by combining spontaneous reactions.

[0005] The object of the present invention is to provide a method for regenerating waste lithium iron phosphate batteries by combining spontaneous reactions.

[0006] The above object of the present invention is achieved by the following technical solutions: A method for regenerating waste lithium iron phosphate batteries by combining spontaneous reactions, and the specific regeneration steps include: Ball-milling the recovered lithium iron phosphate positive electrode material into a powder with a sphericity of 0.8 - 0.9 and a D50 of 1 - 2.5 μm; The powder is ultrasonically dispersed in the dopamine solution, and then the lithium sulfate solution is added. After microwave ultrasonic reaction, the pH is adjusted to 7.6 - 7.8. After continuing the microwave ultrasonic reaction, filtration and drying are carried out to obtain a dry filter cake; The dry filter cake is placed in an inert atmosphere and calcined at a temperature of 600 - 800 °C for 3 - 5 h, then cooled, discharged, and dispersed to obtain the regenerated lithium iron phosphate cathode material.

[0007] The beneficial effects of the above technical solution are as follows: The above technical solution adopts mechanical ball milling and uses the lithium sulfate solution as a lithium supplement agent. By utilizing the microwave ultrasonic reaction process, the spontaneous reaction regeneration of the recovered lithium iron phosphate cathode material is realized. Specifically, first, during the long-term ball milling process, the first thing that occurs is the refinement of particles. During this refinement process, the soft agglomeration between particles is first broken open. Secondly, physical defects formed inside the particles during battery use, such as particle cracks, etc., are easily disintegrated along the cracks or defects under the action of mechanical ball milling pressure. As the ball milling time prolongs, the "fragile" edges around the particles are gradually ground smooth, so that the particles are gradually spheroidized and refined. By screening, particles with relatively high sphericity and appropriate particle size are obtained for the subsequent regeneration process, which can effectively eliminate the physical defects inside the particles. At the same time, spherical particles are more conducive to the effective and uniform intercalation of lithium ions in different directions, thus ensuring the smooth progress of spontaneous lithium intercalation in the subsequent lithium sulfate solution; In addition, by coating dopamine on the surface of the powder before the spontaneous lithium intercalation reaction in the lithium sulfate solution, the lithium ions in the lithium sulfate solution can be adsorbed and enriched by the dopamine coating layer. Part of the lithium ions are intercalated into the powder during the spontaneous lithium intercalation reaction in the solution, while the other part of the lithium ions remain in the coating layer and continue to slowly intercalate into the interior of the cathode material during the subsequent calcination process. Thus, through the spontaneous lithium intercalation in the solution and the subsequent lithium intercalation during the calcination process on the surface, the full lithium supplementation and regeneration of the lithium iron phosphate cathode material are realized; in addition, during the high-temperature calcination process of dopamine, the presence of N elements can also realize the surface doping of the lithium iron phosphate cathode material and improve its surface electron conductivity.

[0008] Furthermore, the concentration of the dopamine solution is 3 - 5 g / L; and the dosage of the dopamine solution is 10 - 12 times the mass of the powder.

[0009] Furthermore, the mass fraction of the lithium sulfate solution is 6 - 8%; and the dosage of the lithium sulfate solution is 60 - 70% of the mass of the powder.

[0010] Further, the microwave ultrasonic reaction includes: reacting under the conditions of a microwave power of 600 - 660 W and an ultrasonic frequency of 120 - 140 kHz for 60 - 80 min.

[0011] The beneficial effects of the above technical solution are as follows: By using the microwave ultrasonic reaction, it can assist lithium ions to smoothly pass through the dopamine coating layer and fully diffuse and penetrate into the lithium iron phosphate cathode material. This is because although the dopamine coating layer can adsorb lithium sulfate in the solution system, due to the limitation of the concentration difference, it is necessary to wait until the lithium sulfate in the coating layer effectively diffuses and penetrates inward before the lithium sulfate in the solution will continue to be adsorbed into the coating layer. That is to say, the existence of the coating layer accelerates the enrichment of lithium sulfate on the surface of lithium iron phosphate in the early stage, but the subsequent diffusion rate will significantly decrease due to the concentration difference, resulting in a significant decrease in the enrichment rate. Under the above microwave ultrasonic reaction conditions, the diffusion and penetration of lithium sulfate into the interior can be accelerated, and this process is uniform. Therefore, the lithium supplement reaction can be completed both uniformly and efficiently.

[0012] Further, the specific regeneration step further includes: The dried filter cake is slowly heated and raised to 300 - 320 °C at a rate of 0.2 - 0.4 °C / min in an inert atmosphere, and then continues to be rapidly heated and raised to 600 - 800 °C at a rate of 6 - 8 °C / min. After holding and calcining for 3 - 5 h, it is cooled to room temperature with the furnace, discharged, and broken up to obtain the regenerated lithium iron phosphate cathode material.

[0013] The beneficial effects of the above technical solution are as follows: The inventor further found that during the calcination process, by controlling the slower heating rate in the early stage and the faster heating rate in the later stage, in this way, it can not only ensure that the time during the calcination process is controllable and not too long, but also avoid the thermal stress of the coating layer on the surface during the rapid heating process due to the faster heating rate in the early stage, resulting in the shedding of the coating layer, so that the lithium-containing components enriched in the coating layer also fall off, leading to the failure of lithium supplementation during the sintering process at higher temperatures in the subsequent stage, or uneven lithium supplementation due to local shedding.

[0014] Further, the dopamine solution further includes a water-soluble aluminum salt accounting for 3 - 5% of the mass of the dopamine solution.

[0015] Further, the water-soluble aluminum salt is selected from any one of aluminum chloride, aluminum sulfate, aluminum nitrate, and aluminum acetate.

[0016] The beneficial effects of the above technical solution are as follows: By mixing a certain amount of water-soluble aluminum salt in the dopamine solution, the surface of lithium iron phosphate can be repaired, so that the surface of the lithium iron phosphate material has good mechanical strength, and the liquid absorption and retention effect of the lithium iron phosphate surface on the electrolyte is ensured.

[0017] Furthermore, the dopamine solution further includes microcrystalline cellulose accounting for 3-5% of the mass of the dopamine solution.

[0018] Furthermore, the crystallinity of the microcrystalline cellulose is 30-45%.

[0019] The beneficial effects of the above technical solution are as follows: By further introducing microcrystalline cellulose with low crystallinity, the above technical solution can coat lithium iron phosphate surface together with dopamine, and transform into a carbon coating layer with electronic conductivity during the calcination process. The reason for using microcrystalline cellulose with low crystallinity is that it has more amorphous regions, and the existence of amorphous regions is more conducive to the penetration of lithium ions through the coating layer and diffusion into the interior during the microwave ultrasonic reaction process. Specific Embodiments

[0020] The following specific embodiments are used to further illustrate the present invention, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

[0021] Unless otherwise specified, the reagents and materials used in the following examples are all commercially available. Example 1

[0022] Ball milling and refinement: Using recycled black powder with a lithium iron phosphate purity of 99.5% as the material to be regenerated; Pour the above-mentioned recycled black powder of lithium iron phosphate cathode material into the ball milling tank, and add zirconia ball milling beads according to the mass ratio of ball to material of 28:1. Among them, the specifications of the ball milling beads are selected as 7 cm, 5 cm and 3 cm, and the quantity ratio of the three is 1:2:4; then under the conditions of a revolution speed of 300 r / min and a rotation speed of 350 r / min, continuously ball mill and mix for 4 h, then discharge and screen to screen out powders with a sphericity of 0.8 and a D50 of 2.5 μm to obtain ball milled materials; Spontaneous lithium intercalation: Mix the ball abrasive and dopamine solution, where the concentration of the dopamine solution is 3 g / L; and the dosage of the dopamine solution is 10 times the mass of the ball abrasive; then, under the condition of an ultrasonic frequency of 70 kHz, disperse for 20 min, and then add a lithium sulfate solution with a mass fraction of 6%; and the dosage of the lithium sulfate solution is 60% of the mass of the ball abrasive; then, under the conditions of a microwave power of 600 W and an ultrasonic frequency of 120 kHz, carry out a microwave ultrasonic reaction for 60 min; after the reaction ends, adjust the pH to 7.6, then continue to carry out a microwave ultrasonic reaction for 60 min under the conditions of a microwave power of 600 W and an ultrasonic frequency of 120 kHz, filter, collect the filter cake, and dry the obtained filter cake to a constant weight at a temperature of 90 °C to obtain a dried filter cake; In the dopamine solution, there is also a water-soluble aluminum salt accounting for 3% of the mass of the dopamine solution, and microcrystalline cellulose accounting for 3% of the mass of the dopamine solution; The water-soluble aluminum salt is selected from: aluminum chloride; The crystallinity of the microcrystalline cellulose is 30%; Calcination: Place the dried filter cake in an inert atmosphere, slowly heat it up to 300 °C at a rate of 0.2 °C / min, then continue to rapidly heat it up to 600 °C at a rate of 6 °C / min, keep it for calcination for 3 h, then cool it to room temperature with the furnace, discharge the material, and break it up to obtain the regenerated lithium iron phosphate cathode material. Example 2

[0023] Ball milling and refinement: Use the recycled black powder material with a lithium iron phosphate purity of 99.5% as the material to be regenerated; Pour the recycled black powder of the lithium iron phosphate cathode material into a ball milling tank, and add zirconia ball milling beads according to a ball-to-material mass ratio of 28:1. Among them, the specifications of the ball milling beads are selected as 7 cm, 5 cm, and 3 cm, and the quantity ratio of the three is 1:2:4; then, under the conditions of a revolution speed of 310 r / min and a rotation speed of 360 r / min, continuously carry out ball milling and mixing for 5 h, then discharge the material and screen it to screen out the powder with a sphericity of 0.86 and a D50 of 2 μm to obtain the ball abrasive; Spontaneous lithium intercalation: Mix the ball abrasive and dopamine solution. Among them, the concentration of the dopamine solution is 4 g / L; and the dosage of the dopamine solution is 11 times the mass of the ball abrasive. Subsequently, under the condition of an ultrasonic frequency of 70 kHz, disperse for 24 min, and then add a lithium sulfate solution. The mass fraction of the lithium sulfate solution is 7%; and the dosage of the lithium sulfate solution is 67% of the mass of the ball abrasive. Then, under the conditions of a microwave power of 620 W and an ultrasonic frequency of 130 kHz, carry out a microwave ultrasonic reaction for 70 min. After the reaction ends, adjust the pH to 7.7, and then continue to carry out a microwave ultrasonic reaction for 70 min under the conditions of a microwave power of 620 W and an ultrasonic frequency of 130 kHz. Filter, collect the filter cake, and dry the obtained filter cake at a temperature of 97 °C until constant weight to obtain a dry filter cake. In the dopamine solution, it also includes a water-soluble aluminum salt accounting for 4% of the mass of the dopamine solution, and microcrystalline cellulose accounting for 4% of the mass of the dopamine solution. The water-soluble aluminum salt is selected from: aluminum sulfate. The crystallinity of the microcrystalline cellulose is 35%. Calcination: Place the dry filter cake in an inert atmosphere, slowly heat it up to 310 °C at a rate of 0.3 °C / min, and then continue to rapidly heat it up to 700 °C at a rate of 7 °C / min. Keep it calcined for 4 h, then cool it to room temperature with the furnace, discharge the material, and break it up to obtain the regenerated lithium iron phosphate cathode material. Example 3

[0024] Ball milling and refinement: Use the recycled black powder with a lithium iron phosphate purity of 99.5% as the material to be regenerated. Pour the recycled black powder of the above lithium iron phosphate cathode material into a ball milling tank, and add zirconia ball milling beads according to a ball-to-material mass ratio of 28:1. Among them, the specifications of the ball milling beads are selected as 7 cm, 5 cm, and 3 cm, and the quantity ratio of the three is 1:2:4. Subsequently, under the conditions of a revolution speed of 320 r / min and a rotation speed of 370 r / min, continuously carry out ball milling and mixing for 6 h, then discharge the material and screen it to screen out the powder with a sphericity of 0.9 and a D50 of 1 μm to obtain the ball abrasive. Spontaneous lithium intercalation: Mix the ball-milled abrasive with the dopamine solution, where the concentration of the dopamine solution is 5 g / L; and the dosage of the dopamine solution is 12 times the mass of the ball-milled abrasive. Subsequently, under the condition of an ultrasonic frequency of 70 kHz, disperse for 30 min, then add the lithium sulfate solution, where the mass fraction of the lithium sulfate solution is 8%; and the dosage of the lithium sulfate solution is 70% of the mass of the ball-milled abrasive. Then, under the conditions of a microwave power of 660 W and an ultrasonic frequency of 140 kHz, carry out a microwave-ultrasonic reaction for 80 min. After the reaction ends, adjust the pH to 7.8, then continue to carry out a microwave-ultrasonic reaction for 80 min under the conditions of a microwave power of 660 W and an ultrasonic frequency of 140 kHz, filter, collect the filter cake, and dry the obtained filter cake to a constant weight at a temperature of 100 °C to obtain a dried filter cake; In the dopamine solution, it also includes a water-soluble aluminum salt accounting for 5% of the mass of the dopamine solution, and microcrystalline cellulose accounting for 5% of the mass of the dopamine solution; The water-soluble aluminum salt is selected from: aluminum nitrate; The crystallinity of the microcrystalline cellulose is 45%; Calcination: Place the dried filter cake in an inert atmosphere, slowly heat it up to 320 °C at a rate of 0.4 °C / min, then continue to rapidly heat it up to 800 °C at a rate of 8 °C / min, keep it for calcination for 5 h, then cool it to room temperature with the furnace, take out the material, and break it up to obtain the regenerated lithium iron phosphate cathode material. Example 4

[0025] Compared with Example 1, the difference in this example is that no water-soluble aluminum salt is added, and the other conditions remain unchanged. Example 5

[0026] Compared with Example 1, the difference in this example is that no microcrystalline cellulose is added, and the other conditions remain unchanged. Example 6

[0027] Compared with Example 1, the difference in this example is that the crystallinity of the microcrystalline cellulose is 50%, and the other conditions remain unchanged. Example 7

[0028] Compared with Example 1, the difference in this example is that: Calcination: Place the dried filter cake in an inert atmosphere, heat it up to 300 °C at a rate of 3 °C / min, then continue to rapidly heat it up to 600 °C at a rate of 6 °C / min, keep it for calcination for 3 h, then cool it to room temperature with the furnace, take out the material, and break it up to obtain the regenerated lithium iron phosphate cathode material.

[0029] The other conditions remain unchanged.

[0030] Comparative Example 1 Compared with Example 1, the difference in this comparative example is that the recycled black powder of the lithium iron phosphate cathode material is not ball-milled and directly undergoes spontaneous lithium intercalation. Specifically, the overall regeneration process is as follows: Spontaneous lithium intercalation: Using the recycled black powder with a lithium iron phosphate purity of 99.5% as the material to be regenerated; Mix the recycled black powder with the dopamine solution. Among them, the concentration of the dopamine solution is 3 g / L; and the dosage of the dopamine solution is 10 times the mass of the recycled black powder. Subsequently, under the condition of an ultrasonic frequency of 70 kHz, after dispersing for 20 min, add the lithium sulfate solution. The mass fraction of the lithium sulfate solution is 6%; and the dosage of the lithium sulfate solution is 60% of the mass of the recycled black powder. Then, under the conditions of a microwave power of 600 W and an ultrasonic frequency of 120 kHz, carry out microwave-ultrasonic reaction for 60 min. After the reaction ends, adjust the pH to 7.6, and then continue to carry out microwave-ultrasonic reaction for 60 min under the conditions of a microwave power of 600 W and an ultrasonic frequency of 120 kHz. Filter, collect the filter cake, and dry the obtained filter cake to constant weight at a temperature of 90 °C to obtain a dried filter cake; In the dopamine solution, it also includes a water-soluble aluminum salt accounting for 3% of the mass of the dopamine solution, and microcrystalline cellulose accounting for 3% of the mass of the dopamine solution; The water-soluble aluminum salt is selected from: aluminum chloride; The crystallinity of the microcrystalline cellulose is 30%; Calcination: Place the dried filter cake in an inert atmosphere, slowly heat it up to 300 °C at a rate of 0.2 °C / min, and then continue to rapidly heat it up to 600 °C at a rate of 6 °C / min. Keep it calcined for 3 h, then cool it to room temperature with the furnace, discharge the material, and break it up to obtain the regenerated lithium iron phosphate cathode material.

[0031] Comparative Example 2 Compared with Example 1, the difference in this comparative example is that the dopamine solution is not added, and the other conditions remain unchanged.

[0032] Perform performance tests on the products obtained in the examples and comparative examples. The specific test methods and test results are as follows: Weigh according to the mass ratio of m(recycled lithium iron phosphate cathode material):m(acetylene black):m(PVDF)= 8:1:1. Place the lithium iron phosphate cathode material and acetylene black in a blast drying oven and dry at 100°C for 2 hours. At the same time, dissolve PVDF in N-methylpyrrolidone and stir magnetically for 2 hours until evenly mixed. Grind and sieve the dried lithium iron phosphate material and acetylene black in a mortar, add them to the above-mentioned N-methylpyrrolidone solution of PVDF, and stir until a uniform black slurry is formed. Coat the slurry on the aluminum foil with a coating thickness of 85μm, then transfer it to a blast drying oven, take it out after drying at 90°C for 2 hours, then roll press it under a pressure of 1.9MPa, and finally slice it using a button battery punching machine to obtain the positive electrode sheet.

[0033] The assembly of the battery is carried out in a vacuum glove box filled with Ar. The assembled battery model is CR2016. Use the above-obtained positive electrode sheet as the positive electrode, the lithium sheet as the counter electrode, and 1mol / L LiPF6 / EC.DMC.EMC as the electrolyte. Place the positive electrode shell, positive electrode sheet, separator (Celgard 2400), lithium sheet, gasket, shrapnel, and negative electrode shell in sequence, and use a tablet press to make a button battery. Age it in the glove box for 12 hours and take it out for testing; Use the LAND CT2001A battery test system to test the cycle performance of the button battery. The test environmental temperature is 25°C, and the voltage window is 2.5 - 4.2V. During the charging process, the charging rate in the constant current stage is 0.3C. After reaching the constant voltage stage, cut off at 0.05C, which is regarded as full charge. The discharge rate is 0.1C, and discharge to the cut-off voltage. Set the nominal specific capacity of LFP to 165mAh / g; Test and obtain the capacity retention rates after 80 cycles and 300 cycles under the corresponding rate conditions respectively to evaluate its cycle performance.

[0034] The detailed test results are shown in Table 1; Table 1: Test Results of Product Performance ;

[0035] It can be seen from the test results in Table 1 that the lithium iron phosphate cathode material obtained by recycling and regeneration in the present invention can effectively recycle and regenerate the material, and has excellent capacity retention rate during use.

[0036] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction, characterized in that: The specific regeneration steps include: The recovered lithium iron phosphate positive electrode material is ball-milled into a powder having a sphericity of 0.8-0.9 and a D50 of 1-2.5 μm; Ultrasonic dispersion of the powder in a dopamine solution, and then adding a lithium sulfate solution, and adjusting the pH to 7.6-7.8 after microwave ultrasonic reaction, and filtering and drying after continuing microwave ultrasonic reaction to obtain a dry filter cake; The dried filter cake is placed in an inert atmosphere at a temperature of 600-800° C. and calcined for 3-5 hours, then cooled, discharged, and broken up to obtain a regenerated lithium iron phosphate positive electrode material.

2. A method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 1, characterized in that: The concentration of the dopamine solution is 3-5 g / L; and the dosage of the dopamine solution is 10-12 times the mass of the powder.

3. The method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 1, characterized in that: The mass fraction of the lithium sulfate solution is 6-8%; and the amount of the lithium sulfate solution is 60-70% of the mass of the powder.

4. The method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 1, characterized in that: The microwave ultrasonic reaction comprises: performing the microwave ultrasonic reaction for 60-80 minutes under the conditions of microwave power of 600-660W and ultrasonic frequency of 120-140kHz.

5. The method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 1, characterized in that: The specific regeneration step also includes: The dried filter cake is slowly heated to 300-320°C at a rate of 0.2-0.4°C / min in an inert atmosphere, and then rapidly heated to 600-800°C at a rate of 6-8°C / min. After calcination for 3-5 hours, it is cooled to room temperature in the furnace, discharged, and broken up to obtain the regenerated lithium iron phosphate positive electrode material.

6. The method of claim 1 for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction, characterized in that: The dopamine solution also includes 3-5% of the mass of the dopamine solution of water-soluble aluminum salt.

7. A method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 6, characterized in that: The water-soluble aluminum salt is selected from any one of aluminum chloride, aluminum sulfate, aluminum nitrate and aluminum acetate.

8. The method of regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 1, characterized in that: The dopamine solution also includes 3-5% of microcrystalline cellulose by mass of the dopamine solution.

9. A method for regenerating waste lithium iron phosphate batteries by combining spontaneous reaction according to claim 8, characterized in that: The crystallinity of the microcrystalline cellulose is 30-45%.

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