CN112510280B

CN112510280B - Physical method based on hash of feature elements in foil of power battery

Info

Publication number: CN112510280B
Application number: CN202011293139.1A
Authority: CN
Inventors: 余海军; 戴宏亮
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2021-11-16
Anticipated expiration: 2040-11-18
Also published as: CN112510280A

Abstract

The invention belongs to the field of battery material recovery, and discloses a physical method based on hash of characteristic elements in a power battery foil and application thereof, wherein the physical method comprises the following steps: taking a waste power battery positive plate, heating and cooling; transferring the mixture to a heat preservation device, adding carbon dioxide, extracting organic matters, and sieving to obtain anode material powder and aluminum foil; washing the anode material powder, and taking filter residue; and transferring the filter residue into an electrolytic bath, adding a sodium salt solution, taking metal platinum as an anode and a cathode, applying voltage and controlling pressure, performing ultrasonic treatment, relieving pressure and standing, discharging solid materials, filtering, taking the filter residue, washing and drying to obtain the battery-grade cathode material. The invention utilizes the difference of the thermal expansion coefficients of different materials such as organic materials, inorganic materials, aluminum foils and the like in the battery pole piece, and hashes are generated among the different materials through high-temperature liquid nitrogen quenching, so as to obtain the mixture of the organic materials, the inorganic materials and the aluminum foils.

Description

Physical method based on hash of feature elements in foil of power battery

Technical Field

The invention belongs to the field of battery material recovery, and particularly relates to a physical method based on hash of feature elements in a power battery foil.

Background

According to Ministry of industry and belief data, in 2019, 124.2 thousands of new energy automobiles and 120.6 thousands of new energy automobiles are produced and sold respectively. Wherein, pure electric vehicles produce and sell 102 ten thousand respectively and 97.2 ten thousand respectively, and under the drive of new energy automobile industry, the power battery industry obtains the rapid development.

The popularization of new energy automobiles in large quantities drives the use of power batteries in large quantities, the service life of the power batteries is usually 5-8 years, after a certain period of use, the performance of the batteries is reduced, the use requirements of consumers are not met, and the batteries need to be recycled and disassembled. The traditional recovery processing method is to disassemble the power battery, take the battery core of the power battery to perform pyrolysis, crushing and sorting in sequence, and obtain the composite powder of the anode and cathode electrode materials. In the traditional method, metal aluminum in the aluminum foil is oxidized into aluminum oxide by pyrolysis, the aluminum oxide is mixed with the anode and cathode electrode material composite powder, and subsequent impurity removal needs to consume a large amount of chemical agents, so that the environmental pollution is large. And because of the oxidation of aluminum, it is difficult to recover the aluminum in the form of metal, the recovery rate of valuable materials in the waste batteries is reduced, and the recovery economic benefit is not optimistic. Lithium hexafluorophosphate in the electrolyte is decomposed into phosphorus pentafluoride and lithium fluoride under the condition of high-temperature pyrolysis, the lithium fluoride is mixed in the composite powder of the anode and cathode electrode materials, the obtained product has various impurity types and high content, and the product cannot be directly used as a raw material for producing and manufacturing batteries, and has obvious limitation.

Hashing means that positive electrode materials and organic substances are quickly and thoroughly separated in a certain mode. By adopting a physical method, under the condition of not damaging the original substrate form, the characteristic elements (the characteristic elements refer to aluminum foil, positive electrode material and adhesive) in the battery foil are hashed, so that the characteristic elements are recovered in a targeted manner, and the method is a new direction for treating the waste battery pole pieces in an energy-saving, environment-friendly and efficient manner.

Therefore, there is a need to develop a physical method based on hashing of feature elements in a power cell foil.

Disclosure of Invention

The invention aims to provide a physical method based on hash of characteristic elements in a power battery foil, which utilizes the difference of thermal expansion coefficients of different materials such as organic materials, inorganic materials, aluminum foil and the like in a battery pole piece to generate hash among different materials through high-temperature liquid nitrogen quenching so as to obtain a mixture of the organic materials, the inorganic materials and the aluminum foil.

The characteristic element hashing is to adopt a certain mode to realize rapid and thorough separation of aluminum foil, anode materials and organic substances. Physical methods are relatively chemical methods, and do not require the addition of excessive chemical reagents.

In order to achieve the purpose, the invention adopts the following technical scheme:

a physical method based on characteristic element hashing in a power battery foil comprises the following steps:

(1) taking a waste power battery positive plate, heating and cooling;

(2) transferring the positive plate into a heat preservation device, adding carbon dioxide, performing pressure reduction-pressurization cyclic extraction on organic matters, recovering the carbon dioxide, and sieving to obtain positive material powder and aluminum foil;

(3) washing the positive electrode material powder to obtain filter residue;

(4) transferring the filter residue into an electrolytic bath, adding a sodium salt solution, taking metal platinum as an anode and a cathode, applying voltage, controlling pressure intensity and ultrasonic treatment, relieving pressure, standing, discharging solid materials, discharging floating materials, filtering the solid materials, taking the filter residue, washing, drying, and performing electrostatic separation to obtain the cathode material.

Preferably, in the step (1), the positive electrode material in the waste power battery positive electrode plate is one of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium manganese oxide, lithium nickel manganese oxide or a lithium-rich manganese-based positive electrode material.

Preferably, in the step (1), the cooling is carried out by rapidly cooling to the temperature of-210 to-190 ℃ for 2-30 s.

Preferably, in the step (1), the heating temperature is 200-400 ℃, and the heating atmosphere is inert gas.

More preferably, the inert gas is one of nitrogen, helium and argon.

Preferably, in step (2), the carbon dioxide is in a liquid state.

Preferably, in the step (2), the temperature of the decompression-pressurization cycle is-20 ℃ to-10 ℃.

Preferably, in step (2), the pressure of the decompression-pressurization cycle is 1.6 to 3 MPa.

Preferably, the decompression-pressurization cycle is carried out to extract the organic matters, so that the carbon dioxide liquid-gas cycle phase change can be carried out.

The strong solubility of the homopolar organic matter in the supercritical carbon dioxide environment is utilized to dissolve the organic matter in liquid carbon dioxide, so that the organic matter is separated from the aluminum foil, and simultaneously, the organic matter is preliminarily separated from the electrode material powder. And the carbon dioxide is circularly changed from liquid state to gaseous state, which is beneficial to continuously separating organic matters from electrode material powder and strengthening the extraction effect. The extracted organic matter is organic matter, because the organic matter contained in the disassembled electrode plates comprises the adhesive and the electrolyte, in the extraction process, the electrolyte is gasified along with carbon dioxide, and the adhesive is separated from the battery material powder after being extracted, and the existence form of the adhesive is solid.

Preferably, in the step (3), the washing process comprises a first water washing and a second water washing.

More preferably, the temperature of the first water washing is 3-6 ℃, and the time of the first water washing is 1-3 h; in the first water washing, the mass-to-volume ratio of the anode material powder to the water is 1: (2-5).

More preferably, the temperature of the second water washing is 80-90 ℃, and the time of the second water washing is 2-8 h; in the second water washing, the mass-to-volume ratio of the filter residue to the water is 1: (3-8).

Preferably, in step (4), the sodium salt is sodium chloride; the mass concentration of the sodium salt solution is 5-26.5%.

Preferably, in the step (4), the applied voltage is 2-5V; the pressure for controlling the pressure intensity is 8-20 MPa.

Preferably, in the step (4), the pressure is controlled for 1 to 10 hours.

Preferably, in the step (4), the power density of the ultrasonic treatment is 0.5-5W/cm²。

Preferably, in step (4), the temperature of the solution for ultrasonic treatment is 30 ℃ to 90 ℃.

Preferably, in the step (4), the electrostatic separation is to separate out the conductive agent.

The invention also provides the application of the physical method in recycling battery materials.

The invention has the advantages that:

1. the invention utilizes the difference of the thermal expansion coefficients of different materials such as organic materials, inorganic materials, aluminum foils and the like in the battery pole piece, and hashes are generated among the different materials through high-temperature liquid nitrogen quenching, so as to obtain the mixture of the organic materials, the inorganic materials and the aluminum foils. Therefore, the high-purity metal aluminum foil can be obtained, different materials can be hashed, the primary hash of the anode material and the binder can be realized, and a foundation is established for the subsequent thorough removal of the binder.

2. According to the invention, the aluminum is removed by quenching in an inert atmosphere, and the aluminum foil is recovered in a metal form, so that the oxidation of aluminum metal in the traditional aerobic high-temperature recovery mode is avoided; on the other hand, the aluminum is separated in the whole process without adopting the traditional crushing and sorting process, the metal aluminum foil is not scattered, the aluminum foil is recovered in a whole integral form during recovery, the recovery rate is very high, and the problem that the metal aluminum foil cannot be effectively purified by a physical method when being mixed with battery material powder after being crushed by the traditional method is solved.

3. The invention adopts the method that chlorine generated by electrolyzing sodium chloride is dissolved in water to generate sodium hypochlorite, and the gas generated by electrolysis is applied with additional ultrasonic waves to generate cavitation in a closed high-pressure electrolytic tank under the condition of high pressure. Under the three-phase synergistic action of chlorine/sodium hypochlorite strong oxidant-high pressure strength-ultrasonic cavitation, organic materials and inorganic materials are quickly removed and separated, the organic materials are corroded and broken, the separated organic materials float on the solution, and the floating materials and solid materials are thoroughly separated by adopting a liquid separation method.

4. The invention adopts the method that the chlorine gas generated by electrolyzing sodium chloride is dissolved in water to generate sodium hypochlorite, on one hand, the electrode material powder is contacted with the electrode in the electrolysis process of the high-voltage electrolytic cell, so that trace metal aluminum possibly remained in the battery material powder is oxidized. On the other hand, sodium hydroxide is generated in the solution after electrolysis, the reaction rate of chlorine and water is slower than that of the generated sodium hydroxide, and the sodium hydroxide in the solution reacts with metallic aluminum or aluminum oxide to generate soluble salt to remove residual trace metallic aluminum (aluminum is amphoteric metal, the metallic aluminum and the aluminum oxide can be dissolved in the sodium hydroxide to generate sodium metaaluminate, and sodium ions and metaaluminate exist after being dissolved in water). Trace impurities in the anode material are removed, so that the anode material has high specific capacity, and finally, the regeneration of the anode material is realized.

5. The invention adopts 2 steps of water washing, namely first freezing water washing, and aims to wash away lithium carbonate contained in the positive electrode material. After the battery material is recycled for a long time, lithium ions which are removed during charging cannot be completely received and inserted by the positive electrode material during discharging, and simple substance lithium can exist in the battery after the battery material is used for a long time. After the battery is disassembled, the elemental lithium reacts with carbon dioxide and water vapor in the air (or used for extraction) to form lithium carbonate and lithium hydroxide. The lithium carbonate has higher solubility under the condition of low temperature, and the low temperature is favorable for promoting the lithium carbonate to be dissolved so as to deeply remove the lithium carbonate. The second hot water washing is performed in order to wash away lithium hydroxide contained in the positive electrode material. After the battery material is recycled for a long time, a small amount of lithium hydroxide can be generated, and the temperature rise is favorable for increasing the solubility of the lithium hydroxide and enhancing the washing effect. Residual lithium in the anode material is removed to realize the performance of long cycle life of the battery material.

6. The whole process for recycling the battery foil adopts physical methods of temperature, pressure, ultrasound, electrification and the like, only carbon dioxide and sodium chloride are used for adding materials, and acid-base or toxic and harmful chemical agents are not required to be added in the whole process. Through the composite comprehensive treatment of various physical processes, the aluminum foil, the anode material and the binder in the foil of the power battery are hashed in a stepped manner, and finally the battery-grade anode material is obtained. The whole process has the advantages of less raw and auxiliary material consumption, low recovery cost, less pollutant discharge and environment-friendly process technology.

Drawings

FIG. 1 is a graph of the life of example 1 and comparative example 1500 cycles at 1C rate.

Detailed Description

For a further understanding of the invention, preferred embodiments of the invention are described below with reference to the examples to further illustrate the features and advantages of the invention, and any changes or modifications that do not depart from the gist of the invention will be understood by those skilled in the art to which the invention pertains, the scope of which is defined by the scope of the appended claims.

Those who do not specify specific conditions in the examples of the present invention follow conventional conditions or conditions recommended by the manufacturer. The raw materials, reagents and the like which are not indicated for manufacturers are all conventional products which can be obtained by commercial purchase.

Example 1

A physical method based on hash of characteristic elements in a power battery foil comprises the following specific steps:

(1) taking a waste power battery positive plate (the positive material in the positive plate is nickel cobalt lithium manganate), heating the positive plate to 200 ℃ in a nitrogen atmosphere, quickly removing the positive plate from a heat source, and cooling the positive plate to-190 ℃ by adopting liquid nitrogen for 2 s;

(2) transferring the positive plate into a heat preservation device, adding liquid carbon dioxide, performing pressure reduction-pressurization circulation at-20 ℃ and 1.6-2MPa to enable the carbon dioxide to undergo liquid-gaseous circulation phase change, extracting organic matters, recovering carbon dioxide, sieving and separating to obtain positive material powder and aluminum foil;

(3) taking out the anode material powder, and mixing the anode material powder with the anode material powder according to a mass-to-volume ratio of 1: 2, mixing the powder with deionized water, controlling the water temperature to be 3 ℃, washing for 1h, filtering, taking filter residues, and mixing the filter residues according to a mass-to-volume ratio of 1: 3, mixing the powder with deionized water, controlling the water temperature to be 80 ℃, washing for 2 hours, filtering, and taking filter residue;

(4) transferring the filter residue to a special high-pressure electrolytic tank, adding 5% sodium chloride solution, electrifying with platinum as anode and cathode, applying 5V voltage at two ends of the anode and cathode, electrifying for a certain time to generate high pressure in the electrolytic tank by the gas generated in the high-pressure electrolytic tank, controlling the pressure in the electrolytic tank to be 20MPa, electrifying at variable time to supplement the pressure, maintaining constant pressure in the electrolytic tank for 1h, maintaining constant pressure at 90 deg.C and power of 0.5W/cm²And (2) performing ultrasonic treatment, relieving pressure, standing for 0.5h, opening a slag discharge valve at the bottom of the high-voltage electrolytic cell, discharging solid materials at the bottom of the high-voltage electrolytic cell from the bottom, completely discharging floating materials on the upper layer of the solution after the solid materials are completely discharged, filtering the solid materials at the bottom and partial solution brought by the solid materials, taking filter residues, washing with water, drying, and performing electrostatic separation on a conductive agent to obtain the battery-grade anode material.

Example 2

(1) taking a waste power battery positive plate (the positive material in the positive plate is lithium iron phosphate), heating the positive plate to 300 ℃ in a helium atmosphere, quickly removing the positive plate from a heat source, and cooling the positive plate to-192 ℃ within 10s by adopting liquid nitrogen;

(2) transferring the positive plate into a heat preservation device, adding liquid carbon dioxide, performing pressure reduction-pressurization circulation at-15 ℃ and 1.8-2.5MPa to enable the carbon dioxide to undergo liquid-gaseous circulation phase change, extracting organic matters, recovering carbon dioxide, sieving and separating to obtain positive material powder and aluminum foil;

(3) taking out the anode material powder, and mixing the anode material powder with the anode material powder according to a mass-to-volume ratio of 1: 3, mixing the powder with deionized water, controlling the water temperature to be 4 ℃ and the washing time to be 2 hours, filtering, taking filter residues, and mixing the filter residues according to a mass-volume ratio of 1: 5, mixing the powder with deionized water, controlling the water temperature to be 85 ℃, washing for 5 hours, filtering, and taking filter residue;

(4) transferring the filter residue into a special high-pressure electrolytic tank, adding a sodium chloride solution with the concentration of 15%, electrifying by taking metal platinum as an anode and a cathode, applying 3V voltage at two ends of the anode and the cathode, electrifying for a certain time (the electrifying time is determined according to the pressure in the high-pressure electrolytic tank, the longer the electrolyzing time is, the more gas is generated in the electrolytic tank, the higher the internal pressure is, the electrifying time is controlled to ensure that the pressure in the electrolytic tank is 15MPa, the electrolysis can generate chlorine, the internal pressure is reduced along with the dissolution of the chlorine in water, the constant pressure process needs to be electrified and supplemented at irregular time), the gas generated in the high-pressure electrolytic tank ensures that the high pressure is generated in the electrolytic tank, the pressure in the electrolytic tank is controlled to be 15MPa, the voltage is supplemented at irregular time, the constant pressure is maintained for 5h in the electrolytic tank, and the constant pressure is maintained at the temperature of 50 ℃ and the power of 2W/cm²And (2) performing ultrasonic treatment, relieving pressure, standing for 2 hours, opening a slag discharge valve at the bottom of the high-voltage electrolytic cell, discharging solid materials at the bottom of the high-voltage electrolytic cell from the bottom, completely discharging floating objects on the upper layer of the solution after the solid materials are completely discharged, filtering the solid materials at the bottom and partial solution brought by the solid materials, taking filter residues, washing with water, drying, and performing electrostatic separation on a conductive agent to obtain the battery-grade anode material.

Example 3

(1) taking a waste power battery positive plate (the positive material in the positive plate is nickel cobalt lithium aluminate), heating the positive plate to 400 ℃ in an argon atmosphere, quickly removing the positive plate from a heat source, and cooling the positive plate to-195 ℃ within 30s by adopting liquid nitrogen;

(2) transferring the positive plate into a heat preservation device, adding liquid carbon dioxide, performing pressure reduction-pressurization circulation at-10 ℃ and 2-3MPa to enable the carbon dioxide to undergo liquid-gaseous circulation phase change, extracting organic matters, recovering carbon dioxide, sieving and separating to obtain positive material powder and aluminum foil;

(3) taking out the anode material powder, and mixing the anode material powder with the anode material powder according to a mass-to-volume ratio of 1: 5, mixing the powder with deionized water, controlling the water temperature to be 6 ℃, washing for 3 hours, filtering, taking filter residues, and mixing the filter residues according to a mass-to-volume ratio of 1: 8, mixing the powder with deionized water, controlling the water temperature to be 90 ℃, washing for 8 hours, filtering, and taking filter residues;

(4) transferring the filter residue to a special high-pressure electrolytic tank, adding saturated sodium chloride solution, electrifying with metal platinum as anode and cathode, applying 2V voltage at two ends of the anode and cathode, electrifying for a certain time, generating high pressure in the electrolytic tank by gas generated in the high-pressure electrolytic tank, controlling the pressure in the electrolytic tank to be 8MPa, electrifying at variable time to supplement pressure, maintaining constant pressure in the electrolytic tank for 10h, and simultaneously maintaining constant pressure at 30 deg.C and 5W/cm power²And (2) performing ultrasonic treatment, relieving pressure, standing for 3 hours, opening a slag discharge valve at the bottom of the high-voltage electrolytic cell, discharging solid materials at the bottom of the high-voltage electrolytic cell from the bottom, completely discharging floating objects on the upper layer of the solution after the solid materials are completely discharged, filtering the solid materials at the bottom and partial solution brought by the solid materials, taking filter residues, washing with water, drying, and performing electrostatic separation on a conductive agent to obtain the battery-grade anode material.

Comparative example

A method of recovering electrode material powder, comprising the steps of:

(1) taking a waste power battery positive plate, pyrolyzing, crushing and sorting the positive plate, and taking electrode material powder obtained by sorting.

And (4) comparing the results:

1. recovery rate

For example, the recovery rate of aluminum foil is the weight of the metal aluminum in the aluminum foil sorted after treatment divided by the weight of the metal aluminum in the electrode sheet before treatment.

Table 1 example 1 and comparative example recovery

2. Purity of

TABLE 2 purity of recovered aluminum foil

Element(s)	Example 1 content/%)	Comparative example content/%)
			Al	99.2	0
Ni	0.058	/
			Co	0.046	/
Mn	0.054	/
			Li	0.036
Cu	0.014	/
			Fe	0.043	/
Na	0.125	/
			Mg	0.031	/
Ca	0.037	/
			Zn	0.015	/
F^-	0.059	/
			Cl^-	0.137	/

As can be seen from tables 1 and 2, the purity includes the purity of 2 substances, which are firstly the aluminum foil recovered and secondly the positive electrode material recovered; the recovery rate of the aluminum foil can reach 99.5%, and the purity of the recovered aluminum foil can reach 99.2%. In contrast, in the comparative example, the recovery rate of aluminum foil was 0, and since the treatment method of the comparative example caused oxidation of metal aluminum to alumina, and the weight of the recovered metal aluminum was 0, the recovery rate of aluminum was 0 and the purity thereof was also 0.

TABLE 3 purity of recovered positive electrode material

The recycled positive material is nickel cobalt lithium manganate, and the chemical formula is as follows: LiNi_xCo_yMn_1-x-yO₂Therefore, there is O element in addition to Ni/Co/Mn/Li main element, so from the data of Table 3, Ni + Co + Mn + Li is not close to 100%, but Ni + Co + Mn content is 59.8%, which is much higher than 47.3% in the comparative example.

And (3) performance detection:

the lithium nickel cobaltate prepared in example 1 and comparative example 1 was used as a positive electrode and graphite as a negative electrode, respectively, to assemble a battery, and a first discharge test was performed at a 1C rate.

TABLE 4 Performance test results

The results are shown in Table 4, at a rate of 1C, the first discharge specific capacity of the nickel cobalt lithium manganate positive electrode material recycled by the method is higher than that of the conventional pyrolysis crushing sorting method, the specific capacity of example 1 is 189.4mAh/g, and the specific capacity of the comparative example is only 107.3 mAh/g.

1500 charge-discharge cycle tests were performed at 1C rate. The results are shown in table 4, after 1500 cycles, the specific capacity of the nickel cobalt lithium manganate positive electrode material recycled by the method is higher than that of the traditional pyrolysis crushing sorting method, the capacity retention rate of example 1 is 83.6%, and the capacity retention rate of the comparative example is only 55.2%. Fig. 1 is a life curve diagram of example 1 and comparative example, which are cycled 1500 times at a rate of 1C, and it can be seen from fig. 1 that the specific capacity of example 1 is significantly higher than that of comparative example, and the capacity retention rate is 83.6%, which is much higher than that of comparative example, which illustrates that the recycled cathode material of the present invention is applied to the preparation of a battery, and meets the requirements of specific capacity and capacity retention rate.

While the above detailed description of the physical method and its application for hash of feature elements in a power cell foil provided by the present invention has been described in detail, specific embodiments thereof have been presented herein for the purpose of illustrating the principles and implementations of the invention, the above detailed description is only provided to facilitate the understanding of the method and its core ideas, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A physical method based on characteristic element hashing in a power battery foil is characterized by comprising the following steps:

(1) taking a waste power battery positive plate, heating and cooling;

(3) washing the positive electrode material powder to obtain filter residue;

(4) transferring the filter residue into an electrolytic bath, adding a sodium salt solution, taking metal platinum as an anode and a cathode, applying voltage, controlling pressure intensity and ultrasonic treatment, relieving pressure, standing, discharging solid materials, discharging floating objects, filtering the solid materials, taking the filter residue, washing, drying and carrying out electrostatic separation to obtain a positive electrode material; in the step (1), the heating temperature is 200-400 ℃, and in the step (4), the sodium salt is sodium chloride.

2. The physical method according to claim 1, wherein in the step (1), the positive electrode material in the waste power battery positive electrode plate is one of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium manganese oxide, lithium nickel manganese oxide or a lithium-rich manganese-based positive electrode material.

3. The physical method according to claim 1, wherein in step (1), the heated atmosphere is an inert gas; the inert gas is one of nitrogen, helium and argon.

4. The physical method according to claim 1, wherein in the step (1), the cooling is carried out by quenching the temperature to-210 to-190 ℃ for 2-30 s.

5. The physical process of claim 1, wherein in step (2), the temperature of the depressurization-pressurization cycle is in the range of-20 ℃ to-10 ℃; the pressure of the decompression-pressurization cycle is 1.6-3 MPa.

6. The physical method according to claim 1, wherein in the step (3), the washing process comprises a first water washing and a second water washing; the temperature of the first water washing is 3-6 ℃, and the time of the first water washing is 1-3 h; in the first water washing, the mass-to-volume ratio of the anode material powder to the water is 1: (2-5); the temperature of the second water washing is 80-90 ℃, and the time of the second water washing is 2-8 h; in the second water washing, the mass-to-volume ratio of the filter residue to the water is 1: (3-8).

7. The physical method according to claim 1, wherein in the step (4), the mass concentration of the sodium salt solution is 5-26.5%.

8. The physical method according to claim 1, wherein in step (4), the applied voltage is 2-5V; the pressure for controlling the pressure intensity is 8-20 MPa.

9. The physical method according to claim 1, wherein in the step (4), the time for controlling the pressure is 1-10 h.

10. Use of the physical process of any one of claims 1 to 9 for recycling battery material.