Method for recycling positive electrode material of lithium battery by using porous oxide

Abstract

The invention belongs to the technical field of lithium battery recovery, and particularly relates to a method for recovering a lithium battery positive electrode material by using a porous oxide. The invention provides a method for recycling a positive electrode material of a lithium battery by using a porous oxide. The method comprises the following steps: (1) pre-treating a retired lithium battery to obtain positive electrode material powder; (2) adding a porous oxide and an acid reagent into deionized water, and uniformly stirring to form a mixed solution; (3) adding positive electrode material powder into the mixed solution for reaction, and performing suction filtration after the reaction is finished to obtain a leaching solution; and (4) sodium oxalate or / and bubbling carbon dioxide is / are added into the leachate for a precipitation reaction, and then filtering treatment is conducted to obtain metal precipitates. According to the method, the positive electrode material of the retired lithium battery is contacted with the treated porous oxide, efficient dissolution and separation of metal elements can be realized by virtue of an electromigration effect under a mild condition without strong acid and alkali or high temperature, resource waste and environmental load are reduced, and an efficient environment-friendly scheme is provided for cyclic utilization of the lithium battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium battery recycling, and in particular relates to a method for recycling lithium battery positive electrode materials by utilizing porous oxides. Background Art

[0002] Driven by the strategic goals of "carbon peak and carbon neutrality," the new energy vehicle industry is experiencing rapid development, and the demand for lithium-ion batteries has also skyrocketed. As the lithium-ion battery market continues to expand, a large number of retired and used lithium batteries are generated. Relevant data show that by 2040, the electric vehicle industry will produce the largest number of lithium-ion batteries (LIBs), with the battery mass potentially exceeding 4 million tons. If these retired and used lithium batteries are not properly handled, they will not only waste precious metal resources such as lithium, cobalt, and nickel, but will also cause serious environmental pollution.

[0003] Currently, lithium-ion battery recycling mainly uses pyrometallurgical recycling, wet recycling, and direct recycling methods. Pyrometallurgical recycling involves high-temperature smelting to oxidize and volatilize the metals in the battery, which are then condensed and recovered. This method has a relatively simple process flow, can process large quantities of used batteries at one time, and has a strong tolerance to impurities. Wet recycling uses acid and alkali solutions to dissolve the batteries, and then separates the metals through extraction and precipitation techniques. This can achieve highly selective separation of multiple metals and is suitable for processing batteries with complex compositions. Direct recycling involves physical disassembly and pulverization of the batteries. This is intuitive to operate, does not require complex chemical reagents, can quickly process simple batteries, and avoids the risk of chemical contamination.

[0004] However, these traditional methods also have significant drawbacks. Pyrometallurgical recovery consumes extremely high energy and easily produces large amounts of harmful gases such as sulfur dioxide and nitrogen oxides. It also places stringent demands on the equipment's high-temperature and corrosion resistance, and has an upper limit on metal recovery rates. Wet metal recovery produces large amounts of wastewater, which is costly to treat, consumes large amounts of acid and alkali reagents, and can easily cause secondary environmental pollution. Direct recovery is only suitable for some simple batteries. For complex lithium-ion batteries, metal separation is incomplete, resulting in low overall recovery rates.

[0005] Therefore, the development of more efficient and environmentally friendly lithium-ion battery recycling technologies has received increasing attention. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention provides a method for recycling lithium battery positive electrode materials using porous oxides.

[0007] The method for recycling lithium battery positive electrode materials using porous oxides according to an embodiment of the present invention comprises the following steps:

[0008] (1) Pre-treating retired lithium batteries to obtain positive electrode material powder;

[0009] (2) adding the porous oxide and the acid reagent into deionized water and stirring to form a mixed solution;

[0010] (3) adding the positive electrode material powder obtained in step (1) to the mixed solution obtained in step (2) to carry out a reaction, and filtering after the reaction is completed to obtain a leachate;

[0011] (4) adding sodium oxalate and / or bubbling carbon dioxide to the leachate obtained in step (3) to carry out a precipitation reaction, and then filtering to obtain a metal precipitate.

[0012] The advantages and technical effects brought by the method of recycling lithium battery positive electrode materials using porous oxides in the embodiment of the present invention are as follows: 1. In the method of the embodiment of the present invention, the superoxide free radicals generated by electron transfer during the contact electrocatalysis process have the ability to promote the reduction of metals. Therefore, the porous oxide with excellent electromigration performance can be used to dissolve, enrich and recover metal substances in the lithium battery positive electrode materials, thereby replacing the traditional high-temperature fire method and strong acid and strong alkali wet process, significantly reducing the energy consumption and carbon emissions of the recovery process, eliminating the need to use a large amount of chemical reagents, avoiding the generation of heavy metal-containing wastewater and harmful gases, effectively reducing the risk of secondary pollution, and meeting the environmental protection requirements of green recycling under the "dual carbon" goal; 2. In the method of the embodiment of the present invention, acid reagents are used to optimize the electromigration performance of porous oxides, constructing an efficient metal separation system, and realizing the rapid dissolution and enrichment of key metals such as lithium, cobalt, and nickel. Compared with traditional methods, at room temperature and pressure The recycling process can be completed in 3 steps, which greatly reduces energy consumption, reduces the damage to the environment caused by raw material mining, and promotes the efficient recycling of resources; 3. The method of the embodiment of the present invention has a wide range of raw materials for preparing porous heterogeneous oxides, low cost, stable structure during the recycling process, and can be reused after simple treatment, which significantly reduces the operating cost of the recycling process and improves the economy and feasibility of the process; 4. The method of the embodiment of the present invention has a simple technical process and does not require complicated separation steps such as extraction and precipitation. By controlling the pore size, specific surface area and surface chemical properties of the porous oxide, its reduction ability to different metal ions can be adjusted to achieve selective recovery of metal elements. The process operation is simple and controllable, easy to scale up, and can be adapted to retired lithium batteries of different types and levels. It has significant potential for industrial application and provides an innovative solution for green management of lithium-ion batteries throughout their life cycle.

[0013] In some embodiments, in step (1), the pretreatment includes disassembly, shredding and crushing.

[0014] In some embodiments, in step (1), the positive electrode material includes at least one of lithium iron phosphate, lithium cobalt oxide, or lithium nickel cobalt manganese oxide.

[0015] In some embodiments, in step (2), the porous oxide comprises porous silica;

[0016] And / or, in step (2), the specific surface area of ​​the porous oxide is 100 to 200 m 2 / g; the particle size of the porous oxide is 10 to 20 nm;

[0017] And / or, in step (2), the preparation method of the porous oxide includes a sol-gel method.

[0018] In some embodiments, in step (2), the acid reagent includes at least one of an organic acid or an inorganic acid, the organic acid includes at least one of citric acid, tartaric acid or succinic acid, and the inorganic acid includes at least one of hydrochloric acid or nitric acid.

[0019] In some embodiments, in step (2), the solid-to-liquid ratio of the porous oxide to deionized water is 5 to 20 g / L, and the concentration of the acid reagent in the mixed solution is 0.4 to 1 mol / L.

[0020] In some embodiments, in step (3), the solid-to-liquid ratio of the positive electrode material powder and the mixed solution is 5 to 20 g / L.

[0021] In some embodiments, in step (3), the reaction is carried out in an ultrasonic instrument or a micro-motion rotary stirrer;

[0022] And / or, in step (3), the reaction time is 4 to 9 hours, and the reaction temperature is 20 to 80°C.

[0023] In some embodiments, when the positive electrode material is lithium cobalt oxide, in step (4), the precipitation reaction specifically comprises: adding sodium oxalate to the leachate at 50-60° C. to selectively precipitate cobalt, filtering to obtain cobalt oxalate and a filtrate, and then introducing CO2 into the filtrate to form lithium carbonate precipitation;

[0024] When the positive electrode material is lithium nickel cobalt manganate, in the step (4), the precipitation reaction specifically includes: adjusting the pH of the leachate to 1.2-1.5 with NaOH, adding sodium oxalate at 50-60°C to form a cobalt oxalate precipitate, and then filtering to obtain a first filtrate and cobalt oxalate; adjusting the pH of the first filtrate to 7.3-7.5 with NaOH, passing CO2 to form a manganese carbonate precipitate, and then filtering to obtain a second filtrate and manganese carbonate; adjusting the pH of the second filtrate to 8.8-9.0 with NaOH, passing CO2 to form a nickel carbonate precipitate, and then filtering to obtain a third filtrate and nickel carbonate; adjusting the pH of the third filtrate to 13.5-14 with NaOH, passing CO2 to form a lithium carbonate precipitate, and then filtering to obtain a fourth filtrate and lithium carbonate;

[0025] When the positive electrode material is lithium iron phosphate, in step (4), NaOH is added to the leachate to precipitate Fe 3+ After obtaining the Fe(OH)3 precipitate, filter to obtain the filtrate and the Fe(OH)3 precipitate, introduce CO2 into the filtrate to form a lithium carbonate precipitate, and then filter.

[0026] In some embodiments, in step (3), the mass ratio of the sodium oxalate and the positive electrode material powder is (1-3):1; the ventilation flow rate of the bubbling carbon dioxide is 0.5-2 L / min, and the mass ratio of the bubbling carbon dioxide to the positive electrode material is (1-3):1. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the process of recycling lithium battery positive electrode materials using porous oxides. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0029] like Figure 1 As shown, the method for recycling lithium battery positive electrode materials using porous oxides according to an embodiment of the present invention includes the following steps:

[0030] (1) Pre-treating retired lithium batteries to obtain positive electrode material powder;

[0031] (2) adding the porous oxide and the acid reagent into deionized water and stirring to form a mixed solution;

[0032] (3) adding the positive electrode material powder obtained in step (1) to the mixed solution obtained in step (2) to carry out a reaction, and filtering after the reaction is completed to obtain a leachate;

[0033] (4) adding sodium oxalate and / or bubbling carbon dioxide to the leachate obtained in step (3) to carry out a precipitation reaction, and then filtering to obtain a metal precipitate.

[0034] The method of recycling lithium battery positive electrode materials using porous oxides in the embodiment of the present invention is that superoxide radicals generated by electron transfer during contact electrocatalysis have the ability to promote the reduction of metals. Therefore, porous oxides with excellent electromigration properties can be used to dissolve, enrich and recover metal substances in lithium battery positive electrode materials, thereby replacing traditional high-temperature pyrolysis and strong acid and strong alkali wet processes, significantly reducing energy consumption and carbon emissions in the recovery process, eliminating the need to use a large amount of chemical reagents, avoiding the generation of heavy metal-containing wastewater and harmful gases, effectively reducing the risk of secondary pollution, and meeting the environmental protection requirements of green recycling under the "dual carbon" goal; the method of the embodiment of the present invention uses acid reagents to optimize the electromigration properties of porous oxides, constructing an efficient metal separation system, and realizing rapid dissolution and enrichment of key metals such as lithium, cobalt, and nickel. Compared with traditional methods, the recovery process can be completed at room temperature and pressure. It greatly reduces energy consumption, reduces the damage to the environment caused by raw material mining, and promotes the efficient recycling of resources. The method of the embodiment of the present invention has a wide range of raw material sources for preparing porous heterogeneous oxides, is low in cost, and has a stable structure during the recycling process. It can be reused after simple treatment, which significantly reduces the operating cost of the recycling process and improves the economy and feasibility of the process. The method of the embodiment of the present invention has a simple technical process and does not require complicated separation steps such as extraction and precipitation. By controlling the pore size, specific surface area and surface chemical properties of the porous oxide, its reduction ability to different metal ions can be adjusted to achieve selective recovery of metal elements. The process operation is simple and controllable, easy to scale up, and can be adapted to retired lithium batteries of different types and levels. It has significant potential for industrial application and provides an innovative solution for the green management of lithium-ion batteries throughout their life cycle.

[0035] In some embodiments, preferably, in the step (1), the pretreatment includes disassembly, shredding and crushing.

[0036] In some embodiments, preferably, in step (1), the positive electrode material includes at least one of lithium iron phosphate, lithium cobalt oxide, or lithium nickel cobalt manganese oxide.

[0037] In some embodiments, preferably, in step (2), the porous oxide comprises porous silica;

[0038] And / or, in step (2), the specific surface area of ​​the porous oxide is 100 to 200 m 2 / g, for example 100m 2 / g、110m 2 / g, 120m 2 / g, 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g, 170m2 / g, 180m 2 / g, 190m 2 / g, 200m 2 / g, etc.; the particle size of the porous oxide is 10 to 20 nm, for example, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0039] In some embodiments, preferably, in step (2), the preparation method of the porous oxide comprises a sol-gel method. The sol-gel method comprises the following steps: first, using tetraethyl orthosilicate (TEOS) as a silicon source, adding an appropriate amount of water, acid or base as a catalyst to form a uniform sol; second, controlling the concentration, pH value and reaction temperature of the sol to gradually gel the sol; and finally, drying and calcining the gel to obtain porous silica.

[0040] In some embodiments, preferably, in step (2), the acid reagent includes at least one of an organic acid or an inorganic acid, the organic acid includes at least one of citric acid, tartaric acid or succinic acid, and the inorganic acid includes at least one of hydrochloric acid or nitric acid.

[0041] In the embodiment of the present invention, the type and concentration of the acid reagent are optimized, and the leaching efficiency is higher.

[0042] In some embodiments, preferably, in step (2), the solid-liquid ratio of the porous oxide and deionized water is 5 to 20 g / L, for example, 5 g / L, 7 g / L, 9 g / L, 11 g / L, 13 g / L, 15 g / L, 17 g / L, 19 g / L, 20 g / L, etc., and the concentration of the acid reagent in the mixed solution is 0.4 to 1 mol / L, for example, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, etc.

[0043] In the embodiment of the present invention, the ratio of the amount of porous oxide to the acid reagent is optimized to further improve the leaching efficiency. If the amount of porous oxide is too much, it may induce ultrasonic scattering, and if the amount of porous oxide is too little, the reaction may be too slow.

[0044] In some embodiments, preferably, in step (3), the solid-to-liquid ratio of the positive electrode material powder and the mixed solution is 5 to 20 g / L, for example, 5 g / L, 7 g / L, 9 g / L, 11 g / L, 13 g / L, 15 g / L, 17 g / L, 19 g / L, 20 g / L, etc.

[0045] In the embodiments of the present invention, the ratio of the amount of positive electrode material powder to the mixed solution is optimized to ensure that the active sites of the acid reagent and the porous oxide are fully utilized, the reaction proceeds fully, and the metal leaching efficiency is improved. If the amount of positive electrode material powder used is too much, the reaction will be insufficient. If the amount of positive electrode material powder used is too little, the leaching efficiency will be reduced, and the active sites of the acid reagent and the porous oxide in the reaction system cannot be fully utilized.

[0046] In some embodiments, preferably, in the step (3), the reaction is carried out in an ultrasonic instrument or a micro-motion rotary stirrer.

[0047] In an embodiment of the present invention, the reaction is carried out in an ultrasonic instrument or a micro-motion rotary stirrer, and the cavitation bubbles generated by the ultrasonic instrument or the micro-motion rotary stirrer are separated and contacted to generate electron transfer, so that superoxide radicals are generated on the surface of the silicon dioxide and the metal ions are reduced.

[0048] In some embodiments, preferably, in step (3), the reaction time is 4 to 9 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, etc., and the reaction temperature is 20 to 80°C, for example, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.

[0049] In the embodiment of the present invention, the reaction temperature and time are optimized to further improve the leaching efficiency.

[0050] In some embodiments, preferably, when the positive electrode material is lithium cobaltate, in the step (4), the precipitation reaction specifically comprises: adding sodium oxalate to the leachate at 50-60° C. to selectively precipitate cobalt, filtering to obtain a cobalt oxalate precipitate and a filtrate, and then introducing CO2 into the filtrate to form a lithium carbonate precipitate;

[0051] When the positive electrode material is lithium nickel cobalt manganate, in the step (4), the precipitation reaction specifically includes: adjusting the pH of the leachate to 1.2-1.5 with NaOH, adding sodium oxalate at 50-60°C to form a cobalt oxalate precipitate, and then filtering to obtain a first filtrate and cobalt oxalate; adjusting the pH of the first filtrate to 7.3-7.5 with NaOH, passing CO2 to form a manganese carbonate precipitate, and then filtering to obtain a second filtrate and manganese carbonate; adjusting the pH of the second filtrate to 8.8-9.0 with NaOH, passing CO2 to form a nickel carbonate precipitate, and then filtering to obtain a third filtrate and nickel carbonate; adjusting the pH of the third filtrate to 13.5-14 with NaOH, passing CO2 to form a lithium carbonate precipitate, and then filtering to obtain a fourth filtrate and lithium carbonate;

[0052] When the positive electrode material is lithium iron phosphate, in step (4), NaOH is added to the leachate to precipitate Fe 3+After obtaining the Fe(OH)3 precipitate, filter to obtain the filtrate and the Fe(OH)3 precipitate, introduce CO2 into the filtrate to form a lithium carbonate precipitate, and then filter.

[0053] In some embodiments, preferably, in the step (3), the mass ratio of the sodium oxalate and the positive electrode material powder is (1-3):1; the ventilation flow rate of the bubbling carbon dioxide is 0.5-2 L / min, and the mass ratio of the introduced mass of the bubbling carbon dioxide and the positive electrode material is (1-3):1.

[0054] The technical solution of the present invention is described in detail below with reference to specific embodiments and drawings.

[0055] Example 1

[0056] (1) disassembling, shredding and crushing retired lithium cobalt oxide batteries to obtain positive electrode material powder;

[0057] (2) Preparation of porous silica (specific surface area of ​​150 m 2 / g, particle size of 15 nm), porous silica and citric acid were added to deionized water and stirred to form a mixed solution, the solid-liquid ratio of porous oxide to deionized water was 9 / L, and the concentration of the acid reagent in the mixed solution was 0.5 mol / L;

[0058] (3) The positive electrode material powder was added to the mixed solution at a solid-liquid ratio of 20 g / L, and the mixture was placed in an ultrasonic instrument and reacted at 80°C for 9 hours. After the reaction, the mixture was transferred to a suction filtration separation device for suction filtration to obtain a leachate with a lithium extraction efficiency of 82.90% and a cobalt extraction efficiency of 81.08%.

[0059] (4) At 50°C, sodium oxalate in a mass ratio of 1:1 to the positive electrode material powder is added to the leachate to combine the cobalt ions with the oxalate ions to form a cobalt oxalate precipitate; after the precipitation reaction is completed, the precipitate is separated by filtration, and CO2 in a mass ratio of 1:1 to the positive electrode material is introduced at a flow rate of 1 L / min to form a lithium carbonate precipitate.

[0060] Example 2

[0061] (1) disassembling, shredding and crushing retired lithium nickel cobalt manganese oxide batteries to obtain positive electrode material powder;

[0062] (2) Preparation of porous silica (specific surface area of ​​180 m 2 / g, particle size of 12 nm), porous silica and citric acid were added to deionized water and stirred to form a mixed solution, the solid-liquid ratio of porous oxide to deionized water was 15 g / L, and the concentration of the acid reagent in the mixed solution was 1 mol / L;

[0063] (3) The cathode material powder was added to the mixed solution at a solid-liquid ratio of 5 g / L, and the mixture was placed in a micro-motion rotary stirrer and reacted at 40°C for 4 h. After the reaction, the mixture was transferred to a suction filtration separation device for suction filtration to obtain a leachate. The extraction efficiencies of lithium, nickel, cobalt, and manganese were 84.56%, 86.62%, 86.54%, and 85.78%, respectively.

[0064] (4) At 50°C, NaOH was added to the leachate to adjust the pH to 1.5, sodium oxalate was added to form a cobalt oxalate precipitate, and then the filtrate and residue were obtained by filtering; the pH of the filtrate was adjusted to 7.5, CO2 with a mass ratio of 1:1 to the positive electrode material was introduced at a flow rate of 1 L / min to form a manganese carbonate precipitate, and then the filtrate and residue were obtained by filtering; the pH of the filtrate was adjusted to 9.0, CO2 with a mass ratio of 1:1 to the positive electrode material was introduced at a flow rate of 1 L / min to form a nickel carbonate precipitate, and then the filtrate and residue were obtained by filtering; the pH of the filtrate was adjusted to 14, CO2 with a mass ratio of 1:1 to the positive electrode material was introduced at a flow rate of 1 L / min to form a lithium carbonate precipitate, and then the filtrate and residue were obtained by filtering.

[0065] Example 3

[0066] (1) disassembling, shredding and crushing retired lithium iron phosphate batteries to obtain positive electrode material powder;

[0067] (2) Preparation of porous silica (specific surface area of ​​200 m 2 / g, particle size of 18 nm), porous silica and citric acid were added to deionized water and stirred to form a mixed solution, the solid-liquid ratio of porous oxide to deionized water was 17 g / L, and the concentration of the acid reagent in the mixed solution was 0.8 mol / L;

[0068] (3) The cathode material powder was added to the mixed solution at a solid-liquid ratio of 13 g / L, and the mixture was placed in a micro-motion rotary stirrer and reacted at 70°C for 6 h. After the reaction, the mixture was transferred to a suction filtration separation device for suction filtration to obtain a leachate with a lithium extraction efficiency of 84.93% and an iron dissolution rate of 86.59%.

[0069] (4) NaOH is added to the leachate to obtain Fe(OH)3 precipitate, which is then filtered to obtain a filtrate and a filter residue. CO2 having a mass ratio of 1:1 to the positive electrode material is introduced into the filtrate at a flow rate of 1.5 L / min to form a lithium carbonate precipitate, which is then filtered.

[0070] Comparative Example 1

[0071] The treatment method of this comparative example is the same as that of Example 1, except that in step (2), only porous fly ash aluminum silicon oxide is added to deionized water to form a solution, without adding citric acid.

[0072] In this comparative example, the extraction efficiency of lithium was 78.26%, and the extraction efficiency of cobalt was 76.52%.

[0073] Comparative Example 2

[0074] The processing method of this comparative example is the same as that of Example 1, except that aluminum silicon oxide without a porous structure is used in step (2).

[0075] In this comparative example, the extraction efficiency of lithium was 75.39%, and the extraction efficiency of cobalt was 75.46%.

[0076] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0077] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. A method for recycling lithium battery positive electrode materials using porous oxides, characterized in that: The following steps are involved: (1) Pre-treating retired lithium batteries to obtain positive electrode material powder; (2) adding the porous oxide and the acid reagent into deionized water and stirring to form a mixed solution; (3) adding the positive electrode material powder obtained in step (1) to the mixed solution obtained in step (2) to carry out a reaction, and filtering after the reaction is completed to obtain a leachate; (4) adding sodium oxalate and / or bubbling carbon dioxide to the leachate obtained in step (3) to carry out a precipitation reaction, and then filtering to obtain a metal precipitate.

2. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 1, characterized in that: In the step (1), the pretreatment includes disassembly, shredding and crushing.

3. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 1, characterized in that: In the step (1), the positive electrode material includes at least one of lithium iron phosphate, lithium cobalt oxide or lithium nickel cobalt manganese oxide.

4. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 1, characterized in that: In the step (2), the porous oxide comprises porous silica; And / or, in step (2), the specific surface area of ​​the porous oxide is 100 to 200 m 2 / g; the particle size of the porous oxide is 10 to 20 nm; And / or, in step (2), the preparation method of the porous oxide includes a sol-gel method.

5. The method for recovering positive electrode materials of lithium batteries using porous oxides according to claim 1 or 4, characterized in that: In the step (2), the acid reagent includes at least one of an organic acid or an inorganic acid, the organic acid includes at least one of citric acid, tartaric acid or succinic acid, and the inorganic acid includes at least one of hydrochloric acid or nitric acid.

6. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 5, characterized in that: In the step (2), the solid-to-liquid ratio of the porous oxide to deionized water is 5 to 20 g / L, and the concentration of the acid reagent in the mixed solution is 0.4 to 1 mol / L.

7. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 1, characterized in that: In the step (3), the solid-to-liquid ratio of the positive electrode material powder and the mixed solution is 5 to 20 g / L.

8. The method for recovering lithium battery positive electrode materials using porous oxide according to claim 1 or 7, characterized in that: In the step (3), the reaction is carried out in an ultrasonic instrument or a micro-motion rotary stirrer; And / or, in step (3), the reaction time is 4 to 9 hours, and the reaction temperature is 20 to 80°C.

9. The method for recycling lithium battery positive electrode materials using porous oxide according to claim 3, characterized in that: When the positive electrode material is lithium cobalt oxide, in step (4), the precipitation reaction specifically comprises: adding sodium oxalate to the leachate at 50-60° C. to selectively precipitate cobalt, filtering to obtain cobalt oxalate and a filtrate, and then introducing CO2 into the filtrate to form lithium carbonate precipitation; When the positive electrode material is lithium nickel cobalt manganate, in the step (4), the precipitation reaction specifically includes: adjusting the pH of the leachate to 1.2-1.5 with NaOH, adding sodium oxalate at 50-60°C to form a cobalt oxalate precipitate, and then filtering to obtain a first filtrate and cobalt oxalate; adjusting the pH of the first filtrate to 7.3-7.5 with NaOH, passing CO2 to form a manganese carbonate precipitate, and then filtering to obtain a second filtrate and manganese carbonate; adjusting the pH of the second filtrate to 8.8-9.0 with NaOH, passing CO2 to form a nickel carbonate precipitate, and then filtering to obtain a third filtrate and nickel carbonate; adjusting the pH of the third filtrate to 13.5-14 with NaOH, passing CO2 to form a lithium carbonate precipitate, and then filtering to obtain a fourth filtrate and lithium carbonate; When the positive electrode material is lithium iron phosphate, in step (4), NaOH is added to the leachate to precipitate Fe 3+ After obtaining the Fe(OH)3 precipitate, the filtrate and the Fe(OH)3 precipitate are obtained by filtration, CO2 is introduced into the filtrate to form a lithium carbonate precipitate, and then the filtrate is filtered.

10. The method for recycling lithium battery positive electrode materials using porous oxides according to claim 1 or 9, characterized in that: In the step (4), the mass ratio of the sodium oxalate to the positive electrode material powder is (1-3):1; the ventilation flow rate of the bubbling carbon dioxide is 0.5-2 L / min, and the mass ratio of the bubbling carbon dioxide to the positive electrode material is (1-3):1.

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