Method for regenerating and preparing high-voltage lithium cobalt oxide by utilizing failed lithium cobalt oxide material

Abstract

The invention discloses a method for regenerating and preparing high-voltage lithium cobalt oxide by using an invalid lithium cobalt oxide material, and belongs to the technical field of battery recovery. The method comprises the following steps: S1, carrying out ball milling and mixing on failed lithium cobalt oxide powder and a sodium source, and then carrying out solid-phase sintering to obtain a P2 type sodium cobalt oxide and lithium cobalt oxide material; s2, the P2 type sodium cobaltate and lithium cobaltate material is placed in a lithium-containing solution for a hydrothermal reaction, a regenerated O2-O3 cotype lithium cobaltate material is obtained, the regenerated O2-O3 cotype lithium cobaltate material has the advantages of being good in cycling stability, high in rate capability, high in low-temperature performance and the like under the high voltage of 4.6 V, and the performance of the regenerated O2-O3 cotype lithium cobaltate material is superior to that of a commercial lithium cobaltate material.

Description

Technical Field

[0001] This invention relates to a method for the direct regeneration of cathode materials from waste lithium-ion batteries, and particularly to a method for regenerating high-voltage lithium cobalt oxide from depleted lithium cobalt oxide materials, belonging to the field of waste battery recycling technology. Background Technology

[0002] In recent years, the widespread use of lithium-ion batteries (LIBs) has triggered a wave of retired batteries, directly driving the rapid development of the lithium battery recycling industry. Currently, the mainstream recycling technologies are still pyrometallurgy and hydrometallurgy, but their extensive use of acid and alkali reagents and high-temperature smelting processes leads to significant environmental pollution and energy consumption, limiting their further application. Therefore, direct regeneration methods such as solid-state processes, molten salt processes, and hydrothermal processes have gained popularity due to their short process time, low cost, and environmental friendliness.

[0003] Lithium cobalt oxide, a mainstream cathode material, belongs to the O3-type layered oxide family. After long-term cycling, it develops irreversible structural defects, including lithium vacancies, cobalt ion dissolution, and cation mixing, accompanied by surface microcracks, spinel phases, and even rock salt phases. Although the aforementioned direct regeneration methods can repair some of the material's damage, the performance of regenerated lithium cobalt oxide remains insufficient to meet the market's ever-increasing demand for high energy density. Therefore, researchers have employed ion doping (such as Mg, Al, Ti) and coating (such as MgO, Al2O3, Li3PO4) techniques to upgrade and regenerate waste lithium cobalt oxide, achieving some success. However, these methods have inherent limitations: on the one hand, the inevitable introduction of foreign elements not only increases the complexity and cost of the process, but may also have an adverse effect on the intrinsic structure and long-term chemical stability of the material, and even bring the risk of secondary pollution; on the other hand, these strategies mainly focus on surface protection or local structural stability, and are difficult to fundamentally solve the problem of drastic phase transition and structural instability of lithium cobalt oxide materials under deep delithiation (>4.55V) to high voltage (e.g. 4.6V), and have limited effect on improving its ultra-high voltage cycling performance. Summary of the Invention

[0004] To address the technical deficiencies of existing technologies, the present invention aims to provide a method for regenerating high-voltage lithium cobalt oxide using degraded lithium cobalt oxide materials. This method uses degraded (delithium-depleted) lithium cobalt oxide materials as raw materials and effectively controls the surface crystal phase structure of the degraded lithium cobalt oxide materials to obtain regenerated lithium cobalt oxide cathode materials with both O3 and O2 crystal structures. The introduction of the O2 crystal phase can effectively alleviate the technical defects of O3 type lithium cobalt oxide cathode materials in terms of severe phase transition and structural instability under high voltage. The resulting regenerated O2-O3 co-type lithium cobalt oxide material has stable cycle performance at a high voltage of 4.6V. Moreover, this method is simple and efficient, requires no introduction of foreign elements, and does not require doping or coating. The performance of the regenerated lithium cobalt oxide cathode material is superior to that of commercial lithium cobalt oxide cathode materials.

[0005] To achieve the above-mentioned technical objectives, the present invention provides a method for preparing high-voltage lithium cobalt oxide by regenerating spent lithium cobalt oxide material, which includes the following steps:

[0006] S1: After ball milling and mixing the spent lithium cobalt oxide powder with sodium source, solid-state sintering is performed to obtain P2 type sodium cobalt oxide@lithium cobalt oxide material;

[0007] S2: Place the P2 type sodium cobalt oxide@lithium cobalt oxide material in a lithium-containing solution for hydrothermal reaction to obtain the regenerated O2-O3 cotype lithium cobalt oxide material.

[0008] The key to this invention lies in the crystal phase regulation of the surface of failed lithium cobalt oxide powder. The main reason for the failure of failed lithium cobalt oxide materials is the varying degrees of delithiation during their use. This invention does not directly replenish lithium to failed lithium cobalt oxide materials, but first replenishes them with sodium. During the high-temperature sintering process, P2-type sodium cobalt oxide is formed. Furthermore, the sodium in the P2-type sodium cobalt oxide on the surface of the lithium cobalt oxide material is efficiently replaced by ion exchange, thereby obtaining regenerated O2-O3 coherent lithium cobalt oxide material. The introduction of O2-type crystalline lithium cobalt oxide material can effectively alleviate the technical defects of O3-type lithium cobalt oxide cathode materials, such as severe phase transition and structural instability under high voltage. The regenerated O2-O3 coherent lithium cobalt oxide material has stable cycle performance at a high voltage of 4.6V, and has strong rate performance and low-temperature performance, which is superior to commercial lithium cobalt oxide materials.

[0009] As a preferred embodiment, the ratio of the depleted lithium cobalt oxide powder to the sodium source is measured as a ratio of the molar amount of lithium missing in the depleted lithium cobalt oxide powder to the molar amount of sodium in the sodium source of 1:(1~1.2). The main function of the sodium source is to provide sodium ions. When its molar proportion relative to the depleted lithium cobalt oxide powder is too low, it is difficult to fully replenish sodium in the depleted lithium cobalt oxide powder, resulting in a low proportion of P2-type sodium cobalt oxide generated. Conversely, when the molar proportion of the sodium source relative to the depleted lithium cobalt oxide powder is too high, it will not further increase the amount of P2-type sodium cobalt oxide generated. The ratio of the depleted lithium cobalt oxide powder to the sodium source is further preferably measured as a ratio of 1:(1.1~1.2). Depleted lithium cobalt oxide powder is generally considered to have reached the end of its lifespan and is completely ineffective when the lithium deficiency reaches 20% or more.

[0010] As a preferred embodiment, the sodium source includes at least one of sodium hydroxide, sodium carbonate, sodium nitrate, and sodium acetate. Preferred sodium sources are more readily decomposed at high temperatures and exhibit higher reactivity.

[0011] As a preferred embodiment, the ball milling mixing conditions are: a ball milling speed of 300~600 r / min and a time of 3~6 h. Under appropriate ball milling mixing conditions, the spent lithium cobalt oxide powder can be refined, its reactivity can be improved, and the spent lithium cobalt oxide powder and sodium source can be mixed uniformly, which is beneficial to the solid-phase reaction.

[0012] As a preferred embodiment, the solid-state sintering conditions are: under an oxygen-containing atmosphere, at 2°C for 2 minutes. -1 ~20℃min -1 The heating rate is increased to 500-1000℃, and calcination is carried out for 12-36 hours. If the calcination temperature is too low or the time is too short, insufficient sodium ion replenishment will easily occur, making it difficult to generate P2-type sodium cobaltate and resulting in incomplete crystal phase structure repair. If the calcination temperature is too high or the time is too long, lithium ion volatilization loss will occur, and cation mixing will be aggravated, leading to abnormal particle growth. A further preferred calcination temperature is 800-1000℃. A further preferred calcination time is 12-24 hours. The oxygen-containing atmosphere can be air or oxygen, or a mixture of gases with other oxygen contents, such as a mixture of nitrogen and oxygen, with oxygen being the most preferred. The heating rate is further preferably 5℃ / min. -1 ~10℃ min -1 .

[0013] As a preferred embodiment, the lithium ion concentration in the lithium-containing solution is 3-7 mol / L. -1 If the lithium ion concentration is too low, it will lead to a slow reaction rate, incomplete ion exchange, and prolonged reaction time; if the lithium ion concentration is too high, although it can speed up the reaction rate, it will cause problems such as particle agglomeration and coarsening, increased side reactions, and increased costs.

[0014] As a preferred embodiment, the lithium-containing solution contains lithium hydroxide and a water-soluble lithium salt in a concentration ratio of (0.5~1.5):1. The water-soluble lithium salt is, for example, lithium chloride. This invention preferably uses a combination of lithium hydroxide and a water-soluble lithium salt as the lithium source. Appropriate amounts of lithium hydroxide can ensure the pH of the solution system, which is beneficial for promoting the dissolution of sodium ions. Furthermore, if a single water-soluble lithium salt is used, for example, lithium chloride hydrolyzes to produce hydrogen chloride (LiCl + H2O). The reaction LiOH + HCl↑ will erode the layered structure of lithium cobalt oxide. Similarly, when using lithium hydroxide alone, the solution system is too alkaline and will also damage the crystal structure of the material. Therefore, a LiOH / LiCl composite salt system with an appropriate ratio is often used to ensure that the structure of lithium cobalt oxide is not destroyed.

[0015] As a preferred embodiment, the hydrothermal reaction conditions are: a reaction temperature of 100~120℃ and a reaction time of 12~36h. These preferred hydrothermal conditions can promote the replacement of sodium ions in P2-type sodium cobalt oxide@lithium cobalt oxide materials by lithium ions.

[0016] The present invention provides a method for separating decommissioned lithium cobalt oxide powder from retired lithium-ion batteries using conventional techniques, comprising the following steps:

[0017] S1: Place the retired lithium-ion battery in a sodium chloride solution until the voltage of the lithium-ion battery is lower than 1.5V, and then disassemble and separate the positive electrode in a glove box.

[0018] S2: The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, filtered, and the filtered powder is vacuum dried at 70℃ for 12 h.

[0019] S3: The failed lithium cobalt oxide powder was heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0020] The retired lithium-ion battery of the present invention, such as a discarded battery from a drone, has lithium cobalt oxide as its positive electrode material.

[0021] The processes of filtration drying and ball milling involved in this invention are conventional operating procedures in the prior art. The purpose is to remove the moisture from the failed lithium cobalt oxide material, promote the uniform mixing of sodium-containing compounds with the failed lithium cobalt oxide material, and facilitate the restoration of the crystal phase structure.

[0022] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0023] This invention uses degraded (delithiated) lithium cobalt oxide material as raw material. By effectively controlling the surface crystal phase structure of the degraded lithium cobalt oxide material, a regenerated lithium cobalt oxide cathode material with both O3 and O2 crystal structures is obtained. The introduction of the O2 crystal phase can effectively alleviate the technical defects of the O3 type lithium cobalt oxide cathode material under high voltage, such as severe phase transition and structural instability. The resulting regenerated O2-O3 co-type lithium cobalt oxide material has stable cycle performance at a high voltage of 4.6V.

[0024] The preparation method of the recycled O2-O3 coherent lithium cobalt oxide material of the present invention is simple and efficient, requiring no introduction of foreign elements, doping, or coating. The performance of the recycled O2-O3 coherent lithium cobalt oxide cathode material is superior to that of commercial lithium cobalt oxide cathode materials. Attached Figure Description

[0025] Figure 1 The image shows the XRD pattern of the regenerated O2-O3 cotype LCO prepared in Example 11.

[0026] Figure 2 The diagram shows the charge-discharge plateau of the regenerated O2-O3 cotype LCO prepared in Example 11.

[0027] Figure 3 Cyclic performance of the regenerated O2-O3 cotype LCO prepared in Example 11.

[0028] Figure 4 The morphological characteristics of the regenerated O2-O3 cotype LCO prepared in Example 11. Detailed Implementation

[0029] The following examples are used to illustrate the content of this invention, but are not intended to limit the scope of protection of the claims of this invention.

[0030] Although this specification describes specific embodiments, it does not imply that each embodiment contains only one independent technical solution. This descriptive method is for clarity only, and those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. Such other embodiments are also within the protection scope of this invention.

[0031] Example 1:

[0032] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0033] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0034] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0035] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 12 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0036] Example 2:

[0037] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0038] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0039] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0040] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 12 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0041] Example 3:

[0042] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0043] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0044] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0045] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 12 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0046] Example 4:

[0047] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0048] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0049] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0050] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0051] Example 5:

[0052] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0053] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0054] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0055] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0056] Example 6:

[0057] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0058] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0059] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0060] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 12 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0061] Example 7:

[0062] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0063] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0064] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0065] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0066] Example 8:

[0067] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0068] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0069] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0070] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0071] Example 9:

[0072] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0073] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0074] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0075] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium supplementation / lithium deficiency = 1.05) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0076] Example 10:

[0077] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0078] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0079] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0080] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0081] Example 11:

[0082] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0083] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0084] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0085] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0086] XRD pattern of regenerated O2-O3 cotype LCO, as shown Figure 1 As shown in the figure, it can be seen that both O2-type lithium cobalt oxide and O3-type lithium cobalt oxide characteristic peaks appear simultaneously.

[0087] Morphological characteristics of recycled O2-O3 cotype lithium cobalt oxide are as follows: Figure 4 As shown in the figure, its crystal structure is complete, and it consists of micro- and nano-sized particles.

[0088] Example 12:

[0089] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0090] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0091] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0092] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0093] Example 13:

[0094] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0095] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0096] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0097] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 120°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0098] Example 14:

[0099] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0100] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0101] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0102] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 120°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0103] Example 15:

[0104] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0105] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0106] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0107] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1The solution was then sealed in a stainless steel autoclave and heated at 120°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0108] Example 16:

[0109] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0110] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0111] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0112] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.2) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0113] Example 17:

[0114] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0115] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0116] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0117] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.2) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0118] Example 18:

[0119] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0120] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0121] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0122] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.2) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0123] Example 19:

[0124] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0125] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0126] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0127] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to air at 5°C for 1 minute. -1 The temperature was increased to 500℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0128] Example 20:

[0129] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0130] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0131] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0132] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to air at 5°C for 1 minute. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0133] Example 21:

[0134] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0135] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0136] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0137] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to air at 5°C for 1 minute. -1 The temperature was increased to 1000℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0138] Example 22:

[0139] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0140] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0141] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0142] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 2°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0143] Example 23:

[0144] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0145] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0146] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0147] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 10°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0148] Example 24:

[0149] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0150] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0151] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0152] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 20°C for 4 minutes under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0153] Example 25:

[0154] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0155] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0156] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0157] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium carbonate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 32 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0158] Example 26:

[0159] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0160] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0161] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0162] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium hydroxide (sodium replenishment / lithium deficiency = 1.1) were subjected to a reaction at 500 r / min. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0163] Example 27:

[0164] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0165] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0166] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0167] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium nitrate (sodium replenishment / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0168] Example 28:

[0169] S1. Place the 20Ah lithium-ion battery removed from the retired drone into a sodium chloride solution (0.5M) for discharge for 48 hours until the voltage of the lithium-ion battery is lower than 1.5V. Then, remove the positive electrode in the glove box.

[0170] S2. The positive electrode sheet is immersed in phytic acid solution (30wt.%) for 5 min, then placed in deionized water to peel off, washed, and filtered. The filtered powder is then vacuum dried at 70℃ for 12 h.

[0171] S3. Waste lithium cobalt oxide powder is heated to 500°C in a muffle furnace at a heating rate of 5°C / min and heat-treated for 4 hours to remove the binder and carbon black from the powder.

[0172] S4. 5g of lithium cobalt oxide powder (Li / Co=0.82) obtained in S3 and sodium acetate (sodium supplementation / lithium deficiency = 1.1) were subjected to a 500 rpm reaction. -1 The material was finely ground in a ball mill at a speed of 4 hours, and then subjected to further grinding at 5°C for 1 minute under an oxygen atmosphere. -1 The temperature was increased to 800℃ and sintered for 24 hours. After natural cooling, it was added to 40 mL of LiCl (2.5 M) and LiOH (2.5 M) solution with continuous stirring, for a total concentration of 5 mol / L. -1 The solution was then sealed in a stainless steel autoclave and heated at 100°C for 24 hours. The ion-exchange product, after washing and drying, became the regenerated O2-O3 cotype lithium cobalt oxide.

[0173] Electrochemical performance tests of recycled O2-O3 cotype lithium cobalt oxide in Examples 1-28 were compared with the performance of commercial materials (Example 29). The test results are shown in Table 1:

[0174] 1) Sample preparation

[0175] Regenerated O2-O3 coherent lithium cobalt oxide and acetylene black were mixed and added to a pre-prepared PVDF gel (dissolved in NMP). The mass ratio of recycled material, acetylene black, and PVDF was 8 / 1 / 1. The resulting slurry was coated onto aluminum foil and then dried in a vacuum oven at 100°C for 12 hours. The resulting electrode was cut into small round pieces using a slicing machine to become the obtained positive electrode material. The aluminum foil was loaded with 2 mg of C14. -2 Active substances.

[0176] The obtained positive electrode sheet, electrolyte, lithium metal, battery casing, separator, etc., are placed in an argon-filled glove box for battery assembly. After sealing, the resulting battery is an assembled coin cell.

[0177] Note: All embodiments use the above-described electrode material preparation method.

[0178] 2) Testing Methods

[0179] After the obtained button cells were left to stand for 8 hours, they were placed on the blue electrode test channel for electrochemical performance testing, with the voltage range set to 3.0~4.6 V. The obtained data are directly displayed on the blue electrode tester and can be directly used.

[0180]

[0181]

Claims

1. A method for preparing high-voltage lithium cobalt oxide from spent lithium cobalt oxide material, characterized in that: Includes the following steps: S1: After ball milling and mixing the spent lithium cobalt oxide powder with sodium source, solid-state sintering is performed to obtain P2 type sodium cobalt oxide@lithium cobalt oxide material; S2: Place the P2 type sodium cobalt oxide@lithium cobalt oxide material in a lithium-containing solution for hydrothermal reaction to obtain the regenerated O2-O3 cotype lithium cobalt oxide material.

2. The method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1, characterized in that: The ratio of the depleted lithium cobalt oxide powder to the sodium source is measured as 1:(1~1.2) based on the ratio of the missing lithium molar amount in the depleted lithium cobalt oxide powder to the molar amount of sodium in the sodium source.

3. A method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1 or 2, characterized in that: The sodium source includes at least one of sodium hydroxide, sodium carbonate, sodium nitrate, and sodium acetate.

4. A method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1 or 2, characterized in that: The conditions for ball milling are: ball milling speed of 300~600 r / min and time of 3~6 h.

5. A method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1 or 2, characterized in that: The solid-state sintering conditions are as follows: under an oxygen-containing atmosphere, at 2°C for 2 min. -1 ~20℃ min -1 The temperature is increased to 500~1000℃ at a heating rate, and calcined for 12~36 hours.

6. The method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1, characterized in that: The lithium ion concentration in the lithium-containing solution is 3-7 mol / L. -1 .

7. A method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 6, characterized in that: The lithium-containing solution contains lithium hydroxide and water-soluble lithium salt in a concentration ratio of (0.5~1.5):

1.

8. A method for preparing high-voltage lithium cobalt oxide from depleted lithium cobalt oxide material according to claim 1, 6, or 7, characterized in that: The conditions for the hydrothermal reaction are: reaction temperature of 100~120℃ and time of 12~36h.

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