CN114956199A - Recycling and regenerating method for anode of waste nickel-cobalt-manganese ternary lithium ion battery - Google Patents

Abstract

A method for recycling and regenerating the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, adjusting the molar ratio of Ni, Co, and Mn according to actual needs, and then precipitation, so that Ni, Co, and Mn in the system are co-precipitated in the form of hydroxides After centrifugation, adding carbonate to the solvent to precipitate Li ₂ CO ₃ ; calcining the nickel-cobalt-manganese hydroxide precursor obtained above and Li ₂ CO ₃ to obtain a new nickel-cobalt-manganate lithium manganate positive electrode material. The present invention utilizes ammonium salts to reduce waste nickel-cobalt-manganese ternary lithium-ion battery cathode materials in the initial stage, on the one hand, utilizes the advantages of convenient fire recovery, and on the other hand avoids the disadvantage of high consumption by fire recovery and reduces the required temperature. At about 300 ℃, it starts to change from solid phase to liquid phase. The liquid phase can greatly increase mass transfer and ion diffusion, and greatly increase the probability of sulfonation reaction with waste nickel-cobalt-manganese ternary lithium-ion battery cathode materials, thereby greatly reducing energy consumption. Improve security.

Description

A method for recycling and regenerating positive electrode of waste nickel-cobalt-manganese ternary lithium ion battery

technical field

The invention belongs to the field of recycling waste lithium ion batteries, and in particular relates to a preparation method for recycling and regenerating waste nickel cobalt lithium manganate ternary lithium ion battery positive active materials as raw materials.

Background technique

With the rapid development of modern society and industry, the demand for sustainable green energy and quality of life is becoming more and more urgent. This further drives the transformation of society towards environmental and sustainable development. The emergence of lithium batteries has greatly alleviated the major petroleum fuel pollution and energy crisis, and is also a good substitute for some new energy sources with uncertain and intermittent characteristics, such as tidal energy, solar energy, hydropower, nuclear energy and wind energy, etc. In the 1990s, Sony successfully commercialized lithium batteries with their unique advantages, including high power density, no storage, small size, light weight, long cycle life and low self-discharge rate. So far, lithium batteries have gained a huge market share after 30 years of development and progress in this field. Widely used in consumer electronics, medical, electric vehicles, industrial, aerospace and defense, energy storage and other industries. In addition, the lithium-ion battery market is currently undergoing major changes, with global lithium-ion batteries expected to grow at hundreds of gigawatt hours per year over the next five years and account for 70% of the rechargeable battery market by 2022. In 2018, the global demand for lithium batteries was 231.326 billion yuan, and the shipment volume was 146.38GWh. In particular, the market demand for lithium batteries will reach 69.4262 billion yuan, and the market capacity will reach 439.32GWh by 2022. Driven by the continuous electrification of the automotive industry, as the main driver of electric and hybrid vehicles, it has reached millions of transactions and will continue to grow in the future. The global market for lithium-ion batteries is estimated to be around $40 billion by 2022, with more than a third of the market expected to come from the hybrid and electric vehicle market. By 2020, China alone can produce 200,000 tons of used lithium-ion batteries, and by 2030, the world is expected to process 11 million tons of used lithium-ion batteries. However, high metal content waste repositories are an important metal. Especially because the global reserves are limited, about 62 million tons of Li and 142 million tons of Co, the supply natural resources of these raw materials will not be able to meet future demand. However, waste lithium-ion batteries contain many valuable metals, such as lithium (Li), cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), copper (Cu), and aluminum (Al), The composition of these metals is not only similar to that of natural minerals, but their content is even higher than that of natural minerals. Prices of various precious metals have risen sharply, with the price of strategic cobalt in particular quadrupling in the past two years, from $22 to $81 per kilogram. Therefore, from the perspective of strategic materials and sustainable development, discarded valuable resources should not be regarded as waste. In addition to alleviating the shortage of raw materials, the recycling of used lithium-ion batteries can also bring huge economic value on the one hand. There are also resource problems in the recycling and utilization of waste lithium-ion batteries, and the environmental and safety hazards caused by waste lithium-ion batteries are also very serious. If these used lithium-ion batteries are not handled properly, they will cause serious environmental pollution and affect human health. Although lithium-ion batteries are of high value, they contain toxic electrolytes and polymers that are difficult to degrade. Heavy metal pollution and toxic carcinogenic chemicals are also unavoidable defects. Casual or direct disposal of spent lithium ions in landfills can cause safety issues such as explosion, electric shock or fire. Therefore, due to the issues and challenges raised in terms of environment, safety and strategic resources, economy, etc., recycling of spent lithium-ion battery cathode materials is not only necessary, but also urgent.

SUMMARY OF THE INVENTION

In order to solve the technical problems of complex composition of cathode active materials of waste lithium-ion batteries, significant resources and pollution, a comprehensive process is required to achieve harmlessness and resource utilization of failed lithium-ion batteries. The invention provides a method for recycling and regenerating the positive electrode material of waste nickel-cobalt-manganese ternary lithium ion battery, aiming at recycling and regenerating the waste material.

In order to realize the above-mentioned technical purpose, the present invention provides a kind of waste nickel-cobalt-manganese ternary lithium-ion battery cathode recycling method, comprising the following steps:

Step 1. Grinding the positive electrode material of waste ternary lithium ion battery nickel cobalt lithium manganate and ammonium salt, and sintering the ground product to obtain product A;

Step 2, dissolving product A in deionized water, and filtering to obtain a filtrate;

Step 3, adjust the molar ratio of Ni, Co and Mn in the filtrate, so that the molar ratio of Ni, Co and Mn in the filtrate is the same as the molar ratio of Ni, Co and Mn in the target product to obtain system A; then add hydroxide and alkaline complexing agent to regulate system A, carry out precipitation, and obtain the turbid liquid containing nickel cobalt manganese hydroxide;

Step 4. After the turbid liquid is centrifuged, the solvent and the solute are collected. The solute is a nickel-cobalt-manganese hydroxide precursor, and carbonate is added to the solvent to obtain Li ₂ CO ₃ , and the nickel-cobalt manganese hydroxide precursor and Li ₂ CO ₃ is uniformly mixed and then calcined to obtain the target product Li(Ni _0.8 Co _0.1 Mn _0.1 )O ₂ .

Further, in step 1, the ammonium salt is NH ₄ Cl, (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₂ SO ₃ , NH ₄ HSO ₄ or (NH ₄ ) ₂ S.

Further, in step 1, the mass ratio of the positive electrode material of the waste ternary lithium ion battery to the ammonium salt is 1:(3-6).

Further, in step 1, the sintering temperature of the ground product is 220°C to 420°C.

Further, in step 1, the sintering time of the ground product is 2h-4h, and the heating rate is 2°C 22in～10°C 22in.

Further, in step 3, the mol ratio of Ni, Co and Mn in the filtrate is regulated by adding at least one of water-soluble nickel, cobalt and manganese salts to the filtrate.

Further, in step 3, after the adjustment is completed, the ratio of Ni, Co and Mn in the filtrate is 8:1:1.

Further, in step 4, the added carbonate makes the molar ratio of Li:(Ni+Co+Mn) in the nickel-cobalt-manganese hydroxide to be (1～1.1):1.

Further, in step 4, the calcination temperature of the nickel cobalt manganese hydroxide precursor and Li ₂ CO ₃ is two-stage sintering, the initial forging temperature is 480°C-220°C, and the final forging temperature is 800°C-1000°C.

Further, in step 4, the initial forging time is 2h-8h, and the final forging time is 13h-20h.

Relative to the prior art, the beneficial effects brought by the technical solution of the present invention:

According to the method of the present invention, the molar ratio of Ni, Co and Mn is adjusted according to actual requirements, and then precipitation is carried out, so that Ni, Co and Mn in the system are co-precipitated in the form of hydroxide; after centrifugation, carbonic acid is added to the solvent Salt precipitation gives Li ₂ CO ₃ . The nickel-cobalt-manganese hydroxide precursor obtained above and Li ₂ CO ₃ are calcined to obtain a new nickel-cobalt lithium manganate cathode material. The present invention utilizes ammonium salts to reduce waste nickel-cobalt-manganese ternary lithium-ion battery cathode materials in the initial stage, on the one hand, utilizes the advantages of convenient fire recovery, and on the other hand avoids the disadvantage of high consumption by fire recovery and reduces the required temperature. At about 300 ℃, the liquid phase starts to change from solid phase to liquid phase. The liquid phase can greatly increase mass transfer and ion diffusion, and greatly increase the probability of sulfonation reaction with waste nickel-cobalt-manganese ternary lithium-ion battery cathode materials, thereby greatly reducing energy consumption. Improve security. At the same time, after the ammonium salt and the positive electrode of the waste nickel-cobalt-manganese ternary lithium-ion battery are fully mixed and reacted, the product is a soluble salt, which reduces the generation of waste and toxic substances.

Further, in step 4 of the present invention, calcination is divided into two stages: initial calcination and final calcination. On the one hand, energy consumption is saved, on the other hand, in order to better fully react nickel cobalt manganese hydroxide and lithium carbonate, lithium carbonate It starts to decompose at about 200 °C, and keeps the temperature at about 200 °C and maintains the temperature to fully decompose into lithium oxide, providing sufficient lithium source for nickel-cobalt-manganese hydroxide to react with it. The final calcination is to make the nickel-cobalt-manganese hydroxide and lithium oxide fully react to form the final product, the nickel-rich polycrystalline 811 ternary positive electrode.

The invention utilizes the precipitation method to prepare the ternary precursor, avoids the separation of different metals, shortens the technological process, is simple to operate, and reduces the difficulty of production. At the same time, it also has the characteristics of high efficiency, cleanliness, low cost, high repeatability, and industrial production.

The invention has the advantages of simple process, wide source of raw materials, high repeatability, high recovery efficiency and large-scale production.

The invention comprehensively utilizes the valuable metals nickel, cobalt, manganese and lithium in the system, and realizes the efficient utilization of resources.

Description of drawings

Fig. 1 is the schematic diagram of embodiment 1;

Fig. 2 is the flow chart of embodiment 1;

Fig. 3 is an electrode made of the regenerated nickel-rich polycrystalline 811 ternary positive electrode material recovered in Example 1, and the specific capacity is cycled for 20 cycles when discharged at a constant current of 0.2C at room temperature;

Figure 4 is an electrode made of the regenerated nickel-rich polycrystalline 811 ternary positive electrode material recovered in Example 2, when it is discharged at a constant current of 0.2C at room temperature, the specific capacity is cycled for 20 cycles;

Figure 5 is an electrode made of the regenerated nickel-rich polycrystalline 811 ternary positive electrode material recovered in Example 3, and the specific capacity is cycled for 20 cycles when it is discharged at a constant current of 0.2C at room temperature;

Fig. 6 is the electrode that the regenerated nickel-rich type polycrystalline 811 ternary positive electrode material of embodiment 4 reclaims is made, and when discharging with 0.2C constant current at room temperature, cycle 20 circle specific capacity;

Figure 7 is an electrode made of the regenerated nickel-rich polycrystalline 811 ternary positive electrode material recovered in Example 2. When discharging at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles.

Detailed ways

In order to achieve the above technical purpose, the present invention provides a method for recycling and regenerating the positive electrode of a waste nickel-cobalt-manganese ternary lithium ion battery, comprising the following steps:

Step 1: fully grind the waste ternary lithium ion battery positive electrode active material and ammonium salt for half an hour, put the ground product into a muffle furnace for sintering, and the sintering temperature is 220°C to 420°C to obtain product A; ammonium salt are NH ₄ Cl, (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₂ SO ₃ , NH ₄ HSO ₄ , (NH ₄ ) ₂ S.

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: The molar ratio of Ni, Co and Mn in the filtrate is adjusted by soluble sulfate, so that the molar ratio of Ni, Co and Mn in the filtrate is the same as the molar ratio of Ni, Co and Mn in the target product to obtain system A, followed by Add hydroxide and alkaline complexing agent to adjust the pH of system A for precipitation to obtain a turbid solution containing nickel cobalt manganese hydroxide. Soluble sulfates are nickel sulfate, manganese sulfate and 2 or cobalt sulfate; hydroxides are NaOH, KOH or Ba(OH) ₂ ; alkaline complexing agents are sodium EDTA, ammonia, sodium citrate or oxalic acid.

Step 4: collect the solvent and solute after centrifuging the turbid liquid, the solute is the precursor of nickel-cobalt-manganese hydroxide, add carbonate to the solvent to precipitate Li ₂ CO ₃ , and use the precursor of nickel-cobalt manganese hydroxide obtained above to obtain Li 2 CO 3 After fully mixing with Li ₂ CO ₃ , a new nickel-rich polycrystalline 811 ternary cathode can be obtained by calcination. Wherein, the carbonate is Na ₂ CO ₃ , K ₂ CO ₃ or (NH ₄ ) ₂ CO ₃ .

In the present invention, in step 1, by adjusting the amount of waste active material to the mass ratio of ammonium salts to be 1:(3～6), the sintering temperature is 220～420° C., the calcination time is 2～4h, and the heating rate is 2 ~10℃22in. Compared with ordinary fire recovery of waste nickel-cobalt-manganese ternary lithium-ion batteries, the temperature is greatly reduced, from thousands of degrees Celsius to about 320 degrees Celsius, and the calcination time is also greatly reduced, which greatly reduces energy consumption and improves safety.

In the present invention, in step 3, the molar ratio of Ni, Co, and Mn in the impurity removal liquid is regulated by adding at least one of water-soluble nickel, cobalt, and manganese salts. The water-soluble nickel salt is Ni ²⁺ sulfate, the water-soluble cobalt salt is Co ²⁺ sulfate, and the water-soluble manganese salt is Mn ²⁺ sulfate.

In the present invention, in step 3, the molar ratio of Ni:Co:Mn is adjusted to be 8:1:1. In step 3, the hydroxide is added in the form of an aqueous solution, and the pH of the hydroxide and alkaline complexing agent control system is 10-12, so that Ni ²⁺ , Co ²⁺ , Mn ²⁺ in the system are hydroxides. Total precipitation.

In the present invention, in step 4, the carbonate is a water-soluble salt that can dissociate carbonate radicals in water. In the form of solid, the added carbonate obtains Li ₂ CO ₃ precipitation, so that in the Li ₂ CO ₃ precipitation and the nickel-cobalt-manganese hydroxide, the molar ratio of Li:(Ni+Co+Mn) is (1～11) ):1.

In the present invention, in step 4, the calcination includes initial forging and final forging, the initial forging temperature is 480-220°C, the calcining time is 2-8h, the final forging temperature is 800-1000°C, and the heating rate of the initial forging and final forging is 3～10℃ 22in, the final forging time is 13～20h. It is divided into two stages: initial forging and final forging. On the one hand, it saves energy consumption and on the other hand, it is to better allow the nickel-cobalt-manganese hydroxide and lithium carbonate to fully react. ℃ and maintain the temperature to fully decompose into lithium oxide, providing sufficient lithium source for nickel-cobalt-manganese hydroxide to react with it. The final forging is to fully react the nickel-cobalt-manganese hydroxide and lithium oxide to form the final product—Li(Ni _0.8 Co _0.1 Mn _0.1 )O ₂ , that is, the nickel-rich polycrystalline 811 ternary positive electrode.

Example 1:

Referring to Figure 1 and Figure 2, a method for recycling the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, comprising the following steps:

Step 1: Mix and grind the waste active material and ammonium salt (NH ₄ ) ₂ SO ₃ , the mass ratio of the waste active material and (NH ₄ ) ₂ SO ₃ is 1:3, and put the ground product into the muffle furnace Sintering, heating up to 220°C for 2h at a rate of 2°C 22in to obtain product A;

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: measure the ratio of Ni, Co and Mn in the filtrate, and add corresponding nickel sulfate, manganese sulfate and 2 or cobalt sulfate to it according to the ratio, and adjust the molar ratio of Ni, Co, Mn to 8:1:1. Then add 0.22ol2L of NaOH solution and 0.362ol2L of ammonia water, adjust pH=10 and after the reaction is complete, add Na ₂ CO ₃ to it to generate precipitated Li ₂ CO ₃ , control the amount of Na ₂ CO ₃ added so that Li:(Ni +Co+Mn)=1:1.

Step 4: After centrifuging the turbid liquid, collect the solvent and the solute, the solute is nickel cobalt manganese hydroxide, add Na ₂ CO ₃ to the solvent, and precipitate to obtain Li ₂ CO ₃ , and the nickel cobalt manganese hydroxide and Li ₂ CO ₃ The material is placed in a tube furnace, heated to 480°C for 2 hours at a rate of 2°C 22in, and calcined at 800°C for 13h at a rate of 3°C 22in to obtain a new nickel-cobalt lithium manganate cathode material—— Nickel-rich polycrystalline 811 ternary positive electrode.

The ternary positive electrode material prepared in this embodiment and the lithium sheet are assembled to form a button battery, and FIG. 2 is a flow chart of the process. It can be seen from Figure 2 that the technological process is simple and easy to operate, with few steps and greatly improved safety.

Figure 3 shows that the electrode made of nickel-rich polycrystalline 811 ternary positive electrode material was prepared by this method. When the electrode was discharged at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles, and the regenerated nickel-rich polycrystalline 811 ternary was recovered. The coulombic efficiency of the cathode material is as high as 92%, the discharge specific capacity is 1202Ah2g, and the operation is stable and the effect is good.

Example 2

Referring to Figure 1 and Figure 2, a method for recycling the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, comprising the following steps:

Step 1: Mix and grind the waste active material and ammonium salt NH ₄ Cl, the mass ratio of waste active material and NH ₄ Cl is 1:4, put the ground product into a muffle furnace for sintering, and heat up at a rate of 4°C 22in calcined at 300°C for 2.2h to obtain product A;

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: measure the ratio of Ni, Co and Mn in the filtrate, and add corresponding nickel sulfate, manganese sulfate and 2 or cobalt sulfate to it according to the ratio, and adjust the molar ratio of Ni, Co, Mn to 8:1:1. Then add 0.22ol2L of KOH solution and 0.362ol2L of sodium citrate solution, adjust pH=10 and after the reaction is complete, add K ₂ CO ₃ to it to form precipitated Li ₂ CO ₃ , and control the amount of K ₂ CO ₃ added , so that Li:(Ni+Co+Mn)=1.02:1.

Step 4: After centrifuging the turbid liquid, collect the solvent and the solute, the solute is nickel cobalt manganese hydroxide, add Na ₂ CO ₃ to the solvent, and precipitate to obtain Li ₂ CO ₃ , and the nickel cobalt manganese hydroxide and Li ₂ CO ₃ The material is placed in a tube furnace, heated to 200°C for 6 hours at a rate of 2°C 22in, and calcined at 900°C for 12h at a rate of 2°C 22in to obtain a new nickel-cobalt lithium manganate cathode material—— Nickel-rich polycrystalline 811 ternary positive electrode.

Figure 4 shows that the electrode made of nickel-rich polycrystalline 811 ternary positive electrode material was prepared by this method. When the electrode was discharged at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles, and the regenerated nickel-rich polycrystalline 811 ternary was recovered. The coulombic efficiency of the cathode material is as high as 92%, the discharge specific capacity is 1222Ah2g, and the operation is stable and the effect is good.

Example 3

Referring to Figure 1 and Figure 2, a method for recycling the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, comprising the following steps:

Step 1: Mix and grind the waste active material and ammonium salt (NH ₄ ) ₂ SO ₄ , the mass ratio of the waste active material and (NH ₄ ) ₂ SO ₄ is 1:2, and put the ground product into a muffle furnace for sintering , heated to 320°C for 3h at a rate of 6°C 22in to obtain product A;

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: measure the ratio of Ni, Co and Mn in the filtrate, and add corresponding nickel sulfate, manganese sulfate and 2 or cobalt sulfate to it according to the ratio, and adjust the molar ratio of Ni, Co, Mn to 8:1:1. Then add 0.22ol2L of Ba(OH) ₂ solution and 0.362ol2L of EDTA sodium salt solution, adjust pH=11 and after the reaction is complete, add (NH ₄ ) ₂ CO ₃ to it to generate precipitated Li ₂ CO ₃ , control _The amount of ( _NH4 )2CO3 added was such that Li:(Ni ₊ Co+Mn)=1.02:1.

Step 4: After centrifuging the turbid liquid, collect the solvent and the solute, the solute is nickel cobalt manganese hydroxide, add Na ₂ CO ₃ to the solvent, and precipitate to obtain Li ₂ CO ₃ , and the nickel cobalt manganese hydroxide and Li ₂ CO ₃ The material is placed in a tube furnace, heated to 220°C for 7 hours at a rate of 8°C 22in, and calcined at 920°C for 18h at a rate of 7°C 22in to obtain a new nickel-cobalt lithium manganate cathode material—— Nickel-rich polycrystalline 811 ternary positive electrode. Figure 2 shows that the electrode made of nickel-rich polycrystalline 811 ternary positive electrode material was prepared by this method. When the electrode was discharged at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles, and the regenerated nickel-rich polycrystalline 811 ternary was recovered. The coulombic efficiency of the cathode material is as high as 93%, the discharge specific capacity is 1422Ah2g, and the operation is stable and the effect is good.

Example 4

Referring to Figure 1 and Figure 2, a method for recycling the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, comprising the following steps:

Step 1: Mix and grind the waste active material and ammonium salt NH ₄ HSO ₄ , the mass ratio of waste active material and NH ₄ HSO ₄ is 1:6, put the ground product into a muffle furnace for sintering, and sinter it at a temperature of 8° C. 22in. The rate was heated to 400 °C and calcined for 3.2 h to obtain product A;

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: measure the ratio of Ni, Co and Mn in the filtrate, and add corresponding nickel sulfate, manganese sulfate and 2 or cobalt sulfate to it according to the ratio, and adjust the molar ratio of Ni, Co, Mn to 8:1:1. Then add 0.22ol2L of NaOH solution and 0.362ol2L of oxalic acid solution, adjust pH=12 and after the reaction is complete, add (NH ₄ ) ₂ CO ₃ to it to generate precipitated Li ₂ CO ₃ , and control the added (NH ₄ ) ₂ CO ₃ amount such that Li:(Ni+Co+Mn)=1.1:1.

Step 4: After centrifuging the turbid liquid, collect the solvent and the solute, the solute is nickel cobalt manganese hydroxide, add Na ₂ CO ₃ to the solvent, and precipitate to obtain Li ₂ CO ₃ , and the nickel cobalt manganese hydroxide and Li ₂ CO ₃ The material is placed in a tube furnace, heated to 220°C for 8 hours at a rate of 9°C 22in, and calcined at 920°C for 20h at a rate of 9°C 22in to obtain a new nickel-cobalt lithium manganate cathode material—— Nickel-rich polycrystalline 811 ternary positive electrode.

Figure 6 shows that the electrode made of nickel-rich polycrystalline 811 ternary positive electrode material was prepared by this method. When the electrode was discharged at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles, and the regenerated nickel-rich polycrystalline 811 ternary was recovered. The coulombic efficiency of the cathode material is as high as 92%, the discharge specific capacity is 1302Ah2g, and the operation is stable and the effect is good.

Example 5

Referring to Figure 1 and Figure 2, a method for recycling the positive electrode of a waste nickel-cobalt-manganese ternary lithium-ion battery, comprising the following steps:

Step 1: mix and grind the waste active material and ammonium salt (NH ₄ ) ₂ S, the mass ratio of the waste active material and (NH ₄ ) ₂ S is 1:6, put the ground product into a muffle furnace for sintering, and use The temperature was raised to 420°C for 4h at a rate of 10°C for 22in to obtain product A;

Step 2: Dissolve product A in deionized water, and filter to obtain a filtrate;

Step 3: measure the ratio of Ni, Co and Mn in the filtrate, and add corresponding nickel sulfate, manganese sulfate and 2 or cobalt sulfate to it according to the ratio, and adjust the molar ratio of Ni, Co, Mn to 8:1:1. Then add 0.22ol2L of NaOH solution and 0.362ol2L of oxalic acid solution, adjust pH ₌ 12 and after the reaction is complete, add (NH4 ₎ 2CO3 to it to generate precipitated _Li2CO3 , control the added _{( NH4 ) 2 The} amount of CO is such that Li:(Ni+Co+Mn)=1.1:1.

Step 4: After centrifuging the turbid liquid, collect the solvent and the solute, the solute is nickel cobalt manganese hydroxide, add Na ₂ CO ₃ to the solvent, and precipitate to obtain Li ₂ CO ₃ , and the nickel cobalt manganese hydroxide and Li ₂ CO ₃ The material is placed in a tube furnace, heated to 220°C for 8 hours at a rate of 10°C 22in, and calcined at 1000°C for 20h at a rate of 10°C 22in to obtain a new nickel-cobalt lithium manganate cathode material—— Nickel-rich polycrystalline 811 ternary positive electrode.

Figure 7 shows that the electrode made of nickel-rich polycrystalline 811 ternary positive electrode material was prepared by this method. When the electrode was discharged at a constant current of 0.2C at room temperature, the specific capacity was cycled for 20 cycles, and the regenerated nickel-rich polycrystalline 811 ternary was recovered. The coulombic efficiency of the element cathode material is as high as 92%, the discharge specific capacity is 1102Ah2g, and the operation is stable and the effect is good.

Claims (10)

1. A method for recycling and regenerating a positive electrode of a waste nickel-cobalt-manganese ternary lithium ion battery is characterized by comprising the following steps:

step 1, grinding nickel cobalt lithium manganate serving as a positive electrode material of a waste ternary lithium ion battery and ammonium salt, and sintering a ground product to obtain a product A;

step 2, dissolving the product A in deionized water, and filtering to obtain a filtrate;

step 3, adjusting the molar ratio of Ni, Co and Mn in the filtrate to ensure that the molar ratio of Ni, Co and Mn in the filtrate is the same as the molar ratio of Ni, Co and Mn in the target product to obtain a system A; then adding hydroxide and an alkaline complexing agent to regulate and control the system A, and precipitating to obtain turbid liquid containing nickel-cobalt-manganese hydroxide;

step 4, centrifuging the turbid solution, collecting a solvent and a solute, adding carbonate into the solvent to precipitate to obtain Li, wherein the solute is a nickel-cobalt-manganese hydroxide precursor ₂ CO ₃ The nickel cobalt manganese hydroxide precursor and Li ₂ CO ₃ Evenly mixing and calcining to obtain the target product Li (Ni) _0.8 Co _0.1 Mn _0.1 )O ₂ 。

2. The method for recycling and regenerating the positive electrode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 1, the ammonium salt is NH ₄ Cl，(NH ₄ ) ₂ SO ₄ ，(NH ₄ ) ₂ SO ₃ ，NH ₄ HSO ₄ Or (NH) ₄ ) ₂ S。

3. The method for recycling the positive electrode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 1, the mass ratio of the positive electrode material of the waste ternary lithium ion battery to the ammonium salt is 1 (3-6).

4. The method for recycling and regenerating the anode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 1, the sintering temperature of the ground product is 250 ℃ to 450 ℃.

5. The method for recycling and regenerating the anode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 1, the sintering time of the ground product is 2-4 h, and the heating rate is 2-10 ℃/min.

6. The method for recycling and regenerating the anode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 3, at least one of water-soluble nickel, cobalt and manganese salts is added into the filtrate to regulate the molar ratio of Ni, Co and Mn in the filtrate.

7. The method for recycling and regenerating the anode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 3, after the adjustment is completed, the ratio of Ni, Co and Mn in the filtrate is 8:1: 1.

8. The method for recycling the positive electrode of the waste nickel cobalt manganese ternary lithium ion battery according to claim 1, wherein in the step 4, the carbonate is added so that the molar ratio of Li (Ni + Co + Mn) in the nickel cobalt manganese hydroxide is (1-1.1): 1.

9. The method for recycling and regenerating the positive electrode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 1, wherein in the step 4, the nickel-cobalt-manganese hydroxide precursor and the Li are used ₂ CO ₃ The calcination temperature is two-stage sintering, and the initial calcination temperature is480-520 ℃ and the finish forging temperature is 800-1000 ℃.

10. The method for recycling and regenerating the positive electrode of the waste nickel-cobalt-manganese ternary lithium ion battery according to claim 9, wherein in the step 4, the initial forging time is 5-8 h, and the final forging time is 13-20 h.

Images