CN110240207A - A method of recycling waste lithium battery to prepare ternary cathode material - Google Patents

Abstract

The invention discloses a method for recycling waste lithium batteries to prepare ternary positive electrode materials. The waste lithium ion batteries are pretreated and separated to obtain waste positive electrode materials, acid leaching agent, reducing agent and water are added, leaching and filtration to obtain filtrate, and then adding Lithium source, nickel source, cobalt source and manganese source are used to prepare a mixed solution, and the mixed solution is spray-dried to obtain a precursor material, and then calcined in two stages to obtain a ternary positive electrode material; the crystallinity of the ternary positive electrode material prepared by the method of the present invention is High, stable structure, excellent cycle performance and rate performance, the invention has simple process, strong applicability, and excellent product performance, and can realize green recycling of waste lithium ion batteries.

Description

A method of recycling waste lithium battery to prepare ternary cathode material

technical field

The invention relates to a method for recycling waste lithium batteries to prepare a ternary positive electrode material, and belongs to the technical field of lithium ion battery recycling.

Background technique

Lithium-ion batteries have the advantages of high discharge voltage, large specific energy, small self-discharge, long cycle life and no memory effect. They are now widely used in 3C electronic equipment, aerospace, medical and other fields. In addition, my country is vigorously developing new energy vehicles. , smart grid, renewable energy and other industries, lithium-ion battery as a good power battery and energy storage material, its demand and output have further increased. It is estimated that by 2020, the output of ternary lithium-ion batteries will reach 71.6Gwh. After the lithium-ion battery is charged and discharged for many times, the active material is inactivated and scrapped due to structural changes. Therefore, the number of waste lithium-ion batteries is huge. It is estimated that by 2020, the scrapped amount of ternary lithium-ion batteries in my country will reach 19.2Gwh , about 300,000 tons.

The release of electrolyte in waste lithium-ion batteries will pollute the environment and harm the ecosystem. At the same time, the electrode materials contain a large amount of valuable metals such as nickel, iron, manganese, cobalt, and lithium. The rapid development of the new energy industry has led to the development of lithium-ion battery raw materials. Mineral resources are decreasing day by day, restricting the healthy development of the lithium-ion battery industry. Therefore, scientific and efficient recycling of waste lithium-ion batteries has become an urgent problem to be solved.

The recycling methods of waste ternary lithium-ion batteries mainly focus on the wet process and the fire process, and mainly focus on the recovery of valuable metal elements. Among them, the fire method has the advantages of high energy consumption, serious pollution and poor separation effect, and the wet method has the advantages of mild conditions and low energy consumption. The high-efficiency separation technology of metal ions is difficult and the separation index is poor. For this reason, some researchers use chemical precipitation and sol-gel methods to recover valuable metal ions from the leaching solution to directly prepare cathode materials, but there are the use of precipitants, The conditions are not easy to control, the repeatability is poor, and the large-scale industrial application is not easy. There is no report on the preparation of ternary cathode materials recovered from the leaching solution by spray drying.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention provides a method for recycling waste lithium batteries to prepare a ternary positive electrode material, comprising the following steps:

(1) Discharging the waste lithium-ion battery, dismantling and separating to obtain waste positive electrode material;

(2) The waste cathode material in step (1) is placed in the reactor, acid leaching agent, reducing agent and water are added, and the mixed solution is reacted at 60-100 ° C for 1-3 hours under stirring conditions, and after the reaction is completed, filter, The filtrate is a precious liquid rich in valuable metal ions;

(3) in the filtrate of step (2), add lithium source, nickel source, cobalt source, manganese source to make mixed solution, and the mol ratio of lithium element, nickel element, cobalt element, manganese element in the mixed solution is 1:x :y:1-x-y, x>0, y>0, x+y<1, adjust the pH value of the solution to 2-7, stir well, and then spray-dry the mixed solution to obtain the ternary precursor powder;

(4) The ternary precursor powder obtained in step (3) is calcined in two stages under an oxygen atmosphere, the first stage of calcination is kept at 400-600°C for 4-6 hours, and the second stage of calcination is kept at 800-900°C For 10 to 12 hours, the ternary cathode material is obtained by cooling with the furnace.

The dismantling method in step (1) is mechanical, manual or a combination of the two.

In step (2), the acid leaching agent is one or more of acetic acid, oxalic acid, lactic acid, tartaric acid, and glycine mixed in any proportion, ^and the H concentration in the mixed solution in the reactor is 1 to 5 mol/L.

In step (2), the reducing agent is one or more of glucose, grape seed, vitamin C, hydrazine hydrate, and sodium borohydride mixed in any proportion, and the concentration of the reducing agent in the mixed solution in the reactor is 1-3 mol/L.

Step (2) The mass-volume ratio g:mL of the positive electrode material to water is 1:10-100.

In step (3), lithium source is one or more arbitrary proportions in lithium hydroxide, lithium carbonate, lithium chloride, lithium acetate or lithium nitrate mixing; nickel source is one in nickel chloride, nickel acetate or nickel nitrate. One or more are mixed in any proportion; the cobalt source is one or more of cobalt chloride, cobalt acetate or cobalt nitrate mixed in any proportion; the manganese source is one or more of manganese chloride, manganese acetate or manganese nitrate Mix in any ratio.

In step (3), ammonia water, ammonium carbonate solution or ammonium bicarbonate solution is used to adjust the pH value.

In the step (3), the inlet temperature of the spray drying is 150-200° C., and the feeding rate is 200-700 mL/h.

In step (4), the amount of oxygen supplied during the two-stage calcination under an oxygen atmosphere is 8-10 mL/min.

Beneficial effects of the present invention: the present invention is mainly aimed at the preparation process of leaching and recycling waste lithium ion batteries, which can effectively alleviate the problems of poor stability, complicated operation, and the use of precipitants in the recycling process, and realize green and efficient cathode materials of waste lithium ion batteries. Recycling, the ternary cathode material prepared by the method of the invention has high crystallinity, stable structure, excellent cycle performance and rate performance, and the invention has simple process, strong applicability and excellent product performance.

Description of drawings

Fig. 1 is the first charge-discharge performance diagram of the battery prepared from the ternary positive electrode material prepared in Example 1;

Fig. 2 is the SEM image of the ternary positive electrode material prepared in Example 2;

FIG. 3 is a cycle performance curve of a battery prepared from the ternary positive electrode material prepared in Example 3. FIG.

Detailed ways

The present invention will be further described in detail below with reference to the specific embodiments, but the protection scope of the present invention is not limited to the content.

Example 1

A method for recycling waste lithium batteries to prepare ternary positive electrode materials, the waste lithium batteries are from a recycling enterprise in Shenzhen, Guangdong Province, and are mainly used lithium batteries for ternary power, which specifically includes the following steps:

(1) The waste lithium-ion battery is discharged, and then the waste positive electrode material is obtained by mechanical disassembly and separation;

(2) The waste positive electrode powder in step (1) is placed in the reactor, the acid leaching agent acetic acid and the reducing agent glucose are added, and then water is added to obtain a mixed solution, and the mass volume ratio g:mL of the positive electrode material and water is 1:20 , the H ⁺ concentration in the mixture is 1mol/L, the concentration of the reducing agent is 1mol/L, the mixture is reacted at 80 °C for 2h under stirring conditions, after the reaction is completed, filtered, and the filtrate is a noble liquid rich in valuable metal ions ;

(3) in the filtrate of step (2), add lithium hydroxide, nickel chloride, cobalt chloride, manganese chloride to make mixed solution, the mol ratio of lithium element, nickel element, cobalt element, manganese element in the mixed solution 1:0.6:0.2:0.2, so that the chemical formula of the obtained ternary material is LiNi _0.6 Co _0.2 Mn _0.2 O ₂ , adjust the pH value of the mixed solution to 2 with ammonia water with a concentration of 28% by mass, stir evenly, and then mix the mixed solution Carry out spray drying, the inlet temperature of the spray dryer is 170°C, and the feed rate is 500mL/h, to obtain the ternary precursor powder;

(4) The ternary precursor powder obtained in step (3) is calcined in two stages in an atmosphere with an oxygen supply rate of 9 mL/min. The ternary cathode material was prepared by holding the temperature at 850°C for 11h, and cooling with the furnace.

The first charge-discharge performance of the battery prepared from the ternary cathode material LiNi _0.6 Co _0.2 Mn _0.2 O ₂ prepared in this example is shown in Figure 1. It can be seen from Figure 1 that the ternary cathode material prepared by this method is at 0.1 The charge-discharge performance under C is excellent, indicating that this method has strong applicability.

Example 2

A method for recycling waste lithium batteries to prepare ternary positive electrode materials. Samples of waste lithium batteries are from a recycling enterprise in Kunming City, Yunnan Province. The samples are mainly used lithium batteries for mobile phones, which specifically includes the following steps:

(1) Discharge the waste lithium-ion battery first, and then disassemble and separate by hand to obtain waste positive electrode material;

(2) place the waste positive electrode powder in the reactor in step (1), add acid leaching agent glycine, reducing agent vitamin C, then add water to obtain a mixed solution, and the mass volume ratio g:mL of positive electrode material and water is 1: 100, the H ⁺ concentration in the mixed solution is 5 mol/L, the concentration of the reducing agent is 3 mol/L, the mixed solution is reacted at 100 °C for 1 h under stirring conditions, after the reaction is completed, filtered, and the filtrate is a precious metal ion rich in precious metal ions. liquid;

(3) in the filtrate of step (2), add lithium hydroxide, nickel acetate, cobalt acetate, manganese acetate to make mixed solution, and the mol ratio of lithium element, nickel element, cobalt element, manganese element in the mixed solution is 1: 0.5:0.2:0.3, so that the chemical formula of the obtained ternary material is LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , adjust the pH of the mixed solution to 3 with an ammonium carbonate solution with a concentration of 0.5 mol/L, stir evenly, and then mix the mixed solution Carry out spray drying, the inlet temperature of the spray dryer is 200°C, and the feed rate is 200mL/h, to obtain the ternary precursor powder;

(4) The ternary precursor powder obtained in step (3) is calcined in two stages in an atmosphere with an oxygen supply rate of 10 mL/min. The ternary cathode material was prepared by holding the temperature at 900°C for 10h and cooling with the furnace.

The SEM of the ternary cathode material LiNi _0.5 Co _0.2 Mn _0.3 O ₂ prepared in this example is shown in Figure 2. It can be seen from Figure 2 that the ternary lithium ion cathode material prepared by this method is spherical and has excellent structural properties.

Example 3

A method for recycling waste lithium batteries to prepare ternary positive electrode materials. Samples of waste lithium batteries are from a recycling enterprise in Changsha City, Hunan Province. The samples are mainly obtained from waste lithium batteries for ternary power, which specifically includes the following steps:

(1) Discharge the waste lithium-ion battery first, and then disassemble the waste cathode material by mechanical and manual joint disassembly;

(2) in the step (1), the waste positive electrode powder is placed in the reactor, and the acid leaching agent tartaric acid and the reducing agent hydrazine hydrate are added, and then water is added to obtain a mixed solution, and the mass volume ratio g:mL of the positive electrode material and water is 1: 10. The H ⁺ concentration in the mixed solution is 2mol/L, and the concentration of the reducing agent is 2mol/L. The mixed solution is reacted at 60°C for 3h under stirring conditions. After the reaction is completed, filter the filtrate. liquid;

(3) in the filtrate of step (2), add lithium acetate, lithium chloride, nickel nitrate, nickel chloride, cobalt nitrate, cobalt acetate, manganese chloride, manganese nitrate to obtain mixed solution, lithium acetate and lithium chloride The molar ratio of nickel nitrate and nickel chloride is 1:1, the molar ratio of cobalt nitrate and cobalt acetate is 1:1, and the molar ratio of manganese chloride and manganese nitrate is 1:1. The molar ratio of lithium element, nickel element, cobalt element and manganese element in the solution is 1:1/3:1/3:1/3, so that the chemical formula of the obtained ternary material is LiNi _1/3 Co _1/3 Mn _{1 /3} O ₂ , adjust the pH of the mixed solution to 7 with a concentration of 1 mol/L ammonium bicarbonate solution, stir evenly, and then spray dry the mixed solution. The inlet temperature of the spray dryer is 150°C, and the feed rate is 700mL/ h, to obtain ternary precursor powder;

(4) The ternary precursor powder obtained in step (3) is calcined in two stages in an atmosphere with an oxygen supply rate of 8 mL/min. The ternary cathode material was prepared by holding the temperature at 800°C for 12h and cooling with the furnace.

The cycle performance of the battery prepared by the ternary cathode material LiNi _1/3 Co _1/3 Mn _1/3 O ₂ prepared in this example is shown in Figure 3. It can be seen from Figure 3 that the regenerated cathode material is The discharge specific capacity in the first cycle reaches 171.21mAh/g, and the capacity retention rate after 50 cycles is about 98.17%. The ternary lithium cathode material prepared by this method has excellent cycle performance.

Claims (10)

1. a method for reclaiming and preparing ternary positive electrode material of waste and old lithium battery, is characterized in that, comprises the following steps: (1) Discharging the waste lithium-ion battery, dismantling and separating to obtain waste positive electrode material; (2) adding acid leaching agent, reducing agent and water to the waste positive electrode material in step (1), the mixed solution is reacted at 60-100° C. for 1-3 hours under stirring conditions, and after the reaction is completed, filtration; (3) in the filtrate of step (2), add lithium source, nickel source, cobalt source, manganese source to make mixed solution, and the mol ratio of lithium element, nickel element, cobalt element, manganese element in the mixed solution is 1:x :y:1-x-y, x>0, y>0, x+y<1, adjust the pH value of the solution to 2-7, stir well, and then spray-dry the mixed solution to obtain the ternary precursor powder; (4) The ternary precursor powder obtained in step (3) is calcined in two stages under an oxygen atmosphere, the first stage of calcination is kept at 400-600°C for 4-6 hours, and the second stage of calcination is kept at 800-900°C For 10 to 12 hours, the ternary cathode material is obtained by cooling with the furnace. 2. the method for preparing ternary positive electrode material by recycling waste lithium battery according to claim 1, is characterized in that, in step (2), acid leaching agent is one or more arbitrary in acetic acid, oxalic acid, lactic acid, tartaric acid, glycine Proportional mix. 3. The method according to claim 1, wherein the H ⁺ concentration in the mixed solution in step (2) is 1-5 mol/L. 4. the method for reclaiming and preparing ternary positive electrode material according to the described waste lithium battery of claim 1, is characterized in that, in step (2), reducing agent is a kind of in glucose, grape seed, dimension C, hydrazine hydrate, sodium borohydride or mixed in any proportion. 5. The method for preparing a ternary positive electrode material by recycling waste lithium batteries according to claim 1, wherein the concentration of the reducing agent in the mixed solution in step (2) is 1-3 mol/L. 6 . The method for preparing a ternary positive electrode material by recycling waste lithium batteries according to claim 1 , wherein the mass-volume ratio g:mL of the positive electrode material and water in step (2) is 1:10～100. 7 . 7. the method for preparing ternary positive electrode material is recovered according to the described waste lithium battery of claim 1, it is characterized in that, in step (3), lithium source is lithium hydroxide, lithium carbonate, lithium chloride, lithium acetate or lithium nitrate. One or more are mixed in any proportion; the nickel source is one or more of nickel chloride, nickel acetate or nickel nitrate mixed in any proportion; the cobalt source is one or more of cobalt chloride, cobalt acetate or cobalt nitrate. mixed in any proportion; the manganese source is one or more of manganese chloride, manganese acetate or manganese nitrate mixed in any proportion. 8. The method for preparing a ternary positive electrode material by recycling waste lithium batteries according to claim 1, wherein in step (3), ammonia water, ammonium carbonate solution or ammonium bicarbonate solution are used to adjust pH value. 9 . The method for preparing a ternary positive electrode material by recycling waste lithium batteries according to claim 1 , wherein the inlet temperature of the spray drying in step (3) is 150-200° C., and the feeding rate is 200-700 mL/h. 10 . 10 . The method for preparing a ternary positive electrode material by recycling a waste lithium battery according to claim 1 , wherein, in the step (4), the feeding rate of oxygen is 8-10 mL/min. 11 .