WO2025086140A1 - Drt-based method for efficiently recovering lithium from retired battery powder, and application thereof - Google Patents

Abstract

The present invention relates to the technical field of retired battery recycling, and to a DRT-based method for efficiently recovering lithium from retired battery powder, and an application thereof. The method comprises: mixing retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions, and carrying out reduction roasting to form reduced battery powder containing a perovskite-type oxide ABO₃; mixing the reduced battery powder with water, and introducing carbon dioxide for carbonization leaching, to obtain a leachate material; carrying out solid-liquid separation on the leachate material, wherein the filtrate contains lithium bicarbonate; and carrying out impurity removal and pyrolysis on the filtrate to obtain battery-grade lithium carbonate. According to the present invention, synthesis of a perovskite-type oxide during reduction of battery powder is coupled and coordinated with carbonization leaching, so that carbon dioxide can be fixed, making the carbonization reaction more complete, and reducing the leaching of nickel, cobalt and manganese metals to obtain a pure lithium solution; subsequently, only simple impurity removal is required to obtain battery-grade lithium carbonate by pyrolysis.

Description

A method for efficiently recovering lithium from retired battery powder based on DRT and its application Technical Field

The present disclosure relates to the technical field of retired battery recycling, and in particular to a method for efficiently recovering lithium from retired battery powder based on DRT and an application thereof.

Background Art

With the rapid development of new energy electric vehicles, the demand for lithium carbonate and lithium hydroxide, raw materials for lithium batteries, continues to expand, which has put the extraction and recycling of lithium resources on the fast track. However, due to the uneven distribution of lithium resources around the world and the limited exploitable reserves, lithium recycling has received widespread attention, especially the recycling of retired lithium-ion batteries.

Recycling of retired lithium-ion batteries is mainly divided into two major methods: pyrometallurgy and hydrometallurgy. Pyrometallurgy directly uses high-temperature treatment methods to extract metals or metal oxides from electrodes, while hydrometallurgy first disassembles the battery shell, crushes and screens it to obtain electrode materials, and then leaches the positive electrode powder with acid. The metal enters the leaching solution in the form of ions, and then separates the valuable metals one by one through precipitation separation, solvent extraction, electrodeposition, ion exchange and other methods to obtain a single metal product or metal compound.

Chinese patent application CN106129511A uses a carbon-containing reducing agent such as lignite, bituminous coal and anthracite or a mixture thereof to mix with a lithium-ion battery positive electrode material, and performs reduction roasting at high temperature. The roasted product is soaked in water and introduced with _CO2 to carbonize to obtain a _LiHCO3 solution. However, the lithium extraction rate obtained by this method is only 90%-91%.

Chinese patent application CN111206154A separates nickel, cobalt, manganese and lithium from the leachate through an extraction process. The leachate of waste ternary battery materials is used as raw material. The leachate contains metal ions such as nickel, cobalt, manganese and lithium. A new extraction system is used to selectively extract and separate nickel, cobalt, manganese and lithium valuable metals in sequence. Lithium is recovered in the final tail liquid. During the pretreatment process, as nickel, cobalt and manganese are removed, a lot of lithium will be lost, which is not conducive to the resource utilization of lithium.

In summary, the current treatment of retired lithium-ion batteries and the post-treatment and impurity removal of leachate have many shortcomings. Therefore, it is urgent to develop a method for extracting lithium from retired lithium-ion batteries with low energy consumption, simple process and high efficiency.

In view of this, the present disclosure is proposed.

Summary of the invention

The purpose of the present disclosure is to provide a method for efficiently recovering lithium from retired battery powder based on DRT and its application.

The present disclosure is implemented as follows:

In a first aspect, the present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising: mixing retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions, and performing reduction roasting to form reduced battery powder containing perovskite-type oxide ABO ₃ ;

Carrying out carbonization leaching of the reduced battery powder with carbon dioxide in an aqueous solution to obtain a leached material;

The leached material is subjected to solid-liquid separation, and the filtrate is subjected to impurity removal and pyrolysis to obtain battery-grade lithium carbonate.

In an optional embodiment, the A-site reactant includes a combination of one or more of rare earth oxides, rare earth nitrates, alkaline earth metal oxides and alkaline earth metal nitrates.

In an optional embodiment, the rare earths in the rare earth oxide and the rare earth nitrate are independently selected from one or more combinations of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium.

In an optional embodiment, the alkaline earth metals in the alkaline earth metal oxide and the alkaline earth metal nitrate are independently selected from a combination of one or more of beryllium, magnesium, calcium, strontium, barium and radium.

In an optional embodiment, the A-site reaction material includes a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide and calcium nitrate.

In an optional embodiment, the contents of nickel, cobalt and manganese in the retired battery powder are detected, and the molar ratio of the A-site reaction material to the total content of nickel, cobalt and manganese in the retired battery powder is 0.5-1:0.5-1.

In an optional embodiment, the amount of the carbon reducing agent used is 10%-50% of the mass of the retired battery powder.

In an alternative embodiment, the carbon reducing agent includes a combination of one or more of inorganic carbon and organic carbon.

In an alternative embodiment, the inorganic carbon includes a combination of one or more of graphite, carbon black, carbon monoxide, lignite, bituminous coal and anthracite.

In an optional embodiment, the organic carbon includes a combination of one or more of wood chips, glucose, lignite, chemical coke and metallurgical coke.

In an optional embodiment, the retired battery powder includes lithium batteries containing at least one element of nickel, cobalt, and manganese.

In an optional embodiment, the retired battery powder includes any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium battery and nickel-cobalt-manganese ternary lithium battery.

In an optional embodiment, the reduction roasting temperature is 900-1200° C., and the roasting time is 2-8 hours.

In an optional embodiment, the reduction roasting temperature is 1100-1200° C., and the roasting time is 2-4 hours.

In an optional embodiment, the solid-liquid ratio of the reduced battery powder to the water is 1:3-10.

In an optional embodiment, the inlet flow rate of carbon dioxide is 0.1 L/min-5 L/min.

In an optional embodiment, the carbonization leaching time is 1-3 hours.

In an optional embodiment, the impurity removal includes refining and removing impurities from the filtrate using a resin.

In an optional embodiment, the resin is at least one of an aminocarboxylic acid chelating resin and an aminophosphoric acid chelating resin.

In an optional embodiment, the resin comprises CH-90Na chelating resin, Lx92, D402 and LS500. Either one.

In an optional embodiment, the pyrolysis temperature is 60-95° C., and the pyrolysis time is 1-5 h.

In a second aspect, the present disclosure provides the application of the method for efficiently recovering lithium from retired battery powder based on DRT as described in the aforementioned embodiment in the recovery of retired lithium-ion batteries.

The present disclosure has the following beneficial effects:

The present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT. The method comprises the following steps: using retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials for reduction roasting. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt and manganese are precipitated in the form of oxides or metal elements. Subsequently, the precipitated transition metal oxides and the A-site reaction material form a perovskite oxide (ABO ₃ ) under high temperature roasting. The perovskite oxide is mixed with the lithium carbonate to form a solid phase of reduced battery powder. Subsequently, the reduced battery powder is carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite oxide can fix carbon dioxide to make the carbonization reaction more complete. Moreover, the perovskite oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements in the carbonization process after adding water and introducing carbon dioxide, thereby reducing the leaching of nickel, cobalt and manganese metals, thereby obtaining a relatively pure lithium bicarbonate solution. Subsequently, the lithium bicarbonate only needs to be simply impurity-removed to obtain battery-grade lithium carbonate by thermal decomposition. The present disclosure adopts the perovskite-type oxide synthesized by reducing the battery powder process and the carbonization leaching coupling synergy, providing a new process for achieving highly selective lithium extraction, effectively facilitating the lithium recovery process of retired lithium-ion batteries. The above-mentioned DRT-based method for efficiently recovering lithium from retired battery powder can be widely used in the recovery of retired lithium-ion batteries.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

FIG1 is a process flow chart of a method for efficiently recovering lithium from retired battery powder based on DRT provided in the present disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present disclosure and should not be considered to limit the scope of the present disclosure. Where specific conditions are not specified in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

The endpoints of the ranges and any values disclosed in this disclosure are not limited to the precise range or value, and these ranges or values are It should be understood that the values close to these ranges or values are included. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

DRT (Directional Recycling Technology) is a directional cycle, which is based on reverse product positioning design. Through a short-range recycling process, the invalid materials in retired products are re-prepared into usable materials for product production along the loop. In the field of power batteries, directional recycling refers to the process of reducing waste batteries into materials needed for manufacturing power batteries through pre-treatment, hydrometallurgy and other processes. Manufacturers can directly use the processed battery raw materials to manufacture high-quality power batteries.

Based on the above design ideas, the present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT, as shown in FIG1 , which includes the following steps:

S1. Prepare materials.

(1) Retired battery powder:

Retired battery powder includes lithium batteries containing at least one of nickel, cobalt and manganese. Specifically, retired battery powder includes but is not limited to any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium battery and nickel-cobalt-manganese ternary lithium battery.

(2) Carbon reducing agent:

The carbon reductant includes one or more combinations of inorganic carbon and organic carbon. Inorganic carbon includes but is not limited to one or more combinations of graphite, carbon black, carbon monoxide, lignite, bituminous coal and anthracite. Organic carbon includes but is not limited to one or more combinations of sawdust, glucose, semi-coke, chemical coke and metallurgical coke.

(3) A-site reaction material containing rare earth ions or alkaline earth ions:

The A-site reaction material includes one or more combinations of rare earth oxides, rare earth nitrates, alkaline earth metal oxides and alkaline earth metal nitrates. The rare earths in the rare earth oxides and rare earth nitrates are independently selected from one or more combinations of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium. The alkaline earth metals in the alkaline earth metal oxides and alkaline earth metal nitrates are independently selected from one or more combinations of beryllium, magnesium, calcium, strontium, barium and radium.

Specifically, in some embodiments of the present disclosure, the A-site reactant may include, for example, a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide, and calcium nitrate.

S2. Reduction roasting.

Retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions are mixed and reduced and calcined to form reduced battery powder containing perovskite-type oxide ABO ₃ .

Among them, the content of nickel, cobalt and manganese in retired battery powder was tested. The molar ratio of the total content of cobalt and manganese is 0.5-1:0.5-1. The amount of carbon reducing agent used is 10%-50% of the mass of the retired battery powder.

During the reduction process, nickel, cobalt and manganese are first precipitated as oxides or metal elements, and lithium is precipitated as lithium carbonate. The precipitated transition metal oxides and the A-site reaction material form perovskite-type oxides (ABO ₃ ) under high temperature calcination.

The process equation is as follows (taking lanthanum nitrate as an example):

1)Li(Ni _x Co _y Mn _1-xy )O ₂ +(1+2x+2y)/4C＝1/2Li ₂ O+xNi+yCo+(1-xy)MnO+(1+2x+2y)/4CO ₂ ;

2) Li ₂ O+CO ₂ =Li ₂ CO ₃ ;

3)La(NO ₃ ) ₃ ·6H ₂ O+Ni/Co/MnO→La(Ni/Co/Mn)O ₃ .

In the present disclosure, the temperature of reduction roasting is 900-1200°C, and the roasting time is 2-8h. In some embodiments, the temperature of reduction roasting can be, for example, any one of 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, or a range between any two thereof, and the roasting time can be, for example, any one of 2h, 3h, 4h, 5h, 6h, 7h, 8h, or a range between any two thereof. Since the perovskite oxide ABO ₃ needs to be formed in the present application, it is further preferred that the temperature of reduction roasting is 1100-1200°C, and the roasting time is 2-4h.

S3, carbonization leaching.

The reduced battery powder and water are mixed at a solid-liquid ratio of 1:3-10, and carbon dioxide is introduced for carbonization leaching, wherein the flow rate of carbon dioxide is 0.1L/min-5L/min. The carbonization leaching time is 1-3h to obtain a leached material.

Since the reduction battery powder contains perovskite oxide ABO ₃ , which is an alkaline oxide, it has a strong ability to capture carbon dioxide and can promote the continuous occurrence _of the carbonization reaction.

The main equation is: Li ₂ CO ₃ +H ₂ O+CO ₂ =2LiHCO ₃ .

S4. Post-processing.

After carbonization leaching is completed, the leached material is separated into solid and liquid, wherein the filtrate is mainly lithium bicarbonate, with only a small amount of nickel, cobalt and manganese leached, and the solid is perovskite-type oxide and nickel, cobalt and manganese slag. After simple impurity removal of the liquid, battery-grade lithium carbonate can be obtained by pyrolysis.

Wherein, impurity removal includes refining and removing impurities from lithium bicarbonate using resin. Wherein, the resin is any one of aminocarboxylic acid chelating resin and aminophosphoric acid chelating resin, including any one of CH-90Na chelating resin, Lx92, D402 and LS500, wherein Lx92, D402 and LS500 are purchased from Xi'an Lanxiao Technology New Materials Co., Ltd., Jiangyin Suqing Resin Co., Ltd. and Xi'an Lanshen New Materials Technology Co., Ltd., respectively, which are the company's product names.

The pyrolysis temperature is 60-95°C and the pyrolysis time is 1-5h.

The main equation for pyrolysis is: 2LiHCO ₃ =Li ₂ CO ₃ +H ₂ O+CO ₂ ↑.

The present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT, which uses retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials for reduction roasting. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt and manganese are precipitated in the form of oxides or metal elements. Subsequently, the precipitated transition metal oxides react with the A-site reaction material to form a reaction product. The reactants are calcined at high temperature to form perovskite oxide (ABO ₃ ), which is mixed in lithium carbonate to form solid-phase reduced battery powder. The reduced battery powder is then carbonized by adding water, and lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite oxide can fix carbon dioxide to make the carbonization reaction more complete. Moreover, the perovskite oxide structure is relatively stable, which can reduce the dissolution of heavy metal elements in the carbonization process after adding water and introducing carbon dioxide, thereby reducing the leaching of nickel, cobalt and manganese metals to obtain a purer lithium bicarbonate solution. Subsequently, only the lithium bicarbonate needs to be simply impurity-removed to obtain battery-grade lithium carbonate by thermal decomposition. The present disclosure uses the perovskite oxide synthesized by the reduction battery powder process and the carbonization leaching coupling synergy to provide a new process for achieving highly selective lithium extraction, which effectively assists the lithium recovery process of retired lithium-ion batteries. The above-mentioned DRT-based method for efficiently recovering lithium from retired battery powder can be widely used in the recovery of retired lithium-ion batteries.

The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

Example 1

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it with 709g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), where the perovskite A:B position = 0.5:1 (mol). Raise the temperature to 1000℃ for 3h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and some nickel, cobalt and manganese oxides will combine with lanthanum nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with CH-90Na chelating resin, and pyrolyze at 85℃ for 2h to obtain battery-grade lithium carbonate.

Example 2

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it with 1419g of lanthanum nitrate hexahydrate powder and 20% carbon reducing agent (graphite), where the perovskite A:B position = 1:1 (mol). Raise the temperature to 1000℃ for 3h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and part of the nickel, cobalt and manganese oxides will combine with lanthanum nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with resin, and pyrolyze at 85℃ for 2h to obtain battery-grade lithium carbonate.

Example 3

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and 2838g of lanthanum nitrate hexahydrate powder and 30% carbon reducing agent (graphite) are fully mixed, wherein the perovskite A:B ratio is 1:0.5 (mol). The temperature is raised to 1000°C for 3 hours, and nickel, cobalt and manganese are precipitated as oxides or metal elements, and part of the nickel, cobalt and manganese oxides are combined with lanthanum nitrate to form perovskite-type oxides, and lithium is precipitated as lithium carbonate. The powder is mixed with water at a liquid-solid ratio of 7:1, and 1L/min of carbon dioxide is introduced for carbonization leaching for 2 hours. The resulting liquid-solid mixture is filtered, and the resulting filtrate is pyrolyzed at 85°C for 2 hours after being impurity-removed by resin to obtain battery-grade lithium carbonate.

Example 4

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it thoroughly with 2838g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), where the perovskite A:B position = 1:0.5 (mol). Raise the temperature to 1100℃ for 3h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and part of the nickel, cobalt and manganese oxides will combine with lanthanum nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with resin, and pyrolyze at 85℃ for 2h to obtain battery-grade lithium carbonate.

Example 5

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it thoroughly with 2838g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), where the perovskite A:B position = 1:0.5 (mol). Raise the temperature to 1200℃ for 3h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and part of the nickel, cobalt and manganese oxides will combine with lanthanum nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with resin, and pyrolyze at 85℃ for 2h to obtain battery-grade lithium carbonate.

Example 6

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it thoroughly with 2118g of cerium nitrate powder and 50% carbon reducing agent (wood chips), where the perovskite A:B ratio is 1:0.5 (mol). Raise the temperature to 1200℃ for 2h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and part of the nickel, cobalt and manganese oxides will combine with cerium nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-to-solid ratio of 3:1, introduce 2L/min of carbon dioxide, and carbonize and leach for 3h. Filter the resulting liquid-solid mixture, and remove impurities from the filtrate with resin. Pyrolysis was carried out at 60°C for 3 h to obtain battery-grade lithium carbonate.

Example 7

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and mix it thoroughly with 364g of calcium oxide powder and 40% carbon reducing agent (glucose), where the perovskite A:B position = 1:0.5 (mol). Raise the temperature to 1200℃ for 4h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and some nickel, cobalt and manganese oxides will combine with calcium oxide to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 10:1, pass 3L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with resin, and pyrolyze the filtrate at 90℃ for 4h to obtain battery-grade lithium carbonate.

Example 8

This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 6.51%, Co: 55.28%) and mix it thoroughly with 4918g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), where the perovskite A:B position = 1:0.5 (mol). Raise the temperature to 1200℃ for 3h, nickel, cobalt and manganese will precipitate as oxides or metal elements, and part of the nickel, cobalt and manganese oxides will combine with lanthanum nitrate to form perovskite-type oxides, and lithium will precipitate as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2h. Filter the resulting liquid-solid mixture, remove impurities with resin, and pyrolyze at 85℃ for 2h to obtain battery-grade lithium carbonate.

Comparative Example 1

This comparative example provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and 10% carbon reducing agent, mix them thoroughly, place them in a reaction pipe, raise the temperature to 650°C, and last for 3 hours. Nickel, cobalt and manganese are precipitated as oxides or metal elements, and lithium is precipitated as lithium carbonate. Mix the powder with water at a liquid-solid ratio of 7:1, pass 1L/min of carbon dioxide, and carbonize and leach for 2 hours. Filter the resulting liquid-solid mixture, and after chemical precipitation and resin impurity removal, pyrolyze the filtrate at 85°C for 2 hours to obtain lithium carbonate.

Comparative Example 2

This comparative example provides a method for efficiently recovering lithium from retired battery powder based on DRT, which is basically the same as Example 1, except that the amount of lanthanum nitrate hexahydrate powder is different. Specifically, it includes the following specific steps:

Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and 283g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent are fully mixed, wherein the perovskite A:B ratio is 0.2:1 (mol). The temperature is raised to 1000°C for 3 hours, and nickel, cobalt and manganese are precipitated as oxides or metal elements, and part of the nickel, cobalt and manganese oxides are combined with lanthanum nitrate to form perovskite-type oxides, and lithium is precipitated as lithium carbonate. The powder is mixed with water at a liquid-solid ratio of 7:1, and 1L/min of carbon dioxide is introduced for carbonization leaching for 2 hours. The resulting liquid-solid mixture is filtered, and the resulting filtrate is pyrolyzed at 85°C for 2 hours after being impurity-removed by resin to obtain battery-grade lithium carbonate.

Experimental example

The Li content of the leachate in the above-mentioned Examples 1-7 and Comparative Examples 1-3 was detected, and the Li leaching rate was calculated, wherein Li leaching rate (%) = C _t * V _t / (w _t * m ₀ ) * 100; wherein C _t and V _t are the lithium concentration (g/L) and liquid volume in the leachate, respectively, wherein the liquid volume is equal to the mass of the battery powder multiplied by the solid-liquid ratio, and w _t and m ₀ are the lithium mass fraction in the battery powder and the mass of the battery powder, respectively. Please refer to Table 1 for the statistical results.

Table 1 Lithium recovery process data of retired lithium-ion batteries

It can be seen from the above table that Examples 1-8 of the present application can all obtain better leaching rates, especially when the perovskite A:B position = 1:0.5, the Li leaching rate reaches more than 98%, which is significantly better than the leaching rate of Comparative Example 1 without adding the A-position reactant. It can be seen from Comparative Example 2 that the addition of the A-position reactant is too small, resulting in less perovskite-type oxide generated, and its ability to capture carbon dioxide is weak, so the leaching rate is also significantly lower than that of Example 1.

In summary, the DRT-based method for efficiently recovering lithium from retired battery powder provided by the present disclosure comprises the following steps: using retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials for reduction roasting; during the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt and manganese are precipitated in the form of oxides or metal elements; then the precipitated transition metal oxides react with the A-site reaction material under high temperature roasting to form a perovskite-type oxide (ABO ₃ ), and the perovskite-type oxide is mixed with the carbon. The solid phase of reduced battery powder is formed in the lithium carbonate, and then the reduced battery powder is carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate, and the perovskite oxide can fix carbon dioxide to make the carbonization reaction more complete. In addition, the perovskite oxide structure is relatively stable, which can reduce the dissolution of heavy metal elements in the carbonization process after adding water and introducing carbon dioxide, and further reduce the leaching of nickel, cobalt and manganese metals to obtain a purer lithium bicarbonate solution. Subsequently, only the lithium bicarbonate needs to be simply impurity-removed to obtain battery-grade lithium carbonate by thermal decomposition. The present invention adopts the perovskite oxide synthesized by the reduction battery powder process and the carbonization leaching coupling synergy, which provides a new process for achieving highly selective lithium extraction, and effectively assists the lithium recovery process of retired lithium-ion batteries. The above-mentioned DRT-based method for efficiently recovering lithium from retired battery powder can be widely used in the recovery of retired lithium-ion batteries.

The optional implementation modes of the present disclosure are described in detail above, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, the technical solution of the present disclosure can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present disclosure and belong to the protection scope of the present disclosure.

Industrial Applicability

The present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT. The method comprises the following steps: using retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials for reduction roasting. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt and manganese are precipitated in the form of oxides or metal elements. Subsequently, the precipitated transition metal oxides and the A-site reaction material form a perovskite oxide (ABO ₃ ) under high temperature roasting. The perovskite oxide is mixed with the lithium carbonate to form a solid phase of reduced battery powder. Subsequently, the reduced battery powder is carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite oxide can fix carbon dioxide to make the carbonization reaction more complete. Moreover, the perovskite oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements in the carbonization process after adding water and introducing carbon dioxide, and further reduce the leaching of nickel, cobalt and manganese metals to obtain a relatively pure lithium bicarbonate solution. Subsequently, the lithium bicarbonate only needs to be simply impurity-removed to obtain battery-grade lithium carbonate by thermal decomposition. The present disclosure adopts the perovskite-type oxide synthesized by reducing the battery powder process and the carbonization leaching coupling synergy, providing a new process for achieving highly selective lithium extraction, effectively facilitating the lithium recovery process of retired lithium-ion batteries. The above-mentioned DRT-based method for efficiently recovering lithium from retired battery powder can be widely used in the recovery of retired lithium-ion batteries.

Claims (22)

A method for efficiently recovering lithium from retired battery powder based on DRT, characterized in that it comprises: mixing retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions, and performing reduction roasting to form reduced battery powder containing perovskite-type oxide ABO ₃ ; Carrying out carbonization leaching of the reduced battery powder with carbon dioxide in an aqueous solution to obtain a leached material; The leached material is subjected to solid-liquid separation, and the filtrate is subjected to impurity removal and pyrolysis to obtain battery-grade lithium carbonate. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 1 is characterized in that the A-site reactant comprises a combination of one or more of rare earth oxides, rare earth nitrates, alkaline earth metal oxides and alkaline earth metal nitrates. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 2 is characterized in that the rare earths in the rare earth oxides and the rare earth nitrates are independently selected from one or more combinations of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 2-3 is characterized in that the alkaline earth metals in the alkaline earth metal oxides and alkaline earth metal nitrates are independently selected from a combination of one or more of beryllium, magnesium, calcium, strontium, barium and radium. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 4 is characterized in that the A-site reaction material comprises a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide and calcium nitrate. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 5, characterized in that the contents of nickel, cobalt and manganese in the retired battery powder are detected, and the molar ratio of the A-site reaction material to the total content of nickel, cobalt and manganese in the retired battery powder is 0.5-1:0.5-1. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 6 is characterized in that the amount of the carbon reducing agent used is 10%-50% of the mass of the retired battery powder. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 7 is characterized in that the carbon reducing agent comprises a combination of one or more of inorganic carbon and organic carbon. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 8 is characterized in that the inorganic carbon includes a combination of one or more of graphite, carbon black, carbon monoxide, lignite, bituminous coal and anthracite. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 8 to 9 is characterized in that the organic carbon comprises a combination of one or more of sawdust, glucose, semi-coke, chemical coke and metallurgical coke. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 10 is characterized in that the retired battery powder comprises lithium batteries containing at least one element of nickel, cobalt and manganese. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 11 is characterized in that the retired battery powder includes any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium battery and nickel-cobalt-manganese ternary lithium battery. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 12, characterized in that the temperature of the reduction roasting is 900-1200° C. and the roasting time is 2-8 h. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 13, characterized in that the temperature of the reduction roasting is 1100-1200° C. and the roasting time is 2-4 h. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 14, characterized in that the solid-liquid ratio of the reduced battery powder to the water is 1:3-10. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 15 is characterized in that the flow rate of the carbon dioxide is 0.1 L/min-5 L/min. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 16, characterized in that the carbonization leaching time is 1 to 3 hours. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 17 is characterized in that the impurity removal includes refining and removing impurities from the filtrate using a resin. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 18, characterized in that the resin is at least one of an aminocarboxylic acid chelate resin and an aminophosphoric acid chelate resin. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 18, characterized in that the resin comprises any one of CH-90Na chelating resin, Lx92, D402 and LS500. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 20 is characterized in that the pyrolysis temperature is 60-95° C. and the pyrolysis time is 1-5 h. Application of the DRT-based method for efficiently recovering lithium from retired battery powder as described in any one of claims 1 to 21 in the recovery of retired lithium-ion batteries.