WO2024108653A1

WO2024108653A1 - Plasma lithium supplementing device and method for positive electrode material for lithium battery

Info

Publication number: WO2024108653A1
Application number: PCT/CN2022/137050
Authority: WO
Inventors: 喻学锋; 黄浩; 高明
Original assignee: 深圳先进技术研究院
Priority date: 2022-11-24
Filing date: 2022-12-06
Publication date: 2024-05-30
Also published as: CN118073675A

Abstract

The present invention provides a plasma lithium supplementing device and method for a positive electrode material for a lithium battery. The present application particularly discloses that the lithium supplementing device comprises a low-temperature plasma activation device, a container containing a lithium ion solution, an atmospheric pressure plasma generation device, a heating and drying device, and an annealing device. The present application further discloses that the lithium supplementing method comprises: S1) cleaning and activating a positive electrode material of a waste lithium battery by using low-temperature plasma; S2) placing the cleaned and activated positive electrode material in a solution containing lithium ions; and S3) treating the solution by using atmospheric pressure plasma, and then drying and annealing a solid material. According to the present invention, rapid lithium supplementing of the positive electrode material for the lithium battery is realized at normal temperature, and by combining the annealing process, repair and regeneration of the positive electrode material for the lithium battery can be completed.

Description

A plasma lithium replenishing device and method for positive electrode material for lithium battery

Technical Field

The present invention belongs to the field of recycling metal materials in waste batteries, and specifically relates to a plasma lithium replenishment system and method for positive electrode materials for lithium batteries.

Background technique

During the charging and discharging process, lithium batteries consume lithium ions in the positive electrode, resulting in irreversible capacity loss. The consumed lithium ions can be replenished by lithium replenishment methods, thereby increasing the capacity of lithium-ion batteries. For example, lithium metal, negative electrode materials and non-aqueous solvents are mixed to form a slurry and coated on the current collector, so that lithium diffuses into the active material to replenish lithium; metal lithium foil is used to bond the negative electrode for composite, and after the battery is filled with liquid, the metal lithium and the negative electrode react and embed into the negative electrode material for lithium replenishment. Chinese patent CN201911413503.0 discloses a liquid phase lithium replenishment method for positive and negative electrode materials of lithium batteries, and CN202210050429.6 also discloses a lithium battery lithium replenishment and manufacturing method. However, these methods are relatively complicated and are not suitable for lithium replenishment of waste lithium batteries.

technical problem

The prior art does not solve the problem of fast and efficient lithium replenishment of lithium battery positive electrode materials. In view of the problems existing in the prior art, the purpose of the present invention is to propose a technical solution for replenishing lithium of waste lithium battery positive electrode materials using low-temperature plasma technology, especially atmospheric pressure plasma.

Technical Solutions

The purpose of the present invention is to use atmospheric pressure plasma technology to replenish lithium for waste lithium battery positive electrode materials, replenish consumed lithium ions, thereby increasing the capacity of lithium ion batteries and achieving regeneration of waste lithium battery positive electrode materials.

One aspect of the present invention provides a lithium replenishing device for lithium battery positive electrode materials, which includes a low-temperature plasma activation device, a container containing a lithium ion solution, an atmospheric pressure plasma generating device, a heating and drying device, and an annealing device.

Furthermore, the atmospheric pressure plasma generating device is selected from a dielectric barrier discharge plasma generating device, a plasma jet plasma generating device, and a surface discharge plasma generating device.

Furthermore, the atmospheric pressure plasma generating device comprises a gas source used for discharge, and the gas of the gas source is a combination of one or more of air, argon, helium, and nitrogen.

Furthermore, the low-temperature plasma activation device is a low-pressure low-temperature plasma or atmospheric pressure plasma generating device.

Furthermore, the low-temperature plasma activation device is selected from a jet plasma generator, a low-pressure air plasma generator, a low-pressure oxygen plasma generator, an atmospheric pressure argon plasma generator, and an atmospheric pressure argon plasma jet generator.

Furthermore, the lithium ion solution is a solution containing at least one of lithium chloride, lithium hydroxide, lithium sulfate, lithium nitrate, lithium bromide, and lithium phosphate. Furthermore, the solvent in the solution is water or an organic solvent that can dissolve lithium ion salts.

Furthermore, the drying device can provide a drying temperature of 50-200°C.

Furthermore, the annealing device can provide an annealing temperature of 400-1000°C.

Furthermore, the positive electrode of the lithium-ion battery is selected from at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide or lithium manganese oxide.

Furthermore, the lithium replenishing device further comprises a flotation device, wherein the flotation device comprises a solvent capable of suspending carbon impurities and precipitating positive electrode materials, and the positive electrode materials are selected from lithium iron phosphate and lithium manganese iron phosphate.

Another aspect of the present invention provides a method for replenishing lithium of a positive electrode material of a lithium battery, the method comprising the following steps:

S1) Using low-temperature plasma to clean and activate the cathode material of waste lithium batteries;

S2) Put the cleaned and activated positive electrode material in a solution containing lithium ions.

S3) The solution is treated with atmospheric pressure plasma, and the solid material is then dried and annealed.

Furthermore, the method does not include a step of heating the solution containing lithium ions.

Furthermore, the lithium ions in the solution containing lithium ions come from at least one of lithium chloride, lithium hydroxide, lithium sulfate, lithium nitrate, lithium bromide, and lithium phosphate.

Furthermore, the concentration of lithium ions in the solution containing lithium ions is 0.1-2 mol/L

Furthermore, the solvent in the solution containing lithium ions is selected from water and a polar organic solvent, and the polar organic solvent is selected from at least one of formamide, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone and tetrahydrofuran.

Furthermore, the solution containing lithium ions does not contain other chemical reagents. The other chemical reagents are selected from acidic compounds, alkaline compounds, catalysts, activators, and surfactants.

Furthermore, the positive electrode material of the lithium-ion battery is selected from at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide or lithium manganese oxide.

Furthermore, the positive electrode of the lithium-ion battery is a waste positive electrode of a lithium-ion battery that has been used for a period of time.

Furthermore, in step S1), the plasma cleaning activation time is 1-10 min to obtain an activated positive electrode material.

Furthermore, in step S1), when the positive electrode material is lithium iron phosphate or lithium iron manganese phosphate, it also includes a step of further removing carbon impurities by flotation method.

Furthermore, the flotation method is a method of dispersing the activated positive electrode material in a solvent to precipitate it, suspending carbon impurities in the solvent at the same time, and collecting the positive electrode material precipitate at the bottom. In some specific embodiments, the solvent used is a mixed solvent of water and a polar organic solvent miscible with water in a volume ratio of 1:0.2-5.

Furthermore, the low-temperature plasma in step S1) is low-pressure low-temperature plasma or atmospheric pressure plasma.

Furthermore, the processing time in step S3) is 1-30 min.

Furthermore, in step S1) or S3), the atmospheric pressure plasma may be produced by dielectric barrier discharge, plasma jet, or surface discharge.

Furthermore, in step S3), the drying temperature is 50-200° C., and the drying time is 0.2-24 h.

Further, the annealing temperature in step S3) is 400-1000°C. In some specific embodiments, according to the classification of the positive electrode material, lithium iron phosphate or lithium iron manganese phosphate is annealed in an inert gas atmosphere at 400-800°C for 0.5-2 h; lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium cobalt oxide, and lithium manganese oxide are annealed in an atmospheric environment at 700-950°C for 0.5-2 h.

Beneficial Effects

Compared with the prior art, the present invention can achieve rapid lithium replenishment of the positive electrode material of the lithium battery at room temperature, and can complete the repair and regeneration of the positive electrode material of the lithium battery in combination with the annealing process.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an XRD diagram of the lithium cobalt oxide positive electrode material before and after lithium supplementation.

Figure 2 is an XRD diagram of the nickel cobalt manganese oxide positive electrode material before and after lithium supplementation.

FIG3 is an XRD diagram of the lithium iron phosphate positive electrode material before and after lithium supplementation.

FIG4 is a charge and discharge diagram of a lithium iron phosphate button half-cell after plasma lithium supplementation.

Embodiments of the present invention

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation modes of the present invention are described in detail below, but it should not be understood as limiting the applicable scope of the present invention.

In the technical solution of the present invention, the discharge power of the plasma is not limited, because those skilled in the art can adjust the discharge power according to the generating device, gas and flow rate and the situation of the solution to be treated, and it is only necessary to ensure that the atmospheric pressure plasma acts on the solution containing the positive electrode material and lithium ions. Moreover, in order to enhance the reaction effect, functional group gases such as oxygen or water vapor can also be added during the generation of the atmospheric pressure plasma. At the same time, on the basis of the present invention, the generation mode of the plasma, the generated gas pressure, the excitation power supply and other conditions can also be adjusted.

In the present invention, the positive electrode material is a material obtained by stripping the current collector from the positive electrode sheet. The stripping means of the current collector may be existing methods, such as manual stripping, aqueous solution stripping (mainly the negative electrode sheet) or organic solvent stripping (mainly the positive electrode sheet).

Example 1 Lithium battery positive electrode material lithium cobalt oxide lithium supplement

The lithium supplementation method comprises the following steps:

S1) Using jet plasma to clean and activate the positive electrode material of lithium cobalt oxide battery for 5 min;

S2) placing 10 g of activated lithium cobalt oxide positive electrode material in 10 mL of 0.2 mol/L lithium hydroxide aqueous solution;

S3) The repaired lithium cobalt oxide positive electrode material is obtained by discharging the material using air dielectric barrier discharge plasma for 10 min, then drying the material at 50° C. for 24 h, and annealing the material at 950° C. in an atmospheric environment for 0.5 h.

The results are shown in FIG1 . From the XRD results, it can be seen that the absorption peak of the untreated positive electrode material at 18.5 disappears after treatment, indicating that lithium replenishment of the positive electrode material is achieved through plasma treatment.

Example 2 Lithium battery positive electrode material lithium cobalt oxide lithium supplement

The lithium supplementation method comprises the following steps:

S1) Using low-pressure air plasma to clean the positive electrode material of lithium cobalt oxide battery for 2 min;

S2) placing 10 g of activated lithium cobalt oxide black powder in 3 mL of 2 mol/L lithium hydroxide aqueous solution to form a muddy slurry;

S3) The repaired lithium cobalt oxide positive electrode material is obtained by discharging the material using an argon plasma jet for 1 min, then drying the material at 80° C. for 10 h, and annealing the material at 700° C. for 2 h in an atmospheric environment in a ceramic crucible.

The capacity of the button half-cell assembled using the repair material was restored to 97% of commercial lithium cobalt oxide.

Example 3 Lithium replenishment of lithium battery positive electrode material lithium nickel cobalt aluminum oxide

The lithium supplementation method comprises the following steps:

S1) treating the positive electrode of the lithium cobalt oxide battery with low-pressure oxygen plasma for 1 min;

S2) placing 10 g of activated nickel cobalt aluminum lithium black powder in 10 mL of 1 mol/L lithium sulfate aqueous solution;

S3) The repaired nickel cobalt aluminum oxide positive electrode material is obtained by performing discharge treatment using air surface discharge plasma for 20 min, then drying at 200° C. for 0.2 h, placing the material in a ceramic crucible and annealing at 850° C. in an atmospheric environment for 2 h.

The capacity of the button half-cell assembled using the repair material was restored to 95% of commercial lithium nickel cobalt aluminum oxide.

Example 4: Lithium replenishment of lithium nickel cobalt manganese oxide, a positive electrode material of lithium batteries

The lithium supplementation method comprises the following steps:

S1) treating lithium nickel cobalt manganese oxide with atmospheric pressure argon plasma for 2 min;

S2) placing 10 g of activated nickel cobalt lithium manganese oxide black powder in 10 mL of 0.1 mol/L lithium nitrate aqueous solution;

S3) The repaired nickel cobalt manganese oxide lithium positive electrode material is obtained by discharging the material using an atmospheric pressure helium plasma jet for 15 min, drying the material at 70° C. for 10 h, and annealing the material at 850° C. for 1 h in an atmospheric environment in a ceramic crucible.

The capacity of the button half-cell assembled using the repair material was restored to 98% of commercial lithium nickel cobalt manganese oxide.

The XRD experimental results are shown in Figure 2. From the XRD results, it can be seen that the peak splitting at about 44 degrees of the original positive electrode material disappears after repair, but the peak splitting at about 37 degrees of the sample without plasma treatment is not obvious. The splitting degree of these two peaks represents the integrity of the layered structure. In addition, the ratio of the two peak intensities (003) and (104) represents the mixing of lithium ions and nickel ions. The larger the value, the smaller the mixing. The sample treated with plasma has a smaller mixing, indicating that lithium replenishment of the positive electrode material is achieved through plasma treatment.

Example 5 Lithium supplementation of lithium iron phosphate, a positive electrode material of a lithium battery

The lithium supplementation method comprises the following steps:

S1) treating lithium iron phosphate black powder with an atmospheric pressure argon plasma jet for 2 min, flotation with a mixed solution of water: N,N-dimethylformamide in a ratio of 1:2, and collecting the bottom material to obtain lithium iron phosphate black powder;

S2) placing 10 g of activated lithium iron phosphate black powder in 10 mL of 0.5 mol/L lithium chloride N,N-dimethylformamide solution;

S3) The repaired lithium iron phosphate positive electrode material is obtained by discharging the material using an argon dielectric barrier discharge plasma for 10 min, then drying the material at 100° C. for 24 h, and annealing the material at 700° C. for 2 h in a graphite crucible in a nitrogen environment.

The performance recovered to 98% of commercial lithium iron phosphate.

The XRD experimental results are shown in Figure 3. The original lithium iron phosphate sample has impurities, and the impurities disappear completely after plasma treatment, indicating that plasma treatment can achieve lithium replenishment and repair of lithium iron phosphate. The charge and discharge results are shown in Figure 4. The discharge capacity of the original lithium iron phosphate decays to 110 mAh/g, and the discharge capacity of the plasma treated sample recovers to 158 mAh/g.

Claims

A lithium replenishing device for lithium battery positive electrode material, characterized in that it comprises a low-temperature plasma activation device, a container containing a lithium ion solution, an atmospheric pressure plasma generating device, a heating and drying device, and an annealing device;

Preferably, the positive electrode of the lithium-ion battery is selected from at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide or lithium manganese oxide.
The lithium replenishment device according to claim 1, characterized in that the low-temperature plasma activation device is a low-pressure low-temperature plasma or atmospheric pressure plasma generating device;

The atmospheric pressure plasma generating device is selected from a dielectric barrier discharge plasma generating device, a plasma jet plasma generating device, and a surface discharge plasma generating device;

Preferably, the atmospheric pressure plasma generating device comprises a gas source used for discharge, and the gas of the gas source is a combination of one or more of air, argon, helium and nitrogen.

Preferably, the low-temperature plasma activation device is selected from a jet plasma generator, a low-pressure air plasma generator, a low-pressure oxygen plasma generator, an atmospheric pressure argon plasma generator, and an atmospheric pressure argon plasma jet generator;

Preferably, the lithium replenishing device further comprises a flotation device, wherein the flotation device comprises a solvent capable of suspending carbon impurities and precipitating positive electrode materials, and the positive electrode materials are selected from lithium iron phosphate and lithium manganese iron phosphate.
The lithium replenishing device according to claim 1, characterized in that the lithium ion solution is a solution containing at least one of lithium chloride, lithium hydroxide, lithium sulfate, lithium nitrate, lithium bromide, and lithium phosphate;

Preferably, the solvent in the solution is water or an organic solvent capable of dissolving lithium ion salts.
The lithium replenishing device according to claim 1 is characterized in that the annealing device can provide an annealing temperature of 400-1000°C.
A lithium replenishment method for a lithium battery positive electrode material, characterized in that the lithium replenishment method comprises the following steps:

S1) Using low-temperature plasma to clean and activate the cathode material of waste lithium batteries;

S2) Put the cleaned and activated positive electrode material in a solution containing lithium ions.

S3) The solution is treated with atmospheric pressure plasma, followed by drying and annealing the solid material;

Preferably, the positive electrode material of the lithium-ion battery is selected from at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide or lithium manganese oxide.
The lithium supplementation method according to claim 5, characterized in that the lithium ions in the solution containing lithium ions are from at least one of lithium chloride, lithium hydroxide, lithium sulfate, lithium nitrate, lithium bromide, and lithium phosphate;

Preferably, the concentration of lithium ions in the solution containing lithium ions is 0.1-2 mol/L;

Preferably, the solvent in the solution containing lithium ions is selected from water and a polar organic solvent, and the polar organic solvent is selected from at least one of formamide, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone and tetrahydrofuran.
The lithium supplementation method according to claim 5 is characterized in that the low-temperature plasma in step S1) is low-pressure low-temperature plasma or atmospheric pressure plasma;

Preferably, in step S1), the plasma cleaning activation time is 1-10 min to obtain an activated positive electrode material;

Preferably, in step S1), when the positive electrode material is lithium iron phosphate or lithium iron manganese phosphate, it also includes a step of further removing carbon impurities by flotation method;

More preferably, the flotation method is a method of dispersing the activated cathode material in a solvent to precipitate the activated cathode material, suspending carbon impurities in the solvent at the same time, and collecting the cathode material precipitate at the bottom.
The lithium replenishment method according to claim 5 is characterized in that the atmospheric pressure plasma in step S1) or S3) can be dielectric barrier discharge, plasma jet, or surface discharge;

Preferably, the atmospheric pressure plasma treatment time in step S3) is 1-30 min.
The lithium supplementation method according to claim 5 is characterized in that in step S3), the drying temperature is 50-200°C and the drying time is 0.1-24 h.
The lithium replenishing method according to claim 5 is characterized in that the annealing temperature in step S3) is 400-1000°C and the annealing time is 0.5-2 hours.