Method for recovering lithium and transition metals from waste ternary lithium battery cathode materials

Abstract

The present invention relates to the technical field of lithium battery recycling, and specifically to a method for recovering lithium and transition metals from waste ternary lithium battery positive electrode materials. The method comprises: crushing the pretreated ternary lithium battery positive electrode material and dispersing it in a solvent for heat treatment, leaching lithium ions, and retaining transition metal elements in the solid material; evaporating the leachate and recovering lithium in the form of lithium hydroxide; wherein the solvent is a solvent that can provide a proton source. The present invention achieves gentle recovery of lithium ions and effective separation from transition metal elements through a method of crushing and simple heat treatment leaching. It has the advantages of mild conditions, high efficiency, environmental friendliness, and high recovery rate, and is suitable for large-scale application in the gentle recovery of waste ternary lithium battery positive electrode materials.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery recycling, and in particular to a method for recycling lithium and transition metals in cathode materials of waste ternary lithium batteries. Background Art

[0002] Ternary lithium battery cathode materials have the advantages of high energy density and high power density and are widely used in power batteries. Recycling lithium and transition metal elements (nickel, cobalt, manganese, etc.) from waste ternary lithium battery cathode materials has very important social and economic value and is in line with the sustainable development strategy. At present, the recycling of waste ternary lithium battery cathode materials mainly adopts wet or pyrolysis to carry out cascade recovery of various metal elements in the cathode materials. All metal elements need to be dissolved together or formed into alloys, and then precipitated and separated based on the chemical characteristics of each element. However, both methods have disadvantages such as high energy consumption, high environmental pollution, and complex processes. There is an urgent need to develop environmentally friendly, high-recovery, and mild-conditioning recycling methods for waste ternary lithium battery cathode materials.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] In order to solve the problems in the background technology, the present invention provides a method for recovering lithium and transition metals in the positive electrode materials of waste ternary lithium batteries.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The method for recovering lithium and transition metals from waste ternary lithium battery cathode materials includes:

[0007] The pre-treated ternary lithium battery positive electrode material is crushed and dispersed in a solvent for heat treatment, lithium ions are leached, and transition metal elements are retained in the solid material;

[0008] The leachate is evaporated and the lithium is recovered as lithium hydroxide;

[0009] Wherein, the solvent is a solvent that can provide a proton source.

[0010] Preferably, the solvent is deionized water or a mixed solution of deionized water and ethylene glycol.

[0011] Preferably, the positive electrode material of the ternary lithium battery is LiNi 1-x-y Co x Mn y O2(x=0~0.5, y= 0~0.5) or LiNi 1-z-w Co z Al w O2(z=0~0.5, w= 0~0.1).

[0012] Preferably, the positive electrode material of the ternary lithium battery comprises LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.88 Co 0.1 Al 0.02 O2、LiNi 0.9 Co 0.05 Mn 0.05 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.33 Co 0.33 Mn 0.33 O2.

[0013] Preferably, the pretreatment is to separate and clean the positive electrode material of the ternary lithium battery from the ternary lithium battery.

[0014] Preferably, the pretreated ternary lithium battery positive electrode material is crushed to 200-600 nm.

[0015] Preferably, the positive electrode material of the ternary lithium battery is mixed with a ball milling solvent and then ball milled, wherein the ball milling solvent is selected from any one or more of ethylene glycol, deionized water, and ethanol.

[0016] Preferably, when the ball milling solvent is a mixed solution of deionized water and ethylene glycol, the volume ratio of ethylene glycol to the mixed solution is 0-1.

[0017] Preferably, the heat treatment temperature is 60-250° C. and the time is 2-72 hours.

[0018] Preferably, during the heat treatment, the volume ratio of the crushed ternary lithium battery positive electrode material to the solvent is 1 to 30 g / L.

[0019] Preferably, when the solvent is a mixed solution of deionized water and ethylene glycol, the volume ratio of ethylene glycol to the mixed solution is 0-1.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention achieves effective separation of lithium metal from transition metal elements by pulverizing waste lithium battery positive electrode active materials and then leaching the lithium element from the ball-milled material under mild conditions using a solvent capable of providing a proton source. The resulting lithium leached solution is evaporated to dryness to yield lithium hydroxide, while the remaining solid material forms transition metal hydroxides or hydroxides. Therefore, the method provided by the present invention for mildly recovering lithium and transition metals from waste ternary lithium battery positive electrode materials using proton replacement can achieve efficient separation and recovery of waste ternary lithium battery positive electrode materials, and has the advantages of being simple, effective, environmentally friendly, and highly operable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the method for leaching and recovering lithium ions from a ternary positive electrode layered structure material using proton replacement according to the present invention;

[0023] Figure 2 The waste ternary lithium battery LiNi of Example 1 of the present invention 0.8 Co 0.1 Mn 0.1 X-ray diffraction patterns of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0024] Figure 3 The waste ternary lithium battery LiNi of Example 1 of the present invention 0.8 Co 0.1 Mn 0.1 ICP test results of O2 cathode active materials before and after ball milling and simple water / solvent thermal delithiation;

[0025] Figure 4 This is the LiNi of Example 1 of the present invention. 0.8 Co 0.1 Mn 0.1 Ni K-edge X-ray absorption spectra of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation, where a is the Ni K-edge X-ray absorption spectrum in E space and b is the Ni K-edge X-ray absorption spectrum in R space;

[0026] Figure 5 This is the LiNi of Example 1 of the present invention. 0.8 Co 0.1 Mn 0.1 Optical photos of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0027] Figure 6 The waste ternary lithium battery LiNi of Example 2 of the present invention 0.88 Co 0.1 Al 0.02 X-ray diffraction patterns of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0028] Figure 7 The waste ternary lithium battery LiNi of Example 2 of the present invention 0.88 Co 0.1 Al 0.02 ICP test results of O2 cathode active materials before and after ball milling and simple water / solvent thermal delithiation;

[0029] Figure 8 This is the second embodiment of the present invention, waste ternary lithium battery LiNi 0.88 Co 0.1 Al 0.02 Ni K-edge X-ray absorption spectra of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation, where a is the Ni K-edge X-ray absorption spectrum in E space and b is the Ni K-edge X-ray absorption spectrum in R space;

[0030] Figure 9 The waste ternary lithium battery LiNi of Example 3 of the present invention 0.9 Co 0.05 Mn 0.05 X-ray diffraction patterns of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0031] Figure 10 The waste ternary lithium battery LiNi of Example 3 of the present invention 0.9 Co 0.05 Mn 0.05 ICP test results of O2 cathode active materials before and after ball milling and simple water / solvent thermal delithiation;

[0032] Figure 11 The waste ternary lithium battery LiNi of Example 3 of the present invention 0.9 Co 0.05 Mn 0.05 Ni K-edge X-ray absorption spectra of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation, where a is the Ni K-edge X-ray absorption spectrum in E space and b is the Ni K-edge X-ray absorption spectrum in R space;

[0033] Figure 12 The waste ternary lithium battery LiNi of Example 4 of the present invention 0.6 Co 0.2 Mn 0.2 X-ray diffraction patterns of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0034] Figure 13 The waste ternary lithium battery LiNi of Example 4 of the present invention 0.6 Co 0.2 Mn 0.2ICP test results of O2 cathode active materials before and after ball milling and simple water / solvent thermal delithiation;

[0035] Figure 14 The waste ternary lithium battery LiNi of Example 4 of the present invention 0.6 Co 0.2 Mn 0.2 Ni K-edge X-ray absorption spectra of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation, where a is the Ni K-edge X-ray absorption spectrum in E space and b is the Ni K-edge X-ray absorption spectrum in R space;

[0036] Figure 15 The waste ternary lithium battery LiNi of Example 5 of the present invention 0.5 Co 0.2 Mn 0.3 X-ray diffraction patterns of the O2 cathode active material before and after ball milling and simple water / solvent thermal delithiation;

[0037] Figure 16 The waste ternary lithium battery LiNi of Example 5 of the present invention 0.5 Co 0.2 Mn 0.3 ICP test results of O2 cathode active materials before and after ball milling and simple water / solvent thermal delithiation;

[0038] Figure 17 The waste ternary lithium battery LiNi of Example 5 of the present invention 0.5 Co 0.2 Mn 0.3 Ni K-edge X-ray absorption spectra of O2 positive electrode active materials before and after ball milling and simple water / solvent thermal delithiation, where a is the Ni K-edge X-ray absorption spectrum in E space and b is the Ni K-edge X-ray absorption spectrum in R space. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies has been omitted to avoid unnecessary confusion of the concept of the present invention. In the embodiments, those not indicating specific conditions are carried out according to the conditions of normal conditions or manufacturer's advice. Reagents used or instruments not indicating manufacturers are conventional products that can be purchased commercially.

[0040] Existing methods for recycling spent ternary lithium battery cathode materials typically employ either pyrolysis or hydrolysis to completely extract lithium and metal elements, followed by subsequent precipitation and separation. Pyrolysis has the disadvantages of high energy input and severe environmental pollution, while hydrolysis requires the use of acidic or alkaline leaching solutions and involves complex metal element separation steps. Therefore, there is an urgent need to develop efficient and environmentally friendly methods for recycling spent ternary lithium battery cathode materials.

[0041] An embodiment of the present invention provides a method for recovering lithium and transition metals from waste ternary lithium battery cathode materials, comprising:

[0042] The pre-treated ternary lithium battery positive electrode material is crushed and dispersed in a solvent for heat treatment, lithium ions are leached, and transition metal elements are retained in the solid material;

[0043] The leachate is evaporated and the lithium is recovered as lithium hydroxide;

[0044] Wherein, the solvent is a solvent that can provide a proton source.

[0045] The embodiment of the present invention is realized by using proton replacement. The crushed ternary lithium battery positive electrode material is dispersed in a solvent that can provide a proton source, and a simple heat treatment is performed. The protons provided by the solvent are used to replace the lithium ion layer in the layered structure material of the ternary lithium battery positive electrode material, so that the Li ions in the layered positive electrode material exchange substances with the protons in the solvent, thereby realizing the leaching of lithium ions under mild conditions. This process can also be called water / solvent thermal delithiation treatment. The transition metal elements are retained in the solid material in the form of oxides or hydroxides, and the lithium elements in the leachate are recovered in the form of lithium hydroxide after evaporating the leachate, thereby realizing the mild recovery of lithium and transition metal elements in the ternary lithium battery positive electrode material. The present invention provides a simple, effective and environmentally friendly ternary lithium battery positive electrode material and provides new ideas for further development and performance improvement.

[0046] It should be noted that the "ternary lithium battery positive electrode material" and "ternary lithium battery positive electrode active material" mentioned in the embodiments of the present invention are the same concept. The ternary lithium battery of the present invention refers to a lithium battery whose positive electrode material uses a ternary positive electrode material of lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminum oxide.

[0047] like Figure 1 The proton replacement method used in the present invention only illustrates the proton replacement process of a ternary lithium battery positive electrode material. The proton replacement methods of other ternary lithium battery positive electrode materials are the same as Figure 1The same. The embodiment of the present invention utilizes protons in the solvent to replace lithium ions in the lithium ion layer in the ternary positive electrode material. Therefore, the solvent used is a solvent that can provide a proton source, including but not limited to water / ethylene glycol, etc. For example, the solvent can be deionized water or a mixed solution of deionized water and ethylene glycol. When the solvent is a mixed solution, there is no special limitation on the content of each component, and any proportion of mixing can achieve the technical effect of the present invention. For example, when the solvent is a mixed solution of deionized water and ethylene glycol, the volume ratio of ethylene glycol to the mixed solution is 0~1, that is, the volume ratio of ethylene glycol can be 0, at this time, no ethylene glycol is contained, only deionized water is contained, and the volume ratio of ethylene glycol can also be 1, here no deionized water is contained, only ethylene glycol is contained.

[0048] The embodiment of the present invention is applicable to the recycling of all ternary lithium battery positive electrode materials, such as LiNi 1-x-y Co x Mn y O2(x=0~0.5, y= 0~0.5) or LiNi 1-z-w Co Z Al w O2 (z=0~0.5, w= 0~0.1). Specifically, it can contain LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.88 Co 0.1 Al 0.02 O2、LiNi 0.9 Co 0.05 Mn 0.05 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.33 Co 0.33 Mn 0.33 O2 and other ternary lithium battery positive electrode materials.

[0049] In a specific embodiment, the pretreatment is to separate and clean the positive electrode material of the ternary lithium battery from the ternary lithium battery.

[0050] In a preferred embodiment, there is no particular limitation on the degree of pulverization of the ternary lithium battery cathode material. Persons skilled in the art may reasonably adjust the degree of pulverization based on the actual effect required during the subsequent proton exchange process. For example, to provide more proton exchange channels for the ternary lithium battery cathode material during the subsequent water / solvent thermal delithiation treatment, the degree of pulverization may be increased, such as by controlling the particle size after pulverization to 200-600 nm.

[0051] In a preferred embodiment, there is no particular limitation on the form of pulverization, and pulverization methods commonly used in the art can be used, such as ball milling. When a planetary ball mill is used for ball milling, the rotation speed can be controlled to be 100-500 rpm, and the ball milling medium is ZrO2 balls. When a vertical / horizontal sand mill is used for sand milling, the rotation speed can be controlled to be 1000-2500 rpm, and the sand milling medium is ZrO2 balls. During the ball milling process, a ball milling solvent is added and mixed with the positive electrode material of the ternary lithium battery. The ball milling solvent is selected from any one or more of ethylene glycol, deionized water, and ethanol. When the ball milling solvent is a mixture of multiple components, the components can be mixed in any proportion.

[0052] In some preferred embodiments, when dispersing the crushed ternary lithium battery positive electrode material in a solvent, those skilled in the art can adjust the relationship between the mass of the ternary lithium battery positive electrode material and the volume of the solvent without particular limitation. For example, the mass of the ternary lithium battery positive electrode material and the volume of the solvent can be controlled to be 1 to 50 g / L.

[0053] In some preferred embodiments, the crushed ternary lithium battery positive electrode material is dispersed in a solvent that can provide a proton source and subjected to a simple water / solvent thermal treatment, i.e., delithiation, with the temperature controlled in the range of 60-250°C for 2-72 hours. Increasing the temperature is beneficial to the rate and extent of proton exchange delithiation, and the longer the delithiation time, the more thorough the proton exchange. This delithiation process utilizes the protons provided by the solvent to replace the lithium ion layer in the layered structure of the ternary lithium battery positive electrode material, exchanging the lithium ions in the layered positive electrode material with the protons in the solution to achieve lithium ion leaching. That is, after delithiation is completed, the lithium ions are dispersed in the leachate, and the transition metal elements remain in the solid material in the form of oxides or hydroxides.

[0054] In order to make the technical solution of the present invention clearer, the recycling method of the waste ternary lithium battery positive electrode material of the present invention and the test results are described in detail using specific examples below.

[0055] Example 1: LiNi 0.8 Co 0.1 Mn 0.1 Recovery of O2 cathode materials

[0056] Waste ternary lithium battery LiNi 0.8 Co 0.1 Mn 0.1 After separation and cleaning of the O2 cathode active material, 5 gLiNi 0.8 Co 0.1 Mn 0.1The O2 active material was added to a 200 mL nylon ball mill and pulverized using a planetary ball mill (100-500 rpm, using ZrO2 balls as the milling medium and anhydrous ethanol as the solvent). The resulting pulverized material was collected by centrifugation and filtration, then washed several times with deionized water and anhydrous ethanol. The resulting cathode material was then dried at 60°C for 2 hours.

[0057] 4 g of the positive electrode active material after the ball milling step was dispersed in 160 mL of deionized water or a mixed solvent of deionized water and ethylene glycol by ultrasonic or mechanical stirring, and then subjected to simple water / solvent thermal treatment at 150 °C for 12 h to achieve LiNi 0.8 Co 0.1 Mn 0.1 The O2 positive electrode material is gently delithiated. The delithiated solid and liquid phases are then separated by centrifugation or filtration, wherein the solid component is further washed with deionized water and anhydrous ethanol and then dried to obtain a transition metal hydroxide or oxyhydroxide. The liquid component is directly dried at 90 ° C to obtain lithium hydroxide. The results are as follows Figures 2 to 5 shown.

[0058] Figure 2 For waste ternary lithium battery LiNi 0.8 Co 0.1 Mn 0.1 The X-ray diffraction patterns of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.8 Co 0.1 Mn 0.1 The O2 positive electrode material has a standard layered LiCoO2 structure and still maintains its original structure after ball milling treatment, with only a decrease in diffraction intensity. After further simple water / solvent thermal delithiation, the original layered LiCoO2 structure characteristic diffraction peak in the sample completely disappears and is transformed into a nickel hydroxide structure. Figure 3 For waste ternary lithium battery LiNi 0.8 Co 0.1 Mn 0.1 ICP test results of O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation. From the ICP results, it can be seen that the ratio of Li element content to transition metal element content of the sample remains basically unchanged before and after ball milling, and after further simple water / solvent thermal delithiation, the Li element content in the sample is only 0.01~0.04 wt%. This indicates that LiNi 0.8 Co 0.1 Mn 0.1 The Li element in the O2 positive electrode active material is completely released into the solution. Figure 4 LiNi 0.8 Co 0.1 Mn0.1 The Ni K-edge X-ray absorption spectrum of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation shows that the sample always maintains the original layered LiCoO2 structure before and after ball milling treatment, while after further simple water / solvent thermal delithiation, the coordination environment of the Ni element in the sample changes significantly, forming a hydroxide structure. Figure 5 LiNi 0.8 Co 0.1 Mn 0.1 The optical photos of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.8 Co 0.1 Mn 0.1 The O2 positive electrode active material can be separated from the lithium element and the transition metal element after ball milling and simple water / solvent thermal delithiation, and pure LiOH and transition metal hydroxide can be effectively recovered.

[0059] Example 2: LiNi 0.88 Co 0.1 Al 0.02 Recovery of O2 cathode materials

[0060] Waste ternary lithium battery LiNi 0.88 Co 0.1 Al 0.02 After separation and cleaning of the O2 cathode active material, 5 gLiNi 0.88 Co 0.1 Al 0.02 The O2 active material was added to a 200 mL nylon ball mill and pulverized using a planetary ball mill (100-500 rpm, using ZrO2 balls as the milling medium and anhydrous ethanol as the solvent). The resulting pulverized material was collected by centrifugation and filtration, then washed several times with deionized water and anhydrous ethanol. The resulting cathode material was then dried at 60°C for 2 hours.

[0061] 4 g of the positive electrode active material after the ball milling step is dispersed in 160 mL of deionized water or a mixed solvent of deionized water and ethylene glycol by ultrasonic or mechanical stirring, and a simple water / solvent heat treatment is performed at 150 degrees Celsius for 12 hours to achieve mild delithiation of the positive electrode material. The solid and liquid phases after delithiation are then separated by centrifugation or filtration, wherein the solid component is further washed with deionized water and anhydrous ethanol and then dried to obtain a transition metal hydroxide or oxyhydroxide. The liquid component is directly dried at 90 ° C to obtain lithium hydroxide, and the results are as follows. Figures 6 to 8 shown.

[0062] Figure 6 For waste ternary lithium battery LiNi 0.88 Co0.1 Al 0.02 The X-ray diffraction patterns of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.88 Co 0.1 Al 0.02 The O2 positive electrode material has a standard layered LiCoO2 structure and still maintains its original structure after ball milling treatment, with only a decrease in diffraction intensity. After further simple water / solvent thermal delithiation, the original layered LiCoO2 structural characteristic diffraction peak in the sample completely disappears and is transformed into a nickel oxyhydroxide structure. Figure 7 For waste ternary lithium battery LiNi 0.88 Co 0.1 Al 0.02 ICP test results of O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation. From the ICP results, it can be seen that the ratio of Li element content to transition metal element content of the sample remains basically unchanged before and after ball milling. After further simple water / solvent thermal delithiation, the Li element content in the sample is only 0.02-0.08 wt%. This indicates that LiNi 0.88 Co 0.1 Al 0.02 The Li element in the O2 positive electrode active material is completely released into the solution. Figure 8 LiNi 0.88 Co 0.1 Al 0.02 The Ni K-edge X-ray absorption spectrum of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation shows that the sample always maintains the original layered LiCoO2 structure before and after ball milling treatment, while after further simple water / solvent thermal delithiation, the coordination environment of the Ni element in the sample changes significantly, forming a hydroxy oxide structure.

[0063] Example 3: LiNi 0.9 Co 0.05 Mn 0.05 Recovery of O2 cathode materials

[0064] Waste ternary lithium battery LiNi 0.9 Co 0.05 Mn 0.05 After separation and cleaning of the O2 cathode active material, 5 gLiNi 0.9 Co 0.05 Mn 0.05The O2 active material was added to a 200 mL nylon ball mill and pulverized using a planetary ball mill (100-500 rpm, using ZrO2 balls as the milling medium and anhydrous ethanol as the solvent). The resulting pulverized material was collected by centrifugation and filtration, then washed several times with deionized water and anhydrous ethanol. The resulting cathode material was then dried at 60°C for 2 hours.

[0065] 4 g of the positive electrode active material after the ball milling step is dispersed in 160 mL of deionized water or a mixed solvent of deionized water and ethylene glycol by ultrasonic or mechanical stirring, and a simple water / solvent heat treatment is performed at 150 degrees Celsius for 12 hours to achieve mild delithiation of the positive electrode material. The delithiation solid and liquid are then separated by centrifugation or filtration, wherein the solid component is further washed with deionized water and anhydrous ethanol and then dried to obtain a transition metal hydroxide or oxyhydroxide. The liquid component is directly dried at 90 ° C to obtain lithium hydroxide, and the results are as follows. Figures 9 to 11 shown.

[0066] Figure 9 For waste ternary lithium battery LiNi 0.9 Co 0.05 Mn 0.05 The X-ray diffraction patterns of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.9 Co 0.05 Mn 0.05 The O2 positive electrode material has a standard layered LiCoO2 structure and still maintains its original structure after ball milling treatment, with only a decrease in diffraction intensity. After further simple water / solvent thermal delithiation, the original layered LiCoO2 structure characteristic diffraction peak in the sample completely disappears and is transformed into a nickel hydroxide structure. Figure 10 For waste ternary lithium battery LiNi 0.9 Co 0.05 Mn 0.05 ICP test results of O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation. From the ICP results, it can be seen that the ratio of Li element content to transition metal element content of the sample remains basically unchanged before and after ball milling. After further simple water / solvent thermal delithiation, the Li element content in the sample is only 0.03-0.16 wt%. This indicates that LiNi 0.9 Co 0.05 Mn 0.05 The Li element in the O2 positive electrode active material is completely released into the solution. Figure 11 LiNi 0.9 Co 0.05 Mn 0.05The Ni K-edge X-ray absorption spectrum of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation shows that the sample always maintains the original layered LiCoO2 structure before and after ball milling treatment, while after further simple water / solvent thermal delithiation, the coordination environment of the Ni element in the sample changes significantly, forming a hydroxide structure.

[0067] Example 4: LiNi 0.6 Co 0.2 Mn 0.2 Recovery of O2 cathode materials

[0068] Waste ternary lithium battery LiNi 0.6 Co 0.2 Mn 0.2 After separation and cleaning of the O2 cathode active material, 5 gLiNi 0.6 Co 0.2 Mn 0.2 The O2 active material was added to a 200 mL nylon ball mill and pulverized using a planetary ball mill (100-500 rpm, using ZrO2 balls as the milling medium and anhydrous ethanol as the solvent). The resulting pulverized material was collected by centrifugation and filtration, then washed several times with deionized water and anhydrous ethanol. The resulting cathode material was then dried at 60°C for 2 hours.

[0069] 4 g of the positive electrode active material after the ball milling step is dispersed in 160 mL of deionized water or a mixed solvent of deionized water and ethylene glycol by ultrasonic or mechanical stirring, and a simple water / solvent heat treatment is performed at 200 degrees Celsius for 24 hours to achieve mild delithiation of the positive electrode material. The delithiation solid and liquid are then separated by centrifugation or filtration, wherein the solid component is further washed with deionized water and anhydrous ethanol and then dried to obtain a transition metal hydroxide or oxyhydroxide. The liquid component is directly dried at 90 ° C to obtain lithium hydroxide, and the results are as follows. Figures 12 to 14 shown.

[0070] Figure 12 For waste ternary lithium battery LiNi 0.6 Co 0.2 Mn 0.2 The X-ray diffraction patterns of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.6 Co 0.2 Mn 0.2 The O2 positive electrode material has a standard layered LiCoO2 structure and still maintains its original structure after ball milling treatment, with only a decrease in diffraction intensity. After further simple water / solvent thermal delithiation, the original layered LiCoO2 structural characteristic diffraction peak in the sample completely disappears. Figure 13For waste ternary lithium battery LiNi 0.6 Co 0.2 Mn 0.2 ICP test results of O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation. From the ICP results, it can be seen that the ratio of Li element content to transition metal element content of the sample remains basically unchanged before and after ball milling, and after further simple water / solvent thermal delithiation, the Li element content in the sample is only 0.08~0.9 wt%. This indicates that LiNi 0.6 Co 0.2 Mn 0.2 The Li element in the O2 positive electrode active material is basically released into the solution. Figure 14 LiNi 0.6 Co 0.2 Mn 0.2 The Ni K-edge X-ray absorption spectrum of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation shows that the sample always maintains the original layered LiCoO2 structure before and after ball milling treatment, while the coordination environment of the Ni element in the sample changes significantly after further simple water / solvent thermal delithiation.

[0071] Example 5: LiNi 0.5 Co 0.2 Mn 0.3 Recovery of O2 cathode materials

[0072] Waste ternary lithium battery LiNi 0.5 Co 0.2 Mn 0.3 After separation and cleaning of the O2 cathode active material, 5 gLiNi 0.5 Co 0.2 Mn 0.3 The O2 active material was added to a 200 mL nylon ball mill and pulverized using a planetary ball mill (100-500 rpm, using ZrO2 balls as the milling medium and anhydrous ethanol as the solvent). The resulting pulverized material was collected by centrifugation and filtration, then washed several times with deionized water and anhydrous ethanol. The resulting cathode material was then dried at 60°C for 2 hours.

[0073] 4 g of the positive electrode active material after the ball milling step is dispersed in 160 mL of deionized water or a mixed solvent of deionized water and ethylene glycol by ultrasonic or mechanical stirring, and a simple water / solvent heat treatment is performed at 200 degrees Celsius for 24 hours to achieve mild delithiation of the positive electrode material. The delithiation solid and liquid are then separated by centrifugation or filtration, wherein the solid component is further washed with deionized water and anhydrous ethanol and then dried to obtain a transition metal hydroxide or oxyhydroxide. The liquid component is directly dried at 90 ° C to obtain lithium hydroxide, and the results are as follows. Figures 15 to 17 shown.

[0074] Figure 15 For waste ternary lithium battery LiNi 0.5 Co 0.2 Mn 0.3 The X-ray diffraction patterns of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation can be seen from the figure. 0.5 Co 0.2 Mn 0.3 The O2 positive electrode material has a standard layered LiCoO2 structure and still maintains its original structure after ball milling treatment, with only a decrease in diffraction intensity. After further simple water / solvent thermal delithiation, the original layered LiCoO2 structural characteristic diffraction peak in the sample completely disappears. Figure 16 For waste ternary lithium battery LiNi 0.5 Co 0.2 Mn 0.3 ICP test results of O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation. From the ICP results, it can be seen that the ratio of Li element content to transition metal element content of the sample remains basically unchanged before and after ball milling, while the Li element content in the sample after further simple water / solvent thermal delithiation is only 0.8~2.2 wt%. This indicates that LiNi 0.5 Co 0.2 Mn 0.3 Most of the Li element in the O2 positive electrode active material is released into the solution. Figure 17 LiNi 0.5 Co 0.2 Mn 0.3 The Ni K-edge X-ray absorption spectrum of the O2 positive electrode active material before and after ball milling and simple water / solvent thermal delithiation shows that the sample always maintains the original layered LiCoO2 structure before and after ball milling treatment, while the coordination environment of the Ni element in the sample changes significantly after further simple water / solvent thermal delithiation.

[0075] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for recovering lithium and transition metals from waste ternary lithium battery cathode materials, characterized in that: Include: The pre-treated ternary lithium battery cathode material is crushed into 200-600 nm and then dispersed in a solvent for heat treatment to achieve proton replacement and lithium ion leaching, while the transition metal elements are retained in the solid material; The leachate is evaporated and the lithium is recovered as lithium hydroxide; Wherein, the solvent is a solvent that can provide a proton source, and the protons in the solvent replace the lithium ions in the layered structure of the positive electrode material of the ternary lithium battery; The pretreatment is to separate and clean the positive electrode material of the ternary lithium battery from the ternary lithium battery.

2. The recycling method according to claim 1, wherein The solvent is deionized water or a mixed solution of deionized water and ethylene glycol.

3. The recycling method according to claim 2, wherein: When the solvent is a mixed solution of deionized water and ethylene glycol, the volume ratio of ethylene glycol to the mixed solution is 0-1.

4. The recycling method according to claim 1, wherein The positive electrode material of the ternary lithium battery is LiNi 1-x- y Co x Mn y O2(x=0~0.5, y= 0~0.5) or LiNi 1-z-w Co z Al w O2 (z=0~0.5, w= 0~0.1).

5. The recycling method according to claim 2, wherein: The positive electrode material of the ternary lithium battery comprises LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.88 Co 0.1 Al 0.02 O2、LiNi 0.9 Co 0.05 Mn 0.05 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.33 Co 0.33 Mn 0.33 O2.

6. The recycling method according to claim 5, wherein: The positive electrode material of the ternary lithium battery is mixed with a ball milling solvent and then ball milled and crushed, wherein the ball milling solvent is selected from any one or more of ethylene glycol, deionized water, and ethanol.

7. The recycling method according to claim 1, wherein: The heat treatment temperature is 60-250° C. and the time is 2-72 hours.

8. The recycling method according to claim 1, wherein: During the heat treatment, the mass ratio of the crushed ternary lithium battery positive electrode material to the volume ratio of the solvent is 1 to 30 g / L.

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