Lithium supplement additive for lithium ion battery and preparation method

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium supplement additive for a lithium ion battery and a preparation method. Comprising the following steps: dissolving a soluble lithium source and a soluble copper source in a solvent to obtain a mixed solution; and carrying out ball milling on the mixed solution and then carrying out microwave reaction to obtain the lithium supplement additive lithium cuprate for the lithium ion battery. The reaction is accelerated and the reaction efficiency is improved by performing vibration, rotation and resonance excitation on molecules of reactants by utilizing the characteristics of microwave radiation, the vibration and rotation of the molecules are initiated by utilizing the mechanism, and energy is provided for changing the reaction activity and reaction speed of the reactants; according to the method, on the basis of preparing copper acid with the same lithium supplement effect, the preparation time is greatly shortened, great economic benefits and industrial potential are achieved, the body structure of the material is not damaged, the particle size of the material can be effectively reduced, and therefore the agglomeration and large particle phenomena in the pulping and coating process are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery lithium supplement additive and a preparation method thereof. Background Art

[0002] After the first charge and discharge of lithium-ion batteries, some lithium ions cannot return to the positive electrode material due to the formation of the solid electrolyte membrane and the low initial charge and discharge efficiency of the negative electrode, which reduces the specific capacity of the lithium-ion battery in the subsequent cycle process. In particular, the use of silicon / carbon high-capacity and low charge and discharge efficiency electrode materials makes this problem more prominent. In order to solve this problem, the development of lithium-ion battery lithium replenishment methods has become an effective way to improve the energy density of lithium-ion batteries.

[0003] Li 2 CuO 2 It is a transition metal oxide with an orthorhombic structure. Its space group structure is 13m, and the unit cell parameters are a=3.659, b=2.861, c=9.387. There is [CuO 4 ] chain, the unit Cu atom is the center and exists in the tetrahedron formed by oxygen atoms, and [CuO 4 ] chains are arranged in a top-to-top manner. 2 CuO 2 It has been proven to have a certain lithium supplement effect. However, currently 2 CuO 2 The preparation method for use as a positive electrode material or a lithium supplement additive is complex, the preparation time is long, and the resulting material has a large particle size, which is not easy for lithium ions to be deintercalated, affecting the lithium supplement effect and is not conducive to industrial production. For example, Chinese patent CN201610212493.4 discloses a preparation method for lithium copper oxide, a positive electrode material for lithium ion batteries. The prepared lithium copper oxide material is used as a battery positive electrode, but its preparation method takes up to 10 hours, the process is complex, and is not conducive to industrial production. Chinese patent CN202311229669.3 discloses a lithium copper oxide positive electrode material and its preparation method. The invention uses a solid phase sintering process. The solid phase sintering process is simple and convenient for mass production of materials. However, the lithium copper oxide material currently prepared by solid phase sintering usually requires 16h to 18h, the preparation time is long, and the resulting material has a large particle size, which is not easy for lithium ions to be deintercalated, affecting the lithium supplement effect and difficult to meet the requirements of industrial applications. Summary of the invention

[0004] The purpose of the present invention is to provide a lithium-ion battery lithium supplement additive and a preparation method, and to provide a microwave-assisted preparation technology for a lithium-ion battery lithium supplement additive with a simple process and a short time, which can quickly obtain a small-particle size lithium-ion battery lithium supplement additive. On the basis of preparing a copper acid process with the same lithium supplement effect, the preparation time is greatly reduced, and it has greater economic benefits and industrialization potential. It does not damage the material's main structure, and can effectively increase and reduce the material particle size, thereby improving the method of agglomeration and large particle phenomena during the pulping and coating process.

[0005] The present invention solves the above technical problems through the following technical solutions.

[0006] The first object of the present invention is to provide a lithium ion battery lithium supplement additive and a preparation method thereof, comprising the following steps:

[0007] S1. Dissolving a soluble lithium source and a soluble copper source in a solvent to obtain a mixed solution.

[0008] S2. Ball-milling the mixed solution to form reactants, subjecting the reactants to microwave reaction, inducing vibration and rotation of the reactant molecules through microwave radiation, thereby increasing the reaction activity and reaction speed, and obtaining lithium cuprate as a lithium supplement additive for lithium-ion batteries.

[0009] It should be noted that the present invention utilizes the characteristics of microwave radiation to accelerate the reaction and improve the reaction efficiency by causing the molecules of the reactants to vibrate, rotate and resonate. This mechanism is used to induce the vibration and rotation of the molecules, and energy is provided to change the reaction activity and reaction rate of the reactants. On the basis of preparing copper acid with the same lithium supplement effect, the preparation time is greatly reduced, and it has great economic benefits and industrialization potential. It does not damage the main structure of the material, and can effectively reduce the particle size of the material, thereby improving the method of agglomeration and large particle phenomena during the pulping and coating process.

[0010] In some specific embodiments, the mixed solution is ball-milled to form a reactant, and the reactant is subjected to a microwave reaction, wherein the frequency of the microwave reaction is 2450 MHz, the power is 1800 W, and the time is 30 min to 90 min.

[0011] In some specific embodiments, the soluble lithium source and the soluble copper source are dissolved in solvent water, wherein the molar volume ratio of the soluble lithium source, the soluble copper source and the water is 2 mol to 2.2 mol: 1 mol: 10 mL to 30 mL. The purpose of the solvent is to make the soluble lithium source and the soluble copper form a uniform mixed solution, and it does not participate in the reaction.

[0012] In some specific embodiments, after the mixed solution is ball-milled and the solvent is removed, it is pressed to obtain an embryo, and the embryo is subjected to microwave reaction to obtain lithium copper oxide, a lithium supplement additive for lithium-ion batteries. It should be noted that the present invention also provides a method for preparing a lithium supplement additive for lithium-ion batteries by pressing to form an embryo for reaction. Compared with dissolving a soluble lithium source and a soluble copper source in a solvent to form a mixed solution, the contact of the embryo is tighter, the heat transfer effect is better, and the preparation time is reduced. Preferably, the frequency of the microwave reaction is 2450MHz, the power is 1800W, and the time is 60min to 120min.

[0013] In some specific embodiments, the molar ratio of the soluble lithium source to the soluble copper source is 2-2.2:1.

[0014] In some specific embodiments, the soluble lithium source is at least one of lithium hydroxide, lithium carbonate, lithium sulfate, lithium bicarbonate, lithium oxide, lithium oxalate, lithium chloride, lithium acetate, lithium perchlorate, lithium iodide, lithium bromide, lithium dihydrogen phosphate, lithium borate, lithium fluoride, and lithium aluminate.

[0015] In some specific embodiments, the soluble copper source is at least one of copper oxide, copper sulfate, copper nitrate, copper chloride, copper acetate, copper bromide, copper iodide, basic copper carbonate, copper phosphate, copper lactate, and copper oxalate.

[0016] In some specific embodiments, the ball milling speed is 350r / min to 450r / min, and the time is 2h to 4h. In the present invention, the ball milling method is to make the mixed solution fully mixed and dissolved evenly, react more fully, reduce the particle size, and make the particle size distribution uniform, so as to improve its lithium supplementation performance.

[0017] In some specific embodiments, the thickness of the embryo is 1 mm to 3 mm, and the diameter is 1.0 cm to 1.5 cm. The present invention prepares lithium copper oxide, a lithium supplement additive for lithium ion batteries, by pressing to form an embryo for reaction. The contact of the embryo is more compact, the heat transfer effect is better, and the preparation time is reduced.

[0018] The second object of the present invention is to provide a lithium ion battery lithium supplement additive prepared by the preparation method of the lithium ion battery lithium supplement additive, wherein the lithium ion battery lithium supplement additive lithium cuprate is Li 2 CuO 2 or LiCuO 2 .

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention proposes a microwave-assisted preparation technology for lithium cuprate, a lithium supplement additive for lithium ion batteries, which has a simple process and a short time and can quickly obtain small-particle lithium cuprate. The technology utilizes the characteristics of microwave radiation to accelerate the reaction and improve the reaction efficiency by vibrating, rotating and resonating the molecules of the reactants. The mechanism is used to induce the vibration and rotation of the molecules, and energy is provided to change the reaction activity and reaction rate of the reactants. On the basis of preparing cuprate with the same lithium supplement effect, the preparation time is greatly reduced, the technology has great economic benefits and industrialization potential, and the material body structure is not damaged. The material particle size can be effectively increased and reduced, thereby improving the agglomeration and large particle phenomena in the pulping and coating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 1 of the present invention.

[0022] Figure 2 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 2 of the present invention.

[0023] Figure 3 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 3 of the present invention.

[0024] Figure 4 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 4 of the present invention.

[0025] Figure 5 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 5 of the present invention.

[0026] Figure 6 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 6 of the present invention.

[0027] Figure 7 This is the X-ray diffraction pattern of the lithium-ion battery lithium supplement additive prepared in Example 1 of the present invention.

[0028] Figure 8 For the present invention 2 CuO 2 The first lap lithium extraction capacity diagram.

[0029] Fig. 9 The LFP@Li 2 CuO 2 The first lap lithium extraction capacity diagram.

[0030] Fig.10 The LFP@Li 2 CuO 2 ||Gr's full battery charge and discharge diagram. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Certain words are used in the present invention to refer to specific components. It should be understood by those skilled in the art that technicians will use different nouns to refer to the same component. The present invention does not distinguish the components by the difference in nouns, but by the difference in functions of the components.

[0033] The invention is further described below through specific examples.

[0034] Example 1

[0035] A method for preparing a lithium-ion battery lithium supplement additive comprises the following steps:

[0036] S1. Dissolve lithium hydroxide and copper oxide in 15 mL of deionized water at a molar ratio of 2:1 to obtain a mixed solution.

[0037] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 3 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0038] S3, placing the slurry in a graphite crucible and placing them in a microwave generator for microwave reaction. The frequency of the microwave reaction is 2450MHz, the power is 1800W, and the reaction time is 30min. After the reaction is completed, the reaction solution is placed in an oven and dried at 80°C to remove excess water to obtain a lithium ion battery lithium supplement additive copper acid. The physical and chemical formula of the lithium ion battery lithium supplement additive copper acid is Li 2 CuO 2 .

[0039] Example 2

[0040] A method for preparing a lithium-ion battery lithium supplement additive comprises the following steps:

[0041] S1. Dissolve lithium hydroxide and copper oxide in 30 mL of deionized water at a molar ratio of 2.2:1 to obtain a mixed solution.

[0042] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 4 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0043] S3, placing the slurry in a graphite crucible and placing them in a microwave generator for microwave reaction. The frequency of the microwave reaction is 2450MHz, the power is 1800W, and the reaction time is 30min. After the reaction is completed, the reaction solution is placed in an oven and dried at 80°C to remove excess water to obtain a lithium ion battery lithium supplement additive copper acid. The physical and chemical formula of the lithium ion battery lithium supplement additive copper acid is Li 2 CuO 2 .

[0044] Example 3

[0045] A lithium-ion battery lithium supplement additive and a preparation method thereof, comprising the following steps:

[0046] S1. Dissolve lithium hydroxide and copper oxide in 20 mL of deionized water at a molar ratio of 2.1:1 to obtain a mixed solution.

[0047] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 3 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0048] S3, placing the slurry in a graphite crucible and placing them in a microwave generator for microwave reaction. The frequency of the microwave reaction is 2450MHz, the power is 1800W, and the reaction time is 60min. After the reaction is completed, the reaction solution is placed in an oven and dried to remove excess water to obtain a lithium ion battery lithium supplement additive copper acid. The physical and chemical formula of the lithium ion battery lithium supplement additive copper acid is Li 2 CuO 2 .

[0049] Example 4

[0050] A method for preparing a lithium-ion battery lithium supplement additive comprises the following steps:

[0051] S1. Dissolve lithium hydroxide and copper oxide in 15 mL of deionized water at a molar ratio of 2:1 to obtain a mixed solution.

[0052] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 4 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0053] S3. Place the slurry in an oven and dry it at 80°C to remove excess water to obtain a mixed powder.

[0054] S4. Grind the mixed powder and then use a tablet press to press it into a round tablet body with a diameter of 1.2 cm and a thickness of 2 mm.

[0055] S5, placing the disc embryo body in a graphite crucible, and putting them together in a microwave generator for microwave reaction, the microwave reaction frequency is 2450MHz, the power is 1800W, the reaction time is 60min, after the reaction is finished, taking out the microwaved disc and grinding and collecting it to obtain the copper acid as a lithium supplement additive for lithium ion batteries, the physical and chemical formula of the copper acid as a lithium supplement additive for lithium ion batteries is Li 2 CuO 2 .

[0056] Example 5

[0057] A method for preparing a lithium-ion battery lithium supplement additive comprises the following steps:

[0058] S1: Lithium hydroxide and copper oxide were dissolved in 15 mL of deionized water at a molar ratio of 2.1:1 to obtain a mixed solution.

[0059] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 3 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0060] S3. Place the slurry in an oven and dry it at 80°C to remove excess water to obtain a mixed powder.

[0061] S4. Grind the mixed powder and then use a tablet press to press it into a round tablet body with a diameter of 1.2 cm and a thickness of 2 mm.

[0062] S5, placing the disc embryo body in a graphite crucible, and putting them together in a microwave generator for microwave reaction, the microwave reaction frequency is 2450MHz, the power is 1800W, the reaction time is 80min, after the reaction is finished, taking out the microwaved disc and grinding and collecting it to obtain the copper acid as a lithium supplement additive for lithium ion batteries, the physical and chemical formula of the copper acid as a lithium supplement additive for lithium ion batteries is Li 2 CuO 2 .

[0063] Example 6

[0064] A method for preparing a lithium-ion battery lithium supplement additive comprises the following steps:

[0065] S1. Dissolve lithium hydroxide and copper oxide in 30 mL of deionized water at a molar ratio of 2.2:1 to obtain a mixed solution.

[0066] S2. The mixed solution is placed in a nano ball mill and ball milled at a speed of 400 r / min for 4 hours. The purpose is to fully grind it so that the lithium hydroxide and copper oxide are fully mixed and contacted. In addition, the particle size of each source can be effectively refined to obtain a slurry.

[0067] S3. Place the slurry in an oven and dry it at 80°C to remove excess water to obtain a mixed powder.

[0068] S4. Grind the mixed powder and then use a tablet press to press it into a round tablet body with a diameter of 1.2 cm and a thickness of 2 mm.

[0069] S5, placing the disc embryo body in a graphite crucible, and putting them together in a microwave generator for microwave reaction, the microwave reaction frequency is 2450MHz, the power is 1800W, the reaction time is 120min, after the reaction is finished, taking out the microwaved disc and grinding and collecting it to obtain the lithium ion battery lithium supplement additive copper acid, the lithium ion battery lithium supplement additive copper acid physical and chemical formula is Li 2 CuO 2 .

[0070] The lithium-ion battery lithium supplement additive Li prepared in Examples 1 to 6 2 CuO 2 The structure and morphology were tested and the results are as follows.

[0071] Figure 1 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 1 of the present invention. Figure 2 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 2 of the present invention. Figure 3 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 3 of the present invention. Figure 4 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 4 of the present invention. Figure 5 This is a morphology and structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 5 of the present invention. Figure 6 This is a morphology structure diagram of the lithium-ion battery lithium supplement additive prepared in Example 6 of the present invention. Figure 1 to Figure 6 As shown, the lithium-ion battery lithium supplement additive Li prepared by the present invention 2 CuO 2 Without damaging the main structure of the material, the particle size range of the lithium-ion battery lithium supplement additive is 1μm to 100μm, which can effectively reduce the particle size of the material and improve the agglomeration and large particles during the pulping and coating process.

[0072] Figure 7This is the X-ray diffraction pattern of the lithium-ion battery lithium supplement additive prepared in Example 1 of the present invention. Figure 7 As shown, compared with Li 2 CuO 2 Standard card PDF-20-0623, it can be seen that the main peak and the secondary peak correspond well, indicating that the main phase has been successfully synthesized and no obvious impurities are generated.

[0073] The lithium ion battery lithium supplement additives prepared in Examples 1 to 6 are applied to lithium ion batteries, specifically comprising the following steps:

[0074] The CR2025 button cell was tested in the Xinwei battery test system. The detailed assembly process of the CR2025 button cell is as follows:

[0075] Step 1: Use N-methylpyrrolidone to dissolve polyvinylidene fluoride. Wait until the polyvinylidene fluoride is completely dissolved, about 12 hours, until there are no bubbles.

[0076] Step 2, according to the existing conventional method, the mass ratio of positive electrode active material: polyvinylidene fluoride: acetylene black, such as the mass ratio of positive electrode active material: polyvinylidene fluoride: acetylene black is 80:5:15, the positive electrode active material and acetylene black are weighed and put into a mixing bottle, and placed on a magnetic stirrer and stirred for 90 minutes, until the slurry is uniformly viscous and has a certain fluidity, to obtain a slurry.

[0077] Step 3: Use an electric coating machine to coat the uniform, viscous and fluid slurry on a clean and flat current collector, which is a copper foil. Transfer the current collector coated with the slurry to a 60°C forced air drying oven for drying for about 10 hours. After the N-methylpyrrolidone evaporates completely, place the current collector in a 120°C forced air drying oven and continue drying under vacuum for about 10 hours.

[0078] Step 4: Roll the dried current collector using an electric roller press to make the contact between the active electrode material and the current collector more firm.

[0079] Step 5: Use a manual punching machine to cut the dried current collector into circular electrode sheets of a certain size. The diameter of the circular electrode sheets is 12 mm. Accurately weigh each electrode sheet and place the weighed electrode sheets in a glove box for later use.

[0080] Step 6, using lithium metal Li or graphite Gr as the counter electrode, assemble in a glove box filled with an inert atmosphere in the order of positive electrode shell, positive electrode sheet, electrolyte, diaphragm, electrolyte, negative electrode, spring sheet, and negative electrode shell, where the negative electrode is a gasket + lithium sheet, and after packaging with a battery sealing machine, a CR2025 button battery is obtained.

[0081] Among them, one way of applying the lithium supplement additive for lithium ion batteries is: the lithium supplement additive prepared in Example 1 is mixed and coated on the positive electrode side separator, wherein the amount of the lithium supplement additive for lithium ion batteries is 5wt.% of the lithium iron phosphate positive electrode material, and additional lithium is released during the first cycle formation process of the positive electrode material to achieve the lithium supplement effect. Performance tests were carried out, and the specific results are as follows:

[0082] Figure 8 For the present invention 2 CuO 2 The first round of lithium extraction capacity diagram. Figure 8 As shown, a specific capacity of 360 mAh / g can be clearly observed, indicating that it has the potential to be a lithium supplement with high specific capacity.

[0083] Another method of applying the lithium-ion battery lithium supplement additive is as follows: the positive electrode sheet in the CR2025 button battery is prepared by mixing the lithium-ion battery lithium supplement additive prepared in Example 1 with the lithium iron phosphate positive electrode material to obtain LFP+Li 2 CuO 2 Composite electrode sheet, lithium-ion battery lithium supplement additive dosage is 5wt.% of positive electrode material to achieve lithium supplement effect. Named LFP@Li 2 CuO 2 ||Li full battery or LFP@Li 2 CuO 2 ||Gr full battery, and without adding Li 2 CuO 2 As a comparison, the electrode sheet with Li 2 CuO 2 The electrode sheet is named LFP||Gr. The full battery is tested for performance. The specific results are as follows:

[0084] Fig. 9 The LFP@Li 2 CuO 2 The first round of lithium extraction capacity diagram. Fig. 9 As shown, the positive electrode lithium replenisher is added to the lithium iron phosphate positive electrode material. The amount of the lithium replenisher additive for the lithium-ion battery is 5wt.% of the lithium iron phosphate positive electrode material. It can be seen that there is a charging specific capacity close to 180mAh / g, that is, there is additional lithium release, indicating that it has a certain lithium replenishment ability.

[0085] Fig.10 The LFP@Li 2 CuO 2 ||Gr full battery charge and discharge diagram. Fig.10As shown, the positive electrode lithium replenisher is added to the lithium iron phosphate positive electrode material in a certain proportion. The amount of the lithium replenisher additive for the lithium ion battery is 5wt.% of the lithium iron phosphate positive electrode material. SEI lithium compensation is performed on graphite. Compared with the control group, it can be seen that an additional 10mAh / g specific capacity is released for negative electrode lithium compensation.

[0086] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a lithium-ion battery lithium supplement additive, characterized in that: The following steps are involved: dissolving a soluble lithium source and a soluble copper source in a solvent to obtain a mixed solution; The mixed solution is ball-milled to form reactants, and the reactants are subjected to microwave reaction. Vibration and rotation of the reactant molecules are induced by microwave radiation, so as to increase the reaction activity and reaction speed, and obtain lithium cuprate, a lithium supplement additive for lithium-ion batteries.

2. The method for preparing the lithium-ion battery lithium supplement additive according to claim 1, characterized in that: The frequency of the microwave reaction is 2450 MHz, the power is 1800 W, and the time is 30 min to 120 min.

3. The method for preparing the lithium-ion battery lithium supplement additive according to claim 2, characterized in that: The mixed solution is ball-milled, the solvent is removed, and then an embryo is obtained by pressing. The embryo is subjected to microwave reaction to obtain lithium cuprate, a lithium supplement additive for lithium-ion batteries.

4. The method for preparing the lithium-ion battery lithium supplement additive according to claim 1, characterized in that: The molar ratio of the soluble lithium source to the soluble copper source is 2 to 2.2:

1.

5. The method for preparing the lithium-ion battery lithium supplement additive according to claim 1, characterized in that: The soluble lithium source is at least one of lithium hydroxide, lithium carbonate, lithium sulfate, lithium bicarbonate, lithium oxide, lithium oxalate, lithium chloride, lithium acetate, lithium perchlorate, lithium iodide, lithium bromide, lithium dihydrogen phosphate, lithium borate, lithium fluoride, and lithium aluminate.

6. The method for preparing the lithium-ion battery lithium supplement additive according to claim 1, characterized in that: The soluble copper source is at least one of copper oxide, copper sulfate, copper nitrate, copper chloride, copper acetate, copper bromide, copper iodide, basic copper carbonate, copper phosphate, copper lactate and copper oxalate.

7. The method for preparing the lithium-ion battery lithium supplement additive according to claim 1, characterized in that: The ball milling speed is 350r / min~450r / min, and the time is 2h~4h.

8. The method for preparing the lithium-ion battery lithium supplement additive according to claim 3, characterized in that: The thickness of the embryo is 1 mm to 3 mm, and the diameter is 1.0 cm to 1.5 cm.

9. A lithium-ion battery lithium-supplement additive prepared by the method for preparing a lithium-ion battery lithium-supplement additive according to any one of claims 1 to 8, characterized in that: The lithium cuprate as the lithium supplement additive for the lithium ion battery is Li2CuO2 or LiCuO2.

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