Preparation method of lithium battery positive electrode lithium supplement additive
By using organic small molecule catechol and its derivatives to synthesize lithium supplementary materials in the positive electrode of lithium battery, the problems of complex preparation and residual effects in the prior art are solved, and the high stability and long life of lithium batteries are achieved.
Patent Information
- Application Number
- CN202211045765.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-30
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2042-08-30
AI Technical Summary
The preparation technology of existing lithium battery positive electrode lithium supplement additives is complex and requires multiple high-temperature roasting, resulting in the residue affecting the service life, and gas production of lithium ferrate during delitting of lithium ferrate affects the charging and discharge stability.
The positive electrode lithium supplement material is synthesized under relatively mild conditions by using organic small molecule catechol and its derivatives. By fully mixing and dissolving the organic lithium salt and hydroxybenzene compound, and adding lithium hydride and other substances, the positive electrode lithium supplement additive of lithium battery is obtained after sufficient reaction and drying.
Effectively compensate for the loss of active lithium in the first round of charging and discharging of lithium batteries, form a good interface layer of positive electrode and negative electrode, improve the stability of the positive electrode and the service life of the battery, improve high-voltage stability and electrochemical stability, and ensure the safe and stable operation of the lithium battery.
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Figure CN115395114B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a technology in the field of lithium battery manufacturing, and specifically to a method for preparing a lithium battery positive electrode lithium supplement additive. Background Art
[0002] Silicon anode has a high theoretical specific capacity (>4000mA·h / g) and has attracted attention from all over the world. However, its large first irreversible capacity loss consumes a large amount of lithium ions released from the electrolyte and positive electrode materials, resulting in lower charge and discharge efficiency, discharge specific capacity and poor stability, reducing the energy density and cycle life of the battery. Positive electrode pre-lithiation technology provides an effective solution to solve the irreversible capacity loss and improve the coulombic efficiency. Summary of the invention
[0003] The present invention aims at the fact that the preparation technology of the existing related positive electrode lithium replenishing additives in the prior art is relatively complicated. For example, the production process of lithium nickelate and lithium ferrite needs to undergo repeated high-temperature roasting for many times, and after mixing with the positive electrode to prepare lithium replenishment, there will be a lot of residues left in the positive electrode, thereby affecting the service life of the positive electrode. In addition, lithium ferrite will also produce gas during the delithiation process, affecting the normal charging and discharging of the battery. A preparation method of a lithium battery positive electrode lithium replenishing additive is proposed. Organic small molecule catechol and its derivatives can be used to synthesize positive electrode lithium replenishing materials under relatively mild conditions, effectively compensate for the loss of active lithium in the first cycle of charging and discharging of the lithium battery, form a good positive and negative electrode interface layer inside the battery, no residue in the positive electrode after lithium replenishment, and greatly improve the stability of the positive electrode and the service life of the battery, comprehensively improve the high-voltage stability of the lithium ion battery positive electrode and the electrochemical stability of the electrolyte, and ensure the safe and stable operation of the lithium battery.
[0004] The present invention is achieved through the following technical solutions:
[0005] The invention relates to a method for preparing a lithium battery positive electrode lithium supplement additive. The method comprises the following steps: fully mixing and dissolving an organic lithium salt and a hydroxybenzene compound in a solvent, further adding lithium hydride, naphthyl lithium / tetrahydrofuran dispersion, lithium metal, lithium hydroxide or lithium carbonate, and after sufficient reaction, filtering the reaction solution and drying to obtain the lithium battery positive electrode lithium supplement additive.
[0006] The organic lithium salt is lithium trifluoromethylsulfonate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorooxalatoborate), lithium 5-sulfo-1,3-phthalate monolithium, lithium tetrafluoroborate or a combination thereof.
[0007] The hydroxybenzene compound is catechol, 3,4-p-hydroxybenzaldehyde, 3,4-p-hydroxybenzoic acid, 3,4-p-hydroxybenzonitrile, 2-fluoro-4-hydroxybenzonitrile, 4-fluoro-1,2-benzene, 3,4,5-trihydroxybenzaldehyde or a combination thereof.
[0008] The fully mixed and dissolved method refers to: taking 30 to 100 mL of tetrahydrofuran, adding 1 to 5 mol of an organic lithium salt and 3 to 15 mol of a hydroxybenzene compound under an inert gas atmosphere, stirring for 10 to 60 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 20 to 60° C., and the high-speed stirring speed is 300 to 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system.
[0009] The concentration of the lithium hydride is 7 to 35 mol.
[0010] The concentration of the naphthyl lithium / tetrahydrofuran dispersion is 0.1-0.2 mol / L.
[0011] The naphthyl lithium / tetrahydrofuran dispersion is prepared by dissolving 0.4-0.8 mol lithium metal and 0.4-0.8 mol naphthalene in 2-4 mol tetrahydrofuran solution under an inert gas atmosphere.
[0012] The concentration of the lithium metal is 7 to 35 mol.
[0013] The concentration of the lithium hydroxide is 7 to 35 mol.
[0014] The concentration of the lithium carbonate is 7 to 35 mol lithium carbonate.
[0015] The sufficient reaction means: adding lithium hydride, naphthyl lithium / tetrahydrofuran dispersion, lithium metal, lithium hydroxide or lithium carbonate and stirring at a speed of 300 to 900 r / min at a reaction temperature of 20 to 60° C. until the reaction is complete.
[0016] The drying is preferably performed at 100-150°C.
[0017] The lithium battery positive electrode lithium supplement additive has an electrochemical window greater than 4.5V and can provide additional capacity during the first charging process of the lithium battery.
[0018] The lithium battery is obtained by assembling the above-mentioned lithium battery positive electrode lithium supplement additive, lithium iron phosphate positive electrode material, ternary lithium nickel cobalt manganese positive electrode material, and lithium cobalt oxide positive electrode material. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 and Figure 2 It is a schematic diagram of the effect of the embodiment. DETAILED DESCRIPTION
[0020] Example 1
[0021] This embodiment includes the following steps:
[0022] Step 1: Under an inert gas atmosphere, take 3000 mL of tetrahydrofuran, add 1 mol of lithium trifluoromethanesulfonate and 3 mol of 3,4-p-hydroxybenzaldehyde, stir for 10 min to dissolve, the dissolution temperature is 20°C, and the high-speed stirring speed is 300 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0023] Step 2: Under an inert gas atmosphere, add 7 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 20° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0024] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0025]
[0026] like Figure 1 As shown, through Figure 1 It can be seen that the prepared lithium-supplementing material exhibits a specific capacity of 360 mAh / g during the first cycle of charging, while the discharge capacity is almost 0, demonstrating its good pre-lithiation ability.
[0027] like Figure 2 As shown, the prepared lithium supplement material is compounded with the lithium iron phosphate positive electrode, and the battery exhibits a higher discharge specific capacity and stable performance during the charge and discharge cycle process.
[0028] Example 2
[0029] This embodiment includes the following steps:
[0030] Step 1: Under an inert gas atmosphere, take 10000 mL of tetrahydrofuran, add 5 mol of lithium trifluoromethanesulfonate and 15 mol of 3,4-p-hydroxybenzaldehyde, stir for 60 min to dissolve, the dissolution temperature of the hydroxybenzene compound is 40° C., and the high-speed stirring speed is 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0031] Step 2: Under an inert gas atmosphere, 0.8 mol of lithium metal and 0.8 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0032] Step 3: Under an inert gas atmosphere, add 40 mol of 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 40° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0033] Step 4: After the reaction is fully completed, the reaction solution is taken out and filtered to obtain the target product containing the solvent, and then dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0034]
[0035] Example 3
[0036] This embodiment includes the following steps:
[0037] Step 1: Under an inert gas atmosphere, take 3000 mL of tetrahydrofuran, add 1 mol of lithium tetrafluoroborate and 3 mol of 3,4-p-hydroxybenzoic acid, stir for 10 min to dissolve, the dissolution temperature is 20°C, and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0038] Step 2: Under an inert gas atmosphere, add 7 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 20° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0039] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0040]
[0041]
[0042] Example 4
[0043] This embodiment includes the following steps:
[0044] Step 1: Under an inert gas atmosphere, take 10000 mL of tetrahydrofuran, add 5 mol of lithium tetrafluoroborate and 15 mol of 3,4-p-hydroxybenzoic acid, stir for 60 min to dissolve, the dissolution temperature of the hydroxybenzene compound is 40° C., and the high-speed stirring speed is 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0045] Step 2: Under an inert gas atmosphere, 0.8 mol of lithium metal and 0.8 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0046] Step 3: Under an inert gas atmosphere, add 40 mol of 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 40° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0047] Step 4: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0048]
[0049] Example 5
[0050] This embodiment includes the following steps:
[0051] Step 1: Under an inert gas atmosphere, take 3000 mL of tetrahydrofuran, add 1 mol of lithium bis(trifluoromethylsulfonyl)imide and 3 mol of 3,4-p-hydroxybenzaldehyde, stir for 10 min to dissolve, the dissolution temperature is 20° C., and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0052] Step 2: Under an inert gas atmosphere, add 7 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 20° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0053] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0054]
[0055]
[0056] Example 6
[0057] This embodiment includes the following steps:
[0058] Step 1: Under an inert gas atmosphere, take 10000 mL of tetrahydrofuran, add 5 mol of lithium bis(trifluoromethylsulfonyl)imide and 15 mol of 3,4-p-hydroxybenzaldehyde, stir for 60 min to dissolve, the dissolution temperature of the hydroxybenzene compound is 40° C., and the high-speed stirring speed is 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0059] Step 2: Under an inert gas atmosphere, 0.8 mol of lithium metal and 0.8 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0060] Step 3: Under an inert gas atmosphere, add 40 mol of 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 40° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0061] Step 4: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0062]
[0063] Example 7
[0064] This embodiment includes the following steps:
[0065] Step 1: Under an inert gas atmosphere, take 3000 mL of tetrahydrofuran, add 1 mol of lithium bis(trifluoromethylsulfonyl)imide and 3 mol of 3,4-p-hydroxybenzoic acid, stir for 10 min to dissolve, the dissolution temperature is 20° C., and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0066] Step 2: Under an inert gas atmosphere, add 7 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 20° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0067] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0068]
[0069] Example 8
[0070] This embodiment includes the following steps:
[0071] Step 1: Under an inert gas atmosphere, take 10000 mL of tetrahydrofuran, add 5 mol of lithium bis(trifluoromethylsulfonyl)imide and 15 mol of 3,4-p-hydroxybenzoic acid, stir for 60 min to dissolve, the dissolution temperature of the hydroxybenzene compound is 40° C., and the high-speed stirring speed is 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0072] Step 2: Under an inert gas atmosphere, 0.8 mol of lithium metal and 0.8 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0073] Step 3: Under an inert gas atmosphere, add 40 mol of 0.2 mol naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 40° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0074] Step 4: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0075]
[0076] Example 9
[0077] This embodiment includes the following steps:
[0078] Step 1: Under an inert gas atmosphere, take 3000 mL of tetrahydrofuran, add 1 mol of lithium bis(trifluoromethylsulfonyl)imide and 3 mol of 3,4-p-hydroxybenzonitrile, stir for 10 min to dissolve, the dissolution temperature is 20° C., and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0079] Step 2: Under an inert gas atmosphere, add 7 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 20° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0080] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0081]
[0082] Example 10
[0083] This embodiment includes the following steps:
[0084] Step 1: Under an inert gas atmosphere, take 10000 mL of tetrahydrofuran, add 5 mol of lithium bis(trifluoromethylsulfonyl)imide and 15 mol of 3,4-p-hydroxybenzonitrile, stir for 60 min to dissolve, the dissolution temperature of the hydroxybenzene compound is 40° C., and the high-speed stirring speed is 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0085] Step 2: Under an inert gas atmosphere, 0.8 mol of lithium metal and 0.8 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.2 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0086] Step 3: Under an inert gas atmosphere, add 40 mol of 0.2 mol naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 40° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0087] Step 4: After the reaction is fully completed, the reaction solution is taken out and filtered to obtain the target product containing the solvent, and then dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0088]
[0089] Embodiment 11
[0090] This embodiment includes the following steps:
[0091] Step 1: Under an inert gas atmosphere, take 5000 mL of tetrahydrofuran, add 2 mol of lithium bis(fluorosulfonyl)imide and 5 mol of 2-fluoro-4-hydroxybenzonitrile, stir for 30 min to dissolve, the dissolution temperature is 20° C., and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0092] Step 2: Under an inert gas atmosphere, add 15 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 500 r / min to allow sufficient reaction.
[0093] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0094]
[0095] Example 12
[0096] This embodiment includes the following steps:
[0097] Step 1: Under an inert gas atmosphere, take 7000 mL of tetrahydrofuran, add 4 mol of lithium bis(fluorosulfonyl)imide and 10 mol of 2-fluoro-4-hydroxybenzonitrile and stir for 50 min to dissolve. The dissolution temperature of the hydroxybenzene compound is 30° C. and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system.
[0098] Step 2: Under an inert gas atmosphere, 0.6 mol of lithium metal and 0.6 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.1 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0099] Step 3: Under an inert gas atmosphere, add 30 mol of 0.1 mol naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithiation reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0100] Step 4: After the reaction is fully completed, the reaction solution is taken out and filtered to obtain the target product containing the solvent, and then dried at 145° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0101]
[0102] Embodiment 13
[0103] This embodiment includes the following steps:
[0104] Step 1: Under an inert gas atmosphere, take 5000 mL of tetrahydrofuran, add 2 mol of 5-sulfo-1,3-phthalic acid monolithium and 5 mol of 4-fluoro-1,2-benzenediol, stir for 30 minutes to dissolve, the dissolution temperature is 20°C, and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0105] Step 2: Under an inert gas atmosphere, add 15 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 500 r / min to allow sufficient reaction.
[0106] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0107]
[0108] Embodiment 14
[0109] This embodiment includes the following steps:
[0110] Step 1: Under an inert gas atmosphere, take 7000 mL of tetrahydrofuran, add 4 mol of lithium difluorooxalate borate and 10 mol of 3,4,5-trihydroxybenzaldehyde, stir for 50 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 30° C., and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0111] Step 2: Under an inert gas atmosphere, 0.6 mol of lithium metal and 0.6 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.1 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0112] Step 3: Under an inert gas atmosphere, add 30 mol of 0.1 mol / L naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0113] Step 4: After the reaction is fully completed, the reaction solution is taken out and filtered to obtain the target product containing the solvent, and then dried at 145° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0114]
[0115] Embodiment 15
[0116] This embodiment includes the following steps:
[0117] Step 1: Under an inert gas atmosphere, take 5000 mL of tetrahydrofuran, add 2 mol of 5-sulfo-1,3-phthalic acid monolithium and 5 mol of 4-fluoro-1,2-benzenediol, stir for 30 minutes to dissolve, the dissolution temperature is 20°C, and the high-speed stirring speed is 300-900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0118] Step 2: Under an inert gas atmosphere, add 15 mol of lithium hydride to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 500 r / min to allow sufficient reaction.
[0119] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 150° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0120]
[0121] Example 16
[0122] This embodiment includes the following steps:
[0123] Step 1: Under an inert gas atmosphere, take 7000 mL of tetrahydrofuran, add 4 mol of 5-sulfo-1,3-phthalic acid monolithium and 10 mol of 4-fluoro-1,2-benzenediol, stir for 50 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 30° C., and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0124] Step 2: Under an inert gas atmosphere, 0.6 mol of lithium metal and 0.6 mol of naphthalene are dissolved in 4 mol of tetrahydrofuran solution to prepare a 0.1 mol / L naphthyl lithium / tetrahydrofuran dispersion;
[0125] Step 3: Under an inert gas atmosphere, add 30 mol of 0.1 mol / L naphthyl lithium / tetrahydrofuran dispersion to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0126] Step 4: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 100° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0127]
[0128] Embodiment 17
[0129] This embodiment includes the following steps:
[0130] Step 1: Under an inert gas atmosphere, take 7000 mL of tetrahydrofuran, add 4 mol of 5-sulfo-1,3-phthalic acid monolithium and 10 mol of catechol, stir for 50 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 30°C, and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0131] Step 2: Under an inert gas atmosphere, add 10 mol of lithium carbonate powder to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithium reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0132] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 145° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0133]
[0134] Embodiment 18
[0135] This embodiment includes the following steps:
[0136] Step 1: Under an inert gas atmosphere, take 9000 mL of tetrahydrofuran, add 4 mol of 5-sulfo-1,3-phthalic acid monolithium and 10 mol of catechol, stir for 50 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 30°C, and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0137] Step 2: Under an inert gas atmosphere, add 10 mol of lithium hydroxide powder to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithiation reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0138] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 130° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0139]
[0140] Embodiment 19
[0141] This embodiment includes the following steps:
[0142] Step 1: Under an inert gas atmosphere, take 7000 mL of tetrahydrofuran, add 4 mol of 5-sulfo-1,3-phthalic acid monolithium and 10 mol of catechol, stir for 50 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 30°C, and the high-speed stirring speed is 800 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system;
[0143] Step 2: Under an inert gas atmosphere, add 10 mol of metallic lithium powder to the solution in step 1, and stir at high speed to allow the solution system in step 1 to react rapidly with the lithiation reagent. The reaction temperature is 30° C. and the stirring speed is 900 r / min to allow sufficient reaction.
[0144] Step 3: After the reaction is fully completed, the reaction solution is taken out, filtered to obtain the target product containing the solvent, and dried at 120° C. under an inert gas atmosphere to obtain the target positive electrode lithium supplement additive.
[0145] Under the specific environment setting of a normal chemical laboratory, the experimental data obtained through the above embodiment are as follows:
[0146]
[0147]
[0148] Compared with the prior art, the present invention adopts organic small molecule catechol and its derivatives to synthesize positive electrode lithium replenishing materials under relatively mild conditions, with low synthesis cost, easy to obtain products, good compatibility of positive electrode lithium replenishing additives with positive electrode, no residue after lithium replenishment and improved stability of positive electrode and service life of battery.
[0149] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.
Claims
1. A method for preparing a lithium battery positive electrode lithium supplement additive, characterized in that: After the organic lithium salt and the hydroxybenzene compound are fully mixed and dissolved in a solvent, lithium hydride, naphthyl lithium / tetrahydrofuran dispersion, lithium metal, lithium hydroxide or lithium carbonate are further added, and after sufficient reaction, the reaction solution is filtered and dried to obtain a lithium battery positive electrode lithium supplement additive; The organic lithium salt is lithium trifluoromethylsulfonate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(trifluoromethylsulfonyl)borate, lithium bis(fluorooxalato)borate, lithium 5-sulfo-1,3-phthalate, lithium tetrafluoroborate or a combination thereof; The hydroxybenzene compound is catechol, 3,4-p-hydroxybenzaldehyde, 3,4-p-hydroxybenzoic acid, 3,4-p-hydroxybenzonitrile, 2-fluoro-4-hydroxybenzonitrile, 4-fluoro-1,2-benzene, 3,4,5-trihydroxybenzaldehyde or a combination thereof.
2. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The fully mixed and dissolved method refers to: taking 30 to 100 mL of tetrahydrofuran, adding 1 to 5 mol of an organic lithium salt and 3 to 15 mol of a hydroxybenzene compound under an inert gas atmosphere, stirring for 10 to 60 minutes to dissolve, the dissolution temperature of the hydroxybenzene compound is 20 to 60° C., and the high-speed stirring speed is 300 to 900 r / min, so that the lithium salt and the hydroxybenzene compound are fully dissolved to form a uniform solution system.
3. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The concentration of the lithium hydride is 7-35 mol / L.
4. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The naphthyl lithium / tetrahydrofuran dispersion has a concentration of 0.1-0.2 mol / L and is prepared by dissolving 0.4-0.8 mol lithium metal and 0.4-0.8 mol naphthalene in 2-4 mol tetrahydrofuran solution under an inert gas atmosphere.
5. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The concentration of the lithium metal is 7 to 35 mol / L.
6. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The concentration of the lithium hydroxide is 7-35 mol / L.
7. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The concentration of the lithium carbonate is 7-35 mol / L.
8. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The sufficient reaction means: adding lithium hydride, naphthyl lithium / tetrahydrofuran dispersion, lithium metal, lithium hydroxide or lithium carbonate and stirring at a speed of 300 to 900 r / min at a reaction temperature of 20 to 60° C. until the reaction is complete.
9. The method for preparing the lithium battery positive electrode lithium supplement additive according to claim 1, characterized in that: The lithium battery is obtained by assembling the prepared lithium battery positive electrode lithium supplement additive with lithium iron phosphate positive electrode material, ternary lithium nickel cobalt manganese positive electrode material, and lithium cobalt oxide positive electrode material.