Lithium supplement material and preparation method thereof
The lithium quaternary acid material with high electrochemical activity prepared by spray drying solves the problem of low electrochemical activity of lithium quaternary acid material, achieves the improvement of lithium battery capacity, and provides an efficient and simple synthesis method suitable for industrial applications. .
Patent Information
- Application Number
- CN202311019341.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-14
- Publication Date
- 2025-02-21
AI Technical Summary
The low electrochemical activity of lithium quaternary acid material and lacks efficient and simple synthesis methods, limiting its industrial application in lithium batteries.
The spray drying method is used to mix the cubic acid and the lithium source in a solvent, and a lithium cuminic acid material with high electrochemical activity is prepared by this method. The process is simple and efficient, and can produce active materials of nano-scale particles, and further enhance the electrochemical activity of the materials by adding conductive agents or catalysts.
The lithium platinum material prepared by spray drying exhibits a high specific capacity under charging and discharging conditions, which can effectively improve the capacity of lithium batteries, and the efficiency and simplicity of the material make it suitable for industrial production.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new energy materials, and in particular to a lithium supplement material and a preparation method thereof. Background Art
[0002] When lithium-ion batteries are charged for the first time, a solid electrolyte interface film (SEI film) will be generated on the surface of the negative electrode, consuming a large amount of active lithium and affecting the battery capacity. Currently, lithium replenishment technology can compensate for the loss of active lithium and reduce or offset the irreversible lithium loss caused by the SEI film. Lithium replenishment technology includes two ideas: positive electrode lithium replenishment and negative electrode lithium replenishment. Negative electrode lithium replenishment includes lithium powder replenishment and lithium foil replenishment. Since the lithium source used is relatively active, special equipment is usually required and it is produced in a harsh production environment. Positive electrode lithium replenishment includes positive electrode overlithiation, positive electrode pre-embedded lithium materials and sacrificial lithium salts. The preparation process of positive electrode overlithiation is complex and the production cost is high; pre-lithiation materials will introduce inactive substances when replenishing the lithium source. Sacrificial lithium salts have the ability to replenish the lithium source without introducing impurities that affect the chemical system, making them a very good choice of lithium replenishment materials.
[0003] Sacrificial lithium salt materials include lithium oxalate, lithium squarate and lithium nitride. Lithium oxalate has a high decomposition potential, and lithium nitride has poor stability in the environment. Compared with the two, lithium squarate is a more suitable choice. It has a lower decomposition potential and is relatively stable in the environment. Its specific capacity can reach ~425mAh / g. However, lithium squarate has very low conductivity and ion mobility, and poor electrochemical activity. These shortcomings greatly limit the industrial application of lithium squarate.
[0004] Therefore, developing lithium squarate materials with better electrochemical activity and synthesizing them through simple and efficient methods is an urgent problem to be solved in promoting the industrialization of lithium squarate materials. Summary of the invention
[0005] The main technical problem solved by the present invention is that the electrochemical activity of lithium quartz material is low and there is no efficient and simple synthesis method. The present invention provides a lithium quartz material and a preparation method thereof. The preparation method is a spray drying method, which has a simple and efficient process and can obtain a lithium quartz material with high electrochemical activity, which can be applied to lithium batteries to effectively increase the capacity of the battery.
[0006] The present invention adopts the following technical scheme: in the provided preparation method, firstly, a squaric acid and a lithium source are mixed in a solvent, or a squaric acid, a lithium source and a composite material are mixed in a solvent, and then the mixed solution is spray-dried to obtain a squaric acid lithium material.
[0007] Preferably, the lithium source includes one or more combinations of lithium salts such as lithium oxide, lithium carbonate, lithium hydroxide, and lithium bicarbonate.
[0008] Preferably, the solvent includes one or more combinations of volatile solvents such as water and ethanol.
[0009] Preferably, the composite material includes one or more combinations of a conductive agent or a catalyst.
[0010] Preferably, the conductive agent includes one or more combinations of conductive agents such as carbon black, carbon nanotubes, and graphene.
[0011] Preferably, the molar ratio of the squaric acid to the lithium in the lithium source is 1:1.8-2.2.
[0012] Advantages and beneficial effects: In the present invention, spray drying is a very efficient and simple synthesis method with high production efficiency. The primary particles obtained by spray drying are nanometer-sized and the secondary particles are micrometer-sized. The electrochemical activity of lithium quartz can be effectively improved by adding composite materials such as conductive agents or catalysts. Under the conditions of 2.0-4.4V and charge and discharge at 0.05C, the specific capacity of the lithium quartz material reaches 425mAh / g. By using the lithium quartz material as a lithium supplement additive, the gram capacity of the lithium iron phosphate material is significantly improved, which can effectively improve the capacity of the lithium battery. Specific implementation cases
[0013] Example 1 Dissolve squaric acid and lithium hydroxide in water at a molar ratio of 1:2, and mix a 0.5% carbon nanotube aqueous solution by weight of lithium squaric acid to form a uniform aqueous solution, spray dry the solution to obtain 1-2um lithium squaric acid composite material particles. The gram capacity of the material reaches 423mAh / g. Adding 3% of the material to lithium iron phosphate batteries can increase the gram capacity of lithium iron phosphate from 144mAh / g to 153mAh / g.
[0014] Example 2 Dissolve squaric acid and lithium bicarbonate in water at a molar ratio of 1:2, and mix a 0.3% carbon nanotube aqueous solution by weight of lithium squaric acid to form a uniform aqueous solution, spray dry the solution to obtain 1-2um squaric acid lithium composite material particles. The gram capacity of the material reaches 425mAh / g. Adding 5% of the material to lithium iron phosphate batteries can increase the gram capacity of lithium iron phosphate from 144mAh / g to 158mAh / g.
[0015] Example 3 Dissolve squaric acid and lithium oxide in water at a molar ratio of 1:1, and mix a 0.5% carbon nanotube aqueous solution by weight of lithium squaric acid to form a uniform aqueous solution, spray dry the solution to obtain 1-2um lithium squaric acid composite material particles. The gram capacity of the material reaches 423mAh / g. Adding 5% of the material to lithium iron phosphate batteries can increase the gram capacity of lithium iron phosphate from 144mAh / g to 158mAh / g.
[0016] Example 4 Dissolve squaric acid and lithium carbonate in water at a molar ratio of 1:1, and mix a 0.3% carbon nanotube aqueous solution by weight of lithium squaric acid to form a uniform aqueous solution, spray dry the solution to obtain 1-2um squaric acid lithium composite material particles. The gram capacity of the material reaches 425mAh / g. Adding 3% of the material to lithium iron phosphate batteries can increase the gram capacity of lithium iron phosphate from 144mAh / g to 153mAh / g.
Claims
1. A lithium supplement material and a preparation method thereof, characterized in that: The lithium supplement material is lithium squarate or a composite material containing lithium squarate; the preparation method is: mixing squarate and a lithium source in a solvent, or mixing squarate, a lithium source and a composite material in a solvent, and spray drying the mixed solution to obtain the lithium squarate material.
2. The lithium source according to claim 1, characterized in that It is one or more combinations of lithium salts such as lithium oxide, lithium carbonate, lithium hydroxide, and lithium bicarbonate.
3. The solvent according to claim 1, characterized in that It is one or more combinations of volatile solvents such as water and ethanol.
4. The composite material according to claim 1, characterized in that It is a conductive agent or a catalyst or a combination of one or more.
5. The conductive agent according to claim 4, characterized in that: It is one or more combinations of conductive agents such as carbon black, carbon nanotubes, graphene, etc.
6. The mixture of squaric acid and a lithium source according to claim 1, characterized in that: The molar ratio of the squaric acid to the lithium in the lithium source is 1:1.8-2.2.