1. The reason why black color appears on the surface of disassembled lithium battery pole pieces
The reason why the surface of the disassembled lithium battery pole pieces appears black may be due to the following reasons:
1. SEI film formation: On the surface of the negative electrode of a lithium-ion battery, a film called the Solid Electrolyte Interphase (SEI) will be formed. This film is produced by the decomposition of the electrolyte and can protect the negative electrode material from direct contact with the electrolyte and prevent the solvents and salts in the electrolyte from reacting with the negative electrode. This membrane may appear black.
2. Decomposition of the electrolyte: The solvents and salts in the electrolyte react with the negative electrode material to produce some by-products, which may appear black.
3. Lithium aggregation: During the cycle of lithium-ion batteries, lithium ions will accumulate on the surface of the negative electrode to form lithium metal. These lithium metals may react on the surface to form a black substance.
2. The impact of the production of this black substance on lithium batteries
1. Battery capacity loss: The formation of black matter may reduce the number of available lithium ions in the battery, thereby reducing the battery’s capacity.
2. Reduced cycle performance: The generation of black matter will increase the internal resistance of the battery, reduce the cycle performance, and shorten the life of the battery.
3. Measures taken to prevent the generation of black matter
1. Optimize battery design: Changing the structure and materials of the battery, such as using coating materials or additives, can improve the cycle performance of the battery and reduce the generation of black matter.
2. Control battery operating conditions: Controlling the charge and discharge rate and temperature of the battery, as well as using the appropriate electrolyte composition, can reduce the generation of black matter.
3. Choose high-quality battery materials: Choosing high-quality battery materials and electrolytes can reduce the generation of by-products.
4. Do a good job in battery maintenance: Check and maintain the battery regularly, and promptly deal with the black matter on the battery surface to maintain battery performance and life.
It should be noted that disassembling lithium batteries is a dangerous operation and should be performed by professionals in an appropriate environment. At the same time, be sure to follow safe operating procedures when handling batteries or battery materials to avoid accidents.
