What are the reasons for the low first efficiency of lithium graphite anode?

1. Low Specific Surface Area (SSA): As you have mentioned, the specific surface area of waste graphite is usually low, which leads to a reduction in the contact area between the electrolyte and the graphite, affecting ion insertion and de-embedding during the first charge/discharge process, and thus lowering the first Coulombic Efficiency (FCE). Compaction and coating treatment can improve the specific surface area, but the effect may be limited, the more fundamental method is to choose a more suitable graphite source or improve the pretreatment method.
2. High impurities and defects: Waste graphite may contain certain impurities and structural defects, which may adversely affect carrier migration and charge transfer and reduce battery performance. This can be improved by purifying the graphite and optimizing the modification method.
3. Uneven distribution of graphite particle size: The specific surface area and structure of graphite with different particle sizes are different, which makes the electrolyte contact with different graphite particles differently and affects the overall performance of the battery. Optimize the powder molding process or in the subsequent addition of processing to improve the uniformity of particle size.
4. Dust pollution is serious: dust pollution graphite in the production process will have an impact on its electrochemical performance, must be strictly controlled.
5. Formulation and process need to be optimized: the formula you provide is a typical reference formula, the actual should be optimized according to the specific graphite properties and requirements. The key point is to control the amount and proportion of conductive agent and binder. Process control is also very important.

In short, to improve the efficiency of the first Coulomb is the most critical from the source to solve the problem of graphite quality and performance. My suggestion is to choose high quality waste graphite source, and then through strict pretreatment, purification and modification methods to improve its specific surface area, reduce impurities and optimize its structure, and through the scientific formulation and process design to produce stable and consistent performance of the product.