A high-energy-density silicon-carbon battery that does not expand at high temperature

Abstract

The invention relates to the field of battery technology, and discloses a high-temperature non-expanding high-energy-density silicon-carbon battery. The electrolyte solvent includes: EC 20-30%, EMC 55-65%, DMC 5-15%, FEC 3-5% ; Additives include methylene disulfonate, tri(trimethyl) silane borate and vinylene carbonate; silicon carbon battery formation process: 0.01C, 0.02C, 0.05C charging for 28-32min respectively; 0.1C After charging to 3.37V, let it stand for 4-6 hours, and take time to remove the gas; charge to 4.3V at 0.1C, and then perform a capacity division after three days. First, discharge at 0.1C, and then perform two 0.5C charge and discharge capacity calibrations. 4.3V is fully charged; after the first capacity division, the battery is aged, then evacuated, placed at room temperature, and then charged and discharged at 0.5C for a second capacity division. The invention can prevent silicon carbon battery from gas generation and expansion at high temperature.

Description

Technical field [0001] The present invention relates to the technical field of batteries, in particular to a high-energy density silicon carbon battery that does not expand at high temperature. Background technique [0002] As the preferred anode material for the next generation of high-energy density batteries, the silicon-carbon anode material has a higher theoretical capacity than graphite. At the same time, compared with pure silicon anode, the silicon-carbon anode has a small volume expansion, is not easy to powder, and has better cycle performance. . At present, the silicon carbon anode has been used in power batteries as the anode material for high energy density batteries. The performance of silicon carbon batteries is relatively stable at room temperature. At present, the problems of volume expansion and flatulence at room temperature can be solved by using a suitable electrolyte. However, in a high-temperature environment, silicon-carbon batteries are prone to gas pro...

AI Technical Summary

Problems solved by technology

However, in a high-temperature environment, silicon-carbon batteries are prone to gas production, resulting in increased battery volume and battery expansion, which seriously affects the cycle and storage performance of batteries at high temperatures, limiting the large-scale use of silicon-carbon batteries in large power batteries. application

[0003] At present, the conventional method is still to optimize the electrolyte additives alone, focusing on the negative film-forming additives to form a dense and stable SEI film to improve the problem of high-temperature gas production. Adding a certain amount of gas-production inhibitors to the electrolyte can from To a certain extent, the high-temperature performance of the battery is improved, but adding too many additives makes the SEI of the battery too thick and the impedance increases, which not only cannot completely solve the high-temperature gas production of the battery, but also affects the capacity and service life of the battery. Increase the cost of using the battery to a certain extent

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