Implantation of Solid Electrolyte Interphase Stabilizer within High-Capacity Silicon Electrode Enabling Enhanced Battery Performance

Abstract

The commercial application of high-capacity silicon (Si) anode in lithium-ion batteries is limited by the marked volume expansion and continuous interface side reactions between the active material and the electrolyte. To address the issues, one popular strategy is to induce functional salt additives to the electrolyte, which could help to construct a robust solid electrolyte interphase (SEI) to resist the undesirable parasitic reactions and fast electrode failure. However, there exists the shortness of the dependency in the solubility of the additive salt and the possible homogeneity of the SEI. In light of this, we propose an innovative method of incorporating an SEI stabilization regent, exemplified by lithium difluorooxalate borate (LiDFOB), in the Si anode. This approach facilitates the effective utilization of the functional SEI stabilizer and impressively enhances the presence of inorganic compounds within the SEI. The resultant stable SEI effectively impedes interfacial side reactions, mitigates substantial expansion/contraction, and promotes the transport of Li + ions. As a result, the Si electrode incorporated with LiDFOB displays superior long cycle life and enhanced rate capability, indicating the advancement of planting LiDFOB in the electrode in promoting the development of advanced high-energy-density lithium-ion batteries.