Multi-strategy synergistic in-situ constructed gel electrolyte-binder system for high-performance lithium-ion batteries with Si-based anode

Silicon-based material have been considered as the most competitive candidate for next-generation anode in lithium-ion batteries (LIBs) due to its high specific energy density, natural abundance and attractive operating voltage. However, silicon-based anodes generally undergo significant volume changes and structural collapse during cycling, resulting in limited battery lifespan. Herein, a multi-strategy optimized in-situ gel electrolyte-binder system (GEBS) is rationally constructed, and electrochemical performances of the LIBs with Silicon-Graphite (Si-Gr) anodes are systematically evaluated by half-cell and full-cells. The in-situ generated polymer skeleton and improved interfacial compatibility of the GEBS effectively preserve the electrode structural integrity. Compared with the commercial liquid electrolyte, the volume change of the anode cycled with GEBS is suppressed from 208 % to 126 %. Benefiting from these merits, the full-cell with LiFePO4 cathode displays stable cycling stability with the capacity retention of 96.8 % after 260 cycles. Besides, the reversible capacity of the LiNi0.6Co0.2Mn0.2O2║Si-Gr full-cell is as high as 121.7 mAh g−1 after 200 cycles (capacity retention of 85.1 %), and the GEBS also exhibits obvious dominance at 55°C. This contribution effectively integrates multiple optimization strategies for Si-based anode and provides a feasible solution to address the challenge of its practical application in LIBs.