A solid-state lithium-ion battery with micron-sized silicon anode operating free from external pressure

作者：Hui Pan, Lei Wang, Yu Shi, Chuanchao Sheng, Sixie Yang, Ping He, Haoshen Zhou · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-46472-9 · 被引用次数：110 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

Abstract Applying high stack pressure (often up to tens of megapascals) to solid-state Li-ion batteries is primarily done to address the issues of internal voids formation and subsequent Li-ion transport blockage within the solid electrode due to volume changes. Whereas, redundant pressurizing devices lower the energy density of batteries and raise the cost. Herein, a mechanical optimization strategy involving elastic electrolyte is proposed for SSBs operating without external pressurizing, but relying solely on the built-in pressure of cells. We combine soft-rigid dual monomer copolymer with deep eutectic mixture to design an elastic solid electrolyte, which exhibits not only high stretchability and deformation recovery capability but also high room-temperature Li-ion conductivity of 2×10 −3 S cm −1 and nonflammability. The micron-sized Si anode without additional stack pressure, paired with the elastic electrolyte, exhibits exceptional stability for 300 cycles with 90.8% capacity retention. Furthermore, the solid Li/elastic electrolyte/LiFePO 4 battery delivers 143.3 mAh g −1 after 400 cycles. Finally, the micron-sized Si/elastic electrolyte/LiFePO 4 full cell operates stably for 100 cycles in the absence of any additional pressure, maintaining a capacity retention rate of 98.3%. This significantly advances the practical applications of solid-state batteries.