Contact us now info@csem.ch • www.csem.ch Developing high-performance and safe electrolyte for silicon and lithium metal batteries Sufu Liu, Leonardo Pires Da Veiga, Chengyin Fu, Mohammed Srout, Andrea Ingenito CSEM Sustainable Energy Center, CSEM SA, Switzerland In-situ thermally triggered polymer for silicon battery electrolyte Abstract: Compared with the state-of-the-art graphite anodes, silicon and lithium metal are considered as the most promising alternatives for higher energy density lithium batteries owning to their high theoretical capacity. However, significant challenges such as low coulombic efficiency, short cycle life and safety concern have seriously hindered their practical applications. [1,2] To enable the use of silicon anode, we are developing a polymer electrolyte with self-healing properties to stabilize the electrode interphase and restrain the huge volume change of silicon material. When compared with commercial carbonate liquid electrolyte with or without additives, our designed polymer electrolyte enables the NMC622//Si full cell with improved capacity retention and combustion resistance. Meanwhile, for rechargeable lithium metal batteries, our designed nonflammable electrolyte also enables the LFP//ultra-thin lithium metal (25 µm) with greatly extended cycling life, which delivers more than 88% capacity retention after 400 cycles. Our research paves the way for safer and more efficient lithium-ion batteries with silicon or lithium metal-based anodes, which will help to realize higher energy density and longer-lasting battery technologies. Conclusion and future work • In-situ thermally triggered polymerization is a promising method for fabricating polymer electrolyte with self-healing properties outperforming the commercial carbonate electrolyte. • Electrolyte engineering with aggregate and contact ion pair structures is an effective strategy to develop advanced electrolyte with high Li metal Coulombic efficiency. • Thermally evaporated thin Li metal and advanced electrolyte design could be an effective combination to promote long-term cycling of lithium metal batteries. References: [1] Park et al., Chem. Sci., vol. 14, pp. 9996-10024, (2023). [2] Narayan et al., Adv. Energy Mater. vol. 12, pp. 2102652, (2022). Advanced electrolyte for lithium metal battery • 99.6% Li Coulombic efficiency could be reached in the obtained electrolyte The mechanism diagram of in-situ polymerization of the thermally triggered polymer The structure design of the advance electrolyte for LMBs • Thermally evaporated Li metal with high purity • 88% capacity retention after 400 cycles has achieved when coupling the in-home prepared ultrathin Li anode with commercial LFP cathode 60% Si coin cell exhibits enhanced capacity retention 20% SiOx punch cell indicates stable cycling Building more reliable and performing batteries by embedding sensors and self-healing functionalities to detect degradation and repair damage via advanced Battery Management Systems Methodology • Develop self-healing battery materials and sensing devices. • Validate the triggering mechanisms and degradation detection. • Assess the manufacturing, recycling, and sustainability process and develop the Battery Management System. Consortium