Elastic Interfacial Layer Enabled the High-Temperature Performance of Lithium-Ion Batteries via Utilization of Synthetic Fluorosulfate Additive

摘要

The key to producing high-energy Li-ion cells is ensuring the interfacialstability of Si-containing anodes and Ni-rich cathodes. Herein, 4-(allyloxy)phenyl fluorosulfate (APFS), a multi-functional electrolyte additive that formsa mechanical strain-adaptive solid electrolyte interphase (SEI) comprising LiFand polymeric species, and a thermally stable cathode–electrolyte interfacecontaining S-O and S-F species. The radical copolymerization of vinylenecarbonate (VC) with APFS via electrochemical initiation creates a spatiallydeformable polymeric SEI on the SiG-C (30 wt. graphite + 70 wt. SiCcomposite) anode, with large volume changes during cycling. Moreover, theAPFS-promoted interfacial layers reduce Ni dissolution and deposition. Furthermore,APFS deactivates the Lewis acid PF5, thereby inhibiting hydrolysesthat produce unwanted HF. These results indicate that the combined useof VC with APFS allows capacity retentions of 72.5 with a high capacity of143.5 mAh g~（?1） in SiG-C/LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2 full cells after 300 cycles at 45 ℃.