High-stable nonflammable electrolyte regulated by coordination-number rule for all-climate and safer lithium-ion batteries

Developing non-flammable phosphate ester-based electrolytes is regarded as one of the most promising approaches to establish highly safe LIBs, whereas the poor compatibility with anodes (especially graphite) as well as the narrow temperature adaptability hinders their commercial application. Herein, by introducing a low coordinating number solvent (FEMC) into TFEP-based electrolyte, we successfully construct a high-stable anion-induced ion-solvent-coordinated (AI-ISC) structure based on coordination-number (CN) rule to form nonflammable CN-rule electrolyte(CNRE), which effectively suppresses the undesired reactivity of the solvent molecules toward the graphite anode and Li anode. As convincing evidence, the 5Ah graphite||LiNi0.8Mn0.1Co0.1O2 pouch cell with this nonflammable CNRE exhibits a favorable electrochemical performance and greatly improved safety in contrast to the cell with commercial LiPF6-EC/EMC electrolyte. In addition to the non-flammable characteristic, the pouch cell with the CNRE enables all-climate operation from -40 to +60 degrees C, even exhibiting similar to 80% of its room-temperature capacity at -40 degrees C. Furthermore, the commendable compatibility of this nonflammable electrolyte with Li-metal anode may pave an avenue towards its extended application in Li-metal batteries.