Electrolyte design for a high energy density Li/Cr8O21 primary battery in a wide-temperature range

Limited storage life and performance fading at wide operation temperature prohibit the further applications of Li/Cr8O21 primary battery in aerial vehicles and military equipment. Electrolyte engineering enables the formation of inorganic-rich solid electrolyte interphase (SEI), which is essential for improving its performance. Here, a LiF/N-rich SEI layer has been constructed on the Li anode by regulating the Li+-solvation structure by using 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) co-solvent. The Li/Cr8O21 primary battery with three-halves volumes ratio of TTE (CEET-3) delivers a specific discharge capacity of 414.6 mAh g(-1). It also demonstrates a capacity of 302.5 mAh g(-1) under -40 degrees C and 440.4 mAh g(-1) under 60 degrees C. Moreover, it gives a capacity retention of 95.3 % even after 40 days aging. Theoretical calculations disclose that the DME coordination has been enhanced by adding TTE co-solvent and inhibits decomposition of organic solvents. Subsequently, dipole-dipole interactions between solvent and diluent molecules mechanism are proposed for the improving of stability and fast ion transfer dynamics at lithium anode surface. This study reveals the electrolyte engineering would be a facile but effective strategy for building a high energy, high power, and long calendar life Li/Cr8O21 primary battery.