间二氟苯稀释剂稳定电极界面助力低温锂金属电池OA北大核心CSTPCD

Lithium-ion batteries are widely used across various industries owing to their superior characteristics such as high energy density,high output voltage,and prolonged cycle life.However,their electrochemical efficiency drastically declines in low-temperature conditions,constraining their practical applications.To overcome this limitation,a novel low-temperature electrolyte,distinguished by exceptional cycling performance at ambient and low temperatures,was developed using fluoro-substituted benzene with varied fluorine substitution positions as diluents.Notably,the use of 1,3-difluorobenzene as a diluent led to the development of an electrolyte,designated as 13DFB,exhibiting a conductivity of 1.252 mS/cm at-20℃ and a broad electrochemical window of 5.2 V.The inclusion of 1,3-difluorobenzene in the electrolyte considerably reduces the formation of Li2CO3 in solid-electrolyte interphase and provides a protective layer to LiNi0.6Co0.2Mn0.2O2(NCM 622)cathode particles.Moreover,when this modified electrolyte is used in a pouch cell configuration with a Li/NCM 622 combination at-20℃ and a cutoff voltage of 4.4 V,it achieves stable cycling for 200 cycles with a capacity retention of 92.8%.This study introduces an effective and straightforward strategy to enhance the low-temperature performance of electrolytes,demonstrating substantial potential for practical deployment.