High-Power, Wide-Temperature Adaptable Li/CFx Cells Assisted by Crown Ethers

Lithium/carbon fluoride (Li/CFx) primary batteries have attracted wide attention because of their high energy density. However, their application in high-power devices is severely hindered by the retarded reaction kinetics caused by lithium fluoride (LiF) accumulation and difficult desolvation, which is further intensified by low temperature. In this work, an electrolyte strategy has been proposed targeting the kinetic issues. The methyl acetate (MA) low-temperature solvent weakens the Li+ coordination and facilitates the Li+ desolvation, while crown ether provides a LiF removal effect through its complexing capability. After comprehensive optimization, the benzo-12-crown-4 (B12C4)- and MA-containing electrolyte significantly enhances the rate performance as well as low-temperature output of the CFx cathode, endowing it with excellent wide-temperature adaptability. This work not only greatly improves the electrochemical property of the CFx electrode but also provides an alternative electrolyte strategy for all-climate and high-power/energy Li/CFx cells.