Engineering high entropy electrolyte for Li/CFx batteries with high capacity and wide temperature range

Fluorinated carbon (CF x ) is considered to be a promising cathode material for lithium primary batteries, which has an ultra-high theoretical energy density of 2180 Wh kg −1 . However, the C-F bonds in CF x materials are strongly covalent, leading to a low intrinsic conductivity and poor electrochenical performance. In this work, a high entropy electrolyte (HE) has proposed to maintain the original discharge platform and exhibit a second discharge voltage platform that appeared around 1.7 V, which effectively improves the specific capacity of Li/CF x batteries (1035 mAh g −1 ). This significant improvement can be attributed to the chelation of the dioxygen atoms in the solvent with the Li + , resulting in the solvated Li + being co-intercalated into the lamellar structure of the graphite. Notably, the Li/CF x batteries in the HE electrolyte exhibit higher specific capacity than the single lithium salt at −40 °C and 80 °C (539 mAh g −1 , 1132 mAh g −1 ). This is mainly due to high entropy changes the point of the electrolyte solidifies, thus avoiding capacity loss caused by solid-phase electrolyte clogging the electrode holes. This work provides an efficient and reliable method for the design of Li/CF x batteries with high specific capacity.