Boosting the rate performance of primary Li/CFx batteries through interlayer conductive network engineering

Abstract

As an attractive cathode material with an ultra-high theoretical capacity and energy density, graphite fluoride (CF_x) is a promising option for lithium primary batteries. However, its application in high-power-demanding scenarios is limited by its poor rate performance, mainly due to its intrinsic low electrical conductivity and sluggish electrochemical kinetics. Herein, we demonstrate an innovative method that could improve the electron-transport properties and electrochemical kinetics of CF_x simultaneously. This was achieved by exfoliating CF_x into quasi-2D flakes and constructing conductive networks within the interlayers. The strong electronic interaction between CF_x and the conductive network enabled facile charge transfer, as reflected by photoluminescence quenching and electrochemical characterization tests. This newly designed CF_x cathode outperformed conventional ones in a lithium primary battery, delivering a specific capacity of 580 mA h g⁻¹ at a high discharge rate of 2C, which was 77% of the charge capacity at 0.1C.