Modulating C─F Bonds of Fluorinated Graphite via Compounding Graphene Oxide for High-Energy/Power Lithium Batteries

Lithium/fluorinated carbon (Li/CF_x) primary batteries have been widely used in industries such as aerospace and military. However, due to its tight structure and strong C─F bond, high energy density and power density cannot be balanced. Herein, an environmentally friendly and scalable liquid-phase exfoliation strategy to modify fluorinated graphite (FG) with graphene oxide (GO) has been proposed. The optimized GO-FG composite, featuring as exfoliated layer structure and a modulated C─F bond, realizes a maximum energy density of 2740.00 Wh kg^-1 at 0.01 C, and a power density of 84.88 and 119.33 kW kg^{- 1} at ultra-high rates of 50 C and 80 C, respectively. Furthermore, flexible pouch cells assembled with this composite deliver capacities of 1.06 Ah at 0.1 C and 0.96 Ah at 5 C. Experimental and theoretical results indicate that the compounding of reduced GO with FG significantly modulates the strength of C─F bond and the in situ exfoliation opens the layer structure of CF_x and constructs the conductive framework, which realizes a uniform LiF transformation and structure collapse of CF_x during discharging, synergistically enhanced the reaction kinetics.