Acetylene/argon mixture plasma to build ultrathin carbon bridge of CF <sub> <i>x</i> </sub> /C/MnO <sub>2</sub> for high‐rate lithium primary battery
Dawei Zou, Xingguang Fu, Gao-Bang Chen, Yifan Liu, Baoshan Wu, Xian Jian
Abstract
Abstract Forming an ultrathin conducting layer on a fluorinated carbon (CF x ) surface for reducing severe electrochemical polarization in lithium/fluorinated carbon primary batteries (Li/CF x ) remains a considerable challenge for achieving batteries with excellent rate capability. Herein, CF x was modified by using acetylene/argon mixture plasma combined with MnO 2 particles. The CF x /C/MnO 2 composite effectively reduced the voltage hysteresis and improved the electrochemical performance of Li/CF x . The excellent rate performance of CF x /C/MnO 2 was due to the high electrochemical activity provided by the atomic‐scale conductive carbon layer and ultrafine MnO 2 particles. Compared with pristine CF x , the charge transfer resistance of the optimized CF x /C/MnO 2 decreased from 218.5 to 48.2 Ω, the discharge rate increased from 2C to 10C, and the power density increased from 3.11 to 13.44 kW·g −1 . The intrinsic reason for the enhanced rate performance was attributed to the fact that the ultrathin carbon layer acted as a conductive bridge to reduce the voltage hysteresis at the initial stage of the Li/CF x discharge, and the high electrochemical activity of the ultrafine MnO 2 particles provided a faster lithium‐ion diffusion rate.