KOH‐Induced Surface Defluorination and Hydroxylation of CF X for Ultrahigh Power Density Primary Batteries

Low power capability remains one of the primary challenges for lithium/fluorinated carbon (Li/CF x ) batteries. Surface modification represents a typical strategy for enhancing the intrinsic conductivity and reaction kinetics of CF x . However, most existing surface modification methods suffer from complex procedures and nonuniform products. To address this problem, this study reports a one‐step liquid‐phase reaction method, KOH as a defluorination agent, to achieve controlled surface defluorination and –OH grafting on CF x . The defluorination process reduces edge‐inert CF 2 /CF 3 groups, exposes CC bonds, and forms an ultrathin, graphene sheet‐like conductive coating (≈1 nm thick) on the CF x surfaces, enhancing lithium‐ion and electron transport kinetics during the early discharge stage. Simultaneously, the grafted –OH groups weaken the surrounding CF bonds via hydrogen bonding, increasing the proportion of semi‐ionic CF bonds and boosting the electrochemical activity of CF x . Their synergistic effect significantly improves the reaction kinetics of CF x during discharge. Relative to pristine CF x cathodes, batteries using KOH‐induced CF x cathodes achieve a 70C discharge capability, attain 98.42 kW kg −1 power density, and exhibit near‐doubled (95%) improvement in energy density at 50C. This work provides a practical new avenue for large‐scale preparation of high‐power fluorinated carbon cathodes, facilitating their industrial application.