Enable Rechargeable Carbon Fluoride Batteries with Unprecedented High Rate and Long Life by Oxygen Doping and Electrolyte Formulation.

Abstract

Here, a rechargeable carbon fluoride battery is demonstrated with unprecedented high rate and long life by oxygen doping and electrolyte formulation. The introductions of Mn²⁺-O catalyst and porous structure during the oxidation process of CF_x cathode can promote the splitting of Li-F during charging. By further modulating the electrolyte with triphenylantimony chloride (TSbCl) as anion acceptor and CsF as product modulator, the more readily dissociable CsLiF₂ product instead of LiF is preferentially formed, and the TSbCl-salt protection interface is constructed to confine Li-F based products and reduce fluoride loss at cathode side. These effects endow Li-CF_x batteries with durable reversible conversion reaction (for at least 600 cycles), ultrahigh rate performance (e.g., 364 mAh g^-1 at 20 A g^-1) and low charging plateau voltage down to 3.2 V. The cathode exhibits the maximum power density of 38342 W kg^-1 and energy density of 1012 Wh kg^-1. Furthermore, this Li-CF_x system demonstrates the promising prospects for applications in view of its low temperature operation (e.g., 280 mAh g^-1 at -20 °C), low self-discharge ability, large-scale pouch cell fabrication and high cathode loading (5-6 mg cm^-2), enabling it to move beyond previous role as primary battery and into new role as fast-charging rechargeable battery with high energy density.