Cage Effect of Nitrogen Oxide Radicals Enables Li‐NO _x Cell with a 3.8 V Cell Voltage

Abstract

Abstract The utilization of redox‐active gas as cathode materials has been proposed as a promising approach to meet the demand for next‐generation battery technologies. Toward this end, nitrogen oxides (NO x )—inexpensive, abundant gases readily produced from ammonia on an industrial scale—is a promising energy storage media; however, its utilization as cathode material has not been achieved. In this work, the cage effect of NO and NO 2 radicals are utilized to stabilize the charge product of Li‐NO x cell as N 2 O 3 . This cell operates via reversible redox of LiNO 3 to N 2 O 3 , achieving a specific capacity of 1,570 mA h g carbon −1 or 25 mA h cm electrode −2  at a full cell voltage of 3.85 V with an average energy efficiency of 89% at a current density up to 2 mA cm electrode −2 . These metrics represent one of the highest areal capacity, current density, cell voltage, and energy efficiency reported for a metal‐gas cells.