Organic Ammonium Ion Battery: A New Strategy for a Nonmetallic Ion Energy Storage System.

Nonmetallic ammonium (NH ) ion batteries are promising candidates for large-scale energy storage systems, which have the merit of low molar mass, sustainability, non-toxicity and non-dendrite. Herein, for the first time, we introduce the novel organic ammonium ion batteries (OAIBs). Significantly, a manganese-based Prussian white analogue (noted as MnHCF) as cathode exhibits a reversible capacity of 104 mAh g with 98 % retention over 100 cycles. We further demonstrate the electrochemical performance of the NH ion full cell, which delivers a reversible capacity of 45 mAh g with a broad electrochemical window. Combining ex situ XPS, ex situ XRD results and electrochemical properties, the NH ion storage mechanism of MnHCF in a non-aqueous electrolyte is clearly revealed. This work verifies the feasibility of employing NH ions as charge carriers in organic energy storage systems and provides new insights for designing organic nonmetallic ion batteries with broad electrochemical windows and high energy density.