A Long Cycle Stability and High Rate Performance Organic Anode for Rechargeable Aqueous Ammonium-Ion Battery

Aqueous ammonium-ion batteries (AAIBs) have received much attention as a valid energy strategy, but their suitable anode materials are deficient. Herein, a synthetic polymer material (PNNI) with a multilayer nanosheet structure is synthesized as an anode for AAIBs. The PNNI contains carbonyl functional groups that can be reversibly oxidized and reduced in aqueous ammonium ion solution, and it illustrates a Coulombic efficiency of 93.8% at 100 mA g–1 in a 1 M NH4Ac electrolyte. At high current density, PNNI still exhibits cycling performance with longevity. The capacity retention of 80.2% is measured up over 10000 cycles at 5 A g–1. A full ammonium-ion battery is assembled with (NH4)2Ni[Fe(CN)6] (Ni-APW) as cathode and PNNI as anode, and it exhibits a capacity retention of around 100% after 10000 cycles at 1 A g–1. This synthetic polymer electrode material maintained its special framework structure during the discharge/charge cycles of ammonium ion batteries.