Ethanediamine Intercalation Induced Hydrogen Bond Network in Vanadium Oxide for Ultralong-Life Aqueous Ammonium Ion Batteries

Aqueous ammonium-ion batteries (AAIBs) have received tremendous attention as a potential energy technology, but their development is severely challenged by the fact that the as-reported electrode materials are usually unable to meet the requirements of high capacity and high stability simultaneously. Herein, an organic-inorganic hybrid material of ethanediamine (EDA) intercalated vanadium oxide (VO-EDA) is synthesized as a high-performance anode material for AAIBs. The intercalated EDA molecules not only act as an electron donor to bind with NH₄⁺, but also form hydrogen bonding network structures with vanadium oxides to facilitate charge/ion transfer. As a result, this hybrid material provides a high specific capacity of 104.4 mAh g⁻¹ at 0.5 A g⁻¹ and good cycling stability after 5000 cycles 10 A g⁻¹ with a coulombic efficiency of ~100 %. Moreover, the ammonium-ion full cell based on VO-EDA anode and NiHCF cathode achieves a specific capacity of 55 mAh g⁻¹ at 0.1 A g⁻¹ and impressive cycling stability with 88.6 % capacity retention after 10000 cycles at 5 A g⁻¹.