Toward Safe and Reliable Aqueous Ammonium Ion Energy Storage Systems

Abstract

Aqueous batteries using non‐metallic charge carriers like proton (H+) and ammonium (NH4+) ions are becoming more popular compared to traditional metal‐ion batteries, owing to their enhanced safety, high performance, and sustainability (they are ecofriendly and derived from abundant resources). Ammonium ion energy storage systems (AIBs), which use NH4+ ions with tetrahedral geometry, a small hydrated ionic radius, and relatively low ionic weight, are emerging as strong candidates in non‐metal ion battery chemistry. Various electrode materials (both inorganic and organic) are investigated as hosts for NH4+ ions, however, a comprehensive understanding of these mechanisms is still lacking. This gap limits the ability to optimize performance and identify further research opportunities in AIBs. In this review, the charge storage mechanisms in AIBs are discussed, offering insights into the interactions between NH4+ ions and different electrode materials. Additionally, existing literature on electrode materials, highlighting key structural, and electrochemical achievements are summarized. The review also outlines various electrolytes and examines how their properties influence AIB performance. Finally, the shortcomings of current research are discussed and potential solutions are suggested to advance AIB technology, with the goal of inspiring researchers to explore real‐world applications for ammonium ion batteries.

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

“…Additionally, metal oxides offer enhanced electrochemical stability and pseudocapacitive behavior, operating over a wide voltage window and contributing to higher energy and power densities in AIHSs. Their facile interaction with electrolytes, improved ion insertion and extraction kinetics, surface wettability, and ion accessibility are key factors driving their superior NH 4 + ion storage capabilities. − In this regard, considerable developments have been made in the metal oxide-based AIHSs. In one report, Dai et al introduced MoO 3 @C (MC700) as a high-performance anode material for ammonium ion supercapacitors where MoO 3 @C refers to the MoO 3 /polyaniline composite annealed at 700 °C.…”