High performance aqueous Prussian blue analogue-hydrogen gas hybrid batteries

Abstract Aqueous rechargeable batteries show promising prospects in large-scale energy storage owing to their low cost and high safety. Compared to single ion batteries, aqueous hybrid batteries have been receiving extensive interests in constructing high-performance electrode systems. In this work, we build new Prussian blue analogues-hydrogen gas (PBA-H2) hybrid battery systems in which PBA-based cathodes operate by different cations (Na+, K+ or NH4+) intercalation chemistry and a hydrogen gas anode operates by electrocatalytic hydrogen evolution/oxidation reactions. The assembled PBA(Na+)-H2 hybrid battery delivers an excellent rate performance of 100 C and long cycling lifetime with capacity retention of 92% after 25,000 cycles. In addition, the PBA(K+)-H2 hybrid battery delivers superior current rate of 100 C and long cycling stability with capacity retention of 88% after 10,000 cycles. This work demonstrates a class of hybrid hydrogen gas batteries with tunable storage chemistries, showing promises as competitive candidates for large-scale energy storage applications.