High-Performance Aqueous Rechargeable Li-Ni Battery Based on Ni(OH)2/NiOOH Redox Couple with High Voltage

New energy storage and conversion systems require large-scale, cost-effective, good safety, high reliability, and high energy density. This study demonstrates a low-cost and safe aqueous rechargeable lithium-nickel (Li-Ni) battery with solid state Ni(OH)(2)/NiOOH redox couple as cathode and hybrid electrolytes separated by a Li-ion-conductive solid electrolyte layer. The proposed aqueous rechargeable Li-Ni battery exhibits an approximately open-circuit potential of 3.5 V, outperforming the theoretic stable window of water 1.23 V, and its energy density can be 912.6 W h kg(-1), which is much higher than that of state-of-the-art lithium ion batteries. The use of a solid-state redox couple as cathode with a metallic lithium anode provides another postlithium chemistry for practical energy storage and conversion.