An organic/inorganic electrode-based hydronium-ion battery

Hydronium-ion batteries are regarded as one of the most promising energy technologies as next-generation power sources, benefiting from their cost effectivity and sustainability merits. Herein, we propose a hydronium-ion battery which is based on an organic pyrene-4,5,9,10-tetraone anode and an inorganic MnO₂@graphite felt cathode in an acid electrolyte. Its operation involves a quinone/hydroquinone redox reaction on anode and a MnO₂/Mn²⁺ conversion reaction on cathode, in parallel with the transfer of H₃O⁺ between two electrodes. The distinct operation mechanism affords this hydronium-ion battery an energy density up to 132.6 Wh kg^-1 and a supercapacitor-comparable power density of 30.8 kW kg^-1, along with a long-term cycling life over 5000 cycles. Furthermore, surprisingly, this hydronium-ion battery works well even with a frozen electrolyte under -40 °C, and superior rate performance and cycle stability remain at -70 °C.