High-capacity proton battery based on ?-conjugated N-containing organic compound

Aqueous proton batteries (APBs) have tremendous potential in the energy storage field. Currently, highperformance electrode materials need to be urgently exploited to satisfy the development of APBs. Here, we introduce a pi-conjugated N-containing organic compound (diquinoxalino [2,3-a:2',3'-c] phenazine, HATN) with abundant active sites as the anode. By assembling HATN with a beta-MnO2 cathode, we produce a high-capacity proton battery with a reversible specific capacity of 260 mAh g-1 at 0.1 A g-1 and an excellent energy density up to 118 Wh kg-1. The high performance is found to result from the abundant C=N moieties and the pi-conjugated structure of HATN, which assure the capability of reversible H+ storage and the corresponding stability.