Ammonium escorted chloride chemistry in stabilizing aqueous chloride ion battery

The blue ocean has attracted great expectations since it can provide sustainable and green energies. We propose and demonstrate a feasible strategy for a novel seawater-based chloride ion battery (CIB). Moreover, a new approach has been proposed to synthetically improve the reaction kinetics on both electrodes in CIB by introducing ammonium ions (NH4+) to the aqueous NaCl electrolyte. In particular, a seawater-based CIB has been developed with an initial discharge specific capacity of 123.7 mAh g−1 at a specific charge current 500 mA g−1 with a stable cyclability and excellent rate capability. The superior electrochemical performance of the CIB can be contributed to the Janus effect on promoting Cl− capture/release from both electrodes, hence enhancing AgCl/Ag conversion and more electrons transferred from trivalent bismuth to low valence state.