Solar-Light-Responsive Zinc–Air Battery with Self-Regulated Charge–Discharge Performance based on Photothermal Effect

It is extremely challenging to significantly increase the voltaic efficiency, power density, and cycle stability of a Zn-air battery by just adjusting the catalytic performance of the cathode with nanometers/atomistic engineering because of the restriction of thermodynamic equilibrium potential. Herein, inspired by solar batteries, the S-atom-bridged FeNi particles and N-doped hollow carbon nanosphere composite configuration (FeNi-S,N-HCS) is presented as a prototype of muti-functional air electrode material (intrinsic electrocatalytic function and additional photothermal function) for designing photoresponsive all-solid-state Zn-air batteries (PR-ZABs) based on the photothermal effect. The local temperature of the FeNi-S,N-HCS electrode can well respond to the stimuli of sunlight irradiation because of their superior photothermal effect. As expected, under illumination, the power density of the as-fabricated PR-ZABs based on the FeNi-S,N-HCS electrode can be improved from 77 mW cm^-2 to 126 mW cm^-2. Simultaneously, charge voltage can be dramatically reduced, and cycle lifetime is also prolonged under illumination, because of the expedited electrocatalytic kinetics, the increased electrical conductivity, and the accelerated desorption rate of O₂ bubbles from the electrode. By exerting the intrinsic electrocatalytic and photothermal efficiency of the electrode materials, this research paves new ways to improve battery performance from kinetic and thermodynamic perspectives.