Dynamics Engineering of Composite MoS ₂ Electrode Toward Photo‐Rechargeable Sodium‐Ion Batteries

ABSTRACT Photo‐rechargeable batteries (PRB) featuring dual‐functional electrode system have emerged as a novel solution to address the solar harvest and energy storage in a highly integrated device. Nevertheless, it is a big challenge to really achieve PRB only with light illumination due to a serious dynamics mismatching between the low storage kinetics and instantaneous photo‐generated carriers. In this study, a 3D carbon nanotube interconnected MoS 2 nanosheets (CNT‐MoS 2 ) are successfully constructed as a dual‐functional electrode for photo‐rechargeable Na‐ion batteries. Theoretically, electrons tend to transfer from the MoS 2 CNTs and accumulate on CNT, while holes tend to accumulate on the MoS 2 . Experimentally, such material exhibits remarkably improved surface potential under light illumination and longer photoluminescence lifetime. It also displays excellent Na‐ion storage kinetics in ether‐based electrolytes and efficient utilization of photo‐generated carriers. As a result, it exhibits significantly enhanced sodium‐ion storage capacity under light illumination and a good photoconversion and storage efficiency of 2.56%. Notably, it has a remarkable photo‐charging response under zero external bias, reaching a high photo‐charging voltage of 2.0 V, while delivering a high capacity of ≈400 mAh g −1 and a reversible photo‐charging cycling. This work firstly demonstrates the achievement of real Na‐ion PRB through regulating the electrochemical kinetics.