Constructing Flower-Shaped NiCo2S4@CoAl-LDH Heterojunction Nanosheets Exhibits Extraordinary Electrochemical Behavior for a Light-Assisted Asymmetric Supercapacitor

The development of high-quality supercapacitors relies heavily on the exploitation of composite electrode materials with well-defined nanostructures such as NiCo2S4 (NCS). In this study, a two-step solvent-thermal approach was used to create a NiCo2S4@CoAl-LDH (NCS@CA) core–shell heterostructure for a light-assisted supercapacitor, yielding a noteworthy advancement in the properties of electrode materials. The resulting flower-shaped NCS@CA nanosheets exhibit great potential for enhancing solar energy utilization. Compared to a solution without light, NCS@CA showed a noticeable increase in specific capacitance when exposed to light. As a result, NCS@CA demonstrated a robust specific capacity of 2120 F g–1 (120.4 F cm–3) when it was operated at 1 A g–1. Also, the electrode showed excellent cycle life; after 10 000 cycles of charge and discharge, 98.96% of the total capacity was still preserved. Light-assisted supercapacitors possessing extraordinary electrochemical properties have been designed with activated carbon (AC) and NCS@CA as the working electrodes. The configuration exhibited an impressive energy density (35.1 Wh kg–1 at 751.2 W kg–1), representing a 36.6% improvement over nonlight conditions. The apparatus also demonstrated exceptional cycling stability, with the specific capacitance holding onto 97.7% after 10 000 cycles. These findings confirm that NCS@CA is a strong contender for building emerging systems for the storage of energy.