In this study, a novel NiO@MnO₂ core-shell was synthesized by a two-step hydrothermal method to improve the capacitive performance of NiO while preserving its excellent electrochromic performance. The MnO₂ shell which hydrothermally for 2 hours (NiMn2) possess an excellent electrochromic performance including high optical modulation (73.03% at 600nm), long cycling-stability (95.40% retention of optical modulation after 500 cycles), and outstanding capacitive performance indicated by prominent areal capacitance (122.29 mF/cm² at 0.2 mA/cm²) alongside large electrochemical specific surface area (ECSA) (0.2038 cm²). This remarkable electrochromic and capacitive performance resulted from a synergy of porous nanosheet structure, a formation of a MnO₂ shell with exceptional capacitive properties, and low charge transfer. This study is the first demonstration that the NiO@MnO₂ core-shell structure can be successfully utilized in electrochromism study to improve the poor capacitive performance of NiO.In this study, a novel NiO@MnO₂ core-shell was synthesized by a two-step hydrothermal method to improve the capacitive performance of NiO while preserving its excellent electrochromic performance. The MnO₂ shell which hydrothermally for 2 hours (NiMn2) possess an excellent electrochromic performance including high optical modulation (73.03% at 600nm), long cycling-stability (95.40% retention of optical modulation after 500 cycles), and outstanding capacitive performance indicated by prominent areal capacitance (122.29 mF/cm² at 0.2 mA/cm²) alongside large electrochemical specific surface area (ECSA) (0.2038 cm²). This remarkable electrochromic and capacitive performance resulted from a synergy of porous nanosheet structure, a formation of a MnO₂ shell with exceptional capacitive properties, and low charge transfer. This study is the first demonstration that the NiO@MnO₂ core-shell structure can be successfully utilized in electrochromism study to improve the poor capacitive performance of NiO.

Electrochromic,NiO,MnO2,Hydrothermal