A novel NiMn2O4@NiMn2S4 core-shell nanoflower@nanosheet as a high-performance electrode material for battery-type capacitors

This study reported a novel NiMn2O4@NiMn2S4 core-shell [email protected] synthesized via a simple two-step hydrothermal method as an excellent electrode material for battery-type capacitors. The NiMn2O4@NiMn2S4 was characterized by XRD, XPS, SEM and EDS. The "core" (NiMn2O4) and "shell" (NiMn2S4) are both active materials, and they both participate in the Faraday redox reaction to facilitate the NiMn2O4@NiMn2S4 electrode to obtain more excellent electrochemical characteristics. The specific capacity for the NiMn2O4@NiMn2S4 electrode reaches 803.08 C g−1 when the current density is 1 A g−1. Moreover, the specific capacity retention rate of the NiMn2O4@NiMn2S4 electrode reaches 91.5% after 5000 charge - discharge cycles when the current density is 20 A g−1. The energy density for the NiMn2O4@NiMn2S4//AC device reaches 73.65 Wh kg−1 at a power density of 775.04 W kg−1. Additionally, the NiMn2O4@NiMn2S4//AC demonstrates excellent self-discharge characteristics. Therefore, the NiMn2O4@NiMn2S4 electrode material presents extensive application prospects for battery-type capacitors.