Carbon Dot Regulating NiSe/MnO₂ Heterostructures for High-Performance Supercapacitors

Structural regulation is an effective strategy for enhancing an electrode's energy storage performance. Herein, lignin-derived carbon dots (LCDs) are explored for the structural tailoring of NiSe/MnO₂ to improve the electrochemical performance in supercapacitors. After the dendritic NiSe microcrystals are synthesized via a microwave method, NF/NiSe/MnO₂-LCDs are prepared by another microwave process to form a composite mixture of LCDs, MnO₂, and NF/NiSe. At 1 A g^-1, NF/NiSe/MnO₂-LCDs possess a specific capacitance of 2268 F g^-1 and superb lifespans (84.43%, 3000 cycles) for their enhanced ion transport and rapid electron transfer. In addition, the NF/NiSe/MnO₂-LCDs//AC ASC showed an energy density of 51.62 Wh kg^-1 at 800 W kg^-1 and extraordinary endurance with 88.46% retention (7000 loops). The NF/NiSe/MnO₂-LCDs offer ideas to improve the capacity retention and storage capacity of electrodes for supercapacitors.