A composite of NiCo-based basic carbonate and Holly leaf derived carbon material for low-cost high performance asymmetric supercapacitors
摘要
NiCo-based basic carbonates (NiCoBC) have the advantages of high theoretical specific capacitance, low cost and good stability. To further enhance the electrochemical performance of NiCoBC, a composite material (NiCoBC@HC) of NiCoBC and carbon derived from Holly leaves was prepared in this study. The NiCoBC@HC electrode achieved a high specific capacitance of 385.8 F g−1 at 1 A g−1, which was 2.2 times that of the carbon-free NiCoBC electrode. The rate performance of NiCoBC@HC is also higher than that of NiCoBC. The excellent performance of NiCoBC@HC stems from the synergy between NiCoBC and HC. The electrochemical performance of NiCoBC@HC is also higher than that of NiCoBC and various high-cost carbon material (such as graphene, graphene oxide, multi-walled carbon nanotubes, hydroxylated or carboxylated multi-walled carbon nanotubes) composites, indicating that HC has significant advantages and can reduce the production cost of electrode materials. NiCoBC@HC electrodes are assembled into an asymmetric supercapacitor (ASC) with the structure of NiCoBC@HC//activated carbon (AC). This device has a high energy density of 19.3 Wh kg−1 at 400 W kg−1. This research provides innovative ideas for the high-value utilization of biomass and lays an experimental foundation for the development of low-cost and sustainable electrode materials.