Neuron-like hierarchical manganese sulfide@Cu2S core/shell arrays on Ni foam as an advanced electrode for an asymmetric supercapacitor

Abstract

Neuron-like hierarchical core–shell manganese sulfide@Cu₂S (MCS) arrays were synthesized on Ni foam by a simple hydrothermal method. The well-aligned manganese sulfide stems covering the Ni foam offered a rough support bridge with the substrate. The graphene-like Cu₂S nanosheets on the top of the stems are connected to each other and acted like neurons, improving the charge accumulation and storage behavior, and providing more pathways for the ion transfer. Benefiting from the unique structure and synergistic effect, the prepared samples achieved a high specific capacitance of 2270.1 F g⁻¹ at 2 A g⁻¹ with excellent cycle stability. Furthermore, the assembled asymmetric supercapacitor with MCS as the anode and activated carbon as the cathode displayed an impressive energy density of 43 W h kg⁻¹ at a power density of 0.825 kW kg⁻¹ and a remarkable cycle stability (97%) after 15 000 cycles, implying its great potential as an efficient electrode material for supercapacitors.