Dual-Phase engineering of Ni3S2/NiCo-MOF nanocomposites for enhanced ion storage and electron migration

Constructing fast dual pathways for electron transferring and ions intercalating is an effective solution to develop outstanding electrode materials with high capacity and long cycle stability. Herein, dual-phase engineering was proposed to design a leaf-like hierarchical structure comprising Ni3S2 nanowires and NiCo-MOF nanosheets, in which the semiconductive Ni3S2 nanowires could serve as electron transferring pathways and organic ligands in NiCo-MOF enlarged ions intercalating channels. The Ni3S2/NiCo-MOF nanocomposites as cathode materials for alkaline batteries performed 255 mAh g−1 at 1 A·g−1. Notably, a full battery with Ni3S2/NiCo-MOF cathode and Fe2O3 anode had a reversible capacity of 215 mAh·g−1 at 2 A·g−1, retained 62.3 % at 8 A·g−1. After 2000 charge/discharge cycles, the initial capacity remained 82 %. Moreover, the highest energy density and power density achieved 129 Wh kg−1 and 5.2 kW kg−1, respectively. This dual-phase engineering boosted intercalating kinetics by constructing speedy ion/electron dual pathways, thereby offering an avenue for designing more robust energy storage systems.