Engineering NiCoP arrays by cross-linked nanowires and nanosheets as advanced materials for hybrid supercapacitors

•The NiCoP arrays consisted of cross-linked nanowires and nanosheets.•The nanostructure increases active sites and facilitates electron/ion transport.•The energy storage capacity is boosted by the self-supporting array structure.•NiCoP shows an ultra-high capacitance of 2564 F g−1 compared to NiP and CoP.