Micro-controlling of the grain boundaries in NiCoO/NiCoS nanowires for enhanced charge storage.

In this work, the micro-controlling of the grain boundaries in NiCoO/NiCoS nanowire arrays was achieved by exposing them to a sulfur containing atmosphere at 300 °C with different exposure times. The results showed that the capacitance of the optimal NiCoS sample reached 400 μA h cm at 30 mA cm with a current retention rate of 58.6%. The assembled NiCoO/NiCoS//activate carbon electrode delivered a capacitance of 299.2 μA h cm and 241.7 μA h cm at a current density of 3 mA cm and 30 mA cm, respectively. The cycling tests showed a good current retention rate of 88.1% after 8000 cycles. Besides, the NiCoO/NiCoS composite exhibited a power density of 480.1 W kg at an energy density of 47.87 W h kg, and 4773.66 W kg at 38.67 W h kg, which indicated its potential for practical applications.