Supercapacitor electrode based on few-layer h-BNNSs/rGO composite for wide-temperature-range operation with robust stable cycling performance

Currently, developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge. In the present work, few-layer hexagonal boron nitride nanosheets (h-BNNSs) with a thickness of 2-4 atomic layers were fabricated via vacuum freeze-drying and nitridation. Then, the h-BNNSs/reduced graphene oxide (rGO) composite were further prepared using a hydrothermal method. Due to the combination of two two-dimensional (2D) van der Waals-bonded materials, the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from -10 to 50 degrees C. When the electrodes worked in a neutral aqueous electrolyte (1 M Na2SO4), they showed a great stable cycling performance with almost 107% reservation of the initial capacitance at 0 degrees C and 111% at 50 degrees C for 5000 charge-discharge cycles.