Low-cost high-performance asymmetric supercapacitors based on ribbon-like Ni(OH)2 and biomass carbon nanofibers enriched with nitrogen and phosphorus

Abstract

Herein, we report a facile and low-cost synthesis of nitrogen and phosphorus co-doped carbonized bacterial cellulose (N, P-CBC) via in-situ soaking bacteria cellulose and carbonization method. The N, P-CBC yielded a high specific capacitance of 232 F g−1 at 1 A g−1 and 92.7% rate capability retention at 5 A g−1. Moreover, the asymmetric supercapacitor (ASC) device was further fabricated with N, P-CBC as the negative electrode and Ni(OH)2, prepared using a simple chemical precipitate method as the positive electrode. The fabricated ASC device provided a maximum working voltage of 1.6 V and high energy density (41.9 Wh kg−1 at a power density of 799.2 W kg−1). The device exhibits remarkable specific capacitance (118 F g−1 at 1 A g−1) and excellent cycle lifetime (76.3% specific capacitance after 5000 cycles). Such an excellent electrochemical performance demonstrated that the as-prepared N, P-CBC and Ni(OH)2 electrodes will be both great potential candidates for supercapacitors.