CoPO Microplate/Bacterial Cellulose-Derived Carbon Nanofiber Composites with Enhanced Electrochemical Performance.

Nanocrystalline CoPO and carbon nanofiber (CoPO/CNFs) composites with enhanced electrochemical performance were obtained by calcination after a hydrothermal process with NHCoPO∙HO/bacterial cellulose precursors under an argon atmosphere. SEM images showed that the CNFs were highly dispersed on the surfaces of CoPO microplates. The diagonal size of the CoPO plates ranged from 5 to 25 µm with thicknesses on a nanometer scale. Notably, with the optimal calcining temperature, the CoPO/CNFs@600 material has higher specific micropore and mesopore surface areas than other samples, and a maximal specific capacitance of 209.9 F g, at a current density of 0.5 A g. Interestingly, CNF composite electrodes can enhance electrochemical properties, and contribute to better electrical conductivity and electron transfer. EIS measurements showed that the charge-transfer resistance (R) of the CNF composite electrodes decreased with increasing calcination temperature. Furthermore, the CoPO/CNF electrodes exhibited higher energy and power densities than CoPO electrodes.