Co₂P₂O₇ Microplate/Bacterial Cellulose-Derived Carbon Nanofiber Composites with Enhanced Electrochemical Performance

Nanocrystalline Co₂P₂O₇ and carbon nanofiber (Co₂P₂O₇/CNFs) composites with enhanced electrochemical performance were obtained by calcination after a hydrothermal process with NH₄CoPO₄∙H₂O/bacterial cellulose precursors under an argon atmosphere. SEM images showed that the CNFs were highly dispersed on the surfaces of Co₂P₂O₇ microplates. The diagonal size of the Co₂P₂O₇ plates ranged from 5 to 25 µm with thicknesses on a nanometer scale. Notably, with the optimal calcining temperature, the Co₂P₂O₇/CNFs@600 material has higher specific micropore and mesopore surface areas than other samples, and a maximal specific capacitance of 209.9 F g^-1, at a current density of 0.5 A g^-1. 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_ct) of the CNF composite electrodes decreased with increasing calcination temperature. Furthermore, the Co₂P₂O₇/CNF electrodes exhibited higher energy and power densities than Co₂P₂O₇ electrodes.