The different effect of Co3O4 or/and carbon fiber originated from biomass on the electrochemical hydrogen storage performance of Co2B alloy

Co2B alloy was synthesized via the method of high temperature solid phase. Carbon fiber (CF) was prepared from cotton by calcination process. The addition of carbon fiber and Co3O4 improves corrosion resistance and charge transfer speed of the composite material electrode. The Rct value of Co2B + 1 wt.% CF was 360 mΩ, lower than the other composite electrode could reduce charge transfer resistance. The overall electrochemical performance of Co2B + 2 wt.% Co3O4 + 1 wt.% CF was best among all the electrodes, and its Cmax could reach 715.3 mAh/g. The high conductivity and multiple reaction sites provided by carbon fiber and the catalytic effect of Co3O4 may be the main reasons for the improvement of electrochemical performance, which enhance the kinetic performance of electrochemical reactions. The synergistic effect of carbon fiber and Co3O4 improves the electrochemical hydrogen storage properties of Co2B alloy. This work presents a simple and effective method to improve the electrochemical hydrogen storage performance of cobalt-boron alloys by adding transition metal oxides and carbon materials derived from biomass.