Porous lamellar carbon assembled from Bacillus mycoides as high-performance electrode materials for vanadium redox flow batteries

Abstract The demand for clean and renewable energy has promoted the rapid development of state-of-the-art energy storage electrochemical systems. Vanadium redox flow batteries attract much more attentions due to low cost and high security, unfortunately the low catalytic activity of electrodes for vanadium ion redox process is the main barrier to achieve a high efficiency. This work proposes a novel composite electrode derived from Bacillus mycoides to overcome the dilemma between high degree of graphitization and uniform heteroatom doping. Consequently, this composite electrode simultaneously achieves rapid charge migration and high electrocatalytic activity and enhances the vanadium ion redox reaction on porous lamellar carbon (PLC) materials. Compared with the pristine electrode, the potential polarization for V(IV)/V(V) and V(II)/V(III) redox couples on PLC electrode decrease by 254 mV and 278 mV, respectively. Moreover, a high stability for cycling continuously for over 1000 cycles at a high current density of 200 mA cm−2 and a high energy efficiency can be realized based on PLC electrode. This work not only paves the way to achieve high energy efficiency of vanadium redox flow batteries, but also provides a feasible and novel way to design carbon materials with high catalytic activity and high electronic conductivity.