Bacteria‐Assisted Synthesis of Fe‐Co‐Ni‐S/Hollow Carbon Spheres as High‐Performance Supercapacitor Electrode Materials

Abstract Transition metal sulfides (TMSs) as an important type of pseudocapacitive material face the problems of low conductivity and limited morphology, when applying as supercapacitor electrodes. To address the above issues, bacterium streptococcus thermophilus is chosen as template to synthesize Fe‐Co‐Ni‐S/hollow carbon submicron sphere (Fe‐Co‐Ni‐S/HCSS) composites. Benefiting from the active Fe‐Co‐Ni‐S providing multiple redox sites and hollow spherical carbon substrate ensuring fast electron/mass transport, the optimum composite delivers a high specific capacitance of 1029.5 F g −1 at 1 A g −1 . When the current density increases to 10 A g −1 , the capacitance is still up to 927.2 F g −1 and retains 88 % of the initial value after 3000 cycles, showing excellent rate capability and stability. This work provides a facile method to synthesize sulfide/carbon composites with elaborate microorganism morphologies for promoting supercapacitor performance. Considering the big structural diversity of bacteria, this method is extendable to other microstructures and compositions, which is of high value for developing advanced electrode materials in new energy fields.