Amorphous Cobalt Boride Alloy Synthesized by Liquid Phase Methods as Electrode Materials for Electrochemical Capacitors

An amorphous cobalt boride alloy with high electronic conductivity is fabricated through the liquid-phase reduction method. Benefiting from large specific surface area and hierarchical pore structure, the as-synthesized Co-B nanoflakes expose substantial electrochemical active sites, promote the transfer of electrons and ions, and accelerate the redox kinetic process. The as-obtained amorphous Co-B alloy sample displays a specific capacitance of 411 F g^?1 at 0.5 A g^?1, and with the current density increased to 10 A g^?1, it maintains 69% of the initial capacitance. The as-assembled asymmetric supercapacitor device reveals electrochemical properties comprising an excellent specific capacitance of 64.3 F g^?1 at 0.25 A g^?1, superior cyclical stability of 105% after 20,000 cycles at 3 A g^?1, and maximum energy density of 22.9 Wh kg^?1 at a power density of 200.3 W kg^?1. This study demonstrates great potential in developing high-conductivity materials for an asymmetric supercapacitor through utilizing an amorphous cobalt boride alloy as a promising electrode material.