Bi-metallic boride as the electrode material of aqueous battery enabling ultrahigh rate and cycling performances

Abstract A facile chemical reduction method for preparation of Co Ni B was designed and developed. The obtained products showed outstanding electrochemical performances as positive electrode materials in aqueous electrolytes at different current densities (from 1 A g −1 to 20 A g −1 ). Co Ni B nanocomposite exhibited reversible specific capacity of 319.4 mAh g −1 , remarkable rate capability over 90% at 20 A g −1 , and excellent cyclability with no obvious decay over 100 cycles. The high surface area of Co Ni B facilitated the mass and charge transfer, which, in turn, boosted the electrochemical performances.