Bismuth oxide as an excellent anode additive for inhibiting dendrite formation in zinc-air secondary batteries

Abstract

With bismuth oxide additive in zinc-air batteries anode, we have demonstrated a controlled dendrite formation at the anode surface by high current densities of 0.1 and 0.2 A/cm2 during charging process. Cyclic voltammetry (CV) was carried out at a voltage range of −2.0 ∼ 0.5 V and a scan rate of 1 mV/s to examine the electrochemical performance of the electrode. Surprisingly, we have been able to reveal that zinc anode with 3 wt% bismuth oxide showed cathodic peaks after 20 cycles with no noticeable loss in performance. Structural characterization via FE-SEM images revealed that 3-dimensional spherical morphology was formed with bismuth oxide at a current density of 0.05 A/cm2 under controlled kinetics. We have no doubt that our additive successfully mitigated the formation of dendrite at the surface of the anode. Thus, we gained sufficient insight on the critical role of bismuth oxide additive to achieving a dendrite free zinc anode with a stable cycle. Hence, this anode can be use as an excellent anode material in zinc-air secondary batteries.