Ni/MH 2차전지의 음극으로써 V-Ti-Ni(V-rich) 수소저장합금의 전극수명 향상에 관한 연구

A Study on the Cycle Life Improvement of V-Ti-Ni(V-rich) Alloy as a Negative Electrode for Ni/MH Rechargeable Battery

The discharge capacity of V-Ti-Ni(V-rich) metal hydride electrode during the charge-discharge cycling was investigated in KOH electrolyte. All electrodes were degraded within 25 cycles. To investigate the cause of the degradation phenomena impedance measurements were performed by using E.I.S(electrochemical impedance spectroscopy). The surfaces of the degraded electrodes were examined by Auger electron spectroscopy (AES). It was observed that all electrodes were covered with oxygen from the surface to the bulk, titanium was enriched near surface, and vanadium was dissolved from the surface to the bulk.