Jang I.-S.,Chonnam National University |
Jang I.-S.,Sebang Global Battery Co. |
Kalubarme R.S.,Chonnam National University |
Yang D.-C.,Chonnam National University |
And 5 more authors.
Metals and Materials International | Year: 2011
Electrode degradation can affect the lifetime and safety of Ni-MH secondary batteries. This study examined the factors responsible for the degradation of metal hydride (MH) electrodes. The charge-discharge characteristics and cycle life of an MmNi 3.9Co 0.6Mn 0.3Al 0.2 (Mm: misch metal) type MH electrode were examined in a cell with a KOH electrolyte. After the charge-discharge cycles, the surface morphology of the electrodes was analyzed to monitor the extent of degradation. Electrochemical impedance spectroscopy provided information on the conductivity of the electrode. X-ray photon spectroscopy (XPS) was used to quantify the degradation of the electrode in terms of its composition. The MH electrodes degraded with cycling. This phenomenon was more prominent at higher C-rates and temperatures. The electrode degradation was attributed to the loss of active material from the current collector by the repeated absorption and desorption of hydrogen and the formation of an Al 2O 3 oxide layer on the electrode surface with cycling. In addition, the effects of the addition of Co nano and Y 2O 3 powder on the degradation of the MmNi 3.9Co 0.6Mn 0.3Al 0.2 electrode were examined. The addition of the Y 2O 3 and Co nano powder significantly improved the performance of the MH electrode by increasing the cycle life and initial activation rate. © KIM and Springer.
Sebang Global Battery Co. | Date: 2016-08-02
Batteries; Electric accumulators; Galvanic batteries; Electric accumulators for vehicles; Wet cells; Electric batteries; Batteries for lighting; Ignition batteries; Secondary cells; Lead acid battery for automotive and deep-cycle application; Batteries for automobiles; Rechargeable batteries.