Long-term storage of nickel—hydrogen cells

On the Origin of the Second Low‐Voltage Plateau in Secondary Alkaline Batteries with Nickel Hydroxide Positive Electrodes

“…Besides the role of both electronic and protonic conductivities upon the formation of the y-phase, another point worth clarifying is the potential at which the phase trans- needed to form the y-phase. 6 Upon discharge, we showed here that in PI electrodes the y-phase transformation occurs at a potential of 0.8 V vs. Cd, while a discharge potential of 1.1 V vs. Cd is reported in the literature. This apparent discrepancy results from the fact that the 1.1 V discharged voltage reported by Barnard et al corresponds to y(III)/a(II) transformation 6 (E= 1.17 V vs. Cd), while we ascribed our observed 0.8 V plateau to the y(III)/3(II) phase transformation, on the basis of TEM and XRD observations.…”

“…It is suggested that the resistance of the electrolyte path causes the potential at the pit bottom to drop to the active regime of the polarization curve 2 ' 3 and pit growth is ohmically controlled. 6 2. Salt film theory.7'--Since sufficient changes in concentration can occur near an active region, the pit surface is covered with a salt layer formed by the cations of the metal and the aggressive anions when a substantial supersaturation is reached.…”

Mechanism of the memory effect in “Nickel” electrodes

“…Parallel to this apparent loss of capacity, a number of investigators have shown over a period of years that a second plateau can appear at a lower potential during discharge [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The length of this plateau varies with the amount of prior charging on the higher oxidation plateau.…”

Corrosion of AB5 alloy during the storage on the performance of nickel-metal-hydride battery

“…Reducing reactions of CoOOH at low voltage (below 1.0 V) with hydrogen may be responsible for it since the same characteristic of discharge curve with capacity loss as shown in Fig. 3 was also found in both Ni-Cd and Ni-H 2 batteries [2,3].…”

“…Previous studies are focused on nickel-hydrogen (Ni-H 2 ) and nickel-cadmium (Ni-Cd) batteries. The work reported in references [1][2][3][4][5] indicates that CoOOH or Co(OH) 3 in the positive electrodes may be reduced slowly by hydrogen in the battery system at lower potential, thus results in capacity fading of them since the cobalt additive has been known to improve the active material utilization of nickel electrodes [6,7]. But for Ni-MH battery, AB 5 alloy is often used as active material in the negative electrodes.…”