Charge-Discharge and Capacity Retention Characteristics of New Type Ni/MH Batteries Using Polymer Hydrogel Electrolyte

Abstract

Positive electrode capacity-controlled nickel/metal hydride (Ni/MH) batteries were assembled using the polymer hydrogel electrolyte and their charge/discharge and capacity retention characteristics were investigated compared to those using a 7.3 M KOH aqueous solution. The interface between the polymer hydrogel electrolyte and nickel positive electrode worked very well and the experimental cell with the polymer hydrogel electrolyte exhibited charge/discharge characteristics such as discharge capacity, cycle performance and high rate capability almost comparable to the cell with a 7.3 M KOH aqueous solution. Moreover, the capacity retention characteristics were markedly improved by using the polymer hydrogel electrolyte. The effects of the polymer hydrogel electrolyte on the capacity retention characteristics were more remarkable at relatively high temperature. These results strongly suggest that the polymer hydrogel electrolyte has a potential applicability to the commercial Ni/MH batteries. © 2003 The Electrochemical Society. All rights reserved.