Evaluation of a resin-bonded graphite auxiliary electrode for sealed lead/acid batteries

A study is made of the hydrogen oxidation performance of partially-immersed resin-bonded graphite electrodes used as auxiliary electrodes for sealed lead/acid batteries. Cyclic voltammetry has been used to obtain certain information on the design of these strongly water-repellent auxiliary electrodes. Considering that, in an actual battery system, the auxiliary electrode is protected from oxygen evolution by a non-linear resistor, the potential is swept dynamically in a range from hydrogen potential to oxygen adsorption potential. The peak current value in each sweep cycle increases to a saturated value with cycling. This saturated value provides some information on the amount of catalyst, amount of resin, and other production conditions such as moulding pressure and sintering temperature. As a result of this investigation, important information is obtained for the design and improvement of auxiliary electrodes.