ELECTROCHEMICAL IMPREGNATION AND PERFORMANCE OF NICKEL-HYDROXIDE ELECTRODES WITH POROUS PLAQUES OF HOLLOW NICKEL FIBERS

Porous plaques that contain hollow nickel fibres are successfully prep ared by a traditional slurry-scraping technology. The fibrous, nickel- plaque materials have high porosity (85-87%) and are for application i n high specific-energy nickel-metal hydride batteries. Nickel electrod es are fabricated by cathodic electrodeposition from metal nitrate sol utions on to the fibrous plaques. Parameter changes in the concentrati on of nickel nitrate, current density, pH, temperature and plaque poro sity, as well as changes in the impregnation time, are examined with r espect to their influence on the weight gain of fibrous nickel plaques . The influence of fibre content on the electrode performance is inves tigated by determining the capacity, utilization, expansion and cyclin g characteristics. Both C-type and D-type electrodes with similar to 8 5% fibrous plaques reach a specific capacity of 141 mAh g(-1). It is f ound that utilization of active material and electrode swelling both d ecrease with increasing content of the hollow fibres.