Effects of ring-metalated phthalocyanine compounds on the performance of an Ni/MH battery

As an alternative power source, it is very important for the nickel/metal hydride (Ni/MH) battery to improve performance. The effects of ring-metalated phthalocyanine (MPc) on inner pressure and cycling characteristics of sealed Ni/MH batteries were investigated. Experiments indicate that MPc is an effective additive against the decay of battery capacity and the pulverization of negative electrode alloy. It is advantageous to reduce the inner pressure and the inner resistance of batteries. First principle density function theory simulation revealed the activities of different MPcs for gases built up in the battery during charge and discharge cycles. It proposed that, to effectively reduce the inner pressure, an MPc should be able to activate both O-2 and H-2 and have large adsorption energy with them. This explained the observed catalytic difference among MPcs. (c) 2006 The Electrochemical Society.