Electrochemical investigation on addition of CNTs to the positive electrodes for Ni/MH rechargeable batteries

The active material β-Ni(OH)2 of positive electrode for Ni/MH battery is a kind of semiconductor. Additives are necessary to improve the conductivity between the active material and the electric collector. Carbon nanotubes (CNTs) have been widely studied for their excellent electrical conductivity and good mechanical properties. In this work, the positive electrodes with CNTs for Ni/MH batteries were prepared and investigated by charge-discharge cycles. Compared to those with acetylene black, the electrodes with CNTs exhibited much better cycle stability, higher discharge voltage, and higher specific capacity. 0.5 wt.% was proved the desired amount and too much CNTs contributed no effect on the improvement of overall performance of the electrodes.