DEVELOPMENT OF CARBON NANOTUBE NI-HM BATTERIES BASED ON CVD DIRECT GROWN TECHNIQUE

In this work,we selected Ni foam as the substrate to grow MWNTs directly by the CVD technique. The MWNT-Ni foam is employed to fabricate the Ni-MH battery current collector and the positive and negative electrodes were by the dry powder roller pressing process. Then,the Ni-MH batteries were investigated from a series of charge-discharge tests. Results showed that MWNTs can root into the Ni foam substrate,and interwove through the active material particles, increasing the bonding force between the substrate and the active material. This electrode structure can effectively inhibit the loss of active material during the charge-discharge cycle and enhance the electron transfer efficiency,the maximum discharge specific capacity increased 17.3% than the electrode without MWNTs,and the charge-discharge cycle stability diminished 24.4% only after 200 cycles.