Investigation on substrates of MmNi5-based alloy electrodes for high power applications

A new substrate (quasi-3D) combined with both three-dimensional (3D) and two-dimensional (2D) networks for MmNi5-based alloy electrodes was developed. The substrate effect on electrode packing density, porosity, loading capacity, electrode thickness, α (=Ws (substrate weight)/We (electrode weight)) and rate capability has been investigated to compare with conventional foamed nickel (3D) and punching metal (2D). The results showed that thin electrodes with punching metal substrates had better rate capability than those with foamed nickel substrates, while both kinds of the substrates had low packing density. Further results indicated that under the condition of the similar electrode thickness, the electrode using the new developed (quasi-3D) substrate showed better performance than those with punching metal and foamed nickel substrates, and could simultaneously keep high packing density and rate capability. It is suggested that this new developed substrate is more suitable for high power applications in nickel/metal hydride batteries.