Abstract: An electroless plating nickel treatment was processed to improve the active behaviors and discharge capacities of Zr-based AB₂ alloys. The effects of the nickel coating on the surface appearance, the structure of the alloy powders and the electrode characteristics were investigated. It is found that the Nirich layer formed through electroless plating nickel treatment plays an important role on the initial activation property and the discharge capacity of Zr-based alloy. The optimal content of electroless plating nickel is about 15%, and the discharge capacity of the electrode can be increased to 400mA·h·g^-1 after 6 cycles. Although coated nickel is beneficial for quick activation and discharge capacity, excessive electroless plating nickel can result in a decreased discharge capacity.

Key words:  Zr-based AB₂ alloy; electroless plating nickel; activation behavior; discharge capacity