Process optimization of electroless copper plating and its influence on electrochemical properties of AB5-type hydrogen storage alloy

The amount of Cu coating by chemical plating was investigated based on quadratic regression orthogonal experimental design being adapted to the variation law of temperature, pH value and Ni²⁺ concentration, and the relevant regression equation was expressed as y=2.1609+0.5295×10^?3T²-0.0342P²-0.0265N²+0.0023TP+0.0020TH+0.0199PN-0.0959T+0.3814P-0.2073N. The results showed that the deposition rate augmented with the increasing in temperature, pH value and Ni²⁺ concentration. The experimental parameters of the optimal coating were temperature 75 °C, pH value 8.5 and Ni²⁺ concentration 1.2 g/L. The electrochemical tests indicated that the cycle stability increased from 60.66% to 75.58%, indicating that the treated alloy exhibited better corrosion resistance.