A ZERO-EMISSION ELECTROLESS NICKEL PLATING BATH

Abstract

A zero-emission electroless nickel plating bath was investigated, which consisted of nickel hypophosphite, hypophosphorous acid, lithium acetate, citric acid and maleic acid. The bath stability, bath life and plating rate were 68.0[Formula: see text]min, 8 cycles and 13.39[Formula: see text][Formula: see text]m/h, respectively. The Ni–P plating layer showed smooth appearance with lots of small continuous nodules, with 12.23[Formula: see text]wt.% phosphorus content. The electrochemical measurements showed that the deposit exhibited excellent corrosion resistance. All of these properties of the zero-emission plating bath and its deposit were better than those of the popular plating solution and its layer. It is most significant that the spent plating bath can be used directly as a raw material to prepare LiFePO4/C materials, which conforms to the concept of circular economy.