Controlling Interfacial Ion-Transport Kinetics Using Polyelectrolyte Membranes for Additive- and Effluent-free, High-Performance Electrodeposition

Kensuke Akamatsu*, Shu-ichi Nakano, Koshi Kimura, Yohei Takashima, Takaaki Tsuruoka, Hidemi Nawafune, Yuki Sato, Junya Murai, and Hiroshi Yanagimoto*

ACS Applied Materials & Interfaces 2021, ASAP.

Here, we show that a 200 μm-thin polyelectrolyte membrane sandwiched between electrodes effectively concentrates metal ions through interfacial penetration, which increases the conductance between the electrodes to 0.30 S and realizes solid-state electrodeposition that produces no mist, sludge, or even waste effluent. Both, experimental results and theoretical calculations, reveal that electrodeposition is controlled by ion penetration at the solution/polyelectrolyte interface, providing an intrinsically different ion-transport mechanism to that of conventional diffusion-controlled electrodeposition. The setup, which includes 0.50 mol L−1 copper sulfate and no additives, delivers a maximum current density of 300 mA cm−2, which is nearly fivefold higher than that of a current commercial plating bath containing organic additives.