A dendrite suppression coating formulated via electrophoretic deposition using Bi-functional surfactants for Zn-ion batteries

Abstract

Aqueous Zn-ion batteries (ZIBs) are promising for large-scale energy storage due to their low cost and high safety. However, ZIBs suffer from Zn dendrite growth and side reactions over the charge-discharge processes. Herein, a facile and scalable strategy was developed based on electrophoretic deposition (EPD) of surfactant-stabilized multi-wall carbon nanotubes (MWCNT) to enhance the reversibility of Zn foil. The MWCNT coating provides high surface area and improved electronic conductivity, thus facilitating rapid charge transfer behavior over the Zn 2+ plating/stripping processes. The results indicated that cationic surfactants, cetyltrimethylammonium bromide (CTAB), are feasible to improve the stability of Zn anode as electrolyte additives in parallel to dispersion and charging of MWCNT. Single-crystalline cryptomelane-type α-MnO 2 nanowires were successfully synthesized by oxalate-reduction of potassium permanganate under ambient conditions. The ZIBs, prepared by α-MnO 2 nanowire cathode and MWCNT coated Zn anode, demonstrated surpassing rate capacity and long cycling stability. The interfacial analysis of electrodes, based on surface tension and contact angle measurements, shed some light on the design and development of multi-functional additives for advanced ZIBs. • A dendrite suppression coating was fabricated by electrophoretic deposition. • Surfactants are found to be electrolyte additives paralleled to CNT deposition. • Single-crystalline α-MnO 2 nanowires were synthesized under ambient conditions. • Interfacial properties were analyzed for wettability and tension measurements.