Spraying amorphous carbon coated zinc to prepare powder-based anodes for long-life zinc-ion batteries†

Abstract

Zinc powder (Zn-P) anodes are more ideal for Zn-ion batteries in practical industrial applications than the commonly used zinc foil anodes due to their low cost, good tunability and easy-processability. However, the Zn-P anodes with high contact surface area suffer from more serious side reactions than zinc foil. Herein, we synthesize an amorphous carbon coated zinc powder-based anode (C@Zn-P) for more homogeneous Zn deposition through a combined simple spraying and annealing method. As a result, the C@Zn-P anode exhibits long-term cycling stability over 600 h with low voltage hysteresis of 20 mV at 1 mA cm⁻² and 0.5 mA h cm⁻², which outperforms most previous results from commercial Zn foil and powder-based anodes. It is worth mentioning that a C@Zn-P||Ti asymmetric cell shows superior reversible properties and higher coulombic efficiency (CE) compared with the Zn||Ti asymmetric cell in plating/stripping of Zn. Moreover, the C@Zn-P anode matched with a multivalent vanadium-based oxide (MVO) cathode shows superior long-term cycling with a capacity retention (CR) of 81.4% after 1000 cycles. This result demonstrates that the Zn powder anode is a promising avenue for further development of rechargeable Zn-ion batteries.