Nanosecond laser lithography enables concave-convex zinc metal battery anodes with ultrahigh areal capacity

Abstract

Laser processing is employed to fabricated zinc-ion battery (ZIB) anodes with state-of-the-art electrochemical performance from commercial zinc foils. Lasers are widely utilized for industrial surface finishing but have received minimal attention for zinc surface modification. Laser lithography patterned zinc foils “[email protected]” are hydrophilic, with an electrolyte contact angle of 0°. This is due to the concave-convex surface geometry that enhances wetting (periodic crests, ridges and valleys, roughness 16.5 times planar). During electrodeposition [email protected]'s surface geometry generates a periodic electric field and associated current density distribution that suppresses tip growth (per continuum simulations). Per Density Functional Theory (DFT) its surface oxide is zincophilic, resulting in low nucleation barriers during plating (e.g. 3.8 mV at 1 mA cm−2). A combination of these attributes leads to stable dendrite-free plating/stripping behavior and low overpotentials at fast charge (e.g. 48.2 mV at 8 mA cm−2 in symmetric cell). Cycling is possible at an unprecedented areal capacity of 50 mA h cm−2, with 400 h stability at 1 mA cm−2. Moreover, exceptional aqueous zinc battery (AZB) performance is achieved, with MnO2-based cathode loading 10 mg cm−2 and corresponding anode capacity 7.6 mA h cm−2. A broad comparison with literature indicates that [email protected] symmetric cell and full battery performance are among most favorable.