Laser Powder Bed Fusion of Pure Zinc Electrodes for the Manufacturing of Biodegradable Batteries: Process Development and Preliminary Electrochemical Testing

Abstract

Rechargeable Zn-based batteries are promising alternatives to Li-ion solutions. However, significant operational challenges remain often associated with the low conductivity of binders used in commercial zinc electrodes. The use of advanced manufacturing techniques represents a promising solution to overcome problems such as electrode polarization and dendrite formation typical of Zn-based batteries. In the present investigation, laser powder bed fusion (LPBF) is employed to deposit pure Zn thin-walled structures with complex surface characteristics. An experimental plan is designed on a flexible LPBF system to discern the influence of the laser power, power density distribution (from Gaussian to ring mode) and velocity on the physical characteristics of the samples. The width of the thin walls could be tailored in the range between 200 and 500 μm, while the roughness remains in the range of Ra = 10–15 μm. The density of the deposits is below the reference level of pure Zn due to the elevated surface complexity and internal porosities. Preliminary electrochemical testing is conducted to demonstrate the applicability of the structures as anodes in phosphate buffered saline PBS and 6M KOH solutions. The thin walls are tested via cyclic voltammetry and galvanostatic charge/discharge showing their applicability as anodes for aqueous batteries.