A Holistic Additive Protocol Steers Dendrite-Free Zn(101) Orientational Electrodeposition

Small. 2024 Mar;20(11):e2308209. doi: 10.1002/smll.202308209. Epub 2023 Oct 25.

Abstract

Orientation guidance has shown its cutting edges in electrodeposition modulation to promote Zn anode stability toward commercialized standards. Nevertheless, large-scale orientational deposition is handicapped by the competition between Zn-ion reduction and mass transfer. Herein, a holistic electrolyte additive protocol is put forward via incorporating bio-derived dextrin molecules into a zinc sulfate electrolyte bath. Electrochemical tests in combination with molecular dynamics simulations demonstrate the alleviation of concentration polarization throughout accelerating Zn2+ diffusion and retarding their reduction. The predominant (101) texture on inert current collectors (i.e., Cu, Ti, and stainless steel) and (101)/(002) textures on Zn foils afford homogeneous electrical field distribution, which is contributed by the work difference to form the 2D nucleus and the adsorption of dextrin molecules, respectively. Consequently, the symmetric cell harvests a longevous cycling lifespan of over 4000 h at 0.5 mA cm-2 /0.5 mAh cm-2 while the Zn@Cu electrode sustains for 240 h at a high depth of discharge of 40%.

Keywords: (101) texture; Zn anodes; dextrin; electrodeposition; electrolyte additives; holistic.