Adjusting zinc ion de-solvation kinetics via rich electron-donating artificial SEI towards high columbic efficiency and stable Zn metal anode

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 442; p. 136081
• Main Authors: Yan, Huibo, Han, Chao, Li, Songmei, Liu, Jianhua, Ren, Jie, Yang, Shubin, Li, Bin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2022
• Subjects: Aqueous zinc ion batteries; De-solvation kinetics; Dendrite; Electron-donating group; Zinc anode; Aqueous zinc ion batteries; De-solvation kinetics; Zinc anode; Electron-donating group; Dendrite
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.136081

A quickly kinetics for de-solvation of hydrate zinc ions benefits from the interaction between electron-donating group and water sheath of hydrated ions. Rich-cyano SEI (rc-SEI) for Zn anode was prepared by coating polyacrylonitrile (PAN) on zinc foil, which realizes low de-solvation activation energy (Ea) of hydrated ions (41.9 kJ mol−1 for rc-SEI@Zn and 63.7 kJ mol−1 for bare Zn). [Display omitted] •Cyano as electron-donating group can interact with sheath of hydrated ions.•Rich-cyano SEI (rc-SEI) reduces de-solvation activation energy of hydrated ions.•Rc-SEI contributes to dendrite-free deposition and high CE of zinc anode.•Rc-SEI improves the cycling performance of a full battery with lean zinc anodes. Aqueous zinc ion batteries (AZIBs) subject to severe sluggish electrodeposition process due to burdensome de-solvation of hydrate zinc ion (Zn(H2O)62+→Zn2+) which leads to high overpotential, low utilization of zinc and high interface impedance. Here, an artificial solid electrolyte interphase (SEI) with rich electron-donating functional group (cyano group) is proposed for zinc anode to achieve favorable de-solvation process and deliver stable rechargeable AZIBs. The rich-cyano SEI (rc-SEI) can improve the de-solvation kinetics by formation interaction force between cyano group and water sheath of hydrated ions. The de-solvation activation energy (Ea) of hydrated ions for rc-SEI@Zn is only 41.9 kJ mol−1, much lower than that of the bare Zn (63.7 kJ mol−1). The rc-SEI@Zn electrode realizes an enhanced CE of over 99.65 % within 550 cycles in Zn||Cu battery, a low polarization of less than 50 mV and ultra-long cycle life of over 1000 h in Zn||Zn battery. Moreover, Zn||MnO2 full cell with rc-SEI@Zn anode shows 78.9% capacity retention after 690 cycles at 2C (218.2 mAh g−1 at 1st cycle and 172.1 mAh g−1 at 690th cycle).