Manipulating Uniform Nucleation to Achieve Dendrite-Free Zn Anodes for Aqueous Zn-Ion Batteries

Abstract

The essence of Zn dendrite formation is ultimately derived from Zn nucleation and growth during the repeated Zn plating/stripping process. Here, the nucleation process of Zn has been analyzed using ex situ scanning electron microscopy to explore the formation of the initial Zn dendrite, demonstrating that the formation of tiny protrusions (the initial state of Zn dendrites) is caused by the inhomogeneity of Zn nucleation. Based on this, the uniform Zn nucleation is promoted by the Ni5Zn21 alloy coating (ZnNi) on the surface of Zn foil by electrodeposition, and the mechanism of ZnNi-promoted even nucleation is further analyzed with the assistance of density functional theory (DFT). The DFT results indicate that the ZnNi displays a stronger binding ability to Zn compared to the bare Zn, suggesting that Zn nuclei will preferentially form around ZnNi instead of continuing to grow on the surface of the initial Zn nuclei. Therefore, the designed Zn metal anode (Zn@ZnNi) can be ultra-stable for over 2200 h at a current density of 2 mA cm–2 in the symmetric cell. Even at a much higher current density of 20 mA cm–2, the extra-long life of over 2200 cycles (over 530 h) can be achieved. Moreover, the full cell with the Zn@ZnNi anode exhibits extra-long cycling performance for 500 cycles with a capacity of 207.7 mA h g–1 and 1100 cycles (148.5 mA h g–1) at a current density of 0.5 and 1 A g–1, respectively.

Elastomer–Alginate Interface for High‐Power and High‐Energy Zn Metal Anodes

“…Cyclic stability of Zn anodes. Voltage profiles of bare Zn and Zn@TPZA anodes at a) 5 mA cm –2 /5 mAh cm –2 and b) 10 mA cm –2 /10 mAh cm –2 ; SEM images of c) bare Zn and d) Zn@TPZA with TPZA layer peeled off after cycling; CE of the two anodes at e) 5 mA cm –2 /5 mAh cm –2 and f) 10 mA cm –2 /10 mAh cm –2 ; g) Comparison of cumulative capacity and cycling capacity of Zn@TPZA and other reported Zn anodes with various coating layers (Kaolin, [ 29 ] indium, [ 12 ] PDMS/TiO 2 , [ 16 ] MOF, [ 30 ] polyamide, [ 31 ] ZnS, [ 32 ] ZnO, [ 33 ] poly(vinyl butyral), [ 34 ] polyimide, [ 35 ] ZnSe, [ 5 ] PAN‐Si 3 N 4 , [ 15 ] PVDF/TiO 2 , [ 17 ] BiTiO 3 , [ 36 ] NaTi 2 (PO 4 ) 3 , [ 37 ] Ga‐In‐Zn, [ 38 ] ZnNi, [ 39 ] PDA, [ 40 ] Poly‐ZnP 2 O 6 /ZnF 2 [ 26 ] ).…”

Recent progress, mechanisms, and perspectives for crystal and interface chemistry applying to the Zn metal anodes in aqueous zinc‐ion batteries

“…Therefore, it is of great significance to characterize the diffusion properties of materials to ions through theoretical calculation. 68…”

“…The diffusion of ions is also very meaningful for zinc ions batteries and all kinds of new battery systems because it is the control step of dynamics. Therefore, it is of great significance to characterize the diffusion properties of materials to ions through theoretical calculation 68 …”

Highly Strengthened and Toughened Zn–Li–Mn Alloys as Long‐Cycling Life and Dendrite‐Free Zn Anode for Aqueous Zinc‐Ion Batteries

“…[33][34][35] On the other hand, it is found that during the long-term charge/discharge process, O 2 in the electrolyte will react with metal state zinc to form zinc-based oxide byproducts which would cause the passivation of the zinc anode and negatively affect the battery performance. [28,36] More recently, binary Zn alloys such as Zn-Al, [37] Zn-Ag, [29,30] and Zn-Ni [38] alloys have been probed to protect Zn anode from dendrite growth and side reactions. Compared with pure Zn, these alloys have distinct features, like higher ionic conductivity, lower surface energy, better wettability, and higher resistance to the presence of oxygen.…”

“…More recently, binary Zn alloys such as Zn–Al, [ 37 ] Zn–Ag, [ 29,30 ] and Zn–Ni [ 38 ] alloys have been probed to protect Zn anode from dendrite growth and side reactions. Compared with pure Zn, these alloys have distinct features, like higher ionic conductivity, lower surface energy, better wettability, and higher resistance to the presence of oxygen.…”