Dendrite‐Free Nanocrystalline Zinc Electrodeposition from an Ionic Liquid Containing Nickel Triflate for Rechargeable Zn‐Based Batteries

Abstract

Metallic zinc is a promising anode material for rechargeable Zn-based batteries. However, the dendritic growth of zinc has prevented practical applications. Herein it is demonstrated that dendrite-free zinc deposits with a nanocrystalline structure can be obtained by using nickel triflate as an additive in a zinc triflate containing ionic liquid. The formation of a thin layer of Zn-Ni alloy (η- and γ-phases) on the surface and in the initial stages of deposition along with the formation of an interfacial layer on the electrode strongly affect the nucleation and growth of zinc. A well-defined and uniform nanocrystalline zinc deposit with particle sizes of about 25 nm was obtained in the presence of Ni(II) . Further, it is shown that the nanocrystalline Zn exhibits a high cycling stability even after 50 deposition/stripping cycles. This strategy of introducing an inorganic metal salt in ionic liquid electrolytes can be considered as an efficient way to obtain dendrite-free zinc.

Voltammetric Study and Electrodeposition of Zinc in Hydrophobic Room-Temperature Ionic Liquid 1-Butyl-1-methylpyrrolidinium Bis((trifluoromethyl)sulfonyl)imide ([BMP][TFSI]): A Comparison between Chloride and TFSI Salts of Zinc

“…[31][32][33][34][35] However, it is very time-consuming. In addition, the Zn(II) species produced from the anodic dissolution of a Zn electrode shows an identical voltammetric behavior as that in [BMP][TFSI] containing Zn(TFSI) 2 . The Zn(II) species produced from the anodic dissolution and the addition of Zn(TFSI) 2 should be identical.…”

“…Voltammetric study of Zn(II) produced from Zn(TFSI) 2 2 and ZnCl 2 , respectively, to compare the properties of different Zn(II) species. Because of the poor solubility of many metal salts in TFSI-based ILs, anodic dissolution is a good technique for introducing metal ions into TFSI-based ILs.…”

“…The former is extremely time-consuming, and the latter is not cost-effective. However, Zn(TFSI) 2 has been used in TFSI-based ILs for the electrochemical study and electrodeposition of Zn successfully. 3,[24][25][26][27][28] ZnCl 2 was seldom used as a Zn(II) source in the air-and water-stable ILs including [BMP][TFSI] because of the conventional prejudice to its * Electrochemical Society Member.…”

“…In this study, however, it was found that ZnCl 2 is actually very soluble in IL [BMP][TFSI]. A comparison between Zn(TFSI) 2 and ZnCl 2 was thus investigated in the perspective of voltammetric behavior, nucleation mechanism, surface morphology and crystallinity of the electrodeposits, and the deposition/stripping efficiency.…”

Mechanical Coating of Zinc Particles with Bi2O3-Li2O-ZnO Glasses as Anode Material for Rechargeable Zinc-Based Batteries

“…To overcome these problems, several methods such as composite addition, electrolyte modification, or surface treatment of zinc particles have been studied [19][20][21][22][23][24][25]. In particular, the addition of p-type electronically conductive Bi2O3 to the zinc electrode seems to be promising.…”