Empowering Zn Electrode Current Capability Along Interfacial Stability by Optimizing Intrinsic Safe Organic Electrolytes

Abstract

Metallic Zn is one of the most promising anodes, but its practical application has been hindered by dendritic growth and serious interfacial reactions in conventional electrolytes. Herein, ionic liquids are adopted to prepare intrinsically safe electrolytes via combining with TEP or TMP solvents. With this synergy effect, the blends of TEP/TMP with an IL fraction of ≈25 wt% are found to be promising electrolytes, with ionic conductivities comparable to those of standard phosphate‐based electrolytes while electrochemical stabilities are considerably improved; over 1000 h at 2.0 mA cm−2 and ≈350 h at 5.0 mA cm−2 with a large areal capacity of 10 mAh cm−2. The use of functionalized IL turns out to be a key factor in enhancing the Zn2+ transport due to the interaction of Zn2+ ions with IL‐zincophilic sites resulting in reduced interfacial resistance between the electrodes and electrolyte upon cycling leading to spongy‐like highly porous, homogeneous, and dendrite‐free zinc as an anode material.

Zincophilic Design and the Electrode/Electrolyte Interface for Aqueous Zinc‐Ion Batteries: A Review

“…In addition to the construction of SEI on the surface of zinc anode through electrolyte and additives, ionic liquids and deep eutectic solvents are also excellent strategies to enhance the zincophilicity of the interface between anode and electrolyte. [68,[73][74][75] Ilyas et al [73] prepared intrinsically safe electrolyte by combining ionic liquid 3-dodecyl-1-vinylimidazolium hexafluorophosphate with triethyl phosphate TEP or trimethyl phosphate TMP. Ionic liquids provide zinophilic sites containing N and F elements.…”

“…In addition to the construction of SEI on the surface of zinc anode through electrolyte and additives, ionic liquids and deep eutectic solvents are also excellent strategies to enhance the zincophilicity of the interface between anode and electrolyte [68,73–75] . Ilyas et al [73] .…”

Polycation‐Regulated Electrolyte and Interfacial Electric Fields for Stable Zinc Metal Batteries

“…Dramatic progress has been accomplished in the pursuit of high performance cathode materials such as transition metal (manganese, vanadium) oxide, organic molecule, and so on [1–5] . Nevertheless, unbounded dendrite growth, corrosion and passivation of zinc (Zn) metal anodes, resulting in low coulombic efficiency (CE) and limited lifetime, which may lead to battery short circuit, is one of the most crucial obstacles for the development of aqueous ZIBs [6–12] . Several strategies have been executed to enhance the electrochemical stability of Zn metal anodes by inhibiting the dendrite formation and banishing the water‐induced parasitic reaction, including electrolyte regulation, interfacial manipulation, substrate modification, etc [13–26] .…”

“…[1][2][3][4][5] Nevertheless, unbounded dendrite growth, corrosion and passivation of zinc (Zn) metal anodes, resulting in low coulombic efficiency (CE) and limited lifetime, which may lead to battery short circuit, is one of the most crucial obstacles for the development of aqueous ZIBs. [6][7][8][9][10][11][12] Several strategies have been executed to enhance the electrochemical stability of Zn metal anodes by inhibiting the dendrite formation and banishing the water-induced parasitic reaction, including electrolyte regulation, interfacial manipulation, substrate modification, etc. [13][14][15][16][17][18][19][20][21][22][23][24][25][26] Among these strategies, electrolyte formulation plays a vital role in regulating the Zn deposition behavior and diminishing the side reaction on Zn metal anodes, because of its effectiveness, simple procedure, and easy implementation.…”

A Janus Separator based on Cation Exchange Resin and Fe Nanoparticles‐decorated Single‐wall Carbon Nanotubes with Triply Synergistic Effects for High‐areal Capacity Zn−I2 Batteries

“…From a fundamental view, both anodic and cathodic reactions are closely associated with electrochemical interfaces, while the separator is an Indispensable component between the anode and cathode. Therefore, the modification of separators, does not involve the complex electrode design, seems to be a more direct and effective way to regulate the interfacial environment of both the anode and cathode [44–49] . Some pioneering investigations have verified that Zn 2+ ion flux can be efficiently homogenized at the separator‐anode interface by introducing functional constituents including BaTiO 3 , [50] Mxene, [51, 52] graphene [53, 54] and sulfonic cellulose [55] .…”