Ionic Liquid-Impregnated ZIF-8/Polypropylene Solid-like Electrolyte for Dendrite-free Lithium-Metal Batteries

Abstract

Metal−organic framework (MOF)-based solid-like electrolytes have attracted more prospective due to the combined merits of solid-state electrolytes and liquid electrolytes. However, most MOF-based solid-like electrolytes using organic liquid electrolytes cannot fundamentally solve the safety issues of lithium-metal batteries, and the ionic conductivity and mechanical strength of the electrolytes should be further enhanced. Herein, the ionic liquid-impregnated polypropylene (PP) porous membrane with integrally distributed ZIF-8 nanoparticles is designed. The solid-like electrolyte possesses an increased ionic conductivity of 2.09 × 10 −4 S cm −1 at 25 °C, lithium-ion transference number (0.45), mechanical strength, electrochemical window, and excellent nanowetted interfaces. Furthermore, the Li symmetrical cell shows excellent Li plating/stripping properties for 550 h at 0.1 mA cm −2 and 0.1 mA h cm −2 . The LiFePO 4 /Li full battery with the solid-like electrolyte demonstrates an excellent rate capability and cycling stability with the initial discharge capacity of 157.9 mA h g −1 and a capacity retention ratio of 91.23% after 450 cycles at 0.2 C. The work offers a new avenue toward MOF-based solid-like electrolytes for high-safety lithium-metal batteries.

Exploring ionic liquid-laden metal-organic framework composite materials as hybrid electrolytes in metal (ion) batteries

“…In this work, the Li [EMIM][TFSI]@ZIF-8 hybrid system is integrated in a LIB using LiFePO 4 as the cathodic active material and obtaining a capacity of 167 mAh g −1 at 0.05C. ZIF-8 impregnated with Li [EMIM][TFSI] was also used in the manufacture of membranes, for which ZIF-8 nanoparticles were deposited on the surface and inside of a polypropylene (PP) membrane, which was subsequently soaked with Li [EMIM][TFSI] ( Qi et al, 2022 ). The presence of ZIF-8 increases the stability of the membrane against dendrite growth, which is extracted from the excellent performance in lithium plating/stripping assays.…”

Uniform In Situ Grown ZIF-L Layer for Suppressing Hydrogen Evolution and Homogenizing Zn Deposition in Aqueous Zn-Ion Batteries

“…Metal–organic frameworks (MOFs) possess porous structures and rich functional groups, which can be considered as hopeful interface materials to modify Zn anode . Zeolitic imidazolate frameworks (ZIFs) as a category of MOFs have been explored and applied in several research fields in the past few years, such as catalysis, gas separation, and energy storage, and so on. − Common ZIFs are made up of metal sites (e.g., Zn 2+ and Co 2+ ) and imidazole organic ligands with zeolite structure, thereby the strong chelation between N and metal ion ensuring its absorption of metal ions. , Meanwhile, ZIFs directly provide a 3D network, which is conducive to the orderly embedding of other materials such as Zn and Li. − From a catalytic view, ZIFs show effective catalytic activities due to the special Lewis acid (neighboring metal ions) and base (N in imidazole) sites. − Moreover, it has been proved that pure ZIFs possess a negligible capacity for hydrogen evolution in the field of photocatalytic hydrogen evolution .…”

“…Metal−organic frameworks (MOFs) possess porous structures and rich functional groups, which can be considered as hopeful interface materials to modify Zn anode. 30 Zeolitic imidazolate frameworks (ZIFs) as a category of MOFs have been explored and applied in several research fields in the past few years, such as catalysis, 31 gas separation, 32 and energy storage, 33 and so on. 34−37 Common ZIFs are made up of metal sites (e.g., Zn 2+ and Co 2+ ) and imidazole organic ligands with zeolite structure, thereby the strong chelation between N and metal ion ensuring its absorption of metal ions.…”

Towards High-Performance Metal-Organic-Framework-Based Solid-State Electrolytes: Tunable Structures and Electrochemical Properties

“…16 This MOF-based electrolyte shows a fast interparticle diffusion of Li + ion, achieved by the nano-wetted interface between LiTFSI/ionic liquid and MOF nanoparticles. Nonetheless, [EMIM]-based ionic liquid has been reported to be unstable towards lithium metal anode and high-voltage cathode, [17][18][19] leading to a relatively narrow electrochemical stability window of this Cu-MOF-525 electrolyte (2.0-4.1 V vs. Li + /Li).…”