Ionic conductivity and ion transport mechanisms of solid‐state lithium‐ion battery electrolytes: A review

Abstract

This review article deals with the ionic conductivity of solid-state electrolytes for lithium batteries. It has discussed the mechanisms of ion conduction in ceramics, polymers, and ceramic-polymer composite electrolytes. In ceramic electrolytes, ion transport is accomplished with mobile point defects in a crystal. Li + ions migrate mainly via the vacancy mechanism, interstitial mechanism, or interstitial-substitutional exchange mechanism. In solid polymer electrolytes, Li + ions are transported mainly via the segment motion, ion hopping (Grotthuss mechanism), or vehicle mechanism (mass diffusion). This study has also introduced various electrolyte materials including perovskite oxides, garnet oxides, sodium superionic conductors, phosphates, sulfides, halides, cross-linked polymers, block-copolymers, metal-organic frameworks, covalent organic frameworks, as well as ceramic-polymer composites. In addition, it has highlighted some strategies to improve the ionic conductivity of solid-state electrolytes, such as doping, defect engineering, microstructure tuning, and interface modification.

Opportunities of Flexible and Portable Electrochemical Devices for Energy Storage: Expanding the Spotlight onto Semi-solid/Solid Electrolytes

“…In general, the exact ion transport mechanisms in a polymer electrolyte are complicated and may occur next to each other . The Grotthuss mechanism is widely accepted and considered to be one of the main ion-conducting mechanism, , which occurs via sequential hydrogen-bonding rearrangements by multiple breaking and reforming of the covalent and hydrogen bonds . The surface site hopping has been investigated as a possible mechanism for ion-conducting, where the ions can transfer from one fixed ionic site to a neighboring one on the polymer side chains.…”

Vinylimidazole–based Polymer Electrolytes with Superior Conductivity and Promising Electrochemical Performance for Calcium Batteries

“…Electrolyte chemistries for calcium-ion conduction have focused primarily on oxygen-based coordination chemistry, owing to their proven suitability for other systems, primarily due to the highly polar ether O atoms that enable good salt dissociation. 2,3 This has inspired analogous calcium electrolytes which use common carbonate-4-6 or ether-7 based solvents and predominately ether-based polymer backbones, 8-10 with ionic moieties being one exception. [11][12][13] In the case of polymer electrolytes, however, ether-containing backbones result in low ionic…”

“…1 To keep pace with current advances in lithium metal battery technology, the development of high performance polymer electrolytes is critical to the realization of practical and desired solid or quasi-solid state calcium metal batteries, especially to support safe battery operation in high demand applications, such as electric vehicles and even grid scale storage.Electrolyte chemistries for calcium-ion conduction have focused primarily on oxygen-based coordination chemistry, owing to their proven suitability for other systems, primarily due to the highly polar ether O atoms that enable good salt dissociation. 2,3 This has inspired analogous calcium electrolytes which use common carbonate-4-6 or ether-7 based solvents and predominately ether-based polymer backbones, 8-10 with ionic moieties being one exception. [11][12][13] In the case of polymer electrolytes, however, ether-containing backbones result in low ionic…”

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

“…In addition to complying with thermal stability in a wide range of operating temperatures (it should not be forgotten that the battery in its natural operation emits heat) ( Xu and He, 2014 ) and a high level of ion transport, it must be mechanically robust enough to prevent the growth of dendrites, but also flexible enough not to crack during handling processes ( Takada, 2018 ). Furthermore, two of the main challenges related to the implementation of SSEs are their low ionic conductivity ( Yang and Wu, 2022 ) and the formation of an inefficient electrode-electrolyte interface ( Chen et al, 2020 ; Gao et al, 2022 ). The function of the electrolyte is to build a channel that enables the movement of metallic ions between the anode and cathode during charge and discharge cycles.…”