Recent advances in separator engineering for effective dendrite suppression of Li‐metal anodes

Abstract

Lithium dendrites cause battery failures and safety hazards in liquid‐electrolyte lithium‐based batteries. To address this problem, each component of the battery, such as cathode, anode, electrolyte and separator, should be well matched and engineered for the integrated battery system. The separator plays an increasingly important role owing to its gradual transformation from an inert to an active component in the battery, especially for resolving Li dendrite issues in Li‐metal batteries. Armed with advanced nanotechnology solutions, separator engineering presents a formidable strategy to suppress dendrite growth dynamics by modifying the electrolyte chemistry, regulating/trapping unwanted ionic species and redirecting dendrite growth direction. This review summarizes recent advances in separator engineering for effective dendrite suppression of Li‐metal anodes. We first introduce the challenges that the Li‐metal anode faces and the irreplaceable role of separators in the battery system. The characterization parameters and design principles of separators are also discussed. Then, the mainstream techniques for separator functionalization and their impacts on dendrite suppression are scrutinized and highlighted. Lastly, the conclusion is drawn and the future outlook for separator engineering is presented.

Covalent functionalization of carbon materials with redox-active organic molecules for energy storage

“…69 After this study, a variety of redoxactive organic molecules have been studied, including small organic molecules such as quinones and dianhydrides and conjugated polymers such as polypyrrole and polyacetylene. The reported redox-active organic molecules can be categorized into carbonyl compounds, 70 organic radicals, 71 organosulfur compounds, 72 phenazine derivatives, 73 and conductive polymers (Fig. 2).…”

Aramid Nanofibers Reinforced Cellulose Paper-Based Lithium-Ion Battery Separator with Improved Safety and Cycling Stability

“…This structure was bene cial to the fast transportation of Li + between the cathode and anode, yielding good rate performance for the battery. However, the large-sized pores of CF membrane easily caused self-discharge and internal short-circuits arising from lithium dendrite growth or the migration of electrode particles (Boateng et al 2021;Pan et al 2017). Thus, aramid nano bers with different ratios were introduced to regulate the pore size of CF membrane through the facile ltration process.…”

Surface-Functionalized Separator for Stable and Reliable Lithium Metal Batteries: A Review

“…In this regard, the polymer separator should maintain its structure integrity even at elevated temperatures, in order to circumvent the potential battery failure. According to USABC requirements for conventional battery separators, the targeted shrinkage of the separator is less than 5% at 200 °C, and the calendar life of the separator is 15 years [ 79 ]. Therefore, the thermal properties of separators should be taken into account when designing functional separators for LMBs.…”