Interface Design Enabling Stable Polymer/Thiophosphate Electrolyte Separators for Dendrite‐Free Lithium Metal Batteries

Abstract

Organic/inorganic interfaces greatly affect Li + transport in composite solid electrolytes (SEs), while SE/ electrode interfacial stability plays a critical role in the cycling performance of solid-state batteries (SSBs). However, incomplete understanding of interfacial (in)stability hinders the practical application of composite SEs in SSBs. Herein, chemical degradation between Li 6 PS 5 Cl (LPSCl) and poly(ethylene glycol) (PEG) is revealed. The high polarity of PEG changes the electronic state and structural bonding of the PS 4 3À tetrahedra, thus triggering a series of side reactions. A substituted terminal group of PEG not only stabilizes the inner interfaces but also extends the electrochemical window of the composite SE. Moreover, a LiF-rich layer can effectively prevent side reactions at the Li/SE interface. The results provide insights into the chemical stability of polymer/sulfide composites and demonstrate an interface design to achieve dendrite-free lithium metal batteries.

Water‐Soluble Inorganic Binders for Lithium‐Ion and Sodium‐Ion Batteries

“…All-solid-state batteries (ASSBs) employing inorganic solid electrolytes have attracted tremendous interest in academia and industry in the past years due to their potentially high energy density. [105][106][107] These batteries use a solid pellet/disc of an electrolyte instead of a salt-solvent-based electrolyte and separator. Despite possessing interesting features and prospects, the largescale commercialization of ASSBs has been challenging due to several obstacles.…”

Targeting the Right Metrics for an Efficient Solvent-Free Formulation of PEO:LiTFSI:Li6PS5Cl Hybrid Solid Electrolyte

“…This study underscores the prime importance of optimizing ionic conductivity and mechanical properties concurrently, for successful HSE formulation, and provides valuable insights into key conduction mechanisms. Future research should focus on reducing membrane thickness through particle size control and limiting chemical reactivity, by polymer end group modification 44 or particle protective coating, 43 to match pure ceramic battery performances. Ultimately, we hope that this work serves as a guideline for HSE rational formulation, with emphasis on metric optimization driving further advancements.…”

Multifunctional Asymmetric Separator Constructed by Polyacrylonitrile-Derived Nanofibers for Lithium–Sulfur Batteries

“…The most common strategy is surface modification by coating or dipping with functional materials to enhance the properties of the separator. Carbon materials are attractive in coating of separator, − due to the ability of regulating current, providing attachment sites for soluble polysulfide and reactivating the polysulfides. − Polymer coatings offer a variety of viable options for capturing polysulfides through chemisorption and physical confinement due to the abundance of polar functional groups. − Furthermore, inorganic materials are widely applied in separator coatings due to their ability to produce multiple chemical bonding sites; particularly, the adsorption and catalytic effects of polysulfides by transition metals and their sulfides, nitrides, and oxides are excellent. ,− However, on account of the strongly nonpolar nature of polyolefin materials, the coating layer usually exhibits poor adhesion with the polyolefin matrix of the separator, especially during the repetitive charge/discharge process. Besides, polyolefin separators with simple coatings can hardly promote thermal stability and still suffer from irreversible crispation or deformation at high temperatures, causing a safety issue.…”