Poor room-temperature ionic conductivities and narrow electrochemical stable windows severely hinder the application of conventional poly(ethylene oxide)-based (PEO-based) solid polymer electrolytes (SPEs) for high-energy-density lithium metal batteries (LMBs). Herein, we designed and synthesized a PEO-based self-healing solid polymer electrolyte (SHSPE) via dynamically cross-linked imine bonds for safe, flexible solid LMBs. The constructed dynamic networks endow this SPE with fascinating intrinsic self-healing ability and excellent mechanical properties (extensibility > 500% and stress >130 kPa). More importantly, this SHSPE exhibits ultrahigh ionic conductivity (7.48 × 10-4 S cm-1 at 25 °C) and wide ESW (5.0 V vs Li/Li+). As a result, Li||Li symmetrical cells with the SHSPE showed reliable stability in a >1200 h cycling test under room temperature. The assembled Li|SHSPE|LiFePO4 cell maintained a discharge capacity of 126.4 mAh g-1 after 300 cycles (0.1C, 27 °C). This work highlights a promising strategy for next-generation room-temperature solid-state LMBs.

Self-Healing Solid Polymer Electrolyte for Room-Temperature Solid-State Lithium Metal Batteries.

A high ion-conducting, self-healing and nonflammable polymer electrolyte with dynamic imine bonds for dendrite-free lithium metal batteries

Poly(ionic liquid)-functionalized graphene oxide towards ambient temperature operation of all-solid-state PEO-based polymer electrolyte lithium metal batteries

Alkali (lithium, sodium)‐based second batteries are considered one of the brightest candidates for energy‐storage applications in order to utilize the random and intermittent renewable energy to achieve carbon neutrality. Conventional lithium/sodium batteries containing liquid organic electrolytes are vulnerable to electrolytes leakage and even combustion, which hinders their large‐scale and reliable application. All‐solid‐state electrolytes which are considered to have better safety have been developed in recent years. However, most of them suffer from low ionic conductivity and large interfacial resistance with the electrode. Ionogel‐electrolyte membranes composed of ionic liquids and solid matrices, have attracted much attention because of their nonvolatility, nonflammability, and superior chemical and electrochemical properties. This review focuses on the most recent advances of ionogel electrolytes that sprang up with the emerging demand and progress of safe lithium/sodium batteries. The ionogel‐electrolyte membranes are discussed based on the framework components and preparation methods. Their structure and properties, including ionic conductivity, mechanical strength, electrochemical stabilities, and so on, are demonstrated in combination with their applications. The current challenges and insights on the future development of ionogel electrolytes for advanced safe lithium/sodium batteries are also proposed.

Ionogel‐Based Membranes for Safe Lithium/Sodium Batteries

Poly(Ionic Liquid)-Functionalized Graphene Oxide Towards Ambient Temperature Operation of All-Solid-State Peo-Based Polymer Electrolyte Lithium Metal Batteries

Solid-state polymer electrolytes (SPEs) with superior self-healing capacity are urgently required for next-generation flexible energy storage devices Herein, a highly stretchable (extensibility > 4000% and stress > 130 kPa), non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte (SHSPE) was prepared based on the combination of a poly(HFBM-co-SBMA) network, imidazole-based ionic liquid (EMI–TFSI) and LiTFSI The incorporation of the imidazole cation and fluorine atom contributed to the formation of supramolecular bonds (ion–dipole interactions) inside the electrolyte framework, thus endowing SHSPE with prominent self-healing ability (recovery time 200 g) The as-assembled Li/SHSPE3/LiFePO4 battery delivered a high discharge capacity of 1448 mA h g−1 at 02C, and its capacity retention ratio reached 82% after 100 cycles with a coulombic efficiency of 97% In particular, the mechanical properties and conductivity of SHSPE3 could fully recover after repeated damage, conferring the derived soft-pack battery excellent anti-fatigue capability The use of intrinsic self-healing principles in the field of SPEs provides new insight for developing reliable and safe flexible electronic devices

Highly stretchable, non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte for stable and safe flexible lithium batteries

Yong Yang

Papers

Highly stretchable, non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte for stable and safe flexible lithium batteries