Lithium Salt-Induced In Situ Living Radical Polymerizations Enable Polymer Electrolytes for Lithium-Ion Batteries

Abstract

Herein, polymer electrolytes (PEs) were designed and fabricated through lithium salt-induced in situ living radical copolymerization of poly­(ethylene glycol) methacrylate (PEGMA) and various (meth)­acrylates monomers (methyl methacrylate (MMA), n-butyl acrylate (BA), n-butyl methacrylate (BMA), or styrene) with 18-crown-6-ether (18CE6) as both the solvent of copolymerization and the plasticizer of PEs. The lithium salt plays a dual role of activator for alkyl halides (R–X, X = Br or I) initiators, and lithium-ion source. The polymer electrolyte in situ formed in the Li/LiFePO4 cell with a cellulose membrane showed excellent compatibility with electrode materials. The Li/P­(PEGMA-co-MMA)-based PE/LiFePO4 cell possessed an initial discharge capacity of 166.5 mAh g–1 at 0.2C and maintained a capacity of 155.3 mAh g–1 at 0.2C after 290 cycles. The lithium salt-induced in situ polymerization offers a new strategy toward polymer electrolytes for high-performance lithium-ion batteries.

Highly Stretchable and Reconfigurable Ionogels with Unprecedented Thermoplasticity and Ultrafast Self-Healability Enabled by Gradient-Responsive Networks

“…An ionogel is a three-dimensional polymer network hosted in ionic liquids (ILs). − Ionogels are popular owing to their softness and high ion-conductive properties. − Ionogels not only inherit the advantages of ILs including high thermal stability, chemical inertness, and excellent ionic conductivity , but also have additional advantages of mechanical flexibility and high stretchability. , Therefore, functionality-designed ionogels have wide prospects in sensors, , solid electrolytes, − actuators, and many other applications. ,, However, conventional ILs are expensive and toxic, which greatly limits their use in wearable i-skins . Furthermore, the enhancements in mechanical strength of ionogels can be achieved through the design of stable chemical bonding and covalent cross-linking structures and the loss of subsequent secondary processability which undoubtedly leads to resource waste and plastic pollution at the end of their use .…”

Mechanically Strong and Electrochemically Stable Single-Ion Conducting Polymer Electrolytes Constructed from Hydrogen Bonding

“…Zhou et al summarized the fundamental properties, mechanisms of ion migration, and preparation methods of different types of PEs. A polymer electrolyte (PE) is a promising material to prepare safe and high-performance LMBs. − In recent years, solid polymer electrolytes (SPEs) were intensively employed to fabricate LMBs due to their excellent chemical stability, flexibility, and high safety. − Unfortunately, SPEs possess low ionic conductivity and poor contact interfaces with electrodes, which hinder their further potential application in high-performance next-generation batteries. , Relatively, gel polymer electrolytes (GPEs) present high ionic conductivity and good compatibility with electrodes, thus leading to be considered as the candidate materials for the energy storage sources. − However, lithium salt is a dual-ion conductor in GPEs, which can cause concentration polarization and is unable to significantly limit the lithium dendrite formation during the plating/stripping processes.…”

Polyacrylonitrile Porous Membrane-Based Gel Polymer Electrolyte by In Situ Free-Radical Polymerization for Stable Li Metal Batteries

“…Only a step at 4 °C is observed, which is assigned as the T g of PETEA-TCGG-PA, demonstrating that the GPEs exists in an amorphous state without further transitions . The amorphous structure of PETEA-TCGG-PAN is favorable for the increased Li + transport. , …”