Poly (vinyl ethylene carbonate)-based dual-salt gel polymer electrolyte enabling high voltage lithium metal batteries

Constructing a High-Performance Semi-interpenetrating Gel Polymer Electrolyte via In Situ Polymerization for Lithium Metal Batteries

“…As shown in the figure, the characteristic peaks of vinyl groups (C�C) at 1600−1690 cm −1 for NPGDA and VEC monomers cannot be detected in NVPH, which proves the complete free-radical copolymerization. 34,37,44 In addition, peak values at 1700−1800 cm −1 in NVPH are C�O bonds inherited from the NPGDA and VEC monomers, which ensures a strong interaction with the liquid electrolyte. 34 The characteristic peaks of the PH membrane before and after polymerization are basically the same, which proves that the PH film act as a structural support in NVPH and does not change its chemical structure during the polymerization.…”

“…34,37,44 In addition, peak values at 1700−1800 cm −1 in NVPH are C�O bonds inherited from the NPGDA and VEC monomers, which ensures a strong interaction with the liquid electrolyte. 34 The characteristic peaks of the PH membrane before and after polymerization are basically the same, which proves that the PH film act as a structural support in NVPH and does not change its chemical structure during the polymerization. The molecular weight distribution of the NPGDA-VEC copolymer was tested by GPC, as revealed by Figure S1.…”

“…One representative is the polymer membranes prepared by electrostatic spinning, , which possess a three-dimensional nanofiber network structure with high porosity and hence high electrolyte adsorption and ionic conductivity. In situ polymerization of the gel electrolyte in cells is also conducive to satisfactory electrochemical performance. − The approach can form good interfacial contact with the active material because of its low liquid viscosity, ease of handling, and good wetting ability. ,, In addition, the dissolved electrolyte in the cross-linked network promotes uniform lithium-ion transport and accommodates the volume change of Li deposition, thus preventing the growth of lithium dendrites. − However, this approach requires suitable monomers and initiators that are compatible with the electrolyte solvent, and the polymerization reaction can be initiated in some way after the cell assembly. Besides, for in situ-polymerized GPEs, the solid content and conformation of the polymer can affect the ionic conductivity, physical integrity, and mechanical strength of GPEs.…”

“…Besides, the sole CC bond in VEC can be polymerized with multi-branched polymers, reducing the cross-linking degree of the cross-linked network. The CO groups in NPGDA and VEC can promote ion transport by coupling/decoupling with Li + , thus achieving high ionic conductivity. ,,, Electrospun PVDF-HFP with a high porosity is used as a supporting matrix, which can accommodate more electrolytes and ensure high ionic conductivity. The preparation of GPE via in situ polymerization is conducted in sealed cells at 65 °C for 6 h, which is quite compatible with current lithium battery technology and also brings additional benefits.…”

In situ Synthesis of Gel Polymer Electrolytes for Lithium Batteries

“…Carbonyl-containing polymers, such as polyacrylates and polycarbonates, have strong interactions with the oxygen groups in carbonate solvents, thus exhibiting high electrolyte absorption and excellent ionic conductivity. They are usually synthesized in situ by free radical polymerization of monomers, such as methyl methacrylate (MMA), [11] butyl acrylate (BA), [12] butyl ethoxylated trimethylolpropane triacrylate (ETPTA), [13] pentaerythritol tetraacrylate (PETEA), [14] vinylene carbonate (VC) [15] and vinyl ethylene carbonate (VEC), [16] or crosslinking of oligomers, such as poly(ethylene glycol) methyl ether acrylate (PEGMEA), [17] poly (ethylene glycol)diacrylate (PEGDA). [18] In this Section, polyester-based GPEs are classified into polyacrylates and polycarbonates based on polymer matrix, and different modification strategies are introduced.…”