Synthesis of Single Lithium-Ion Conducting Polymer Electrolyte Membrane for Solid-State Lithium Metal Batteries

Abstract

Synthesis of single lithium-ion conducting polymer electrolyte membrane (SLIC-PEM) composed of polymerized lithium 4-styrenesulfonyl(trifluoromethylsulfonyl)imide (PLiSTFSI), poly-(ethylene glycol) methyl ether methacrylate (PEGM), poly(ethylene glycol) dimethacrylate (PEGDMA), and ethylene carbonate (EC) is reported. SLIC-PEM combines the advantages of single lithium-ion conducting polymer electrolytes, cross-linked flexible polymer electrolytes, and the liquid electrolyte of carbonate. The synthesized SLIC-PEMs have superior thermostability, high ionic conductivity, a wide electrochemical window, and high lithium-ion transference number. The corresponding LiFePO 4 |SLIC-PEM|Li cell delivers high Coulombic efficiency and excellent discharge capacity and cycling performance, demonstrating that SLIC-PEMs will have promising application in nextgeneration safe lithium metal batteries.

Comprehensive Review of Polymer Architecture for All-Solid-State Lithium Rechargeable Batteries

“…Furthermore, when single-ion segments are incorporated into an SPE network, the transference number improves. Nevertheless, the use of a liquid plasticizer remains advantageous for ion conduction and improving the flexibility of the SPE membrane [101,102]. [98].…”

Conductivity–modulus–Tg relationships in solvent‐free, single lithium ion conducting network electrolytes

“…[67,68] A polar PEO chemistry further improves ion solvation and increases conductivity. [67,69,70] In contrast to prior work on a Li-conducting gel [29,49,50] or networks, [55] our acrylic EO monomers were synthesized to have precise lengths of crosslinker and comonomer rather than using commercially available EO diacrylates with a chain length distribution. By tuning the molar ratio between the crosslinker and comonomer, control of crosslinking density was achieved.…”

“…[33,52,53,76,[80][81][82][83][84] In many cases, small molecule organic solvent is added to boost the performance and form a gel electrolyte. [29,49,80,84] As shown in Figure S8, we have also measured ionic conductivity of the 1% 12,3 1:20 network electrolyte swollen with propylene carbonate (PC). At high temperature (90 C), the ionic conductivity exceeds 10 −4 S/cm and a preliminary transference number test indicates it is essentially a single-ion conductor with t + = 0.85 ( Figure S11).…”

“…Such single-ion conducting gel systems (filled with electrochemically stable organic solvent) have t Li + higher than 0.5 and they have shown better dendrite suppression capability. [29,[49][50][51] Most commonly, a derivative of trifluoromethane sulfonimide (TFSI) is tethered to a linear, random, or block copolymer, [51][52][53][54] or a network. [29,49,50,55] The advantages of a network structure and improved transference number make crosslinked Li + single-ion conductors an attractive candidate for safer solid-state electrolyte with improved dendrite suppression capability.…”

“…[29,[49][50][51] Most commonly, a derivative of trifluoromethane sulfonimide (TFSI) is tethered to a linear, random, or block copolymer, [51][52][53][54] or a network. [29,49,50,55] The advantages of a network structure and improved transference number make crosslinked Li + single-ion conductors an attractive candidate for safer solid-state electrolyte with improved dendrite suppression capability. Although block copolymers can have higher modulus, [53,54,56] they also present tortuous pathways for ions and alignment may be important for efficient conduction.…”