Polymeric Ionic Liquid‐poly(ethylene glycol) Composite Polymer Electrolytes for High‐Temperature Lithium‐Ion Batteries

Abstract

A new family of composite polymer electrolytes (CPEs) is developed by blending pyrrolidinium‐based polymeric ionic liquid [P(DADMA)TFSI], poly(ethylene glycol) [PEG800], and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). The structure, thermal behavior, electrochemical properties of these CPEs, as well as their potential application in high‐temperature lithium‐ion batteries (LIBs) are studied. The FTIR result reveals the interactions among P(DADMA)TFSI, PEG800, and Li+ cations. X‐ray diffraction and differential scanning calorimetry measurements show that the as‐prepared CPEs have amorphous structures. Furthermore, CPEs exhibit satisfactory ionic conductivity, as well as high thermal and electrochemical stabilities. In addition, Li/LiFePO4 cells with the as‐prepared CPE at 0.2C rate can achieve a discharge capacity of about 150 mA h g−1 at 80oC, with good capacity retention. These findings indicate that the as‐obtained CPEs have great potential for applications as safe electrolytes in high‐temperature LIBs.

Pyrrolidinium‐PEG Ionic Copolyester: Li‐Ion Accelerator in Polymer Network Solid‐State Electrolytes

“…[20][21][22][23] In particular, polymerized ionic liquids (PILs) were originally designed to provide both the ion-conducting properties of ionic liquids and the mechanical strength of polymers for solid-state electrolytes. [24][25][26][27] Unlike ionic liquids, however, pure PILs tethered to solid-state films usually do not show enough room-temperature ionic conductivity to be applicable in Nonflammable lithium-ion batteries (LIBs) are developed by adapting polymer solid electrolytes, but their insufficient electrochemical performance has not been fully addressed to date. Crosslinked polymer gel electrolytes with minimal organic solvents (hard gels) are proven to be nonflammable electrolytes, but their lithium metal battery performance is not comparable to those of conventional liquid electrolyte-based systems.…”

Covalent Organic Frameworks-Enhanced Ionic Conductivity of Polymeric Ionic Liquid-Based Ionic Gel Electrolyte for Lithium Metal Battery

“…For the IL, the bands associated with the TFSI anion can be observed at 1057 (v s O 2 SN-SO 2 ), 1134 (v s SO 2 ), 1194 (v as CF 3 ), and 1227 (v s CF 3 ). 22,48 An obvious peak shift is observed when PDADMA TFSI is blended with the ILs. Taking the Set G sample as an example, the peak of the −SO 2 group at 1134 cm −1 and the peak of −SO 2 −N−SO 2 − group at 1057 cm −1 are shifted to lower wavenumbers, indicating weaker interactions of TFSI anions with positively charged species such as Li + , PYR 14 + , and other charged aggregates.…”

Poly(ionic liquid)-Based Quasi-Solid-State Copolymer Electrolytes for Dynamic-Reversible Adsorption of Lithium Polysulfides in Lithium–Sulfur Batteries

“…The introduction of ILs into the ester-rich polymer backbone by copolymerization can significantly reduce the shuttle of LiPSs. At the same time, the ionic conductivity of the polymer electrolyte can be improved by the synergy between the components. − However, to our knowledge, there are no publications on the above poly­(ionic liquid)-based QPEs up to now.…”