In situ forming asymmetric bi-functional gel polymer electrolyte in lithium–sulfur batteries

Abstract

An asymmetric gel polymer electrolyte with dual functions of immobilizing polysulfides and promoting uniform Li deposition.

In situ prepared “polymer-in-salt” electrolytes enabling high-voltage lithium metal batteries

“…1b, and peaks appeared at around 2800-2900, 1760-1726 and 1176 cm À1 , corresponding to the stretching vibration of C-H, C]O and C-O-C, respectively. [30][31][32] However, the redshi of the stretching vibration peak of C]O for the PISE (Fig. S3a †) is attributed to the coordination between Li + and C]O.…”

Composite gel-polymer electrolyte for high-loading polysulfide cathodes

“…The carbonyl group on PMMA strongly interacts with lithium ions. 22,25,29 The absence of the peaks of carbonyl and TFSI À anion groups in the GPE sample with 10 wt% LiTFSI indicates that no redundant carbonyl groups or TFSI À anion groups remained inside the GPE. In contrast, the spectrum of the PMMA-based GPE without LiTFSI featured a peak at 1729 cm À1 due to the absence of lithium salts, whereas the spectra of the GPEs with 15 and 20 wt% LiTFSI featured a peak at 741 cm À1 , indicating an overdosage of lithium salts.…”

“…We first fabricated the PMMA-based GPE with PMMA and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) integrated to a polymeric separator. PMMA, which features a carbonyl group (–CO), has high binding energies to liquid polysulfides and Li 2 S. 29 LiTFSI can improve the ionic conductivity of GPEs. 20 The polymeric separator offers the skeleton of the GPE membrane.…”

Emerging Strategies for Gel Polymer Electrolytes with Improved Dual‐Electrode Side Regulation Mechanisms for Lithium‐Sulfur Batteries

“…Therefore, this GPE exhibits a high ionic conductivity of 2.1 × 10 À 3 S cm À 1 and a high lithium ion transfer number of 0.68 as well as good lithium-anode interfacial compatibility. An asymmetric bifunctional IPN-GPE with interpenetrating network was prepared by cross-linking for LiÀ S batteries by Yang et al [87] The polyvinyl alcohol cyanoethyl (PVA-CN) prepared on the cathode side can effectively suppress polysulfides, while the 1,3-dioxolane (DOL) (PDXL) by in-situ cationic polymerization can effectively promote the uniform deposition of lithium on the anode side (Figure 8c). As a result, the IPN-GPE achieves a high ionic conductivity of 3.23 × 10 À 3 S cm À 1 and a high lithium transfer number of 0.81 at 25 °C, and exhibits stable lithium plating/exfoliation behavior and a homogeneous anode interface layer.…”