Fabrication of a nano-Li⁺-channel interlayer for high performance Li–S battery application

Abstract

Nano-Li+-channel membranes were first proposed and prepared for a Li–S battery, based on a concept of separating the polysulfide particles via size exclusion. This concept could help overcome the polysulfide permeating problems and provide more options for Li–S development.

Phase Inversion: A Universal Method to Create High‐Performance Porous Electrodes for Nanoparticle‐Based Energy Storage Devices

“…As for the phase inversion process, the PVDF‐HFP polymer could be solidified immediately in water, which is a zero‐strain process and could keep the electrode intact. As shown in Figure S5 in the Supporting Information, similar to the PVDF‐based membranes in previous reports, the surface and cross‐section morphology of PVDF‐HFP binder obtained by direct drying process (labeled as PVDF‐HFP‐DD) are dense, while the binder obtained by phase inversion (labeled as PVDF‐HFP‐PI) presented a porous structure . The porous structure of PVDF‐HFP‐PI leads to a decreased degree of crystallinity (Figure S4b, Supporting Information), which is also reported to enhance the adhesive strength of PVDF based materials .…”

Hierarchical sulfur electrodes as a testing platform for understanding the high-loading capability of Li-S batteries

“…Thus, the development of structural cathode configurations paves a new way toward effectively utilizing the unique materials chemistry of sulfur and developing corresponding Li-S battery chemistries based on high loading cathodes [12,15,29,30]. Many efforts have focused on suppressing the active-material loss using a porous current collector [30][31][32][33][34][35][36] and blocking the active-material diffusion using a free-standing interlayer [35][36][37][38][39][40][41] or a multifunctional separator [42][43][44][45][46][47][48][49][50][51][52][53]. These two approaches either create a polysulfide reservoir to absorb the dissolved polysulfides [31][32][33][34][35][36] or establish a polysulfide filter to maintain the diffusing polysulfides within the cathode region of the cell [37][38][39][40][41][42][43][44]…”

Anode Improvement in Rechargeable Lithium–Sulfur Batteries

“…The Li–S cell containing the polypyrrole nanotube interlayer and an electrolyte consisted of 1 m LiTFSI in DOL and DME (1:1 v/v) with no LiNO 3 additive exhibits a high specific capacity (>1100 mAh g −1 ), good cycle stability (>700 mAh g −1 over 300 cycles) and high Coulombic efficiency (about 92%) in a voltage range of 2.8–1.8 V (vs Li/Li + ) . A nano‐Li + ‐channel interlayer of the Li–S battery was synthesized by swelling the dense polyvinylidene fluoride (PVDF) membrane in an electrolyte containing 1 m LiTFSI in DOL and DME (1:1 v/v) without LiNO 3 additive, and its special ions transport channels could selectively separate the Li + and polysulfide . Consequently, the nano‐Li + ‐channel interlayer can confine the lithium polysulfide shuttling, leading to a high specific capacity as well as a good cyclability between 1.5 and 2.8V.…”