A highly-concentrated poly(ethylene carbonate)-based electrolyte for all-solid-state Li battery working at room temperature

Abstract

We report an all-solid-state Li rechargeable battery based on a hybrid membrane comprising a highly-concentrated poly(ethylene carbonate) (PEC) electrolyte with 80 wt% of lithium bis(fluorosulfonyl)imide (LiFSI) and a three-dimensionally ordered macroporous polyimide matrix operating at room temperature. The PEC-LiFSI 80 wt% electrolyte showed an ionic conductivity of the order of 10 -5 S cm -1 at 30 o C and quite high Li transference number, and was employed as a good ion-conductive solid polymer membrane for all-solid-state Li battery. To assure the mechanical stability, the polyimide matrix was combined as a porous substrate to support the electrolyte. A Li|PEC-LiFSI|LiFePO 4 cell with the hybrid membrane delivered a reversible charge-discharge capacity close to 120~130 mAh g -1 at 30 o C and C/20 rate.

Carbonate-linked poly(ethylene oxide) polymer electrolytes towards high performance solid state lithium batteries

“…2(b) presented the temperature dependence of ionic conductivity for PDEC-LiTFSI and PTEC-LiTFSI electrolytes. It could be observed that the temperature dependence agreed well with the Arrhenius equation over the range of C. These electrolytes behaved like the poly(ethylene carbonate) based electrolytes due to similar chemical structures, which was in good accordance with the previous reports by Tominaga [46,47]. The ionic conductivity of PDEC-LiTFSI was 3.81 Â10 À6 S cm À1 at 25 C and 8.11 Â10 À5 S cm À1 at 80 C, respectively.…”

“…These results were much superior to the PEO based lithium batteries [60] and comparable to the PEC and P (CL-co-TMC) based lithium batteries [46,47,49]. The rate capability of the Li/LiFePO 4 cell from 0.1C to 0.5C at 55 C is presented in Fig.…”

“…It was noted that PTEC possessing one more EO repeating unit in the main chains presented higher ionic conductivity and lower activation energy than those of PDEC. The high ionic conductivity up to 10 À5 S cm À1 was comparable to the PEC and P(CL-co-TMC) based polymer electrolytes reported by others [46,47,49]. The lithium ion transference number of PTECLiTFSI electrolyte estimated to be 0.39 by a steady-state current method (Fig.…”

“…Inspired by the advantages of the conventional liquid carbonate electrolytes readily decomposed into polycarbonate species and resulting in stable SEI on both electrodes [2], polycarbonate-based electrolytes have recently attracted great interests in lithium battery field. Since poly(vinylene carbonate) and poly(trimethylene carbonate) based solid electrolyte were firstly reported by Shriver and Smith, respectively, fifteen years ago [44,45], Some more polycarbonate-based solid polymer electrolytes, such as poly (ethylene carbonate) [46,47], p(CL-co-TMC) [48][49][50] and poly (propylene carbonate) [51] have achieved great success in high performance of solid polymer lithium batteries. Moreover, poly (ethylene carbonate) and poly(vinylene carbonate) electrolytes possessing short ethylene oxide (EO) side chains were also reported and both revealed that longer side chains favored better ionic conductivity [52,53].…”

Aliphatic Polycarbonate‐Based Solid‐State Polymer Electrolytes for Advanced Lithium Batteries: Advances and Perspective

“…Adjusting lithium‐salt concentration can also improve the lithium conduction of PEC solid polymer electrolyte. Tominaga reported macroporous polyimide‐supported PEC/LiFSI (in which, the weight ratio of LiFSI to PEC was 4:1). The conductivity reached 1.6 × 10 −5 S cm −1 at 30 °C.…”