Upgrading Traditional Organic Electrolytes toward Future Lithium Metal Batteries: A Hierarchical Nano-SiO₂-Supported Gel Polymer Electrolyte

Abstract

Developing safe and high-energy-density lithium metal batteries (LMBs) is considered to be the focus of next-generation rechargeable batteries. However, the inevitable lithium reaction with the liquid electrolyte and the subsequent formation of Li dendrites must be overcome, and upgrading traditional liquid electrolytes is a key strategy for achieving this goal. Here, we report a nano-SiO2-supported gel polymer electrolyte (SiO2-GPE) with a hierarchical structure fabricated via in situ gelation of a traditional organic liquid electrolyte supported on a functionally modified SiO2 layer, which displayed high ionic conductivity (1.98 × 10–3 S cm–1 at 25 °C) and wide electrochemical window (>4.9 V vs Li/Li+). The LiFePO4/SiO2-GPE/Li cells exhibited a high capacity of 125.5 mAh g–1 at 1 C with capacity retention of 88.42% after 700 cycles. The superior electrochemical performance is mainly due to the highly compatible electrode/electrolyte interface and the effective inhibition of Li dendrite growth provided by the synergistic effects of this SiO2-GPE membrane.

Single‐Ion Conducting Polymer Electrolytes for Solid‐State Lithium–Metal Batteries: Design, Performance, and Challenges

“…One of the main issues for SICPEs is their relatively lower ionic conductivity (commonly not exceeding 10 −6 S cm −1 at room temperature) compared to that of conventional liquid electrolytes, ceramic electrolytes, and dual‐ion SPEs. [ 157 ] The possible explanation is that compared with ceramic electrolytes, only a small portion of cation mobility contributes to the cationic conductivity of SICPEs, which is mainly due to their limited concentration of mobile ions and relatively slow segmental dynamics. [ 158 ] It is crucial to research intensively on synthesizing SICPEs with proper chemical structures, which can be associated with ML techniques to select the alternative materials in a reasonable time scale.…”

“…Status of published studies using SICPEs and DICPEs in symmetric Li/Li cells. [ 126–128,130–133,136,138,143,144,146,147,156,157 ] …”

Excellent Performances of Composite Polymer Electrolytes with Porous Vinyl-Functionalized SiO2 Nanoparticles for Lithium Metal Batteries

“…Yang's group proposed a strategy for synthesizing nano-sized SiO 2 particles in situ within PEO matrix through acid-base interaction and hydrogen bonding, showing an improved ionic conductivity (≈1.1 × 10 −4 S cm −1 at 30 • C) [39]. Furthermore, functionalized mesoporous silicon materials have been widely researched in the past decades due to the large specific surface area and controllable microstructure, which endow them with great potential for applications in CPEs [40]. Kim's group introduced mesoporous organosilica into PEO and the CPE demonstrated an ion transfer number up to 0.9 [41].…”

A Review of Emerging Dual‐Ion Batteries: Fundamentals and Recent Advances

“…Typically, GPEs are comprised of liquid electrolytes immobilized in different polymer hosts with the addition of other nanofillers (e.g., SiO 2 , ZrO 2 , Al 2 O 3 , TiO 2 ), which reinforce the porosity, mechanical, and thermal properties. [ 121 ]…”