POS6-0475
Mechanically Optimized Fluorinated Elastomer Electrolytes for Stable Operation of Lithium Metal Batteries at Low Temperature
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Dongkyu Lee (Korea Advanced Institute of Science and Technology)
Co-Author(s)
Abstract
The mechanical properties of polymer electrolytes are critical for stable lithium metal battery (LMB) operation, as they accommodate volumetric changes of the Li metal anode, suppress dendrite formation, and maintain conformal interfacial contact. Here, we present a systematic study on fluorinated elastomeric electrolytes (FEEs) with a bicontinuous structure comprising an elastomer phase and a plastic crystal phase. By modulating the crosslinking density of the elastomer phase, the mechanical properties are independently tuned while preserving high ionic conductivity through the plastic crystal phase. The optimized FEE exhibits excellent ionic conductivity of ~1.1 mS cm⁻¹ at 25 °C and ~0.24 mS cm⁻¹ at −10 °C, along with balanced mechanical properties (toughness of 140.6 kJ m⁻³, adhesion energy of 31.4 J m⁻²) and elastic recovery under cyclic compression. These characteristics enable a Li|FEE|NCM811 full cell to achieve high initial discharge capacity (153 mAh g⁻¹) and retain 76% of the capacity after 150 cycles at −10 °C. In contrast, low crosslinking density leads to plastic deformation and interfacial loss, while excessive crosslinking induces brittleness, both resulting in poor cycling performance. This study highlights the importance of optimizing the mechanical properties of elastomeric electrolytes for stable LMB operation under demanding conditions and provides critical insights for the design of high-performance solid-state batteries.
