Semi-Interpenetrating Network Electrolytes Utilizing Ester-Functionalized Low Tg Polysiloxanes in Lithium-Metal Batteries

Title data

Petry, Jannik ; Dietel, Markus ; Thelakkat, Mukundan:
Semi-Interpenetrating Network Electrolytes Utilizing Ester-Functionalized Low Tg Polysiloxanes in Lithium-Metal Batteries.
In: Advanced Energy Materials. Vol. 15 (2025) Issue 12 . - 2403531.
ISSN 1614-6840
DOI: https://doi.org/10.1002/aenm.202403531

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Abstract in another language

Solid polymer electrolytes (SPE) obtained from polyesters are viable alternatives to polyethylene oxide-based materials, especially for room-temperature applications. In SPEs, the ion conduction is dependent on the polymer segmental mobility and is thus facilitated by low glass transition temperature (Tg). Here, the study synthesizes an ester-funtionalized polysiloxane-based polymer electrolyte with an exceptionally low Tg of −76 °C, resulting in a high ionic conductivity of 2.6 × 10⁻⁵ S cm⁻¹ at room temperature and a lithium transference number of 0.72. However, the low Tg and consequently low mechanical stability require reinforcement to promote the formation of stable lithium-electrolyte interfaces in lithium plating stripping experiments and stable battery cycling in lithium-metal batteries (LMBs). For this, the SPE is incorporated into a network structure to yield a semi-interpenetrating network electrolyte (SPE20-SIPN) which results in significantly improved storage modulus by three orders of magnitude and ionic conductivity is maintained upon crosslinking. The SPE20-SIPN exhibits stable cycling for up to 50 cycles with fluctuation (voltage noise) in some of the cells. A combination of crosslinking and nanoparticle addition (SPE20-N10-SIPN) overcomes the voltage noise and results in high coulombic efficiencies and high capacity retention above 80% for 200 cycles in solvent-free, all-solid-state LMBs at 30 °C.