and mechanical resilience. While ceramic electrolytes offer high Li⁺ conductivity, their brittleness and poor electrode interfacial contact limit practical adoption.
UV-cured polymer electrolytes present a promising alternative, enabling rapid, solvent-free synthesis with tunable network structures and enhanced interfacial adhesion.
However, SPEs often suffer from low ionic conductivity and narrow voltage stability windows. To address these challenges, we investigate the role of inorganic fillers (oxides, carbides, nitrides) in UV-cured polyethylene glycol diacrylate (PEGDA)-succinonitrile composite electrolytes.
A systematic study was conducted using electrochemical impedance spectroscopy (EIS) and voltammetric techniques to evaluate filler-dependent ionic conductivity and stability.
Membranes were synthesized via UV polymerization in a stainless-steel blocking electrode setup, with EIS measurements (1 MHz–1 kHz) used to determine Li⁺ transport properties.
Cyclic and linear sweep voltammetry assessed electrochemical stability windows, while filler-polymer interactions were probed to elucidate conductivity mechanisms.
Key findings reveal stark trade-offs between filler chemistry and performance:
Nitrides offered amelioration to the ionic conductivity (~10-6 s/cm) at low loadings (1 ~ 3 % weight), carbides showed dependence on chemical composition as
tungsten carbide (3.37-5 S/cm) outperformed both silicon carbide and titanium carbide(~1.56-6 S/cm). Oxides investigated offered better ionic conductivity such
as Vanadium oxide (2.54-5 S/cm at 8% loading). Other oxides were not as successful, with lithium lanthanum zirconium oxide only offering conductivities on the order of 10-7 S/cm.
This work underscores the critical impact of filler selection in UV-cured SPE design, offering guidelines to tailor conductivity-stability balances for high-voltage
or high-energy-density applications. The results pave the way for scalable, fabrication-friendly electrolyte membranes that bridge the gap between ceramic and polymer-based systems.