The rapid evolution of technology requires the development of next-generation lithium-based batteries that transcend the energy density and safety limitations of current liquid-based electrolyte systems. Solid-state lithium batteries (SSLBs) have emerged as a potential solution to mitigate the leakage risks, flammability, and dendrite growth typical of commercial lithium-ion batteries. This study explores the potential of poly(trimethylene carbonate) (PTMC) with lithium bis(fluorosulfonyl)amide (LiFSA) salt and pyrrolidinium-based organic ionic plastic crystal (OIPC) N, N -diethylpyrrolidinium bis(fluorosulfonyl)amide C 2 epyrFSA as an additive. Initially, the thermal properties, ionic conductivities, and transference numbers of binary PTMC/LiFSA composites were assessed. Subsequently, the influence of adding OIPC at various concentrations to the polymer matrix was investigated. The glass transition ( T g ) decreased monotonically with increasing OIPC concentration, while a melting endotherm was observed at high loadings. All ternary composites exhibited high thermal stability, required for battery applications. The ionic conductivity improved significantly in the ternary composite system, reaching a maximum value of 1.24 × 10 –2 S cm –1 for 22PT80 at 100 °C. The lithium transference number ( t Li + ) of 22PT5 achieved a value of 0.61, exceeding that of conventional electrolytes. Structural analysis confirmed a largely amorphous and homogeneous morphology at low OIPC loading. Fourier-transform infrared (FTIR) and Raman spectroscopy further elucidated the coordination chemistry, indicating that Li + and FSA – interactions are favored over Li + coordination with carbonyl groups, as OIPC was added gradually until a specific concentration threshold was reached. Finally, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) demonstrated excellent electrochemical stability up to 5.0 V and improved Coulombic efficiency of up to 94.75% for the ternary composites compared to the binary composites. These characteristics suggest that PTMC/LiFSA/OIPC ternary composites are promising candidates for safe, high-voltage SSLBs.
Tomimatsu et al. (Thu,) studied this question.