LLZO‐Assisted PEO‐PVDF Blend‐Based Polymer Electrolytes for Device Application

ABSTRACT This study uses a polymer blend as a host polymer prepared by PEO and PVDF‐HFP, with Li 7 La 3 Zr 2 O 12 (C‐LLZO) and Li 6.5 La 3 Zr 1.75 Te 0.25 O 12 (Te‐LLZO) as ceramic fillers and lithium trifluoro methane sulfonate (LiCF 3 SO 3 ) as a salt. Using the XRD and FTIR spectra, the impact of ceramic (C‐LLZO and Te‐LLZO) on enhancing the salt dissociation and cation coordination with oxygen atoms in PEO and fluorine atoms in PVDF‐HFP has been investigated. Notable changes in ceramic peak intensity, peak position, and the existence of an amorphous hump in XRD spectra indicate an increased amorphous content with low ceramic loading. However, the crystallinity of the electrolyte increases with increasing ceramic loading. With different ceramic loading, the vibrational bands of CF 2 and COC have shifted and varied. It shows that ceramic loading has significantly impacted cation coordination with those peaks. Conversely, the enhanced ion dissociation with ceramic variation is established by the deconvolution of FTIR in the wavenumber region of 1020–1050 cm −1 . The free anion content is substantial at 20 wt% ceramic loading, according to FTIR measurements. It suggests a greater likelihood of available cations for coordination. The optimized polymer blend‐salt‐ceramic composite sample shows an excellent DC conductivity at room temperature of 0.613 × 10 −3 Scm −1 . This is an enhancement of approximately two orders compared to the blend‐salt system. Along with that, this optimized polymer blend composite shows excellent voltage stability of 5.90 V and thermal stability up to ~400°C. Furthermore, an EDLC device has been developed using the optimized composite electrolyte. It shows an impressive specific capacitance of 6.52 mF/g at a 10 mV/s scan rate.