Effects of lithium perchlorate on the electrochemical performance of PVDF-HFP/CA composite-based solid-state electrolytes

Composite-based polymer electrolytes have attracted considerable attention due to their high ionic conductivity and excellent electrochemical performance in energy storage applications. This study explores the influence of Lithium Perchlorate (LiClO ₄ ) loading on the electrochemical performance of composite-based solid-state electrolytes (SSEs) based on a composite of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and 20% cellulose acetate (CA), referred to as PVDF-HFP/20%CA. Utilizing a solution casting method, four SSE samples were fabricated: a control (0% LiClO ₄ ) and three samples with varying LiClO ₄ concentrations (5%, 10%, and 15%). Comprehensive characterizations, including scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), physical characterization, and electrochemical impedance spectroscopy (EIS) were conducted to assess the impact of LiClO ₄ on the composites. The Nyquist plot and DC ionic conductivity analysis further validate the superior performance of PH20CA-15Li (PVDF-HFP/20% cellulose acetate with 15% LiClO ₄ ), with ionic conductivity increasing from 1.15 × 10 ⁻⁶   S cm ⁻¹ for the control sample to 3.7 × 10 ⁻⁶   S cm ⁻¹ . Loss Tangent and Cyclic Voltammetry analyses underscore the dynamic electrochemical behavior and stability of PH20CA-15Li, with the voltage window expanding from 0.996 V in the control sample to 1.398 V, highlighting its enhanced dielectric properties and energy storage capabilities. Electrolyte uptake and porosity analyses reveal a decrease in both parameters with increased LiClO ₄ content, suggesting a trade-off between electrochemical performance and physical properties. SEM and FTIR analyses show structural and chemical changes, confirming the interaction between LiClO ₄ and the composite matrix. The study concludes that 15% LiClO ₄ loading optimally balances conductivity with physical properties, making it a promising candidate for advanced solid-state electrolyte applications.