Tailoring Li-ion transport in hybrid biopolymer electrolyte from Maydis stigma for supercapattery applications

Abstract

Corn Silk Biopolymer (CSBP), a potent biomaterial shed light on offering a sustainable solution to agrowaste and achieve waste valorization. Hybrid Biopolymer Electrolyte (HBPE) was synthesized using corn silk extract by simple solution casting strategy. Freshly synthesized [30wt % CSBP+70 wt % PVDF-Co-HFP] system exemplifies conductivity of 2.35 × 10⁻⁸ Scm⁻¹ and while loading 3.2 v/v % LiClO₄ salt, the conductivity increased to 4.05 × 10⁻⁴ Scm⁻¹ at 25 °C. Structural studies indicate complex formation between the Li⁺ and polar groups within polymer-salt system. From FTIR studies, prominent peaks noticed at 1651 and 1628 cm⁻¹ are due to the interaction of –C=O group with Li⁺ and 625 cm⁻¹ for unbound ClO₄⁻.Our best conducting system reveal Li⁺ ions (t_ion = 0.98) are the major charge carriers. Electrochemical behaviour from CV demonstrates a good reversibility with a specific capacity (Q_s = 25.6 Cg^-1) and specific capacitance (C_sp = 10.67 Fg^-1) at a scan rate of 1 mV s⁻¹. Also, the relation between the peak current with different scan rates for CPL 2 system is estimated from the slope as b = 0.7 suggesting the extraordinary behavior of a hybrid battery and super capacitor offering a unique platform for the sustainable energy storage technology.