Fabrication and characterization of boron carbide-reinforced poly (lactic acid)-poly(butylene adipate terephthalate) membranes for supercapacitor applications

Boron carbide (B 4 C) reinforced poly(lactic acid) (PLA)-poly(butylene adipate-co-terephthalate) (PBAT) composites were systematically analysed to understand their structural, thermal, morphological, and electrochemical behaviour. Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy revealed physical interactions between B 4 C and the polymer matrix, while X-ray diffraction (XRD) indicated that B 4 C remained largely amorphous at low loadings. Scanning electron microscopy (SEM) imaging showed uniform nanoparticle. Thermal properties assessed via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) demonstrated a concentration-dependent effect of B 4 C on stability. Electrochemical performance was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) tests, identifying 0.75 wt% B 4 C@PLA-PBAT as the optimal composition. This electrode exhibited a high specific capacitance of 372 F g⁻ 1 at 2 A g⁻ 1 . It delivered an energy density of 206.7 Wh kg⁻ 1 at a power density of 8000 W kg⁻ 1 and retained 87 % capacitance over 5000 cycles, confirming durability. Compared to pristine PLA-PBAT and other reported biopolymer-based composites, the B 4 C reinforcement significantly enhanced charge storage efficiency and cyclic stability, highlighting a clear improvement in electrochemical performance. This demonstrates the novelty of integrating B 4 C as an active filler to synergistically enhance conductivity, interfacial charge transfer, and mechanical robustness. These findings establish B 4 C-reinforced PLA-PBAT as a promising material for high-performance supercapacitors. • B 4 C nanoparticles were uniformly dispersed in PLA-PBAT, confirmed by FTIR, Raman, XRD, and SEM. • Thermal stability improved with increasing B 4 C content, as shown by TGA and DSC. • Optimal electrochemical performance was achieved at 0.75 wt% B4C. • The composite showed 372 F g −1 capacitance and 206.7 Wh kg −1 energy density. • Excellent cycling stability with 87 % capacitance retention after 5000 cycles.