Al2O3 nanofiber-decorated B4C heterostructures for high-power hybrid supercapacitors
Journal of Energy Storage, cilt.14, sa.5, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 14 Sayı: 5
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.est.2026.124379
- Dergi Adı: Journal of Energy Storage
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
- Anahtar Kelimeler: B4C/Al2O3, Boron carbide (B4C), Electrochemical energy storage, Hybrid supercapacitor, Sol–gel synthesis
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
The development of electrode materials that combine high energy density, rapid charge–discharge capability, and long-term cycling stability remains a major challenge for hybrid supercapacitors. Herein, B4C and B4C/Al2O3 powders were synthesized through a glycerol-based sol–gel route using citric acid or tartaric acid as gel modifiers, followed by pyrolysis and final heat treatment in graphite or alumina crucibles. Tartaric acid promoted more complete conversion to crystalline B4C and predominantly equiaxed particle formation, whereas the citric-acid-derived samples retained a minor B2O3 phase and exhibited more pronounced liquid-phase-assisted morphological evolution. The combined use of citric acid as the gel modifier and an alumina crucible enabled the in-situ formation of Al2O3 nanofibers on the surfaces of B4C particles, producing a hierarchical B4C/Al2O3 architecture. The highest electrochemical performance was obtained for the citric-acid-derived sample heat-treated in an alumina crucible, demonstrating that the electrochemical response was governed by the coupled effects of gel-modifier chemistry and crucible environment. The heterostructured electrode delivered a specific capacity of 254C g−1 at 2 A g−1 with excellent rate capability. The corresponding hybrid supercapacitor assembled with an O,N-enriched activated-carbon negative electrode achieved a specific capacitance of 65 F g−1 at 0.5 A g−1, an energy density of 19.5 Wh kg−1 at a power density of 450 W kg−1 and maintained 4.5 Wh kg−1 at 10,500 W kg−1. The device retained approximately 94% of its initial capacitance after 10,000 cycles. These results demonstrate that controlling the interaction between gel-modifier chemistry and crucible-mediated phase evolution provides an effective route for tailoring the phase composition, microstructure, and electrochemical behavior of B₄C- based heterostructured electrodes.