Lignin-Assisted NiO Nanocomposite Electrode for High-Performance Supercapacitors: Structural Insights and Charge Storage Mechanism
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS, sa.1, ss.1-13, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10904-026-04520-5
- Dergi Adı: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
- Derginin Tarandığı İndeksler: Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Science Citation Index Expanded (SCI-EXPANDED), Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Sayfa Sayıları: ss.1-13
- Hakkari Üniversitesi Adresli: Evet
Özet
The development of sustainable electrode materials requires the integration of renewable components without compromising electrochemical kinetics or structural durability. Herein, a NiO/lignin nanocomposite was prepared through ligninassisted hydrothermal synthesis followed by thermal treatment at 350 °C. Structural and spectroscopic analyses confirmed the formation of cubic NiO crystallites within a thermally transformed lignin-derived matrix containing residual aromatic and oxygen-bearing functionalities. The composite exhibited an average particle size of approximately 33 nm, a BET surface area of 86.4 m2 g−1, a total pore volume of 0.31 cm3 g−1, and a mesopore diameter centred at approximately 8.7 nm. The higher surface area and pore volume relative to pristine NiO support the structure-regulating effect of lignin incorporation. Electrochemical performance was evaluated in 1 M KOH using a three-electrode configuration, with pristine NiO and pristine lignin electrodes examined under identical fabrication and testing conditions. The NiO/lignin electrode delivered a specific capacitance of 812 F g−1 at 1 A g−1 and retained 74.1% of this value at 20 A g−1. Its equivalent series and charge-transfer resistances were 0.82 and 3.35 Ω, respectively, indicating reduced ohmic losses and facilitated interfacial charge transfer. The anodic and cathodic b-values of 0.84 and 0.79, together with the Dunn analysis, revealed a mixed charge-storage mechanism involving surface-controlled and diffusion-dependent Faradaic contributions. Moreover, the electrode retained 94.2% of its initial capacitance with a Coulombic efficiency of 99.1% after 5000 cycles. The combined structural, kinetic, and control-electrode results indicate that NiO provides the primary Ni2+/Ni3+ redox sites, whereas the lignin-derived matrix improves particle dispersion, electrolyte accessibility, interfacial transport, and cycling stability. These findings establish the NiO/lignin nanocomposite as a promising electrode material while recognizing that its practical device performance requires further validation in a mass-balanced two-electrode configuration.