The development of high specific surface area and mesoporous activated carbons is required to improve the electrochemical performance of EDLC. In this study, kenaf-derived activated carbons (PK-AC) were prepared for high-power-density EDLC via phosphoric acid stabilization and steam activation. The pyrolysis behavior of kenaf with respect to the phosphoric acid stabilization conditions were examined via TGA and DTG. The textural properties of PK-AC were studied with N2/ 77 K adsorption–desorption isotherms. In addition, the crystalline structure of PK-AC was observed via X-ray diffraction. The specific surface area and mesopore volume ratio of PK-AC were determined to be 1570–2400 m2/ g and 7.7–44.5%, respectively. In addition, PK-AC was observed to have a high specific surface area and mesopore volume ratio than commercial coconut-derived activated carbon (YP-50F). The specific capacitance of PK-AC was increased from 77.0–99.5 F/g (at 0.1 A/g) to 49.3–88.9 F/g (at 10.0 A/g) with activation time increased. In particular, K-P-15-H-9–10 observed an approximately 35% improvement in specific capacitance at a higher current density of 10.0 A/g compared to YP-50F. As a result, the phosphoric acid stabilization method was confirmed to be an efficient process for the preparation of high specific surface area and mesoporous biomass-derived activated carbons, and the kenaf-derived activated carbons prepared by this process have great potential for application as electrode active materials in high-power EDLC.

Kenaf-derived mesoporous activated carbons and its application as a high-power density electric double-layer capacitor electrode
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Chemical stabilization
        2.3 Steam activation
        2.4 Characterization
        2.5 Electrochemical performance
        2.6 Electrochemical performance
    3 Results and discussion
        3.1 Thermal gravimetric analysis
        3.2 Crystal structure characteristics
        3.3 Morphological characteristics
        3.4 Adsorption isotherm and textural properties
        3.5 Electrochemical performance
    4 Conclusions
    References

• Hye‑Min Lee(Industrialization Division, Korea Carbon Industry Promotion Agency, Jeonju 54853, Republic of Korea)
• Ju‑Hwan Kim(Industrialization Division, Korea Carbon Industry Promotion Agency, Jeonju 54853, Republic of Korea, Department of Polymer Engineering, Chonnam National University, Gwangju 611186, Republic of Korea)
• Dong‑Shin Jo(Industrialization Division, Korea Carbon Industry Promotion Agency, Jeonju 54853, Republic of Korea, Department of Carbon Materials and Fiber Engineering, Jeonbuk University, Jeonju 54896, Republic of Korea)
• Yoong Ahm Kim(Department of Polymer Engineering, Chonnam National University, Gwangju 611186, Republic of Korea)
• Byung‑Joo Kim(Material Application Research Institute, Jeonju University, Jeonju 55069, Republic of Korea, Department of Materials Science and Chemical Engineering, Jeonju University, Jeonju, 55069, Republic of Korea)