In this study, we have fabricated the phenolic resin (PR)/polyacrylonitrile (PAN) blend-derived core-sheath nanostructured carbon nanofibers (CNFs) via one-pot solution electrospinning. The obtained core-sheath nanostructured carbon nanofibers were further treated by mixed salt activation process to develop the activated porous CNFs (CNF-A). Compared to pure PAN-based CNFs, the activated PR/PAN blend with PR 20% (CNF28-A)-derived core-sheath nanostructured CNFs showed enhanced specific capacitance of ~ 223 F g− 1 under a three-electrode configuration. Besides, the assembled symmetric CNF28-A//CNF28-A device possessed a specific capacitance of 76.7 F g− 1 at a current density of 1 A g− 1 and exhibited good stability of 111% after 5,000 galvanostatic charge/discharge (GCD) cycles, which verifies the outstanding long-term cycle stability of the device. Moreover, the fabricated supercapacitor device delivered an energy density of 8.63 Wh kg− 1 at a power density of 450 W kg− 1.

Salt-activated phenolic resinPAN-derived core-sheath nanostructured carbon nanofiber composites for capacitive energy storage
    Abstract
    1 Introduction
    2 Experimental
        2.1 Preparation and stabilization of the PRPAN-based nanofibers
        2.2 Salt activation and carbonization of the stabilized PRPAN-based nanofibers
        2.3 Characterization
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Danyun Lei(College of Urban Construction, Wuchang Shouyi University, Wuhan 430064, People’s Republic of China, Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan 430074, Hubei, People’s Republic of China)
• Xiang‑Dan Li(Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan 430074, Hubei, People’s Republic of China)
• Min‑Jung Ma(Department of Organic Materials & Fiber Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea, Department of Carbon Composites Convergence Materials Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea)
• Da‑Young Kim(Department of Organic Materials & Fiber Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea, Department of Carbon Composites Convergence Materials Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea)
• Jae‑Hyun Noh(Department of Organic Materials & Fiber Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea, Department of Carbon Composites Convergence Materials Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea)
• Byoung‑Suhk Kim(Department of Organic Materials & Fiber Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea, Department of Carbon Composites Convergence Materials Engineering, Jeonbuk National University, 567 Baekje‑daero, Deokjin‑gu, Jeonju‑si, Jeollabuk‑do 561‑756, Republic of Korea)