Preparation of Porous Carbon Nanofibers with Tailored Porosity for Electrochemical Capacitor Electrodes.

Jisu Kim,Sung-Kon Kim,Youn-Ji Heo,Jin-Yong Hong

doi:10.3390/ma13030729

Abstract

Porous carbon electrodes that accumulate charges at the electrode/electrolyte interface have been extensively investigated for use as electrochemical capacitor (EC) electrodes because of their great attributes for driving high-performance energy storage. Here, we report porous carbon nanofibers (p-CNFs) for EC electrodes made by the formation of a composite of monodisperse silica nanoparticles and polyacrylonitrile (PAN), oxidation/carbonization of the composite, and then silica etching. The pore features are controlled by changing the weight ratio of PAN to silica nanoparticles. The electrochemical performances of p-CNF as an electrode are estimated by measuring cyclic voltammetry and galvanostatic charge/discharge. Particularly, the p-CNF electrode shows exceptional areal capacitance (13 mF cm−2 at a current of 0.5 mA cm−2), good rate-retention capability (~98% retention of low-current capacitance), and long-term cycle stability for at least 5000 charge/discharge cycles. Based on the results, we believe that this electrode has potential for use as high-performance EC electrodes.

Highlights

Among the different kinds of energy storage devices, electrochemical capacitors (ECs), termed supercapacitors, are creating new opportunities in applications in which high power, fast charge/discharge, and long-lasting operation are needed [1,2,3,4,5], because energy for ECs can be stored as the charge accumulates on the electrode surface
The present work demonstrated that the concept of porous carbon design holds great potential as an electrochemical energy storage
Starting from electrospun PAN/silica composites, porous carbon nanofibers (p-CNFs) were formed via oxidation/carbonization and subsequent silica etching

Summary

Introduction

Among the different kinds of energy storage devices, electrochemical capacitors (ECs), termed supercapacitors, are creating new opportunities in applications in which high power, fast charge/discharge, and long-lasting operation are needed [1,2,3,4,5], because energy for ECs can be stored as the charge accumulates on the electrode surface. For high energy and power, a significant electrical conductivity and high surface area are required for electrode materials In spite of these advantages, the relatively small energy density of ECs over those of conventional rechargeable batteries limits their commercial utilization [6,7,8,9,10]. In this regard, advances in high-energy ECs have been devoted toward the preparation of highly efficient electrodes that are a determinant of electrochemical performances [11,12]. Three-dimensional (3D) porous nanoarchitecture have been created, in which pores and active materials are interconnected, leading to fast movements for both ions and electrons [17,18,19,20]

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Conclusion