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Updated: Jun 19, 2026
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Evaluating the Electrochemical Properties of Supercapacitors using the Three-Electrode System
Published on: January 7, 2022
Controllable Carbon Shell Encapsulation via Rapid Joule Heating Calcination for High-Performance Asymmetric
Qiang Zhou1, Zheng Yang1, Zhen Cao1
1School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou, China.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|June 18, 2026
Summary
This study introduces a carbon shell encapsulation method to improve asymmetric supercapacitors (ASCs). The new ASCs show enhanced energy density, suppressed self-discharge, and extended cycle life, making them more practical for applications.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Asymmetric supercapacitors (ASCs) offer high energy density but suffer from self-discharge and poor cycle life.
- These limitations hinder the widespread adoption of ASCs in practical applications.
Purpose of the Study:
- To develop a high-performance ASC with suppressed self-discharge and improved cycling stability.
- To investigate a controllable carbon shell encapsulation strategy for pseudocapacitive electrodes.
Main Methods:
- Fabrication of ASCs using a rapid Joule heating calcination method for carbon shell encapsulation.
- Characterization of electrode materials and assembled ASC performance, including energy density, power density, cycling stability, and self-discharge behavior.
- Theoretical analysis using density functional theory (DFT) to understand the mechanism of self-discharge suppression.
Main Results:
- The assembled ASC (H-Fe3O4@C-15//H-NiCo2S4@C-40) achieved a maximum energy density of 105.6 W h kg−1 at 749 W kg−1.
- Demonstrated robust cycling stability with 93.7% capacitance retention after 25,000 cycles.
- Exhibited moderated self-discharge, with open-circuit voltage decaying from 1.48 to 0.75 V over 31,102 seconds.
Conclusions:
- The controllable carbon shell encapsulation strategy effectively suppresses self-discharge and enhances cycle life in ASCs.
- The improved performance is attributed to increased adsorption energy between electrode and electrolyte ions, as confirmed by DFT.
- This strategy offers a universal and feasible approach for developing advanced ASCs.
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