High-Performance Structural Supercapacitors Based on Aligned Discontinuous Carbon Fiber Electrodes and Solid Polymer Electrolytes

Yanfang Xu; Shaopeng Pei; Yushan Yan; Liyun Wang; Guangbiao Xu; Shridhar Yarlagadda; Tsu-Wei Chou

doi:10.1021/acsami.0c19550

High-Performance Structural Supercapacitors Based on Aligned Discontinuous Carbon Fiber Electrodes and Solid Polymer Electrolytes

ACS Appl Mater Interfaces. 2021 Mar 17;13(10):11774-11782. doi: 10.1021/acsami.0c19550. Epub 2021 Mar 8.

Authors

Yanfang Xu^{1

2}, Shaopeng Pei², Yushan Yan³, Liyun Wang², Guangbiao Xu¹, Shridhar Yarlagadda⁴, Tsu-Wei Chou²

Affiliations

¹ College of Textiles, Donghua University, Shanghai 201620, P. R. China.
² Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716, United States.
³ Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
⁴ Center for Composite Materials, University of Delaware, Newark, Delaware 19716, United States.

PMID: 33683859
DOI: 10.1021/acsami.0c19550

Abstract

This paper presents an investigation of the potential to use aligned discontinuous carbon fiber dry prepregs as electrodes in structural supercapacitors (SSCs). The high fiber-matrix interfacial bonding of the structural composite was achieved by adopting a solid polymer electrolyte, consisting of poly(vinylidene), lithium triflate, and epoxy. Processing of the SSC was carried out via dip-coating of the polymer electrolyte and then cured using a vacuum bag. The electrochemical performance of the SSCs was measured before and after mechanical loading. The microstructures of the SSCs as-fabricated and damaged under flexural loading were identified by μ-CT imaging. An SSC with a specific capacitance of 0.128 mF/cm² (11.62 mF/g), a flexural strength of 47.49 MPa, and a flexural modulus of 8.48 GPa has been achieved, demonstrating significant improvements in mechanical properties over those of SSCs based on woven carbon fiber fabric-based electrodes. The mechanical behavior of the supercapacitors was evaluated by both quasi-static and cyclic flexural loading tests. The excellent electrochemical stability of the supercapacitors was validated by a capacitance retention of above 96% under galvanostatic charge-discharge cycling tests. The knowledge gained in this work will benefit future research in the optimization of SSC performance.

Keywords: aligned discontinuous carbon fiber; electrochemical property; mechanical property; solid polymer electrolyte; structural supercapacitor.