Oxygen defect enriched hematite nanorods @ reduced graphene oxide core-sheath fiber for superior flexible asymmetric supercapacitor

Min Li; Zhengxin Luo; Jiaxin Quan; Ting Ding; Bilin Xu; Wanfei Li; Qinghui Mao; Wujun Ma; Hengxue Xiang; Meifang Zhu

doi:10.1016/j.jcis.2023.09.055

Oxygen defect enriched hematite nanorods @ reduced graphene oxide core-sheath fiber for superior flexible asymmetric supercapacitor

J Colloid Interface Sci. 2024 Jan;653(Pt A):77-84. doi: 10.1016/j.jcis.2023.09.055. Epub 2023 Sep 9.

Authors

Min Li¹, Zhengxin Luo¹, Jiaxin Quan¹, Ting Ding¹, Bilin Xu¹, Wanfei Li², Qinghui Mao¹, Wujun Ma³, Hengxue Xiang⁴, Meifang Zhu⁵

Affiliations

¹ College of Textile and Garment, Nantong University, Nantong 226019, China.
² School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
³ College of Textile and Garment, Nantong University, Nantong 226019, China; State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China. Electronic address: mawj@ntu.edu.cn.
⁴ State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China. Electronic address: hengxuexiang@dhu.edu.cn.
⁵ State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China.

PMID: 37708734
DOI: 10.1016/j.jcis.2023.09.055

Abstract

The development of flexible asymmetric supercapacitors with high operating potential, superior energy density, and exceptional rate performance holds significant implications for the advancement of flexible electronics. Herein, oxygen-deficient hematite nanorods @ reduced graphene oxide (Fe₂O_3-x@RGO) core-sheath fiber was rationally designed and fabricated. The introduction of oxygen defects can simultaneously enhance the conductivity, create a mesoporous crystalline structure, increase active surface area and sites. This leads to a significantly improved electrochemical performance, exhibiting a high specific capacitance of 525.2F cm^-3 at 5 mV s^-1 and remarkable rate capability (53.7 % retention from 5 to 100 mV s^-1). Additionally, a flexible asymmetric supercapacitor was assembled employing Fe₂O_3-x@RGO fibers as anode and MnO₂/RGO fibers as cathode. This design achieved a maximum operating voltage of 2.35 V, high energy density of 71.4 mWh cm^-3, and outstanding cycling stability with 97.1 % retention after 5000 cycles. This study proposes a straightforward and efficient strategy to substantially enhance the electrochemical performances of transition metal oxide anodes, thereby promoting their practical application in asymmetric supercapacitors.

Keywords: Asymmetric supercapacitor; Fe(2)O(3) nanorods; Graphene fiber; High energy density; Oxygen vacancy.