Fe3O4nanoparticles anchored on carbon nanotubes as high-performance anodes for asymmetric supercapacitors

S H Gong; J Kuai; J D Wang; F Liu; J F Wu; X C Wang; J P Cheng

doi:10.1088/1361-6528/acf9af

Fe₃O₄nanoparticles anchored on carbon nanotubes as high-performance anodes for asymmetric supercapacitors

Nanotechnology. 2023 Oct 4;34(50). doi: 10.1088/1361-6528/acf9af.

Authors

S H Gong¹, J Kuai¹, J D Wang¹, F Liu¹, J F Wu², X C Wang³, J P Cheng¹

Affiliations

¹ State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, People's Republic of China.
² College of Information Science & Technology, Zhejiang Shuren University, Hangzhou 310015, People's Republic of China.
³ Key Laboratory of Material Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, People's Republic of China.

PMID: 37708883
DOI: 10.1088/1361-6528/acf9af

Abstract

Fe₃O₄/CNT composites are synthesized with ethylene glycol as solvent by a one-step solvothermal method and used as anode materials for asymmetric supercapacitors (ASC). An appropriate amount of water in ethylene glycol can accelerate the formation of Fe₃O₄and reduce the average size of Fe₃O₄to around 20 nm. However, spherical Fe₃O₄particles larger than 100 nm will form in pure ethylene glycol for long reaction time. The Fe₃O₄/CNT composite with small Fe₃O₄nanoparticles exhibits a high specific surface area, promoted electron transfer ability, as well as a high utilization rate of active materials. The optimized electrode shows a high specific capacity of 689 C g^-1at 1 A g^-1, and remains 443 C g^-1at 10 A g^-1. The inferior long-term cycling stability is due to the phase transition of Fe₃O₄and a reductive effect to form metallic Fe. An ASC using Fe₃O₄/CNT and NiCoO₂/C composites as anode and cathode, respectively, delivers a high energy density of 58.1 Wh kg^-1at a power density of 1007 W kg^-1in a voltage window of 1.67 V and has a capacity retention of 63% after 5000 cycles. The self-discharge behavior of the ASC is also investigated.

Keywords: Fe3O4; anode material; asymmetric supercapacitors; carbon nanotubes.