FeS2 Nanoparticles Encapsulated in S/N Co-Doped Carbon Nanofibers With a Three-Dimensional Multi-Channel Structure for Lithium-Ion Batteries

Xiaochang Cao; Yi Zhang; Chujiang Luo; Yansheng Yin; Yingying Huang

doi:10.3389/fchem.2022.957462

FeS₂ Nanoparticles Encapsulated in S/N Co-Doped Carbon Nanofibers With a Three-Dimensional Multi-Channel Structure for Lithium-Ion Batteries

Front Chem. 2022 Jul 15:10:957462. doi: 10.3389/fchem.2022.957462. eCollection 2022.

Authors

Xiaochang Cao^{1

2}, Yi Zhang³, Chujiang Luo³, Yansheng Yin³, Yingying Huang³

Affiliations

¹ College of Mechanical Engineering, Dongguan University of Technology, Dongguan, China.
² Institute of Science and Technology Innovation, Dongguan University of Technology, Dongguan, China.
³ Research Center for Corrosion and Erosion Process Control of Equipment and Material in Marine Harsh Environment, Guangzhou Maritime University, Guangzhou, China.

Abstract

Pyrite (FeS₂) is one of the potential candidates for advanced rechargeable Li-ion batteries (LIBs) owing to its inherent capacity (849 mAh g^-1), environmental friendliness, and abundant natural resources. However, the volume expansion of FeS₂ and the dissolution of polysulfide in the electrochemical reaction severely limit its application in the field of energy conversion and storage. Herein, FeS₂ nanoparticles are encapsulated in S/N co-doped three-dimensional multi-channel structural carbon nanofibers (FeS₂@CNFs) through the electrospinning method. As a cathode material for LIBs, FeS₂@CNFs demonstrated excellent rate property and cyclic stability. The 3FeS₂@CNFs (weight ratio of FeS₂ is 30%) present the initial capacity of 1,336.7 mAh g^-1 and the remaining 856.5 mAh g^-1 at 0.02A g^-1 after 100 circles. The favorable electrochemical properties have confirmed that carbon nanofibers can enhance the electroconductivity of electrodes, reduce the volume collapse of FeS₂, and remit the dissolution of polysulfide during the Li⁺ ions insertion/de-insertion process. In addition, co-doped S/N can supply abundant active sites for electrochemical reactions, providing enough space for Li⁺ ion storage. The results indicate that 3FeS₂@CNFs is a cathode with a developmental prospect for LIBs.

Keywords: FeS2; carbon nanofibers; cathode material; lithium-ion batteries; three-dimensional multi-channel structure.