Volume 20, Issue 18 2309717
Research Article

Spontaneous Built-In Electric Field in C3N4-CoSe2 Modified Multifunctional Separator with Accelerating Sulfur Evolution Kinetics and Li Deposition for Lithium-Sulfur Batteries

Ziwei Liang

Ziwei Liang

School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 P. R. China

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Chao Peng

Chao Peng

Multiscale Crystal Materials Research Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen, 518055 P. R. China

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Jiadong Shen

Jiadong Shen

School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 P. R. China

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Jujun Yuan

Jujun Yuan

Key Laboratory of New Energy Materials and Low Carbon Technologies, College of Physics and Electronics, Gannan Normal University, Ganzhou, 341000 P. R. China

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Yan Yang

Yan Yang

School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 P. R. China

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Dongfeng Xue

Dongfeng Xue

Multiscale Crystal Materials Research Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen, 518055 P. R. China

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Min Zhu

Min Zhu

School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 P. R. China

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Jun Liu

Corresponding Author

Jun Liu

School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 P. R. China

E-mail: [email protected]

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First published: 06 December 2023
Citations: 14

Abstract

The discovery of the heterostructures that is combining two materials with different properties has brought new opportunities for the development of lithium sulfur batteries (LSBs). Here, C3N4-CoSe2 composite is elaborately designed and used as a functional coating on the LSBs separator. The abundant chemisorption sites of C3N4-CoSe2 form chemical bonding with polysulfides, provides suitable adsorption energy for lithium polysulfides (LiPSs). More importantly, the spontaneously formed internal electric field accelerates the charge flow in the C3N4-CoSe2 interface, thus facilitating the transport of LiPSs and electrons and promoting the bidirectional conversion of sulfur. Meanwhile, the lithiophilic C3N4-CoSe2 sample with catalytic activity can effectively regulate the uniform distribution of lithium when Li+ penetrates the separator, avoiding the formation of lithium dendrites in the lithium (Li) metal anode. Therefore, LSBs based on C3N4-CoSe2 functionalized membranes exhibit a stable long cycle life at 1C (with capacity decay of 0.0819% per cycle) and a large areal capacity of 10.30 mAh cm−2 at 0.1C (sulfur load: 8.26 mg cm−2, lean electrolyte 5.4 µL mgs−1). Even under high-temperature conditions of 60 °C, a capacity retention rate of 81.8% after 100 cycles at 1 C current density is maintained.

Conflict of Interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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