Boron dopant- and nitrogen defect-decorated C3N5 porous nanostructure as an efficient sulfur host for lithium-sulfur batteries

Minjie Zhou; Xianglin Deng; Na Zhang; Bing Chen; Gangyong Li; Haihua Yang

doi:10.1016/j.jcis.2024.04.023

Boron dopant- and nitrogen defect-decorated C₃N₅ porous nanostructure as an efficient sulfur host for lithium-sulfur batteries

J Colloid Interface Sci. 2024 Jul 15:666:151-161. doi: 10.1016/j.jcis.2024.04.023. Epub 2024 Apr 4.

Authors

Minjie Zhou¹, Xianglin Deng¹, Na Zhang², Bing Chen¹, Gangyong Li¹, Haihua Yang³

Affiliations

¹ Key Laboratory of Hunan Province for Advanced Carbon-Based Functional Materials, Hunan Institute of Science and Technology, Yueyang, Hunan Province, 414006, P.R. China; School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan Province, 414006, P.R. China.
² School of Physics and Electronic Science, Hunan Institute of Science and Technology, Yueyang, Hunan Province, 414006, P.R. China.
³ Key Laboratory of Hunan Province for Advanced Carbon-Based Functional Materials, Hunan Institute of Science and Technology, Yueyang, Hunan Province, 414006, P.R. China; School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan Province, 414006, P.R. China. Electronic address: hhyang@126.com.

PMID: 38593650
DOI: 10.1016/j.jcis.2024.04.023

Abstract

Active site implantation and morphology manipulation are efficient protocols for boosting the electrochemical performance of carbon nitrides. As a promising sulfur host for lithium-sulfur batteries (LSBs), in this study, C₃N₅ porous nanostructure incorporated with both boron (B) atoms and nitrogen (N) defects was constructed (denoted as ND-B-C₃N₅) using a two-step strategy, i.e., pyrolysis of the mixture of 3-amino-1,2, 4-triazole and boric acid to obtain B-doped C₃N₅ porous nanostructure and then KOH etching under hydrothermal condition to generate N defects. The doped B atoms in the C₃N₅ porous nanostructure are in the form of B-N bonds and grafted B-O bonds. N defects are primarily created at the CN-C positions of the triazine unit, leaving behind some N vacancies and cyano groups. Benefiting from the involvement of B dopants and N defects, the optimized ND-B-C₃N₅-12 sample exhibits ameliorative conductivity, mass transport, lithium polysulfides (LiPSs) adsorption ability, diffusion of Li⁺ ions, Li₂S deposition capacity, sulfur redox polarization, and a reversible solid-solid sulfur redox process. Consequently, the ND-B-C₃N₅-12/S cathode delivers accelerated redox performance of polysulfides for LSBs, revealing capacities of 1091 ± 44 and 753 ± 20 mAh/g at 0.2C for the initial and 300th cycles, respectively. The ND-B-C₃N₅-12/S cathode is also endowed with desired sulfur redox activity and stability at 2C for 1000 cycles, holding an initial discharging capacity of 788 ± 24 mAh/g and a low decay rate of 0.05 % per cycle.

Keywords: Boron Doping; C(3)N(5); Lithium–Sulfur Batteries; Nitrogen Defect; Sulfur Host.