Halide-mediated endogenous ZnO domain-confined etching strategy: Realizing superior potassium storage in carbon anode

Fei Yuan; Ziyu Wu; Sijia Zhang; Zhaojin Li; Qiujun Wang; Huilan Sun; Di Zhang; Wei Wang; Bo Wang

doi:10.1016/j.jcis.2024.01.021

Halide-mediated endogenous ZnO domain-confined etching strategy: Realizing superior potassium storage in carbon anode

J Colloid Interface Sci. 2024 Apr:659:811-820. doi: 10.1016/j.jcis.2024.01.021. Epub 2024 Jan 9.

Authors

Fei Yuan¹, Ziyu Wu¹, Sijia Zhang¹, Zhaojin Li¹, Qiujun Wang¹, Huilan Sun¹, Di Zhang², Wei Wang³, Bo Wang⁴

Affiliations

¹ Hebei Key Laboratory of Flexible Functional Materials, School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050000, China.
² Hebei Key Laboratory of Flexible Functional Materials, School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050000, China. Electronic address: snowfoxzd@hebust.edu.cn.
³ School of Metallurgical and Ecological Engineering, University of Science and Technology, Beijing 100083, China.
⁴ Hebei Key Laboratory of Flexible Functional Materials, School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050000, China. Electronic address: wangbo1996@gmail.com.

PMID: 38218085
DOI: 10.1016/j.jcis.2024.01.021

Abstract

Coupling sites of nitrogen-dopants and intrinsic carbon defects (N/DC) are highly attractive to improve potassium-storage capacity and cycling stability, yet it is hard to effectively construct them. Herein, a novel strategy is proposed to establish abundant N/DC sites in N-doped carbon (ZIF8/NaBr-1-900) by pyrolyzing the mixture of metal-organic framework (ZIF8)/sodium bromide (NaBr). Systematic investigations disclose that the introduced NaBr can promote the full conversion of Zn-N₄ moieties into zinc oxide (ZnO) via a "bait and switch" mechanism. Such formed endogenous ZnO can etch the carbon matrix of the confined domains around the N dopants during pyrolysis process, and meanwhile the released N-atoms from Zn-N₄ moieties can largely form edge-N. As such, these N/DC coupling sites enable the resultant carbon to have a more significant capacitive behavior related to fast K-ion migration and high structural stability, leading to 255.3 mAh/g at 2 A/g with a prolonged cycle lifespan over 2000 cycles. Moreover, the assembled K-full battery presents a high energy density of 171.2 Wh kg^-1 and excellent cyclability over 5000 cycles. This NaBr-mediated endogenous ZnO domain-confined etching strategy provides a new insight into the exploration of advanced carbon anode.

Keywords: Carbon anode; Coupling sites; Domain-confined etching; Potassium-ion battery.