Issue 1, 2025

Breakage of the dense structure of coal precursors increases the plateau capacity of hard carbon for sodium storage

Abstract

Hard carbon is considered the most commercially viable anode material for sodium ion batteries due to its excellent sodium storage properties. However, the production cost of hard carbon is high, so optimizing the electrochemical performance of coal-derived hard carbon is adopted. However, due to the dense structure of coal, it is difficult to prepare closed pores inside the coal-derived hard carbon, which is not conducive to increasing capacity. Therefore, we propose Zn2(OH)2CO3 assisted ball milling pretreatment followed by carbonization to generate closed pores in coal-derived hard carbon. The reason for the formation of closed pores is that the uniform pores on the coal surface generated by the wear and etching of Zn2(OH)2CO3 are repaired at high temperatures. Via mechanism characterization, we verified that the plateau capacity is related to the filling of sodium ions in closed pores. Therefore, the as-prepared coal-derived hard carbon delivers a high capacity of 325.3 mA h g−1 (plateau capacity accounting for 45.1%) at a current density of 0.03 A g−1 with a capacity retention rate of 83.5% over 500 cycles. This work has demonstrated that reasonable pore design is an effective strategy to improve the electrochemical sodium storage performance of coal-derived hard carbon, providing an effective approach for the high value-added utilization of coal.

Graphical abstract: Breakage of the dense structure of coal precursors increases the plateau capacity of hard carbon for sodium storage

Supplementary files

Article information

Article type
Edge Article
Submitted
27 Sep 2024
Accepted
22 Nov 2024
First published
02 Dec 2024
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2025,16, 104-112

Breakage of the dense structure of coal precursors increases the plateau capacity of hard carbon for sodium storage

W. Qian, X. Zhou, X. Liu, M. Su, K. Zhang and X. Wu, Chem. Sci., 2025, 16, 104 DOI: 10.1039/D4SC06549B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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