Utilizing the capacity below 0 V to maximize lithium storage of hard carbon anodes (Open Access)--颗粒学报PARTICUOLOGY

Liu, Q., Dai, L., Xie, L., Yi, Z., Song, M., Fan, Y., . . . Chen, C.-M. (2023). Utilizing the capacity below 0 V to maximize lithium storage of hard carbon anodes. Particuology, 83, 169-177. https://doi.org/10.1016/j.partic.2023.03.001

Utilizing the capacity below 0 V to maximize lithium storage of hard carbon anodes (Open Access)

Qianlei Liu ^{a b}, Liqin Dai ^a *, Lijing Xie ^a, Zonglin Yi ^{a b}, Mingxin Song ^{a b}, Yafeng Fan ^{a b}, Guohua Sun ^a, Fangyuan Su ^a, Cheng-Meng Chen ^{a c *}

a CAS Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China
b University of Chinese Academy of Sciences, Beijing, 100049, China
c Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China

10.1016/j.partic.2023.03.001

Volume 83, December 2023, Pages 169-177

Received 14 February 2023, Revised 4 March 2023, Accepted 5 March 2023, Available online 12 March 2023, Version of Record 17 March 2023.

E-mail: dailiqin@sxicc.ac.cn; ccm@sxicc.ac.cn

Highlights

• A new lithiation boundary is proposed by utilizing capacity below 0 V of hard carbons (HCs).

• The boundary provides a nearly twice capacity improvement.

• The lithium storage mechanism below 0 V of HCs is investigated.

Abstract

Compared with conventional graphite anode, hard carbons have the potential to make reversible lithium storage below 0 V accessible due to the formation of dendrites is slow. However, under certain conditions of high currents and lithiation depths, the irreversible plated lithium occurs and then results in the capacity losses. Herein, we systematically explore the true reversibility of hard carbon anodes below 0 V. We identify the lithiation boundary parameters that control the reversible capacity of hard carbon anodes. When the boundary capacity is controlled below 400 mAh g⁻¹ with current density below 50 mA g⁻¹, no lithium dendrites are observed during the lithiation process. Compared with the discharge cut-off voltage to 0 V, this boundary provides a nearly twice reversible capacity with the capacity retention of 80% after 172 cycles. The results of characterization and finite element model reveal that the large reversible capacity below 0 V of hard carbon anodes is mainly benefited from the dual effect of lithium intercalation and reversible lithium film. After the lithium intercalation, the over-lithiation induces the quick growth of lithium dendrites, worsening the electrochemical irreversibility. This work enables insights of the potentially low-voltage performance of hard carbons in lithium-ion batteries.

Graphical abstract

Keywords

Low voltage; Li intercalation; Reversible capacity; Li dendrites; Hard carbon

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