Distribution and Transport of Lithium Ions at Interfaces between Graphite and Carboxymethyl Celluloses

Authors

• Zi-Jun Huang, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
• Zhen-Ying Zheng, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
• Hua-Wei Cao, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China; Shenzhen Haodyne Technology Co., Ltd., Shenzhen 518115, China
• Jian Wang, Shenzhen Haodyne Technology Co., Ltd., Shenzhen 518115, China
• Qing-Feng Zhang, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, ChinaFollow
• Sheng-Li Chen, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, ChinaFollow

Corresponding Author

Qing-Feng Zhang (zhangqf@whu.edu.cn);
Sheng-Li Chen (slchen@whu.edu.cn)

Abstract

Carboxymethyl cellulose (CMC) is a water-processable binder widely used for graphite anodes. However, a microscopic understanding of why the identity of CMC counterions (Li⁺/Na⁺/K⁺) strongly affects electrode performance remains limited. Here, molecular dynamics (MD) simulations are used to track Li⁺ transport accessibility across electrolyte/CMC/graphite three-phase interfaces, comparing pure CMC-Li, CMC-Na, CMC-K, and mixed-counterion CMC binders. We find that CMC-Li sustains a continuous Li⁺ transport pathway from the electrolyte through the binder phase toward graphite. In contrast, in CMC-Na and CMC-K, Na⁺/K⁺ ions preferentially enrich at the graphite/binder interface, forming a cationenriched interfacial layer which reduces Li⁺ accessibility to graphite. Partial replacement of Na⁺/K⁺ in CMC-Na and CMC-K with Li⁺ weakens this interfacial blocking effect and increases Li⁺ accessibility. Furthermore, a stage-resolved kinetic analysis visualizes the progressive suppression of Li⁺ crossing the binder phase upon the barrier layer formation. These results provide a microscopic rationale for the experimentally observed performance advantage of CMC-Li over CMC-Na and CMC-K binders.

Graphical Abstract

Keywords

Carboxymethyl cellulose binder, Graphite anode, Binder counterions, Interfacial ion transport, Cation-enriched interfacial barrier

DOI Link

https://doi.org/10.61558/2993-074X.3611

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Date

2026-06-28

Online Available Date

2026-04-09

Revised Date

2026-03-22

Received Date

2026-02-10

Recommended Citation

Zi-Jun Huang, Zhen-Ying Zheng, Hua-Wei Cao, Jian Wang, Qing-Feng Zhang, Sheng-Li Chen. Distribution and Transport of Lithium Ions at Interfaces between Graphite and Carboxymethyl Celluloses[J]. Journal of Electrochemistry, 2026, 32(6): 2614001.
DOI: 10.61558/2993-074X.3611
Available at: https://jelectrochem.xmu.edu.cn/journal/vol32/iss6/2