Stabilized Conductive Agent/Sulfide Solid Electrolyte Interface via a Halide Solid Electrolyte Coating for All-Solid-State Batteries

Abstract

All-solid-state batteries (ASSBs) have garnered significant interest as the next-generation in battery technology, praised for their superior safety and high energy density. However, a conductive agent accelerates the undesirable side reactions of sulfide-based solid electrolytes, resulting in poor electrochemical properties with increased interfacial resistance. Here, we propose a wet chemical method rationally designed to achieve a conformal coating of lithium–indium chloride (Li₃InCl₆) onto vapor-grown carbon fibers (VGCFs) as conductive agents. First, with the advantage of the Li₃InCl₆ protective layer, use of VGCF@Li₃InCl₆ leads to enhanced interfacial stability and improved electrochemical properties, including stable cycle performance. These results indicate that the Li₃InCl₆ protective layer suppresses the unwanted reaction between Li₆PS₅Cl and VGCF. Second, VGCF@Li₃InCl₆ effectively promotes polytetrafluoroethylene fibrillization, leading to a homogeneous electrode microstructure. The uniform distribution of the cathode active material in the electrode results in reduced charge-transfer resistance and enhanced Li-ion kinetics. As a result, a full cell with the LiNi_xMn_yCo_zO₂/VGCF@Li₃InCl₆ electrode shows an areal capacity of 7.7 mAh cm⁻² at 0.05 C and long-term cycle stability of 77.9% over 400 cycles at 0.2 C. This study offers a strategy for utilizing stable carbon-based conductive agents in sulfide-based ASSBs to enhance their electrochemical performance.

Keywords

all-solid-state batteries / conductive agent / halide solid electrolyte / protection layer / solvent-free electrode / sulfide solid electrode

References

[1] Q. Zhang, D. Cao, Y. Ma, A. Natan, P. Aurora, and H. Zhu, “Sulfide-Based Solid-State Electrolytes: Synthesis, Stability, and Potential for All-Solid-State Batteries,” Advanced Materials 31, no. 44 (2019): e1901131.

[2] J. Lau, R. H. DeBlock, D. M. Butts, D. S. Ashby, C. S. Choi, and B. S. Dunn, “Sulfide Solid Electrolytes for Lithium Battery Applications,” Advanced Energy Materials 8, no. 27 (2018): 1800933.

[3] S. Su, J. Ma, L. Zhao, et al., “Progress and Perspective of the Cathode/Electrolyte Interface Construction in All-Solid-State Lithium Batteries,” Carbon Energy 3, no. 6 (2021): 866-894.

[4] Y. Xiao, Y. Wang, S.-H. Bo, J. C. Kim, L. J. Miara, and G. Ceder, “Understanding Interface Stability in Solid-State Batteries,” Nature Reviews Materials 5, no. 2 (2019): 105-126.

[5] D. Lee, H. Lee, T. Song, and U. Paik, “Toward High Rate Performance Solid-State Batteries,” Advanced Energy Materials 12, no. 27 (2022): 2200948.

[6] S. P. Culver, R. Koerver, W. G. Zeier, and J. Janek, “On the Functionality of Coatings for Cathode Active Materials in Thiophosphate-Based All-Solid-State Batteries,” Advanced Energy Materials 9, no. 24 (2019): 1900626.

[7] L. Xi, D. Zhang, X. Xu, et al., “Interface Engineering of All-Solid-State Batteries Based on Inorganic Solid Electrolytes,” Chemsuschem 16, no. 9 (2023): e202202158.

[8] W. Zhang, T. Leichtweiß, S. P. Culver, et al., “The Detrimental Effects of Carbon Additives in Li₁₀GeP₂S₁₂-Based Solid-State Batteries,” ACS Applied Materials & Interfaces 9, no. 41 (2017): 35888-35896.

[9] F. Walther, S. Randau, Y. Schneider, et al., “Influence of Carbon Additives on the Decomposition Pathways in Cathodes of Lithium Thiophosphate-Based All-Solid-State Batteries,” Chemistry of Materials 32, no. 14 (2020): 6123-6136.

[10] S. Randau, F. Walther, A. Neumann, et al., “On the Additive Microstructure in Composite Cathodes and Alumina-Coated Carbon Microwires for Improved All-Solid-State Batteries,” Chemistry of Materials 33, no. 4 (2021): 1380-1393.

[11] T. Ates, M. Keller, J. Kulisch, T. Adermann, and S. Passerini, “Development of an All-Solid-State Lithium Battery by Slurry-Coating Procedures Using a Sulfidic Electrolyte,” Energy Storage Materials 17 (2019): 204-210.

[12] S. W. Park, G. Oh, J. W. Park, et al., “Graphitic Hollow Nanocarbon as a Promising Conducting Agent for Solid-State Lithium Batteries,” Small 15, no. 18 (2019): e1900235.

[13] J. Li, D. Xu, S. Yao, and F. Du, “Engineering Detrimental Functional Groups in Conductive Additives Toward High-Performance All-Solid-State Batteries,” Chemistry—A European Journal 30, no. 22 (2024): e202400074.

[14] N. Lee, J. Lee, T. Lee, et al., “Rationally Designed Solution-Processible Conductive Carbon Additive Coating for Sulfide-Based All-Solid-State Batteries,” ACS Applied Materials & Interfaces 15, no. 29 (2023): 34931-34940.

[15] G. G. Tibbetts, G. L. Doll, D. W. Gorkiewicz, et al., “Physical Properties of Vapor-Grown Carbon Fibers,” Carbon 31, no. 7 (1993): 1039-1047.

[16] K.-H. Liao, D. K. Mishra, C.-M. Chuang, and J.-M. Ting, “Large Area Vapor Grown Carbon Fiber Mat and Its Composite,” Composites, Part B: Engineering 42, no. 5 (2011): 1251-1256.

[17] D. Zhu, C. Xu, N. Nakura, and M. Matsuo, “Study of Carbon Films From PAN/VGCF Composites by Gelation/Crystallization From Solution,” Carbon 40, no. 3 (2002): 363-373.

[18] S. Wang, X. Xu, C. Cui, et al., “Air Sensitivity and Degradation Evolution of Halide Solid State Electrolytes Upon Exposure,” Advanced Functional Materials 32, no. 7 (2022): 2108805.

[19] X. Li, J. Liang, J. Luo, et al, “Air-Stable Li₃InCl₆ Electrolyte With High Voltage Compatibility for All-Solid-State Batteries,” Energy & Environmental Science 12, no. 9 (2019): 2665-2671.

[20] T. Swamy, X. Chen, and Y.-M. Chiang, “Electrochemical Redox Behavior of Li Ion Conducting Sulfide Solid Electrolytes,” Chemistry of Materials 31, no. 3 (2019): 707-713.

[21] H. Shen, S. Jing, S. Liu, et al., “Tailoring the Electronic Conductivity of High-Loading Cathode Electrodes for Practical Sulfide-Based All-Solid-State Batteries,” Advanced Powder Materials 2, no. 4 (2023): 100136.

[22] T. P. Poudel, M. J. Deck, P. Wang, and Y.-Y. Hu, “Transforming Li₃PS₄ via Halide Incorporation: A Path to Improved Ionic Conductivity and Stability in All-Solid-State Batteries,” Advanced Functional Materials 34, no. 4 (2024): 2309656.

[23] D. Cao, X. Sun, F. Li, et al., “Understanding Electrochemical Reaction Mechanisms of Sulfur in All-Solid-State Batteries Through Operando and Theoretical Studies,” Angewandte Chemie (International Ed) 62, no. 20 (2023): e202302363.

[24] J. Zhang, C. Zheng, L. Li, et al., “Unraveling the Intra and Intercycle Interfacial Evolution of Li₆PS₅Cl-Based All-Solid-State Lithium Batteries,” Advanced Energy Materials 10, no. 4 (2020): 1903311.

[25] J. Y. Jung, S. A. Han, H. Kim, et al., “Dry-Electrode All-Solid-State Batteries Fortified With a Moisture Absorbent,” ACS Nano 17, no. 16 (2023): 15931-15941.

[26] J. Lee, C. Zhao, C. Wang, et al., “Bridging the Gap Between Academic Research and Industrial Development in Advanced All-Solid-State Lithium-Sulfur Batteries,” Chemical Society Reviews 53, no. 10 (2024): 5264-5290.

[27] D. H. S. Tan, E. A. Wu, H. Nguyen, et al., “Elucidating Reversible Electrochemical Redox of Li₆PS₅Cl Solid Electrolyte,” ACS Energy Letters 4, no. 10 (2019): 2418-2427.

[28] W. Du, Q. Shao, Y. Wei, et al., “High-Energy and Long-Cycling All-Solid-State Lithium-Ion Batteries With Li- and Mn-Rich Layered Oxide Cathodes and Sulfide Electrolytes,” ACS Energy Letters 7, no. 9 (2022): 3006-3014.

[29] J. Kim, M. J. Kim, J. Kim, et al., “High-Performance All-Solid-State Batteries Enabled by Intimate Interfacial Contact Between the Cathode and Sulfide-Based Solid Electrolytes,” Advanced Functional Materials 33, no. 12 (2023): 2211355.

[30] J. Kim, S. Lee, H. Lee, et al., “A Facile Approach to Form an Artificial CEI Layer Induced by Residual Li Compounds on LiNi_0.9Co_0.05Mn_0.05O₂ and Li₆PS₅Cl for All-Solid-State Batteries,” eTransportation 19 (2024): 100306.

[31] P. Vadhva, J. Hu, M. J. Johnson, et al., “Electrochemical Impedance Spectroscopy for All-Solid-State Batteries: Theory, Methods and Future Outlook,” ChemElectroChem 8, no. 11 (2021): 1930-1947.

[32] F. Jin, L. Fadillah, H. Q. Nguyen, et al., “Elucidating the Impact of Li₃InCl₆-Coated LiNi_0.8Co_0.15Al_0.05O₂ on the Electro-Chemo-Mechanics of Li₆PS₅Cl-Based Solid-State Batteries,” Chemistry of Materials 36, no. 12 (2024): 6017-6026.

[33] X. Wang, C. Chen, S. Wu, et al., “High-Rate and Long-Life Au Nanorods/LiFePO₄ Composite Cathode for Lithium-Ion Batteries,” Energy Technology 10, no. 3 (2022): 2100841.

[34] L. Liu, H. Wang, D. Ye, H. Zhao, J. Zhang, and Y. Tang, “Fluorine-Like BH₄-Doped Li₆PS₅Cl With Improved Ionic Conductivity and Electrochemical Stability,” ACS Applied Materials & Interfaces 16, no. 24 (2024): 31341-31347.

[35] L. Wang, X. Sun, J. Ma, et al., “Bidirectionally Compatible Buffering Layer Enables Highly Stable and Conductive Interface for 4.5 V Sulfide-Based All-Solid-State Lithium Batteries,” Advanced Energy Materials 11, no. 32 (2021): 2100881.

RIGHTS & PERMISSIONS

2025 The Author(s). Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.