2025 AIChE Annual Meeting

(694d) Anomalous Doping Effects on Aluminum Anode Stability in Lithium-Ion Batteries: Insights from Combined Ab Initio and Deep Learning Molecular Dynamics

Authors

Gyeong S. Hwang, The University of Texas at Austin
Alloy materials, such as Al, Si, Ge, and Sn, have emerged as promising alternatives to conventional carbon-based anodes for lithium-ion batteries (LIBs)1–5, offering significantly higher theoretical capacities. 6,7 Among these, aluminum (Al) is particularly attractive due to its moderate lithiation potential, high natural abundance, excellent recyclability, and non-toxicity. 7,8 However, Al anodes face practical challenges including poor cyclic stability and rapid mechanical degradation, mainly due to large volume changes and loss of electrical contact during lithiation and delithiation cycles.

Recent experimental studies have shown that the amorphization of Al significantly improves its electrochemical and transport properties.9 By disrupting the long-range order of the crystalline phase, amorphization reduces internal strain and facilitates more uniform lithium diffusion, thereby mitigating mechanical failure as also shown in previous theoretical studies.10–12 Furthermore, atomic-scale doping with small amounts of elements such as Si, Cu, and Fe has been reported to enhance cyclic life and structural integrity of Al. 13–15 Nevertheless, the atomistic mechanisms underlying dopant-induced improvements remain unclear, and a fundamental understanding is essential for the rational design of stable, high-capacity Al-based anodes for next-generation lithium-ion batteries.

In this work, we employ first-principles-based atomistic modeling and molecular dynamics simulations powered by neural network potentials (NNPs) to explore the dopant chemistry on the nanostructured Al-alloy anodes. We developed a highly accurate NNP model for the Li/Al/Si system, rigorously validated against density functional theory (DFT) calculations, to enable large-scale simulations of lithiation dynamics.

Based on our recent progress, this talk will highlight (1) the impact of the Al host phase on lithiation thermodynamics, (2) the role of dopants (such as Si, Fe, Cu) in stabilizing the host matrix, and (3) Li transport varies depending on the atomic structure of host matrix, as demonstrated through large-scale molecular dynamics simulations using NNPs. Our results clearly explain the structural effects of host matrix and the role of dopants in Al-based matrix.These findings offer valuable insights into designing high-performance Al-based alloy anodes for next-generation batteries and highlight the reliability and effectiveness of neural network-based interatomic potentials to model complex alloy systems.

References

(1) Chen, S.; Du, A.; Yan, C. Molecular Dynamic Investigation of the Structure and Stress in Crystalline and Amorphous Silicon during Lithiation. Computational Materials Science 2020, 183, 109811.

(2) Liang, S.; Cheng, Y.; Zhu, J.; Xia, Y.; Müller‐Buschbaum, P. A Chronicle Review of Nonsilicon (Sn, Sb, Ge)‐Based Lithium/Sodium‐Ion Battery Alloying Anodes. Small Methods 2020, 4 (8), 2000218. https://doi.org/10.1002/smtd.202000218.

(3) Thackeray, M. M.; Vaughey, J. T.; Johnson, C. S.; Kropf, A. J.; Benedek, R.; Fransson, L. M. L.; Edstrom, K. Structural Considerations of Intermetallic Electrodes for Lithium Batteries. Journal of Power Sources 2003, 113 (1), 124–130. https://doi.org/10.1016/S0378-7753(02)00538-4.

(4) Nithyadharseni, P.; Reddy, M. V.; Nalini, B.; Kalpana, M.; Chowdari, B. V. R. Sn-Based Intermetallic Alloy Anode Materials for the Application of Lithium Ion Batteries. Electrochimica Acta 2015, 161, 261–268. https://doi.org/10.1016/j.electacta.2015.02.057.

(5) Kepler, K. D.; Vaughey, J. T.; Thackeray, M. M. LixCu6Sn5 (0<x<13): An Intermetallic Insertion Electrode for Rechargeable Lithium Batteries. 1999.

(6) Dey, A. Electrochemical Alloying of Lithium in Organic Electrolytes. Journal of The Electrochemical Society1971, 118 (10), 1547.

(7) McDowell, M. T.; Lee, S. W.; Nix, W. D.; Cui, Y. 25th Anniversary Article: Understanding the Lithiation of Silicon and Other Alloying Anodes for Lithium-Ion Batteries. Advanced materials 2013, 25 (36), 4966–4985.

(8) Tahmasebi, M. H.; Kramer, D.; Mönig, R.; Boles, S. T. Insights into Phase Transformations and Degradation Mechanisms in Aluminum Anodes for Lithium-Ion Batteries. Journal of The Electrochemical Society 2018, 166 (3), A5001.

(9) Yan, C.; Lv, C.; Jia, B.-E.; Zhong, L.; Cao, X.; Guo, X.; Liu, H.; Xu, W.; Liu, D.; Yang, L.; others. Reversible Al Metal Anodes Enabled by Amorphization for Aqueous Aluminum Batteries. Journal of the American Chemical Society2022, 144 (25), 11444–11455.

(10) Chou, C.-Y.; Hwang, G. S. On the Origin of the Significant Difference in Lithiation Behavior between Silicon and Germanium. Journal of Power Sources 2014, 263, 252–258. https://doi.org/10.1016/j.jpowsour.2014.04.011.

(11) Chou, C.-Y.; Hwang, G. S. Lithiation Behavior of Silicon-Rich Oxide (SiO1/3 ): A First-Principles Study. Chem. Mater. 2013, 25 (17), 3435–3440. https://doi.org/10.1021/cm401303n.

(12) Kim, H.; Chou, C.-Y.; Ekerdt, J. G.; Hwang, G. S. Structure and Properties of Li−Si Alloys: A First-Principles Study. J. Phys. Chem. C 2011, 115 (5), 2514–2521. https://doi.org/10.1021/jp1083899.

(13) Li, Q.; Bjerrum, N. J. Aluminum as Anode for Energy Storage and Conversion: A Review. Journal of Power Sources 2002, 110 (1), 1–10. https://doi.org/10.1016/S0378-7753(01)01014-X.

(14) Heligman, B. T.; Manthiram, A. Elemental Foil Anodes for Lithium-Ion Batteries. ACS Energy Lett. 2021, 6 (8), 2666–2672. https://doi.org/10.1021/acsenergylett.1c01145.

(15) Sharma, S. S.; Crowley, P. J.; Manthiram, A. Aluminum–Silicon Alloy Foils as Low-Cost, Environmentally Friendly Anodes for Lithium-Ion Batteries. ACS Sustainable Chemistry & Engineering 2021, 9 (43), 14515–14524.