Tailoring Loose Mg²⁺ Solvation Structure by Steric and Competitive Solvent Coordination for Fast-Charging Magnesium Batteries

Abstract

Magnesium batteries are attracting growing interest as next-generation energy storage technology due to their high safety, cost-effectiveness, and resource abundance. However, their development remains limited by sluggish Mg²⁺ transport kinetics at the electrode/electrolyte interface. Herein, we propose an electrolyte design strategy that modulates the Mg²⁺ solvation structure by introducing tetrahydrofuran (THF) as a co-solvent into a borate-based electrolyte, Mg[B(hfip)₄] (MBF) in dimethoxyethane (DME). THF, selected from a series of linear and cyclic ethers, has a comparable dielectric constant and donor number to DME, but its cyclic structure introduces steric hindrance that induces competitive coordination with Mg²⁺. This competition weakens Mg²⁺ − solvent interactions, yielding a more labile solvation structure and enhanced desolvation kinetics. As a result, Mg||Mg cells employing the optimized MBF/1D1T electrolyte (DME: THF = 1:1, v:v) exhibit a significantly reduced Mg plating/stripping overpotential of 120 mV at 10 mA cm⁻², compared with 316 mV at 8 mA cm⁻² with MBF/DME, along with exceptional cycling stability exceeding 1200 h. Furthermore, representative sulfide cathodes such as CuS and VS₄ demonstrate faster activation and improved high-rate performance in the presence of MBF/1D1T.

Keywords

co-solvents / electrode/electrolyte interface / kinetics / magnesium batteries / solvation structure / steric hindrance

References

[1] R. Mohtadi, O. Tutusaus, T. S. Arthur, Z. Zhao-Karger, M. Fichtner, Joule 2021, 5, 581.

[2] D. Chen, X. Ren, T. Li, Z. Chen, Y. Cao, F. Xu, Energy Environ. Mater. 2023, 6, e12486.

[3] P. Bonnick, J. Muldoon, Adv. Funct. Mater. 2020, 30, 1910510.

[4] F. Liu, T. Wang, X. Liu, L.-Z. Fan, Adv. Energy Mater. 2021, 11, 2000787.

[5] Y. Pang, Z. Nie, F. Xu, L. Sun, J. Yang, D. Sun, F. Fang, S. Zheng, Energy Environ. Mater. 2024, 7, e12527.

[6] T. Koketsu, J. Ma, B. J. Morgan, M. Body, C. Legein, W. Dachraoui, M. Giannini, A. Demortiere, M. Salanne, F. Dardoize, Nat. Mater. 2017, 16, 1142.

[7] J. L. Andrews, A. Mukherjee, H. D. Yoo, A. Parija, P. M. Marley, S. Fakra, D. Prendergast, J. Cabana, R. F. Klie, S. Banerjee, Chem 2018, 4, 564.

[8] L. Thanh Son, T. H. Hoa, D. Q. Truong, J. Electroanal. Chem. 2019, 848, 113293.

[9] Y. Shen, Q. Zhang, Y. Wang, L. Gu, X. Zhao, X. Shen, Adv. Mater. 2021, 33, 2103881.

[10] Y. Shen, Y. Wang, Y. Miao, M. Yang, X. Zhao, X. Shen, Adv. Mater. 2020, 32, 1905524.

[11] Z. Li, X. Mu, Z. Zhao-Karger, T. Diemant, R. J. Behm, C. Kubel, M. Fichtner, Nat. Commun. 2018, 9, 5115.

[12] Y. Zhang, J. Gui, T. Li, Z. Chen, S.-a. Cao, F. Xu, Chem. Eng. J. 2020, 399, 125689.

[13] H. Dong, O. Tutusaus, Y. Liang, Y. Zhang, Z. Lebens-Higgins, W. Yang, R. Mohtadi, Y. Yao, Nat. Energy 2020, 5, 1043.

[14] X. Zhou, J. Tian, J. Hu, C. Li, Adv. Mater. 2018, 30, 1704166.

[15] V. Duffort, X. Sun, L. F. Nazar, Chem. Commun. 2016, 52, 12458.

[16] H. Tian, T. Gao, X. Li, X. Wang, C. Luo, X. Fan, C. Yang, L. Suo, Z. Ma, W. Han, Nat. Commun. 2017, 8, 14083.

[17] Y. Xu, X. Deng, Q. Li, G. Zhang, F. Xiong, S. Tan, Q. Wei, J. Lu, J. Li, Q. An, Chem 2019, 5, 1194.

[18] L. Zhou, F. Xiong, S. Tan, Q. An, Z. Wang, W. Yang, Z. Tao, Y. Yao, J. Chen, L. Mai, Nano Energy 2018, 54, 360.

[19] M. Mao, T. Gao, S. Hou, F. Wang, J. Chen, Z. Wei, X. Fan, X. Ji, J. Ma, C. Wang, Nano Lett. 2019, 19, 6665.

[20] H. D. Yoo, Y. L. Liang, H. Dong, J. H. Lin, H. Wang, Y. S. Liu, L. Ma, T. P. Wu, Y. F. Li, Q. Ru, Nat. Commun. 2017, 8, 339.

[21] H. Cheng, Q. Sun, L. Li, Y. Zou, Y. Wang, T. Cai, F. Zhao, G. Liu, Z. Ma, W. Wahyudi, ACS Energy Lett. 2022, 7, 490.

[22] H. Fan, X. Zhang, J. Xiao, W. Chen, Q. Lin, Z. S. Ng, Y. Lin, Y. Su, L. Pan, Y. Su, S. Ren, H. Liu, X. Li, Y. Zhang, Energy Environ. Mater. 2024, 7, e12792.

[23] J. Cao, Y. Liu, K. Li, I. Zatovsky, J. Yang, H. Liu, Z. Gu, X. Gao, K. Zhang, S. Zheng, X. Wu, Natl. Sci. Rev. 2025, 12, nwaf074.

[24] G. Li, K. Chen, M. Lei, T. Wang, M. Hu, C. Li, Adv. Energy Mater. 2024, 14, 2401507.

[25] M. Hu, G. Li, K. Chen, X. Zhou, C. Li, Chem. Eng. J. 2024, 480, 148193.

[26] Y. Xu, G. Zhou, S. Zhao, W. Li, F. Shi, J. Li, J. Feng, Y. Zhao, Y. Wu, J. Guo, Adv. Sci. 2019, 6, 1800981.

[27] X. Li, T. Gao, F. Han, Z. Ma, X. Fan, S. Hou, N. Eidson, W. Li, C. Wang, Adv. Energy Mater. 2018, 8, 1701728.

[28] Y. Shi, Y. Chen, L. Shi, K. Wang, B. Wang, L. Li, Y. Ma, Y. Li, Z. Sun, W. Ali, Small 2020, 16, 2000730.

[29] H. Ren, S. Li, B. Wang, Y. Zhang, T. Wang, Q. Lv, X. Zhang, L. Wang, X. Han, F. Jin, Adv. Mater. 2023, 35, e2208237.

[30] S. Hou, X. Ji, K. Gaskell, P.-F. Wang, L. Wang, J. Xu, R. Sun, O. Borodin, C. Wang, Science 2021, 374, 172.

[31] Z. Hou, R. Zhou, Y. Yao, Z. Min, Z. Lu, Y. Zhu, J. M. Tarascon, B. Zhang, Angew. Chem. Int. Ed. 2022, 61, e202214796.

[32] Y. Shen, Y. Wang, Y. Miao, Q. Li, X. Zhao, X. Shen, Adv. Mater. 2023, 35, e2208289.

[33] X. Li, M. Zhao, Y. Song, C. Bi, Z. Li, Z. Chen, X. Zhang, B. Li, J. Huang, Chem. Soc. Rev. 2025, 54, 4822.

[34] Y. Sun, Y. Wang, L. Jiang, D. Dong, W. Wang, J. Fan, Y. Lu, Energy Environ. Sci. 2023, 16, 265.

[35] F. Neese, WIREs Comput. Mol. Sci. 2011, 2, 73.

[36] A. Schäfer, J. Chem. Phys. 1994, 100, 5829.

[37] F. Weigend, Chem. Phys. Lett. 1998, 294, 143.

[38] F. Weigend, Phys. Chem. Chem. Phys. 2006, 8, 1057.

[39] S. Grimme, J. Chem. Phys. 2010, 132, 154104.

RIGHTS & PERMISSIONS

2025 The Author(s). Energy & Environmental Materials published by John Wiley & Sons Australia, Ltd on behalf of Zhengzhou University.