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Hydrotropic solubilization of zinc acetates for sustainable aqueous battery electrolytes

Nature Sustainability volume 6, pages 1474–1484 (2023)Cite this article

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Abstract

Among the more sustainable battery chemistries, the aqueous zinc system is receiving renewed interest. To accelerate the practical applications of this promising technology, an effective strategy is to deploy high salt concentration electrolytes that could address the critical technical barriers, notably hydrogen evolution reaction and dendrite growth at the anode side. However, the state-of-the-art recipes are either zinc-ion deficient or halogen salt dependent, both of which unfortunately create extra challenges. Here we show a highly concentrated aqueous electrolyte formula utilizing zinc acetate, an otherwise poorly water-soluble but cheap and eco-friendly salt. The unprecedented solubility (up to 23 m) is a result of the introduction of hydrotropic agents that transform the acetate anion ligands to a hydrophilic coordination structure. All three hydrotropic agents including potassium acetate, urea and acetamide are effective in constructing highly concentrated zinc acetate electrolytes with which the assembled Zn//pyrene-4,5,9,10-tetraone full cell retains 70% of its initial capacity after 4,000 cycles. This work provides a unique opportunity to design high-performance electrolytes for applications in the wide battery space.

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Fig. 1: Solvation-sheath structure of Zn2+.
Fig. 2: Advantages of Zn-rich highly concentrated electrolytes.
Fig. 3: H2O structure and inhibited hydrogen evolution reaction.
Fig. 4: High Zn2+/Zn reversibility and uniform Zn metal deposits.
Fig. 5: Zn symmetric cells and Zn//PTO full cells.

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Data availability

The datasets generated and/or analysed during the current study are available from the corresponding authors on reasonable request.

References

  1. Xie, J. & Lu, Y.-C. A retrospective on lithium-ion batteries. Nat. Commun. 11, 2499 (2020).

    Article  CAS  Google Scholar 

  2. Bauer, C. et al. Charging sustainable batteries. Nat. Sustain. 5, 176–178 (2022).

    Article  Google Scholar 

  3. Han, D. et al. A non-flammable hydrous organic electrolyte for sustainable zinc batteries. Nat. Sustain. 5, 205–213 (2022).

    Article  Google Scholar 

  4. Jiang, H. et al. Chloride electrolyte enabled practical zinc metal battery with a near-unity coulombic efficiency. Nat. Sustain. https://doi.org/10.1038/s41893-41023-01092-x (2023).

  5. Kundu, D., Adams, B. D., Duffort, V., Vajargah, S. H. & Nazar, L. F. A high-capacity and long-life aqueous rechargeable zinc battery using a metal oxide intercalation cathode. Nat. Energy 1, 16119 (2016).

    Article  CAS  Google Scholar 

  6. Wang, F. et al. Highly reversible zinc metal anode for aqueous batteries. Nat. Mater. 17, 543–549 (2018).

    Article  CAS  Google Scholar 

  7. Yang, C. et al. All-temperature zinc batteries with high-entropy aqueous electrolyte. Nat. Sustain. 6, 325–335 (2023).

    Article  Google Scholar 

  8. Cao, L. et al. Fluorinated interphase enables reversible aqueous zinc battery chemistries. Nat. Nanotechnol. 16, 902–910 (2021).

    Article  CAS  Google Scholar 

  9. Jin, Y. et al. Stabilizing zinc anode reactions by polyethylene oxide polymer in mild aqueous electrolytes. Adv. Funct. Mater. 30, 2003932 (2020).

    Article  CAS  Google Scholar 

  10. Dong, Y. et al. Non-concentrated aqueous electrolytes with organic solvent additives for stable zinc batteries. Chem. Sci. 12, 5843–5852 (2021).

    Article  CAS  Google Scholar 

  11. Wang, N. et al. Stabilized rechargeable aqueous zinc batteries using ethylene glycol as water blocker. ChemSusChem 13, 5556–5564 (2020).

    Article  CAS  Google Scholar 

  12. Yang, W. et al. Hydrated eutectic electrolytes with ligand-oriented solvation shells for long-cycling zinc-organic batteries. Joule 4, 1557–1574 (2020).

    Article  CAS  Google Scholar 

  13. Song, X. et al. Enhanced reversibility and electrochemical window of Zn-ion batteries with an acetonitrile/water-in-salt electrolyte. Chem. Commun. 57, 1246–1249 (2021).

    Article  CAS  Google Scholar 

  14. Cao, L. et al. Solvation structure design for aqueous Zn metal batteries. J. Am. Chem. Soc. 142, 21404–21409 (2020).

    Article  CAS  Google Scholar 

  15. Cui, J. et al. Improved electrochemical reversibility of Zn plating/stripping: a promising approach to suppress water-induced issues through the formation of H-bonding. Mater. Today Energy 18, 100563 (2020).

    Article  CAS  Google Scholar 

  16. Wu, Y. et al. Electrolyte engineering enables stable Zn-ion deposition for long-cycling life aqueous Zn-ion batteries. Energy Storage Mater. 45, 1084–1091 (2022).

    Article  Google Scholar 

  17. Lin, R., Ke, C., Chen, J., Liu, S. & Wang, J. Asymmetric donor-acceptor molecule-regulated core-shell-solvation electrolyte for high-voltage aqueous batteries. Joule 6, 399–417 (2022).

    Article  CAS  Google Scholar 

  18. Chu, Y. et al. In situ built interphase with high interface energy and fast kinetics for high performance Zn metal anodes. Energy Environ. Sci. 14, 3609–3620 (2021).

    Article  CAS  Google Scholar 

  19. Li, C. et al. Highly reversible Zn anode with a practical areal capacity enabled by a sustainable electrolyte and superacid interfacial chemistry. Joule 6, 1103–1120 (2022).

    Article  CAS  Google Scholar 

  20. Parker, J. F. et al. Rechargeable nickel-3d zinc batteries: an energy-dense, safer alternative to lithium-ion. Science 356, 415–418 (2017).

    Article  CAS  Google Scholar 

  21. Wang, Z. et al. A metal-organic framework host for highly reversible dendrite-free zinc metal anodes. Joule 3, 1289–1300 (2019).

    Article  CAS  Google Scholar 

  22. Zhao, Z. et al. Long-life and deeply rechargeable aqueous Zn anodes enabled by a multifunctional brightener-inspired interphase. Energy Environ. Sci. 12, 1938–1949 (2019).

    Article  CAS  Google Scholar 

  23. Zhu, Y. et al. Concentrated dual-cation electrolyte strategy for aqueous zinc-ion batteries. Energy Environ. Sci. 14, 4463–4473 (2021).

    Article  CAS  Google Scholar 

  24. Chen, S. et al. Acetate-based ‘oversaturated gel electrolyte’ enabling highly stable aqueous zn-mno2 battery. Energy Storage Mater. 42, 240–251 (2021).

    Article  Google Scholar 

  25. Ji, X. A perspective of ZnCl2 electrolytes: the physical and electrochemical properties. eScience 1, 99–107 (2021).

    Article  Google Scholar 

  26. Zhang, C. et al. A ZnCl2 water-in-salt electrolyte for a reversible Zn metal anode. Chem. Commun. 54, 14097–14099 (2018).

    Article  CAS  Google Scholar 

  27. Olbasa, B. W. et al. Highly reversible Zn metal anode stabilized by dense and anion-derived passivation layer obtained from concentrated hybrid aqueous electrolyte. Adv. Funct. Mater. 32, 2103959 (2021).

    Article  Google Scholar 

  28. Zhao, J. et al. High-voltage Zn/LiMn0.8Fe0.2PO4 aqueous rechargeable battery by virtue of “water-in-salt” electrolyte. Electrochem. Commun. 69, 6–10 (2016).

    Article  CAS  Google Scholar 

  29. Chen, S., Lan, R., Humphreys, J. & Tao, S. Salt-concentrated acetate electrolytes for a high voltage aqueous Zn/MnO2 battery. Energy Storage Mater. 28, 205–215 (2020).

    Article  Google Scholar 

  30. Han, J., Mariani, A., Varzi, A. & Passerini, S. Green and low-cost acetate-based electrolytes for the highly reversible zinc anode. J. Power Sources 485, 229329 (2021).

    Article  CAS  Google Scholar 

  31. Suo, L. et al. “Water-in-salt” electrolyte enables high-voltage aqueous lithium-ion chemistries. Science 350, 938–943 (2015).

    Article  CAS  Google Scholar 

  32. Lukatskaya, M. R. et al. Concentrated mixed cation acetate “water-in-salt” solutions as green and low-cost high voltage electrolytes for aqueous batteries. Energy Environ. Sci. 11, 2876–2883 (2018).

    Article  CAS  Google Scholar 

  33. Zhang, Y. et al. Pursuit of reversible Zn electrochemistry: a time-honored challenge towards low-cost and green energy storage. NPG Asia Mater. 12, 4 (2020).

    Article  CAS  Google Scholar 

  34. Du, Y. et al. Electrolyte salts and additives regulation enables high performance aqueous zinc ion batteries: a mini review. Small 18, 2104640 (2021).

    Article  Google Scholar 

  35. Ding, Y. et al. Insights into hydrotropic solubilization for hybrid ion redox flow batteries. ACS Energy Lett. 3, 2641–2648 (2018).

    Article  CAS  Google Scholar 

  36. Orita, A., Verde, M. G., Sakai, M. & Meng, Y. S. A biomimetic redox flow battery based on flavin mononucleotide. Nat. Commun. 7, 13230 (2016).

    Article  CAS  Google Scholar 

  37. Mu, L. et al. Anthraquinone derivative as high-performance anode material for sodium-ion batteries using ether-based electrolytes. Green Energy Environ. 3, 63–70 (2018).

    Article  Google Scholar 

  38. Dhapte, V. & Mehta, P. Advances in hydrotropic solutions: an updated review. St. Petersburg Polytech. Univ. J. 1, 424–435 (2015).

    Google Scholar 

  39. Cao, J., Tao, M., Chen, H., Xu, J. & Chen, Z. A highly reversible anthraquinone-based anolyte for alkaline aqueous redox flow batteries. J. Power Sources 386, 40–46 (2018).

    Article  CAS  Google Scholar 

  40. Kim, J. Y., Kim, S., Papp, M., Park, K. & Pinal, R. Hydrotropic solubilization of poorly water-soluble drugs. J. Pharm. Sci. Res. 99, 3953–3965 (2010).

    CAS  Google Scholar 

  41. Kunz, W., Holmberg, K. & Zemb, T. Hydrotropes. Curr. Opin. Colloid Interface Sci. 22, 99–107 (2016).

    Article  CAS  Google Scholar 

  42. Vallet, V., Wahlgren, U. & Grenthe, I. Chelate effect and thermodynamics of metal complex formation in solution: a quantum chemical study. J. Am. Chem. Soc. 125, 14941–14950 (2003).

    Article  CAS  Google Scholar 

  43. Findoráková, L. et al. Novel zinc(ii) benzoate complex compounds with caffeine and urea. J. Therm. Anal. Calorim. 95, 923–928 (2009).

    Article  Google Scholar 

  44. Deacon, G. B. & Phillips, R. J. Relationships between the carbon-oxygen stretching frequencies of carboxylato complexes and the type of carboxylate coordination. Coord. Chem. Rev. 33, 227–250 (1980).

    Article  CAS  Google Scholar 

  45. Chen, R. et al. Zwitterionic bifunctional layer for reversible Zn anode. ACS Energy Lett. 7, 1719–1727 (2022).

    Article  CAS  Google Scholar 

  46. Linert, W., Jameson, R. F. & Taha, A. Donor numbers of anions in solution: the use of solvatochromic Lewis acid–base indicators. J. Chem. Soc. Dalton Trans. https://doi.org/10.1039/DT9930003181 (1993).

  47. Bai, P., Li, J., Brushett, F. R. & Bazant, M. Z. Transition of lithium growth mechanisms in liquid electrolytes. Energy Environ. Sci. 9, 3221–3229 (2016).

    Article  CAS  Google Scholar 

  48. Pang, Q. et al. Fast-charging aluminium–chalcogen batteries resistant to dendritic shorting. Nature 608, 704–711 (2022).

    Article  CAS  Google Scholar 

  49. Yamada, Y., Wang, J., Ko, S., Watanabe, E. & Yamada, A. Advances and issues in developing salt-concentrated battery electrolytes. Nat. Energy 4, 269–280 (2019).

    Article  CAS  Google Scholar 

  50. Cong, G., Zhou, Y., Li, Z. & Lu, Y.-C. A highly concentrated catholyte enabled by a low-melting-point ferrocene derivative. ACS Energy Lett. 2, 869–875 (2017).

    Article  CAS  Google Scholar 

  51. Hou, S. et al. Solvation sheath reorganization enables divalent metal batteries with fast interfacial charge transfer kinetics. Science 374, 172–178 (2021).

    Article  CAS  Google Scholar 

  52. Meng, R. et al. Tuning Zn‐ion solvation chemistry with chelating ligands toward stable aqueous Zn anodes. Adv. Mater. 34, 2200677 (2022).

    Article  CAS  Google Scholar 

  53. Ko, S. et al. Electrode potential influences the reversibility of lithium-metal anodes. Nat. Energy 7, 1217–1224 (2022).

    Article  CAS  Google Scholar 

  54. Yamada, Y. et al. Hydrate-melt electrolytes for high-energy-density aqueous batteries. Nat. Energy 1, 16129 (2016).

    Article  CAS  Google Scholar 

  55. Cai, S. et al. Water–salt oligomers enable supersoluble electrolytes for high-performance aqueous batteries. Adv. Mater. 33, 2007470 (2021).

    Article  CAS  Google Scholar 

  56. Jiang, L. et al. High-voltage aqueous Na-ion battery enabled by inert-cation-assisted water-in-salt electrolyte. Adv. Mater. 32, 1904427 (2020).

    Article  CAS  Google Scholar 

  57. Sui, Y. & Ji, X. Anticatalytic strategies to suppress water electrolysis in aqueous batteries. Chem. Rev. 121, 6654–6695 (2021).

    Article  CAS  Google Scholar 

  58. Zhao, J. et al. “Water-in-deep eutectic solvent” electrolytes enable zinc metal anodes for rechargeable aqueous batteries. Nano Energy 57, 625–634 (2019).

    Article  CAS  Google Scholar 

  59. Zhang, Q. et al. Modulating electrolyte structure for ultralow temperature aqueous zinc batteries. Nat. Commun. 11, 4463 (2020).

    Article  CAS  Google Scholar 

  60. Xie, J., Liang, Z. & Lu, Y.-C. Molecular crowding electrolytes for high-voltage aqueous batteries. Nat. Mater. 19, 1006–1011 (2020).

    Article  CAS  Google Scholar 

  61. Dong, D., Xie, J., Liang, Z. & Lu, Y.-C. Tuning intermolecular interactions of molecular crowding electrolyte for high-performance aqueous batteries. ACS Energy Lett. 7, 123–130 (2022).

    Article  CAS  Google Scholar 

  62. Cai, Z. et al. Chemically resistant Cu–Zn/Zn composite anode for long cycling aqueous batteries. Energy Storage Mater. 27, 205–211 (2020).

    Article  Google Scholar 

  63. Ma, L. et al. Ammonium enables reversible aqueous Zn battery chemistries by tailoring the interphase. One Earth 5, 413–421 (2022).

    Article  Google Scholar 

  64. Suo, L., Hu, Y.-S., Li, H., Armand, M. & Chen, L. A new class of solvent-in-salt electrolyte for high-energy rechargeable metallic lithium batteries. Nat. Commun. 4, 1481 (2013).

    Article  Google Scholar 

  65. Gonzalez, G., Marshall, G., Molina, F. V., Dengra, S. & Rosso, M. Viscosity effects in thin-layer electrodeposition. J. Electrochem. Soc. 148, C479 (2001).

    Article  CAS  Google Scholar 

  66. Guo, Z. et al. An environmentally friendly and flexible aqueous zinc battery using an organic cathode. Angew. Chem. Int. Ed. 57, 11737–11741 (2018).

    Article  CAS  Google Scholar 

  67. Evans, J., Vincent, C. A. & Bruce, P. G. Electrochemical measurement of transference numbers in polymer electrolytes. Polymer 28, 2324–2328 (1987).

    Article  CAS  Google Scholar 

  68. Ravel, B. & Newville, M. ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy usingIFEFFIT. J. Synchrotron Radiat. 12, 537–541 (2005).

    Article  CAS  Google Scholar 

  69. Grimme, S., Antony, J., Ehrlich, S. & Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 132, 154104 (2010).

    Article  Google Scholar 

  70. Iannuzzi, M., Laio, A. & Parrinello, M. Efficient exploration of reactive potential energy surfaces using Car-Parrinello molecular dynamics. Phys. Rev. Lett. 90, 238302 (2003).

    Article  Google Scholar 

  71. Li, P., Song, L. F. & Merz, K. M. Jr. Systematic parameterization of monovalent ions employing the nonbonded model. J. Chem. Theory Comput. 11, 1645–1657 (2015).

    Article  CAS  Google Scholar 

  72. Wang, J., Wolf, R. M., Caldwell, J. W., Kollman, P. A. & Case, D. A. Development and testing of a general amber force field. J. Comput. Chem. 25, 1157–1174 (2004).

    Article  CAS  Google Scholar 

  73. Wang, J., Cieplak, P. & Kollman, P. A. How well does a restrained electrostatic potential (resp) model perform in calculating conformational energies of organic and biological molecules? J. Comput. Chem. 21, 1049–1074 (2000).

    Article  CAS  Google Scholar 

  74. Lu, T. & Chen, F. Multiwfn: a multifunctional wavefunction analyzer. J. Comput. Chem. 33, 580–592 (2012).

    Article  Google Scholar 

  75. Neese, F., Wennmohs, F., Becker, U. & Riplinger, C. The orca quantum chemistry program package. J. Chem. Phys. 152, 224108 (2020).

    Article  CAS  Google Scholar 

  76. Martínez, L., Andrade, R., Birgin, E. G. & Martínez, J. M. Packmol: a package for building initial configurations for molecular dynamics simulations. J. Comput. Chem. 30, 2157–2164 (2009).

    Article  Google Scholar 

  77. Brehm, M., Thomas, M., Gehrke, S. & Kirchner, B. Travis—a free analyzer for trajectories from molecular simulation. J. Chem. Phys. 152, 164105 (2020).

    Article  CAS  Google Scholar 

  78. Humphrey, W., Dalke, A. & Schulten, K. Vmd: visual molecular dynamics. J. Mol. Graph. 14, 33–38 (1996).

    Article  CAS  Google Scholar 

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Acknowledgements

The work described in this paper was fully supported by two grants from the Research Grant Council of the Hong Kong Special Administrative Region, China (No. CUHK14308321, Y.-C.L. and C1002-21GF, Y.-C.L. and J.F.). We thank Z. J. Liang and J. Xie for the OEMS tests, J. F. Lei and W. W. Wang for the SEM tests, and L. W. Jiang for insightful discussion of the mechanism.

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Authors and Affiliations

  1. Electrochemical Energy and Interfaces Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China

    Dejian Dong, Yue Sun & Yi-Chun Lu

  2. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, China

    Tairan Wang & Jun Fan

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Contributions

D.D. and Y.-C.L. conceived the project; D.D. carried out electrochemical tests and characterizations; T.W. and J.F. conducted MD simulations. Y.S. carried out cathode synthesis. D.D. and Y.-C.L. wrote the paper; all authors participated in manuscript preparation.

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Correspondence to Yi-Chun Lu.

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Dong, D., Wang, T., Sun, Y. et al. Hydrotropic solubilization of zinc acetates for sustainable aqueous battery electrolytes. Nat Sustain 6, 1474–1484 (2023). https://doi.org/10.1038/s41893-023-01172-y

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