New Tree-Derived Material Could Pave the Way for Better and Safer Batteries

Researchers from Brown University and the University of Maryland have developed a new material derived from trees that could replace liquid electrolytes in next-generation batteries. Published in the journal Nature, the study introduces a thin and flexible solid ion conductor made by combining copper with cellulose nanofibrils, which are polymer tubes derived from wood. The material exhibits ion conductivity 10 to 100 times better than other polymer ion conductors and can be used as a solid battery electrolyte or an ion-conducting binder for the cathode in solid-state batteries.

The team, led by Liangbing Hu from the University of Maryland, discovered that by incorporating copper with cellulose nanofibrils, the cellulose, which is typically an ion-insulating material, enables faster lithium-ion transport within the polymer chains. This ion conductor achieved a record high ionic conductivity among all solid polymer electrolytes. The collaboration between Hu’s lab and Yue Qi’s lab at Brown University was instrumental in this research.

Lithium-ion batteries

Current lithium-ion batteries use liquid electrolytes composed of lithium salt dissolved in an organic solvent. While liquid electrolytes perform well, they have drawbacks such as dendrite formation and flammability. Solid electrolytes, made from non-flammable materials, have the potential to overcome these challenges. However, most solid electrolytes studied so far are ceramics, which are thick, rigid, and prone to fractures. In contrast, the material developed in this study is thin, flexible, and exhibits ion conductivity comparable to ceramics.

Computer simulations conducted by Qi and Qisheng Wu from Brown University revealed that the copper-cellulose material increases the spacing between cellulose polymer chains, creating pathways for lithium ions to move freely. This unique structure enables high ion conductivity similar to inorganic ceramics. The researchers believe that utilizing materials sourced from nature will reduce the environmental impact of battery manufacturing.

In addition to serving as a solid electrolyte, the new material can also act as a cathode binder in solid-state batteries. Thicker cathodes require ion-conducting binders to maintain efficiency, and the researchers demonstrated the viability of their material as a binder for one of the thickest cathodes reported.

The researchers are optimistic that this new material could be a significant step toward the widespread adoption of solid-state battery technology.

Originally published by scitechdaily.com. Read the original article.

Read more: A New Way to Store Sustainable Energy: ‘Information Batteries’

Reference: “Copper-coordinated cellulose ion conductors for solid-state batteries” by Chunpeng Yang, Qisheng Wu, Weiqi Xie, Xin Zhang, Alexandra Brozena, Jin Zheng, Mounesha N. Garaga, Byung Hee Ko, Yimin Mao, Shuaiming He, Yue Gao, Pengbo Wang, Madhusudan Tyagi, Feng Jiao, Robert Briber, Paul Albertus, Chunsheng Wang, Steven Greenbaum, Yan-Yan Hu, Akira Isogai, Martin Winter, Kang Xu, Yue Qi and Liangbing Hu, 20 October 2021, Nature.
DOI: 10.1038/s41586-021-03885-6