"Decoupling of mechanical properties and ionic conductivity in supramolecular lithium ion conductors"

David G. Mackanic: Xuzhou Yan, Qiuhong Zhang, Naoji Matsuhisa, Zhiao Yu, Yuanwen Jiang, Tuheen Manika, Jeffrey Lopez, Hongping Yan, Kai Liu, Xiaodong Chen, Yi Cui & Zhenan Bao; Nature Communications, 11/26/19.

Additional Authors: Xuzhou Yan, Qiuhong Zhang, Naoji Matsuhisa, Zhiao Yu, Yuanwen Jiang, Tuheen Manika, Jeffrey Lopez, Hongping Yan, Kai Liu, Xiaodong Chen, Yi Cui & Zhenan Bao

Abstract:

The emergence of wearable electronics puts batteries closer to the human skin, exacerbating the need for battery materials that are robust, highly ionically conductive, and stretchable. Herein, we introduce a supramolecular design as an effective strategy to overcome the canonical tradeoff between mechanical robustness and ionic conductivity in polymer electrolytes. The supramolecular lithium ion conductor utilizes orthogonally functional H-bonding domains and ion-conducting domains to create a polymer electrolyte with unprecedented toughness (29.3 MJ m−3) and high ionic conductivity (1.2 × 10−4 S cm−1 at 25 °C). Implementation of the supramolecular ion conductor as a binder material allows for the creation of stretchable lithium-ion battery electrodes with strain capability of over 900% via a conventional slurry process. The supramolecular nature of these battery components enables intimate bonding at the electrode-electrolyte interface. Combination of these stretchable components leads to a stretchable battery with a capacity of 1.1 mAh cm−2 that functions even when stretched to 70% strain. The method reported here of decoupling ionic conductivity from mechanical properties opens a promising route to create high-toughness ion transport materials for energy storage applications.