Flexible lithium-ion conducting ceramic textile. The lithium-ion conducting ceramic textile is flexible and retained the physical characteristics of the original template. The unique textile structure enables long-range lithium-ion transport pathways via continuous fibers and yarns, high surface area/volume ratio of solid ion conductors and multi-level porosity distribution. Gong et al. Click to enlarge.

The textile also provided an electrolyte framework when designing a 3D electrode to realize ultrahigh cathode loading (10.8 g/cm² sulfur) for high-performance Li-metal batteries. The resulting battery delivered a high capacity of 1000 mAh/g.

Characterization of garnet textile 3D electrode architecture for solid state Li-S batteries loaded with 10.8 mg/cm2 sulfur. (a) Photograph of a garnet textile sintered on the dense supporting electrolyte. (b) SEM image of the sulfur cathode infiltrated garnet textile electrode architecture; (c) EDX elemental mapping of the sulfur/carbon mixture loaded single garnet fiber; (d) charge–discharge profiles of the solid-state lithium-sulfur battery. Gong et al. Click to enlarge.

In the last few years, much time, effort and resources have been put into the development of battery technology that is safe, efficient, cheap to produce, and eco-friendly. Conventional Lithium-ion (L-ion) batteries typically use liquid electrolytes due to their very high ionic conductivities; however, these liquid electrolytes have numerous drawbacks including flammability, leakage and the formation of dendrites in the electrodes.

In an effort to avoid these issues, researchers at the University of Maryland Clark School of Engineering—led by Eric Wachsman (Professor with appointments in both MSE and ChBE and Director of the MD Energy Innovation Institute) and Liangbing Hu (MSE Professor)—have focused their efforts on the development of solid-state-batteries. (Earlier post.)

The goal of this research is to develop safe solid-state components for use in lithium-metal batteries. Such components should have good ionic conductivity, abundant surface area and scalable production potential. We have successfully developed a garnet-fiber textile to meet these key requirements.

—Dr. Gong

In their research, the team used commercially available fabrics as a template for creating Li-conducting garnet fiber mat textiles, and then filled in the pore space between the fibers with a solid polymer electrolyte. The result is a highly scalable process to make hybrid ceramic/polymer Li-electrolytes with the enhanced properties of higher conductivity and strength of the garnet ceramic electrolyte. Moreover, the ceramic textile is flexible and cuttable.

Nothing like this has ever been done before. The resulting hybrid structure is capable of fast-ion conduction through the continuous ceramic fibers, but with the flexibility of more traditional polymer electrolytes. What’s more, the garnet fibers will help block the formation of Li-dendrites, thus enabling higher capacity Li-metal anodes.

—Dr. Wachsman

The group intends to continue their research with this technology, planning to make the textile even thinner to reduce resistance to ionic transport between electrodes. The technology will have a wide-range of applications in commercial electronics.

Resources

• Gong,Y. et al., Hu, L. Wachsman, E. 2018 “Lithium-ion conductive ceramic textile: A new architecture for flexible solid-state lithium metal batteries.” Materials Today doi: 10.1016/j.mattod.2018.01.001