An international team of researchers led by Monash University has developed an ultra-high capacity Li-S battery that has better performance and less environmental impact than current lithium-ion products. An open-access paper on their work is published in Science Advances.
Lithium-sulfur batteries can displace lithium-ion by delivering higher specific energy. Presently, however, the superior energy performance fades rapidly when the sulfur electrode is loaded to the required levels—5 to 10 mg cm−2—due to substantial volume change of lithiation/delithiation and the resultant stresses.
Inspired by the classical approaches in particle agglomeration theories, we found an approach that places minimum amounts of a high-modulus binder between neighboring particles, leaving increased space for material expansion and ion diffusion. These expansion-tolerant electrodes with loadings up to 15 mg cm−2 yield high gravimetric (>1200 mA·hour g−1) and areal (19 mA·hour cm−2) capacities. The cells are stable for more than 200 cycles, unprecedented in such thick cathodes, with Coulombic efficiency above 99%.—Shaibani et al.
Using the same materials in standard lithium-ion batteries, researchers reconfigured the design of sulfur cathodes so they could accommodate higher stress loads without a drop in overall capacity or performance.
Inspired by unique bridging architecture first recorded in processing detergent powders in the 1970s, the team engineered a method that created bonds between particles to accommodate stress and deliver a high level of stability.
The researchers have an approved filed patent (PCT/AU 2019/051239) for their manufacturing process, and prototype cells have been successfully fabricated by German R&D partners Fraunhofer Institute for Material and Beam Technology.
Some of the world’s largest manufacturers of lithium batteries in China and Europe have expressed interest in upscaling production, with further testing to take place in Australia in early 2020.
Mahdokht Shaibani, Meysam Sharifzadeh Mirshekarloo, Ruhani Singh, Christopher D. Easton, M. C. Dilusha Cooray, Nicolas Eshraghi, Thomas Abendroth, Susanne Dörfler, Holger Althues, Stefan Kaskel, Anthony F. Hollenkamp, Matthew R. Hill, Mainak Majumder (2020) “Expansion-tolerant architectures for stable cycling of ultrahigh-loading sulfur cathodes in lithium-sulfur batteries” Science Advances doi: 10.1126/sciadv.aay2757