In-operando imaging of polysulfide catholytes for Li–S batteries and implications for kinetics and mechanical stability
| Autor: | Coleman Fincher, Matt Pharr, Yuwei Zhang, Scott McProuty |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Energy Engineering and Power Technology chemistry.chemical_element Lithium–sulfur battery 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Redox 0104 chemical sciences chemistry.chemical_compound chemistry Lithium sulfide Chemical engineering Deposition (phase transition) Lithium Electrical and Electronic Engineering Physical and Theoretical Chemistry Thin film 0210 nano-technology Polysulfide |
| Zdroj: | Journal of Power Sources. 434:226727 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2019.226727 |
| Popis: | Enhancing the electrochemical performance of lithium-sulfur batteries requires improved fundamental understanding of the reduction and oxidation of the soluble lithium polysulfide species. To this end, we have designed a ‘donut-shaped’ cell to enable direct optical observation of phase transformations of a liquid polysulfide catholyte to solid lithium sulfide during electrochemical cycling. We use this technique to image the spatio-temporal distribution of the solid lithium sulfide as it deposits on a carbon matrix at different charging rates. These experiments indicate that the reduction and oxidation of polysulfide catholyte occurs as a thin film deposition and growth process during both lithiation and delithiation. We then investigate the ramifications of these morpological changes in terms of mechanical stability by measuring the evolution of stress during discharge of the polysulfide catholyte. The stress measurements indicate that the average stress during discharging decreases with increasing the charging rate, which we attribute to less dense deposition of lithium sulfide at high discharge rates. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect