| Autor: |
Fu, Chengyin, Venturi, Victor, Ahmad, Zeeshan, Ells, Andrew W., Viswanathan, Venkatasubramanian, Helms, Brett A. |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
Nature Materials, 19, 758-766 (2020) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1038/s41563-020-0655-2 |
| Popis: |
Dendrite formation during electrodeposition while charging lithium metal batteries compromises their safety. While high shear modulus solid-ion conductors (SICs) have been prioritized to resolve pressure-driven instabilities that lead to dendrite propagation and cell shorting, it is unclear whether these or alternatives are needed to guide uniform lithium electrodeposition, which is intrinsically density-driven. Here, we show that SICs can be designed within a universal chemomechanical paradigm to access either pressure-driven dendrite-blocking or density-driven dendrite-suppressing properties, but not both. This dichotomy reflects the competing influence of the SICs mechanical properties and partial molar volume of Li+ relative to those of the lithium anode on plating outcomes. Within this paradigm, we explore SICs in a previously unrecognized dendrite-suppressing regime that are concomitantly soft, as is typical of polymer electrolytes, but feature atypically low Li+ partial molar volume, more reminiscent of hard ceramics. Li plating mediated by these SICs is uniform, as revealed using synchrotron hard x-ray microtomography. As a result, cell cycle-life is extended, even when assembled with thin Li anodes and high-voltage NMC-622 cathodes, where 20 percent of the Li inventory is reversibly cycled. |
| Databáze: |
arXiv |
| Externí odkaz: |
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