| 1. |
- Jiao, Xingxing, et al.
(författare)
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Grain size and grain boundary strength: Dominative role in electro-chemo-mechanical failure of polycrystalline solid-state electrolytes
- 2024
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Ingår i: Energy Storage Materials. - 2405-8297. ; 65
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Tidskriftsartikel (refereegranskat)abstract
- Solid-state batteries with lithium metal anode have been accepted extensively as the competitive option to fulfill the upping requirement for safe and efficient energy devices. Nevertheless, its wide-ranging application has been impeded by the failure of solid-state electrolyte (SSE) induced by development of lithium (Li) filament. Based on the nature of polycrystalline ceramic SSE with varying grain size and boundary strength, the constitutive equation coupled with electrochemical kinetics was applied to picture the propagation of damage and corresponding disintegration caused by the development of Li filament. Based on the results, we found that the stress generated along with the growth of Li filament spreads away via the opening and sliding of grain boundary. Thus, damage occurs along grain boundaries, of which propagation behavior and damage level are controlled by grain size. Especially, over-refinement and under-refinement of grains of SSE can cause flocculent damage with inordinate damage degree and accelerate the failure time of SSE, respectively. On the other hand, the failure time is powerfully prolongated through strengthening the grain boundary of SSE. Eventually, grain size of 0.2 μm and tensile strength of grain boundary of 0.8-time-of-grain are posted as the threshold to realize the postponed failure of NASICON-based SSE. Inspiringly, electro-chemo-mechanical model in this contribution is generally applicable to other type of ceramic SSE to reveal the failure process and provide the design guideline, fostering the improvement of solid-state batteries.
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| 2. |
- Liu, Yangyang, et al.
(författare)
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Electro-Chemo-Mechanical Modeling of Artificial Solid Electrolyte Interphase to Enable Uniform Electrodeposition of Lithium Metal Anodes
- 2022
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- Nonuniform electrodeposition of lithium during charging processes is the key issue hindering development of rechargeable Li metal batteries. This deposition process is largely controlled by the solid electrolyte interphase (SEI) on the metal surface and the design of artificial SEIs is an essential pathway to regulate electrodeposition of Li. In this work, an electro-chemo-mechanical model is built and implemented in a phase-field modelling to understand the correlation between the physical properties of artificial SEIs and deposition of Li. The results show that improving ionic conductivity of the SEI above a critical level can mitigate stress concentration and preferred deposition of Li. In addition, the mechanical strength of the SEI is found to also mitigate non-uniform deposition and influence electrochemical kinetics, with a Young's modulus around 4.0 GPa being a threshold value for even deposition of Li. By comparison of the results to experimental results for artificial SEIs it is clear that the most important direction for future work is to improve the ionic conductivity without compromising mechanical strength. In addition, the findings and methodology presented here not only provide detailed guidelines for design of artificial SEI on Li-metal anodes but also pave the way to explore strategies for regulating deposition of other metal anodes.
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