Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, USA.
Electrification and Energy Infrastructures Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
Nat Mater. 2022 Nov;21(11):1298-1305. doi: 10.1038/s41563-022-01333-y. Epub 2022 Sep 1.
Understanding and mitigating filament formation, short-circuit and solid electrolyte fracture is necessary for advanced all-solid-state batteries. Here, we employ a coupled far-field high-energy diffraction microscopy and tomography approach for assessing the chemo-mechanical behaviour for dense, polycrystalline garnet (LiLaZrO) solid electrolytes with grain-level resolution. In situ monitoring of grain-level stress responses reveals that the failure mechanism is stochastic and affected by local microstructural heterogeneity. Coupling high-energy X-ray diffraction and far-field high-energy diffraction microscopy measurements reveals the presence of phase heterogeneity that can alter local chemo-mechanics within the bulk solid electrolyte. These local regions are proposed to be regions with the presence of a cubic polymorph of LLZO, potentially arising from local dopant concentration variation. The coupled tomography and FF-HEDM experiments are combined with transport and mechanics modelling to illustrate the degradation of polycrystalline garnet solid electrolytes. The results showcase the pathways for processing high-performing solid-state batteries.
理解和减轻丝状形成、短路和固体电解质断裂对于先进的全固态电池是必要的。在这里，我们采用远场高能衍射显微镜和断层扫描方法，以评估具有晶粒级分辨率的致密多晶石榴石（LiLaZrO）固体电解质的化学机械行为。对晶粒级应力响应的原位监测表明，失效机制是随机的，并受局部微观结构异质性的影响。高能 X 射线衍射和远场高能衍射显微镜测量的耦合揭示了存在相异质性，这可能会改变大块固体电解质内的局部化学机械性能。这些局部区域被认为是存在 LLZO 立方多晶型的区域，可能是由于局部掺杂浓度的变化引起的。结合传输和力学建模，对断层扫描和 FF-HEDM 实验进行了组合，以说明多晶石榴石固体电解质的降解。结果展示了高性能全固态电池的处理途径。
