Effect of crystallite geometries on electrochemical performance of porous intercalation electrodes by multiscale operando investigation
Effect of crystallite geometries on electrochemical performance of porous intercalation electrodes by multiscale operando investigation
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DOI：
10.1038/s41563-021-01151-8
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发表时间：
2021-11-25
期刊：
影响因子：
41.2
通讯作者：
Banerjee, Sarbajit
中科院分区：
文献类型：
--
作者：
Luo, Yuting;Bai, Yang;Banerjee, Sarbajit
锂离子电池尚未实现其全部承诺，因为电极架构的设计和构造存在挑战，这些挑战允许其整个内部体积可逆地可用于离子存储。由相同的材料和相同的规格构造的电极，其仅在组成颗粒的尺寸和几何形状方面不同，可以在极化、应力积累和容量衰减方面显示出令人惊讶的差异。在这里，使用同步辐射X射线衍射和能量色散X射线衍射（EDXRD），我们探测的显着的颗粒几何形状相关的修改的锂化诱导的相变在V2O5作为模型相变阴极的机械起源。一个显着的调制相共存制度观察作为一个功能的粒子几何形状。具体而言，亚稳相是稳定的纳米尺寸的球形V2O5颗粒，以避免形成大的失配应变。空间分辨EDXRD测量表明，颗粒的几何形状强烈修改的多孔阴极结构的曲折。在包括微米尺寸的片晶的电极结构中更大的离子传输限制导致在电极厚度上相当大的锂化不均匀性。这些见解确立了亚稳相态和电极弯曲度的颗粒几何形状相关的修改作为实现嵌入式cathodes.Designing锂离子电池的电极架构，可以可逆地访问离子存储的承诺的关键设计原则可以是具有挑战性的。使用operando技术的锂化诱导相变的V2O5模型阴极的机械起源现在澄清。
Lithium-ion batteries are yet to realize their full promise because of challenges in the design and construction of electrode architectures that allow for their entire interior volumes to be reversibly accessible for ion storage. Electrodes constructed from the same material and with the same specifications, which differ only in terms of dimensions and geometries of the constituent particles, can show surprising differences in polarization, stress accumulation and capacity fade. Here, using operando synchrotron X-ray diffraction and energy dispersive X-ray diffraction (EDXRD), we probe the mechanistic origins of the remarkable particle geometry-dependent modification of lithiation-induced phase transformations in V2O5 as a model phase-transforming cathode. A pronounced modulation of phase coexistence regimes is observed as a function of particle geometry. Specifically, a metastable phase is stabilized for nanometre-sized spherical V2O5 particles, to circumvent the formation of large misfit strains. Spatially resolved EDXRD measurements demonstrate that particle geometries strongly modify the tortuosity of the porous cathode architecture. Greater ion-transport limitations in electrode architectures comprising micrometre-sized platelets result in considerable lithiation heterogeneities across the thickness of the electrode. These insights establish particle geometry-dependent modification of metastable phase regimes and electrode tortuosity as key design principles for realizing the promise of intercalation cathodes.Designing electrode architectures for Li-ion batteries that can be reversibly accessible for ion storage can be challenging. Using operando techniques the mechanistic origin of lithiation-induced phase transformations in a V2O5 model cathode is now clarified.