Curvature-Induced Modification of Mechano-Electrochemical Coupling and Nucleation Kinetics in a Cathode Material
Curvature-Induced Modification of Mechano-Electrochemical Coupling and Nucleation Kinetics in a Cathode Material
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DOI：
10.1016/j.matt.2020.08.030
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发表时间：
2020-11-04
期刊：
影响因子：
18.9
通讯作者：
Banerjee, Sarbajit
中科院分区：
文献类型：
--
作者：
Andrews, Justin L.;Stein, Peter;Banerjee, Sarbajit
锂离子电池电极材料中的嵌入诱导相变引起单个颗粒内的多相共存状态，从而在动态演变的界面上产生显著的晶格相干应变。我们在这里证明，晶格相干应变可以减轻利用耦合的电化学，力学和粒子的几何形状，以实现可控的成核和确定性的离子输运。在这里，我们对比奇异扭结和连续曲率作为一种手段，使均匀的锂化，而不会在模型阴极材料V2 O 5内产生大的应力。奇异扭结证实，局部曲率有利于锂化，但也加剧了锂化的不均匀性和弹性失配应变。相比之下，连续曲率的并入使得能够实现均匀的单相锂化，从而减轻晶格相干应变。这些研究提供了晶体电极内力学和电化学耦合的直接视图，并表明介观结构可以帮助解决限制储能系统性能的关键故障机制，而不会牺牲充电/放电动力学。
Intercalation-induced phase transformations in Li-ion battery electrode materials give rise to multi-phase coexistence regimes within individual particles, generating significant lattice coherency strain across dynamically evolving interfaces. We demonstrate here that the lattice coherency strain can be alleviated by leveraging the coupling of electrochemistry, mechanics, and particle geometry to achieve controllable nucleation and deterministic ion transport. Here, we contrast singular kinks and continuous curvature as a means of enabling homogeneous lithiation without developing large stresses within a model cathode material, V2O5 The singular kink confirms that local curvature facilitates lithiation but also exacerbates lithiation inhomogeneities and elastic misfit strain. In contrast, the incorporation of continuous curvature enables homogeneous single-phase lithiation, mitigating lattice coherency strain. The studies provide a direct view of the coupling of mechanics and electrochemistry within crystalline electrodes and suggest that mesoscale architectures can help resolve key failure mechanisms limiting the performance of energy-storage systems without sacrificing charge/discharge kinetics.