Theory of SEI Formation in Rechargeable Batteries: Capacity Fade, Accelerated Aging and Lifetime Prediction
Theory of SEI Formation in Rechargeable Batteries: Capacity Fade, Accelerated Aging and Lifetime Prediction
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DOI：
10.1149/2.044302jes
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发表时间：
2013-01-01
影响因子：
3.9
通讯作者：
Bazant, Martin Z.
中科院分区：
文献类型：
--
作者：
Pinson, Matthew B.;Bazant, Martin Z.
在可充电电池的应用中，循环寿命至关重要，但寿命预测大多基于经验趋势，而不是数学模型。在实际的锂离子电池中，容量衰减会发生数千次循环，受缓慢的电化学过程的限制，例如在负极形成固体-电解液界面(SEI)，这与可逆的锂嵌入竞争。聚焦于SEI生长作为典型的降解机制，我们展示了一个简单的单粒子模型可以准确地解释在使用石墨阳极的商业电池中实验观察到的容量衰减，并基于有限的短时间和高温加速老化数据来预测未来的衰减。该理论被扩展到多孔电极，预测SEI的生长在整个电极上基本上是均匀的，即使在高速率下也是如此。正如单粒子模型所预测的那样，电池样本的寿命分布符合高斯统计。我们还将该理论扩展到快速降解的阳极，如纳米结构硅，它们在离子嵌入上表现出较大的膨胀。在这种情况下，骑行过程中的大面积变化会促进SEI的损失和更快的SEI增长。我们的简单模型能够准确地符合各种已发表的石墨和硅阳极实验数据。(C)2012年电化学会。[DOI：10.1149/2.044302jes]版权所有。
Cycle life is critically important in applications of rechargeable batteries, but lifetime prediction is mostly based on empirical trends, rather than mathematical models. In practical lithium-ion batteries, capacity fade occurs over thousands of cycles, limited by slow electrochemical processes, such as the formation of a solid-electrolyte interphase (SEI) in the negative electrode, which compete with reversible lithium intercalation. Focusing on SEI growth as the canonical degradation mechanism, we show that a simple single-particle model can accurately explain experimentally observed capacity fade in commercial cells with graphite anodes, and predict future fade based on limited accelerated aging data for short times and elevated temperatures. The theory is extended to porous electrodes, predicting that SEI growth is essentially homogeneous throughout the electrode, even at high rates. The lifetime distribution for a sample of batteries is found to be consistent with Gaussian statistics, as predicted by the single-particle model. We also extend the theory to rapidly degrading anodes, such as nanostructured silicon, which exhibit large expansion on ion intercalation. In such cases, large area changes during cycling promote SEI loss and faster SEI growth. Our simple models are able to accurately fit a variety of published experimental data for graphite and silicon anodes. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.044302jes] All rights reserved.