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arXiv 1901.01190cond-mat.mtrl-scicond-mat.mes-hallphysics.chem-ph
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SEI在炭黑上生长的电化学动力学,I:实验

Electrochemical kinetics of SEI growth on carbon black, I: Experiments

Peter M. Attia, Supratim Das, Stephen J. Harris, Martin Z. Bazant, William C. Chueh

摘要:

固体电解质界面(SEI)的生长是锂离子电池中容量衰减的主要驱动因素。尽管其对该设备的重要性和强烈的研究兴趣,但支撑SEI增长的基本机制仍不清楚。在这项工作的第一部分中,我们提出了一种电分析方法来测量的依赖性的SEI生长的电位,电流大小,和电流方向在恒电流循环的炭黑/锂半电池。我们发现,SEI的增长强烈依赖于所有三个参数,最值得注意的是,我们发现SEI的增长率与名义C率增加,并显着高于锂化比脱锂。我们在恒电流和恒电位实验中观察到这种定向效应,并讨论了可以解释这种观察的假设。这项工作确定了SEI生长和电荷存储之间的强耦合(例如,嵌入和电容)。

英文摘要:

Growth of the solid electrolyte interphase (SEI) is a primary driver of capacity fade in lithium-ion batteries. Despite its importance to this device and intense research interest, the fundamental mechanisms underpinning SEI growth remain unclear. In Part I of this work, we present an electroanalytical method to measure the dependence of SEI growth on potential, current magnitude, and current direction during galvanostatic cycling of carbon black/Li half cells. We find that SEI growth strongly depends on all three parameters; most notably, we find SEI growth rates increase with nominal C rate and are significantly higher on lithiation than on delithiation. We observe this directional effect in both galvanostatic and potentiostatic experiments and discuss hypotheses that could explain this observation. This work identifies a strong coupling between SEI growth and charge storage (e.g., intercalation and capacitance) in carbon negative electrodes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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