Lithium transport at silicon thin film: Barrier for high-rate capability anode
Lithium transport at silicon thin film: Barrier for high-rate capability anode
复制标题
硅薄膜上的锂传输：高倍率性能阳极的势垒
DOI：
10.1063/1.3462998
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发表时间：
2010-07-21
影响因子：
4.4
通讯作者：
Chen, Jun
中科院分区：
文献类型：
--
作者：
Peng, Bo;Cheng, Fangyi;Chen, Jun
阻碍纳米结构硅阳极在可再充电锂离子电池中的实际应用的主要障碍是锂化/脱锂过程期间的容量保持率，特别是在高电流速率下（例如，> 5C）。由于Li在电极中的快速输运是高倍率性能的必要条件，因此在Li输运过程中存在速率限制步骤，需要确定。本文通过第一性原理计算研究了Si薄膜阳极的Li输运性质，发现Li表面嵌入的高本征能垒（0.88 eV）阻碍了Li的快速输运。然而，这种能量势垒可以通过表面改性有效地降低，例如，P或Al掺杂。研究结果对高倍率性能锂离子电池硅负极的设计具有一定的指导意义。(C)2010年美国物理学会。[doi：10.1063/1.3462998]
The major hurdle that retards the practical application of nanostructured silicon anode in rechargeable Li-ion batteries is the capacity retention during lithiation/delithiation processes, especially at high current rate (e.g., >5 C). Since fast Li transport in the electrode is the essential of high-rate capability, the rate-limiting step exists during Li transport process and needs to be determined. We here investigate Li transport properties of Si thin film anode by first-principles calculation and find that high intrinsic energy barrier (0.88 eV) of Li surface intercalation retards fast Li transport. However, this energy barrier can be efficiently reduced by surface modification, e.g., P or Al doping. The present results should shed light on designing Si anode of Li-ion batteries with high-rate capability. (C) 2010 American Institute of Physics. [doi:10.1063/1.3462998]