First-Principles Studies of the Lithiation and Delithiation Paths in Si Anodes in Li-Ion Batteries
First-Principles Studies of the Lithiation and Delithiation Paths in Si Anodes in Li-Ion Batteries
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DOI：
10.1021/acs.jpcc.9b05933
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发表时间：
2019-08
期刊：
影响因子：
--
通讯作者：
K. Chan;W. Liang;Candace K. Chan
中科院分区：
文献类型：
--
作者：
K. Chan;W. Liang;Candace K. Chan
由于硅阳极对于下一代高能量密度锂电池的重要性，了解硅的锂化以及由此形成的非晶硅化锂 (a-LixSi) 已成为众多研究的主题。实验研究表明，2 ≤ x ≤ 3.75 的 a-LixSi 是锂化和脱锂过程中 Si 转变的一个突出相，但计算研究尚未阐明原因。在这项工作中，进行了第一原理分子动力学计算，以模拟与锂离子半电池中硅阳极的锂化和脱锂相关的各种直接步骤。相关 LixSi 相和 Si 的形成能和晶胞体积已针对晶态和非晶态进行了计算。第一原理结果用于构建锂化和脱锂路径并计算阳极的电压、容量和电池体积的相应变化。这些结果表明，多...
Understanding the lithiation of Si and the resulting formation of amorphous lithium silicides (a-LixSi) has been the subject of numerous studies due to the importance of silicon anodes for next generation, high energy density lithium batteries. Experimental studies have shown that a-LixSi with 2 ≤ x ≤ 3.75 appears as a prominent phase in the transformation of Si during lithiation and delithiation, but computational studies have yet to elucidate why. In this work, first-principles molecular dynamics computations were performed to simulate the various immediate steps associated with lithiation and delithiation of Si anodes in a Li-ion half-cell battery. The energy of formation and unit-cell volume for relevant LixSi phases and Si have been computed for both crystalline and amorphous states. The first-principles results are utilized to construct lithiation and delithiation pathways and compute the corresponding changes in the voltage, capacity, and cell volume of the anode. These results indicate that multip...