First-Principles Study of Microscopic Electrochemistry at the LiCoO2 Cathode/LiNbO3 Coating/β-Li3PS4 Solid Electrolyte Interfaces in an All-Solid-State Battery
First-Principles Study of Microscopic Electrochemistry at the LiCoO2 Cathode/LiNbO3 Coating/β-Li3PS4 Solid Electrolyte Interfaces in an All-Solid-State Battery
复制标题
全固态电池中LiCoO2阴极/LiNbO3涂层/β-Li3PS4固体电解质界面微观电化学第一性原理研究
DOI：
10.1021/acsami.0c19091
复制
发表时间：
2021-03-05
影响因子：
9.5
通讯作者：
Tateyama, Yoshitaka
中科院分区：
文献类型：
--
作者：
Gao, Bo;Jalem, Randy;Tateyama, Yoshitaka
电极与固体电解质之间的界面电阻高是全固态电池（ASSB）商业化应用的主要挑战之一，在界面处涂覆涂层是降低界面电阻的有效途径。然而，微观电化学，特别是电化学电位和Li+在界面上的分布还没有很好地建立，阻碍了深入了解界面Li+传输。在这里，我们已经介绍了一个潜在的能量分布为Li+，η（Li+），并表明，界面η（Li+）可以从计算的界面Li空位形成能或体空位形成能和界面能带排列进行评估。采用基于CALYPSO方法的新型界面结构预测方案，对LiCoO 2阴极/LiNbO 3涂层/beta-Li 3 PS4 SE界面进行了计算分析，发现界面重构影响下，LiCoO 2/beta-Li 3 PS4界面的η（Li+）高度无序，具有较强的电子导电性. LiNbO_3涂层的插入可以有效地降低离子混合的优先性。此外，能带取向的适当变化导致界面η（Li+）的差异减小，界面处的电阻降低。结果为实验观察到的涂层的有效性提供了可靠的解释。此外，我们的研究提供了一个指导未来的模拟在ASSB电极/SE界面的微观电化学。
High interfacial resistance between electrode and solid electrolyte (SE) is one of the major challenges for the commercial application of all-solid-state batteries (ASSBs), and coating at the interface is an effective way for decreasing the resistance. However, microscopic electrochemistry especially for the electrochemical potential and the distribution of Li+ at the interface has not been well established yet, impeding the in-depth understanding of interfacial Li+ transport. Herein, we have introduced a potential energy profile for Li+, eta(Li+), and demonstrated that the interfacial eta(Li+) can be evaluated from the calculated interfacial Li vacancy formation energy or the bulk vacancy formation energy and the interface band alignment. Through computational analysis of the representative LiCoO2 cathode/LiNbO3 coating/beta-Li3PS4 SE interfaces using the novel interface structure prediction scheme based on the CALYPSO method, we found that eta(Li+) at the LiCoO2/beta-Li3PS4 interface is highly disordered under the influence of the interface reconstruction and is rather electronic conductive. Insertion of LiNbO3 coating can effectively decrease the preference of ion mixing. Besides, the appropriate changes in band alignments lead to a decrease of difference in the interfacial eta(Li+) and lower resistances at the interfaces. The results provide a reliable explanation for the effectiveness of the coating layer observed experimentally. Furthermore, our study provides a guidance for the future simulation of the microscopic electrochemistry at the electrode/SE interfaces in ASSBs.