In-situ formed Li2CO3-free garnet/Li interface by rapid acid treatment for dendrite-free solid-state batteries
In-situ formed Li2CO3-free garnet/Li interface by rapid acid treatment for dendrite-free solid-state batteries
复制标题
通过快速酸处理原位形成无Li2CO3石榴石/Li界面，用于无枝晶固态电池
DOI：
10.1016/j.nanoen.2019.04.058
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发表时间：
2019-07-01
期刊：
影响因子：
17.6
通讯作者：
Sun, Xueliang
中科院分区：
文献类型：
--
作者：
Huo, Hanyu;Chen, Yue;Sun, Xueliang
石榴石型固体电解质具有室温离子电导率高、对锂离子稳定性好等优点，是一种很有发展前途的固体电解质。然而，Li 2CO 3表面污染导致的石榴石/Li界面接触不良会导致锂枝晶生长和固态电池性能下降，阻碍了其实际应用。在此，提出了一种通用且简单的快速酸处理方法，以完全去除表面Li 2CO 3并恢复亲锂SSE表面。SSE/Li界面电阻在30 ℃时从940 Ω cm（2）急剧降低至26 Ω cm（2）。酸处理的石榴石-SSE粒料表现出与具有各种表面涂层的粒料相当的界面阻力。此外，本征石榴石/Li界面在循环期间保持稳定，这使得Li对称电池在0.2mA cm（-2）下在30 ℃下连续循环超过700 h。采用酸处理石榴石-SSE制备的LiFePO 4/Li和LiCoO 2/Li电池在去除表面污染物后，具有良好的循环性能和倍率性能。这些结果表明，快速酸处理不仅引导了一个新的理解本征石榴石/锂界面，但也是一个简单而高效的策略，很好地解决界面问题的SSB。
Garnet-type solid-state electrolytes (SSEs) are very promising due to their high ionic conductivities at room temperature and high stability against Li metal. However, the poor garnet/Li interfacial contact caused by Li2CO3 surface contaminant can lead to lithium dendrite growth and the performance decay of solid-state batteries (SSBs), which still hinders their practical application. Herein, a universal and simple method of rapid acid treatment is proposed to perfectly remove the surface Li2CO3 and retrieve a lithiophilic SSE surface. The SSE/Li interfacial resistance dramatically decreases from 940 Omega cm(2) to 26 Omega cm(2) at 30 degrees C. The acid treated garnet-SSE pellets exhibit an interfacial resistance comparable to the pellets with various surface coatings. In addition, the intrinsic garnet/Li interface remains stable during cycling, which enables the Li symmetric cells continuously cycle over 700 h under 0.2 mA cm(-2) at 30 degrees C. And the LiFePO4/Li and LiCoO2/Li cells with acid treated garnet-SSE show excellent cycle and rate performances after eliminating the surface contaminant. These results indicate that rapid acid treatment not only guides a new understanding for an intrinsic garnet/Li interface but also is a simple and high-efficiency strategy to well address the interfacial issue for SSBs.