Sustainable Interfaces between Si Anodes and Garnet Electrolytes for Room-Temperature Solid-State Batteries
Sustainable Interfaces between Si Anodes and Garnet Electrolytes for Room-Temperature Solid-State Batteries
复制标题
室温固态电池的硅阳极和石榴石电解质之间的可持续界面
DOI：
10.1021/acsami.7b16385
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发表时间：
2018-01-17
影响因子：
9.5
通讯作者：
Li, Hong
中科院分区：
文献类型：
--
作者：
Chen, Cheng;Li, Quan;Li, Hong
近年来，固态电池（SSB）因其提供远超当前商业化锂离子电池的高能量密度和优异安全性的潜力而重新引起研究兴趣。研究了Si阳极与Ta掺杂的Li_7 La_3 Zr_2 O_（12）（Li_（6.4）La_3 Zr_（1.4）Ta_（0.6）O_（12），LLZTO）固体电解质的相容性及Si阳极的稳定性。结果表明，薄于180 nm的Si层阳极与LLZTO电解质保持良好的接触，使得Li/LLZTO/Si电池具有良好的循环性能，100次循环后容量保持率超过85%。当Si层厚度增加到大于300 nm时，Li/LLZTO/Si电池的容量保持率在100次循环后变为77%。当厚度接近900 nm时，由于界面处的破坏性体积变化，电池只能循环有限的次数。由于具有180 nm厚度的Si层阳极的可持续Si/LLZTO界面，具有LiFePO 4阴极的全电池在室温下显示出LiFePO 4的120 mA h g（-1）和Si阳极的2200 mA h g（-1）的放电容量。它们循环100次，容量保持率为72%。这些结果表明，硅阳极和石榴石电解质之间的组合是一个有前途的策略，用于构建高性能的SSB。
Solid-state batteries (SSBs) have seen a resurgence of research interests in recent years for their potential to offer high energy density and excellent safety far beyond current commercialized lithium-ion batteries. The compatibility of Si anodes and Ta-doped Li7La3Zr2O12 (Li6.4La3Zr1.4Ta0.6O12, LLZTO) solid electrolytes and the stability of the Si anode have been investigated. It is found that Si layer anodes thinner than 180 nm can maintain good contact with the LLZTO plate electrolytes, leading the Li/LLZTO/Si cells to exhibit excellent cycling performance with a capacity retention over 85% after 100 cycles. As the Si layer thickness is increased to larger than 300 nm, the capacity retention of Li/LLZTO/Si cells becomes 77% after 100 cycles. When the thickness is close to 900 nm, the cells can cycle only for a limited number of times because of the destructive volume change at the interfaces. Because of the sustainable Si/LLZTO interfaces with the Si layer anodes with a thickness of 180 nm, full cells with the LiFePO4 cathodes show discharge capacities of 120 mA h g(-1) for LiFePO4 and 2200 mA h g(-1) for the Si anodes at room temperature. They cycle 100 times with a capacity retention of 72%. These results indicate that the combination between the Si anodes and the garnet electrolytes is a promising strategy for constructing high-performance SSBs.