The crystal structure and electrical/thermal transport properties of Li1?xSn2+xP2 and its performance as a Li-ion battery anode material
The crystal structure and electrical/thermal transport properties of Li1?xSn2+xP2 and its performance as a Li-ion battery anode material
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Li1?xSn2xP2的晶体结构、电/热传输性能及其作为锂离子电池负极材料的性能
DOI：
10.1039/d0ta11045k
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发表时间：
2021
影响因子：
11.9
通讯作者：
Mizuguchi Yoshikazu
中科院分区：
文献类型：
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作者：
Goto Yosuke;Nakanishi Shota;Nakai Yusuke;Mito Takeshi;Miura Akira;Moriyoshi Chikako;Kuroiwa Yoshihiro;Usui Hidetomo;Matsuda Tatsuma D.;Aoki Yuji;Nakacho Yoshifumi;Yamada Yuto;Kanamura Kiyoshi;Mizuguchi Yoshikazu
采用固相法合成了一种新的三元层状结构化合物Li1−xSn2+XP2，并对其性能进行了测试，以探索其作为多功能材料的潜力。该化合物在Rm空间群(编号166)中以层状结构结晶，其中弯曲的蜂窝状SnP层被混合占据的Li/Sn层隔开。同步辐射X-射线衍射法的晶体结构分析表明，锡取代锂的程度为x=0.38。用~(31)P核磁共振分析证实了Li/Sn占位的局域有序化。热学和电学输运性质受这种局域有序化的影响很大。Li1−xSn2+xP2的晶格热导率较低(525K时为1.2Wm−1K−1)。Li1−xSn2+xP2的室温电阻率为0.3~0.4mΩcm，金属电导率为0.5K。第一性原理计算表明，Li1−xSn2+xP2的电子结构和费米能显著依赖于x，而且Li1−xSn2+xP2的电子结构与相关化合物NaSn2As2不同，表现为超导转变。用单颗粒电化学测试技术证明了Li1xSn2+−作为二次锂离子电池负极材料的活性。
A new ternary layered pnictide, Li1−xSn2+xP2, was synthesized by a solid-state reaction and its properties were examined to explore its potential as a multifunctional material. The compound crystallizes in a layered structure in the Rm space group (no. 166) with buckled honeycomb Sn–P layers separated by mixed-occupation Li/Sn layers. Crystal structure analysis by synchrotron X-ray diffraction showed that the substitution degree of Li by Sn is x = 0.38. The local ordering of Li/Sn occupation was demonstrated using 31P nuclear magnetic resonance analysis. The thermal and electrical transport properties are significantly affected by this local ordering. The lattice thermal conductivity of Li1−xSn2+xP2 was found to be relatively low (1.2 W m−1 K−1 at 525 K). The room-temperature electrical resistivity of Li1−xSn2+xP2 was found to be 0.3–0.4 mΩ cm and metallic conductivity was observed down to 0.5 K. First-principles calculations demonstrated that the electronic structure and Fermi energy of Li1−xSn2+xP2 are significantly dependent upon x. Moreover, the electronic structure of Li1−xSn2+xP2 is different from that of the related compound NaSn2As2, which shows a superconducting transition. Electrochemical measurements using a single-particle technique demonstrated the activity of Li1−xSn2+xP2 as an anode material for rechargeable Li-ion batteries.