In Situ Monitoring of Fast Li-Ion Conductor Li7P3S11 Crystallization Inside a Hot-Press Setup
In Situ Monitoring of Fast Li-Ion Conductor Li7P3S11 Crystallization Inside a Hot-Press Setup
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DOI：
10.1021/acs.chemmater.6b02163
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发表时间：
2016-09-13
影响因子：
8.6
通讯作者：
Janek, Juergen
中科院分区：
文献类型：
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作者：
Busche, Martin R.;Weber, Dominik A.;Janek, Juergen
可充电固态锂离子电池 (SSLB) 需要快速离子传导固体电解质 (SE) 才能实现高充电和放电速率。 Li7P3S11是一种特别有前途的锂固体电解质，具有高达17 mS cm(-1)的极高室温电导率和高延展性，允许离子快速传输穿过本体并与高表面电极紧密接触。在这里，我们提出了一种新颖的热压装置，通过将原位电化学阻抗谱（EIS）与同时温度和压力监测相结合，促进固体电解质的合成。虽然通过这种设计，相纯Li7P3S11很容易实现10 mS.cm(-1)量级的高室温电导率，但它进一步能够监测从非晶Li2S-P2S5玻璃到三斜晶Li7P3S11的不同结晶步骤。实时分析材料的成核、结晶以及在超过 280 摄氏度的温度下的分解，从而实现工艺优化。该结果通过 X 射线衍射、X 射线光电子能谱、扫描电子显微镜和拉曼光谱进行非原位支持。原理验证实验表明 Li0.3In0.7/Li7P3S11/S 复合全固态电池具有良好的循环和倍率性能。此外还提出，低于 1.2V 极限的放电会导致 SE/阴极界面的分解。
Rechargeable solid-state lithium ion batteries (SSLB) require fast ion conducting solid electrolytes (SEs) to enable high charge and discharge rates. Li7P3S11 is a particularly promising lithium solid electrolyte, exhibiting very high room temperature conductivities of up to 17 mS cm(-1) and high ductility, allowing fast ion transport through the bulk and intimate contact to high surface electrodes. Here we present a novel hot-press setup that facilitates the synthesis of solid electrolytes by combining in situ electrochemical impedance spectroscopy (EIS) with simultaneous temperature- and pressure-monitoring. While a high room temperature conductivity in the order of 10 mS.cm(-1) is readily achieved for phase pure Li7P3S11 with this design, it further enables monitoring of the different steps of crystallization from an amorphous Li2S-P2S5 glass to triclinic Li7P3S11. Nucleation, crystallization and at temperatures exceeding 280 degrees C-decomposition of the material are analyzed in real time, enabling process optimization. The results are supported ex situ by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and Raman spectroscopy. Proof-of-principle experiments show the promising cycling- and rate capability of Li0.3In0.7/Li7P3S11/S-composite all-solid-state batteries. It is furthermore presented that discharging below a limit of 1.2 V results in decomposition of the SE/cathode interface.