Nagata Hiroshi, Akimoto Junji
National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
ACS Appl Mater Interfaces. 2021 Aug 4;13(30):35785-35794. doi: 10.1021/acsami.1c09120. Epub 2021 Jul 21.
Oxide-type all-solid-state lithium-ion batteries have attracted great attention as a candidate for a next-generation battery with high safety performance. However, batteries based on oxide systems exhibit much lower energy densities and rate performances than liquid-type lithium-ion batteries, owing to the difficulty in preparing the ion- and electron-transfer path between particles. In this study, LiSO-LiCO-LiX (X = Cl, Br, and I) glass systems are investigated as highly deformable and high-ionic-conductive oxide electrolytes. These electrolytes show excellent deformable properties and better ionic conductivity. The LiI oxide glass system is a suitable electrolyte for the negative electrode because it shows a higher ionic conductivity and is stable up to 2.8 V. The LiCl or LiBr oxide glass systems are suitable electrolytes for the positive electrode and separation layer because they show high ionic conductivity and kinetic stability up to 3.2 V. The LiS positive and Si negative composite electrodes employing LiBr and LiI oxide glass electrolytes, respectively, show high battery performances because of increased reaction points between active materials and the solid electrolyte and carbon via a mechanical milling process and are capable of forming good interparticle contact. Therefore, it suggests that the excellent deformable electrolytes are suitable for solid electrolytes in composite electrodes because their ionic conductivity does not change by the mechanical milling process. Furthermore, an oxide-type all-solid-state LiS-Si full-battery cell employing these positive and negative composite electrodes and a LiBr oxide glass electrolyte separation layer is demonstrated. The full-battery cell indicates a relatively high discharge capacity of 740 mA h g(LiS) and an area capacity of 2.8 mA h cm at 0.064 mA cm and 45 °C despite using only safe oxide electrolytes.
氧化物型全固态锂离子电池作为具有高安全性能的下一代电池候选者，已引起了广泛关注。然而，由于难以制备颗粒间的离子和电子传输路径，基于氧化物体系的电池在能量密度和倍率性能方面比液体型锂离子电池低得多。在本研究中，LiSO-LiCO-LiX（X = Cl、Br和I）玻璃体系作为具有高可变形性和高离子导电性的氧化物电解质进行了研究。这些电解质表现出优异的可变形性能和更好的离子导电性。LiI氧化物玻璃体系是适合负极的电解质，因为它具有较高的离子导电性，并且在高达2.8 V时稳定。LiCl或LiBr氧化物玻璃体系是适合正极和隔离层的电解质，因为它们在高达3.2 V时表现出高离子导电性和动力学稳定性。分别采用LiBr和LiI氧化物玻璃电解质的LiS正极和Si负极复合电极，由于通过机械球磨过程增加了活性材料与固体电解质和碳之间的反应点，并且能够形成良好的颗粒间接触，因而表现出高电池性能。因此，这表明优异的可变形电解质适用于复合电极中的固体电解质，因为它们的离子导电性不会因机械球磨过程而改变。此外，展示了一种采用这些正负极复合电极和LiBr氧化物玻璃电解质隔离层的氧化物型全固态LiS-Si全电池。尽管仅使用安全的氧化物电解质，但该全电池在0.064 mA cm和45 °C下仍显示出相对较高的放电容量740 mA h g(LiS)和面积容量2.8 mA h cm 。
