Dry coating of active material particles with sulfide solid electrolytes for an all-solid-state lithium battery
Dry coating of active material particles with sulfide solid electrolytes for an all-solid-state lithium battery
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DOI：
10.1016/j.jpowsour.2019.227579
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发表时间：
2020-02-01
影响因子：
9.2
通讯作者：
Watano, Satoru
中科院分区：
文献类型：
--
作者：
Nakamura, Hideya;Kawaguchi, Takashi;Watano, Satoru
在这项研究中，我们提出了一种干燥涂层工艺，用于生产全固态锂电池的核壳复合颗粒，其中活性材料的单个颗粒被固体电解质包裹。采用了典型的正极活性材料LiNi1/3 Co1/3Mn1/3O2 （NCM）和Li3PS4 （LPS）两种硫化物固体电解质。采用干式冲击混合装置进行干涂工艺。我们证明了通过干涂工艺将单个NCM颗粒均匀地涂上一层连续的LPS，而不会破坏或磨损NCM，从而产生NCM@LPS核壳颗粒。充放电循环实验表明，NCM@LPS核壳颗粒制备的全固态半电池的倍率和循环性能均有显著提高。利用FIB-SEM和图像重建技术分析了复合阴极的三维内部结构。结果表明，NCM@LPS核壳颗粒制备的复合阴极具有(1)NCM与LPS之间高的界面接触面积和(2)良好的渗透离子传输途径。综上所述，核壳复合颗粒有助于复合阴极的结构，从而提高了电池性能。
In this study, we present a dry coating process to produce a core-shell composite particle for an all-solid-state lithium battery, where a single particle of the active material is coated with solid electrolytes. LiNi1/3 Co1/3Mn1/3O2 (NCM) and Li3PS4 (LPS), which are typical cathode active material and sulfide solid electrolyte, were used. A dry impact-blending device was employed for the dry coating process. We demonstrated that a single particle of NCM was uniformly coated with a continuous layer of LPS by the dry coating process without any breakage or attrition of NCM, to produce an NCM@LPS core-shell particle. The charge-discharge cycling tests showed that the rate and cycle performances of an all-solid-state half-cell prepared with the NCM@LPS core-shell particles significantly improved. The three-dimensional internal structure of the composite cathode was subsequently analyzed using FIB-SEM with an image reconstruction technique. The results revealed that the composite cathode prepared with the NCM@LPS core-shell particles had a (i) high interfacial contact area between NCM and LPS and (ii) well-percolated ion transport pathway. In conclusion, the core-shell composite particle contributed to the structure of the composite cathode, thus resulting in improved cell performance.