Drastic Reduction of the Solid Electrolyte-Electrode Interface Resistance via Annealing in Battery Form

Shigeru Kobayashi; Elvis F Arguelles; Tetsuroh Shirasawa; Shusuke Kasamatsu; Koji Shimizu; Kazunori Nishio; Yuki Watanabe; Yusuke Kubota; Ryota Shimizu; Satoshi Watanabe; Taro Hitosugi

doi:10.1021/acsami.1c17945

Drastic Reduction of the Solid Electrolyte-Electrode Interface Resistance via Annealing in Battery Form

ACS Appl Mater Interfaces. 2022 Jan 19;14(2):2703-2710. doi: 10.1021/acsami.1c17945. Epub 2022 Jan 6.

Authors

Affiliations

¹ School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8552, Japan.
² Department of Materials Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
³ National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
⁴ Faculty of Science, Yamagata University, Yamagata 990-8560, Japan.
⁵ Tokyo Electron Technology Solutions Limited, 650 Mitsuzawa, Hosaka-cho, Nirasaki, Yamanashi 407-0192, Japan.
⁶ PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.

PMID: 34991318
DOI: 10.1021/acsami.1c17945

Abstract

The origin of electrical resistance at the interface between the positive electrode and solid electrolyte of an all-solid-state Li battery has not been fully determined. It is well known that the interface resistance increases when the electrode surface is exposed to air. However, an effective method of reducing this resistance has not been developed. This report demonstrates that drastic reduction of the resistance is achievable by annealing the entire battery cell. Exposing the LiCoO₂ positive electrode surface to H₂O vapor increases the resistance by more than 10 times (to greater than 136 Ω cm²). The magnitude can be reduced to the initial value (10.3 Ω cm²) by annealing the sample in a battery form. First-principles calculations reveal that the protons incorporated into the LiCoO₂ structure are spontaneously deintercalated during annealing to restore the low-resistance interface. These results provide fundamental insights into the fabrication of high-performance all-solid-state Li batteries.

Keywords: X-ray crystal truncation rod scattering; all-solid-state lithium battery; annealing; first-principles calculation; interface resistance; interfacial reaction.