Amorphous Ni‐Rich Li(Ni1−x−yMnxCoy)O2–Li2SO4 Positive Electrode Materials for Bulk‐Type All‐Oxide Solid‐State Batteries. Issue 8 (14th March 2019)

• Record Type: Journal Article
• Authors: Nagao, Kenji; Sakuda, Atsushi; Hayashi, Akitoshi; Tsukasaki, Hirofumi; Mori, Shigeo; Tatsumisago, Masahiro
• Is Part Of: Advanced materials interfaces. Volume 6:Issue 8(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-14
• Subjects: amorphous positive electrodes -- Ni‐rich Li(Ni1−x−yMnxCoy)O2 -- oxide‐type all‐solid‐state batteries; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.201802016
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: All‐solid‐state batteries attract significant attention owing to their potential to realize an energy storage system with high safety and energy density. In this paper, a mechanochemical synthesis of novel amorphous positive electrode materials of the Ni‐rich LiNi1− x − y Mn x Co y O2 (NMC)–Li2 SO4 system suitable for oxide‐type all‐solid‐state batteries is reported. Through the mechanochemical treatment with Li2 SO4, excellent formabilities of the electrode materials as those of ductile solid electrolytes are obtained. Owing to the deformability of the active material, a good electrode/electrolyte interface is provided simply by pressing at room temperature. In all‐oxide solid‐state cells using 80NMCs·20Li2 SO4 (mol%) positive electrode materials, the cell capacity increases with the Ni content in the NMC. The all‐solid‐state cell using the 80NMC811·20Li2 SO4 positive electrode active material exhibits a high capacity larger than 250 mAh g −1 in a voltage range of 1.6–4.8 V versus Li at 100 °C. Furthermore, bulk‐type all‐oxide solid‐state batteries (Li4 Ti5 O12 /80NMC532·20Li2 SO4 (mol%)) successfully function as secondary batteries with excellent cycle performances. Abstract : Oxide‐type all‐solid‐state secondary batteries are constructed by pressing at room temperature. A dense and thick electrode layer is obtained owing to the excellent deformability of electrode and electrolyte. Bulk‐type all‐solid‐state batteries (Li4 Ti5 O12 /80NMC532·20Li2 SO4 ) work as a secondary battery with excellent cycle characteristics. Bipolar stacked cell also works at 100 °C, showing the same capacity and the twice high operation voltage.