Reaction uniformity visualized by Raman imaging in the composite electrode layers of all-solid-state lithium batteries

• Published in: Physical chemistry chemical physics : PCCP Vol. 22; no. 23; pp. 13271 - 13276
• Main Authors: Otoyama, Misae, Ito, Yusuke, Sakuda, Atsushi, Tatsumisago, Masahiro, Hayashi, Akitoshi
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 17.06.2020
• Subjects: Electrodes; Electrolytes; Electrolytic cells; Ions; Lithium batteries; Lithium compounds; Mapping; Molten salt electrolytes; Quantitative analysis; Solid electrolytes; Solid state; State of charge
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d0cp00508h

The reaction uniformity of LiCoO 2 composite positive electrodes in all-solid-state cells was compared quantitatively by investigating the Raman band shifts corresponding to the state-of-charge (SOC) of LiCoO 2 . The quantitative SOC analysis was conducted using the Raman imaging data of composite electrodes with smaller or larger solid electrolytes. The electrodes exhibited different reaction uniformity although the cells showed similar initial charge capacities and average SOC. In the case of larger solid electrolytes, most LiCoO 2 particles showed higher or lower SOC than the average SOC, and lower battery performance. The quantitative analysis of SOC in each LiCoO 2 electrode demonstrated that a variable SOC outside the average SOC resulted in larger irreversible capacity and lower rate performance. The quantitative SOC analysis newly developed in the present study is a useful technique for designing composite electrodes showing higher battery performance. The reaction uniformity of LiCoO 2 composite positive electrodes in all-solid-state cells was compared quantitatively by investigating the Raman band shifts corresponding to the state-of-charge (SOC) of LiCoO 2 .