High-Temperature Storage Performance of Li-Ion Batteries Using a Mixture of Li-Mn Spinel and Li-Ni-Co-Mn Oxide as a Positive Electrode Material

• Published in: Electrochemical and solid-state letters Vol. 8; no. 2; pp. A87 - A90
• Main Authors: Kitao, Hideki, Fujihara, Toyoki, Takeda, Kazuhisa, Nakanishi, Naoya, Nohma, Toshiyuki
• Format: Journal Article
• Language: English
• Published: 01.01.2005
• ISSN: 1099-0062
• DOI: 10.1149/1.1843792

To improve the storage performance of Li-Mn spinel at high temperatures, a mixture of Li-Mn spinel (Li1.1Mn1.9O4) and Li-Ni-Co-Mn oxide (LiNi0.4Co0.3Mn0.3O2) as a positive electrode material was investigated. A battery using such a mixture as a positive electrode material showed better storage characteristics at 45 C for 30 days than batteries using both a single material Li-Mn spinel and a single material Li-Ni-Co-Mn oxide. This improved storage performance resulted from the suppression of capacity loss of Li-Mn spinel in the mixture. The differences in Li-Mn spinel were compared to clarify the reasons for its improved storage performance in the mixture and found two changes during charging in the potential and lattice constant of Li-Mn spinel in the mixture that were different from those of single material Li-Mn spinel. In single material, changes in potential and lattice constants of Li-Mn spinel showed two-step change when charged, while Li-Mn spinel in a mixture showed continuous change. 17 refs.