Gs Yuasa International Ltd.

Takashi Egawa

Toshiyuki Nukuda

Hiroe Nakagawa

Tokuo Inamasu

Akihiro Fujii

Toru Tabuchi

Yoshinobu Yasunaga

Yukiko Fujino

Yohei Shibata

Mariko Kohmoto

The invention provides a polyanion-based positive active material which can improve storage stability (especially, high temperature storage stability), charge and discharge cycle performance and the like of a lithium secondary battery, and a lithium secondary battery using the same. The positive active material for a lithium ion secondary battery contains lithium iron cobalt phosphate represented by the general formula: LiFeCoPO(0&#x3c;x&#x2266;0.019, 0&#x2266;y&#x2266;1.2). By using the positive active material for a lithium secondary battery, high temperature storage stability and charge and discharge cycle performance can be improved in comparison with a case where LiFePOcontaining no Co is used. By using the positive active material, a lithium ion secondary battery can be suitable for applications in fields of electric automobiles and industrial batteries in which long lives, high capacities, and high output powers are required.

Positive active material for lithium secondary battery and lithium secondary battery

Growing community of inventors

Kyoto, Japan

Takashi Egawa