Kabushiki Kaisha Toshiba

Nao Shimura

Masahiro Sekino

Asako Satoh

Masayuki Oguchi

Akira Yajima

Shusuke Inada

Hiroshi Kitayama

Hiroyuki Hasebe

Kaoru Koiwa

Masashi Fujiwara

Koshin Tanaka

Masayuki Onuma

A nonaqueous electrolyte secondary battery includes an electrode group having a positive electrode and a negative electrode wound flatly by way of an interposed separator, a positive electrode tab electrically connected to the positive electrode, and projecting from a spiral winding surface of the electrode group, a negative electrode tab electrically connected to the negative electrode, and projecting from the spiral winding surface, and a nonaqueous electrolyte, wherein the nonaqueous solvent contains sultone compound including a ring having at least one double bond, and a distance between the positive electrode tab and the negative electrode tab is 6 mm to 18 mm.

Nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery includes a nonaqueous electrolyte and a positive electrode including an active material containing lithium composite oxide powder, the lithium composite oxide powder includes secondary particles, exhibits a peak intensity ratio satisfying the following formula (4), satisfies the following formula (5), and has a particle distribution wherein a particle diameter at a volumetric cumulative frequency of 90% (D90) falls within the range of 10 to 25 m, and the nonaqueous electrolyte contains a sultone compound including a ring having at least one double bond;2&#x2266;()&#x3c;5 &#x2003;&#x2003;(4)0.95&#x2266;()&#x2266;1.02. &#x2003;&#x2003;(5)

Disclosed is a nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in the case, a negative electrode provided in the case and the negative electrode containing a carbonaceous material capable of absorbing-desorbing lithium ions, and a nonaqueous electrolyte provided in the case and the nonaqueous electrolyte containing a nonaqueous solvent including &#x3b3;-butyrolactone and a solute dissolved in the nonaqueous solvent, wherein after being discharged to 3V with a current of 0.2 C at room temperature, the voltage reduction caused by the self-discharge at 60&#xb0; C. is not larger than 1.5V in 3 weeks.

Nonaqueous electrolyte secondary battery having a carbonaceous material containing negative electrode and a nonaqueous electrolyte containing a nonaqueous solvent

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Minato-ku, Japan

Nao Shimura