Sony Corporation

Tsuyoshi Okawa

Yuzuru Fukushima

Junji Kuyama

Mamoru Hosoya

Takashi Sato

Yoshikatsu Yamamoto

Kei Yonezawa

A battery capable of improving load characteristics, low-temperature characteristics and high-temperature cycle characteristics is provided. A cathode () includes a lithium cobalt complex oxide represented by LiCoMIMIIO(MI includes at least one kind selected from the group consisting of Al, Cr, V, Mn and Fe, MII includes at least one kind selected from the group consisting of Mg and Ca, 0.9&#x2266;a&#x2266;1.1, 0.9&#x2266;x&#x3c;1, 0.001&#x2266;y&#x2266;0.05, 0.001&#x2266;z&#x2266;0.05, x+y+z=1), and further includes Zr as a sub-component element. The content of Zr is within a range from 0.01 mol % to 10 mol % both inclusive as a ratio (Zr/Co) of Zr to Co in the lithium cobalt complex oxide.

Cathode active material with zirconium in crystal grain boundary of lithium cobalt complex oxide

A cell in which liquid leakage or destruction may be prevented as the apparent energy density per unit volume of the cell is maintained. The cell uses, as a cathode active material, a compound of an olivinic crystal structure having the formula LiFeMPO, where M is at least one selected from the group of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05&#x2266;x&#x2266;1.2 and 0&#x2266;y&#x2266;0.8. By adjusting the amount of the electrolyte solution, the amount of the void in the container is set so as to be not less than 0.14 cc and not more than 0.3 cc per 1 Ah of the cell capacity.

Non-aqueous electrolyte secondary cell with a lithium metal phosphate cathode

A non-aqueous electrolyte secondary cell containing a compound of an olivinic structure as a cathode active material is to be improved in load characteristics and cell capacity. To this end, there is provided a non-aqueous electrolyte secondary cell including a cathode having a layer of a cathode active material containing a compound represented by the general formula Li Fe M PO , where M is at least one selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05&lE;x&lE;1.2 and 0&lE;y&lE;0.8, an anode having a layer of a cathode active material containing the anode active material and a non-aqueous electrolyte, wherein the layer of the cathode active material has a film thickness in a range from 25 to 110 &mgr;m. If a layer of a cathode active material is provided on each surface of a cathode current collector, the sum of the film thicknesses of the layers of the cathode active material ranges between 50 and 220 &mgr;m. The non-aqueous electrolyte may be a liquid-based electrolyte or a polymer electrolyte.

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Fukushima, Japan

Tsuyoshi Okawa