Sony Corporation

Takuya Endo

Shinichiro Yamada

Hiroshi Inoue

Shigeru Fujita

Hiroshi Imoto

Yuzuru Fukushima

Guohua Li

Momoe Adachi

Goro Shibamoto

Hiroaki Tanizaki

Yusuke Fujishige

Yasunobu Iwakoshi

Fumiko Kimura

An electrolyte whose battery capacity, cycle characteristics, load characteristics, and low temperature characteristics are all excellent, and a battery using it. A cathode and an anode are layered and wound with a separator and electrolyte layer in between. The electrolyte layer contains an electrolytic solution containing at least one from the group consisting of vinylethylene carbonate and its derivatives in the range of 0.05 wt % to 5 wt % in total and a polymer. Therefore, chemical stability of the electrolyte layer is improved. It is preferable that the electrolytic solution further contains ethylene carbonate and propylene carbonate with a mass ratio of ethylene carbonate to propylene carbonate ranging from about 15/85 to about 75/25.

Electrolyte having a polymer and battery using it

A battery with a high battery voltage at charging and improved energy density is provided. A cathode () and an anode () are laminated with a separator () sandwiched therebetween which is impregnated with an electrolyte. The cathode () has a cathode active material including a lithium composite oxide which contains lithium, at least either cobalt or nickel, and oxygen. The battery voltage at charging is 4.25 V or more. The total amount of lithium carbonate and lithium sulphate in the cathode () to the cathode active material is 1.0 wt % or less, a concentration of protic impurities in the electrolyte, which is converted to a mass ratio of protons to the electrolyte, is 20 ppm or less, or moisture content in the electrolyte is 20 ppm mass ratio or less to the electrolyte. This inhibits metal eluting from the lithium composite oxide even at high voltages.

Battery

A negative electrode material and a battery which have an excellent cycle characteristic as well as a high capacity are provided. A positive electrode housed in an exterior can and a negative electrode housed in an exterior cup are laminated with a separator therebetween. An electrolytic solution of lithium salt dissolved in a solvent is poured into the inside of both the exterior can and the exterior cup. The negative electrode contains MgMIIMI. MI expresses a first element such as Si, Sn, Ge, Pb, or the like. MII expresses a second element which is a metallic element, preferably Mn, Cu, Zn, or the like except both Mg and the first element. X is preferably in the range of 0.1&#x2266;x&#x2266;1.9. Substituting part of Mg by the second element MII can produce the distortion of the crystal structure, ease distortion accompanying the occluding/releasing lithium, and improve the charge and discharge efficiency and the cycle characteristic.

Negative electrode material and battery using the same

A material for a negative electrode capable of preventing change in the volume of an active material occurring when lithium is doped/dedoped to improve resistance against cycle operations. A material for a negative electrode contains a mixture of a non-carbon material and a carbon material, wherein when an assumption is made that the average particle size of the non-carbon material is R,and the average particle size of the carbon material is R,, the ratio R,/R,is not higher than one, and when an assumption is made that the weight of the non-carbon material is W,and the weight of the carbon is W,, the ratio W,/W,is not higher than one or a mixture of a silicon compound and a carbon material, wherein when an assumption is made that the average particle size of the silicon compound is R,and the average particle size of the carbon material is R,, the ratio R,/R,is not higher than one.

Material for negative electrode and nonaqueous-electrolyte battery incorporating the same

Disclosed is a non-aqueous electrolyte secondary cell comprising a cathode made from a cathode compound that comprises a manganese oxide or a lithium-manganese composite oxide, a lithium metal anode or an anode comprising lithium or capable of doping and dedoping lithium ions, and a non-aqueous electrolyte, which is characterized in that the cathode compound contains an alkali metal carbonate of being from 0.5 to 20% by weight of the dry cathode compound. Even when used at high temperatures over room temperature for a long period of time, the cell is deteriorated little.

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Kanagawa, Japan

Takuya Endo