Sanyo Electric Co., Ltd.

Atsushi Yanai

Toshiyuki Nohma

Katsunori Yanagida

Ikuo Yonezu

Yoshinori Kida

Atsuhiro Funahashi

Takeshi Maeda

Koji Nishio

Yoshito Chikano

Kazunari Ohkita

Naoya Nakanishi

Toyoki Fujihara

Takanobu Chiga

Keisuke Minami

Takaaki Ikemachi

A nonaqueous electrolyte secondary batteryaccording to an embodiment of the present invention includes a positive electrodehaving a positive electrode active material that can intercalate and deintercalate lithium, a negative electrodehaving a negative electrode active material that can intercalate and deintercalate lithium, and a nonaqueous electrolyte having lithium ion conductivity. The positive electrode active material is a layered lithium transition metal composite oxide (for example, one represented by Li(NiCoMn)O(where 0&#x2266;x&#x2266;0.15, 0.1&#x2266;y&#x2266;0.6, and 0&#x2266;z&#x2266;0.5)) to which an IVa group element (Zr) and a Va group element (Nb) are added. According to these features, it is possible to provide a nonaqueous electrolyte secondary battery with a selected element to be added to the lithium transition metal composite oxide to reduce the I-V resistance (improve the I-V characteristic), and thereby improving the output/input characteristics.

Nonaqueous electrolyte secondary battery

A lithium secondary battery including a positive electrode, a negative electrode including a carbon material as an active material, and a nonaqueous electrolyte comprising a solute dissolved in a nonaqueous solvent in which &#x3b3;-butyrolactone is the main solvent, wherein the carbon material has a ratio (I/I) of a Raman spectrum intensity (a peak intensity ratio) (R) obtained by Raman spectroscopy of 0.2 or greater, and the nonaqueous electrolyte includes at least 0.1 part by weight of vinylene carbonate and at least 0.1 part by weight of vinyl ethylene carbonate in 100 parts by weight of the nonaqueous electrolyte.

Lithium secondary battery

Storage performance in a charged state is improved with a non-aqueous electrolyte secondary battery using gamma-butyrolactone as a solvent. A non-aqueous electrolyte secondary battery includes a positive electrode () containing a positive electrode active material including a lithium-containing transition metal oxide; a negative electrode () containing a negative electrode active material capable of intercalating and deintercalating lithium; and a non-aqueous electrolyte including a solute and a solvent; wherein the solvent contains 50 volume % or more of gamma-butyrolactone with respect to the total volume of the solvent, and the positive electrode active material contains a phosphate salt MPO, where Mis a metal element capable of having a valency of 3.

Non-aqueous electrolyte secondary battery

Cycle performance is improved without degrading initial efficiency of a non-aqueous electrolyte secondary battery that includes a positive electrode, a negative electrode, a non-aqueous electrolyte containing a solute and a solvent, the positive electrode including a positive electrode active material made of a lithium-containing transition metal oxide that contains lithium and cobalt and has a layered structure. The lithium-containing transition metal oxide is at least partially covered with a surface-treatment layer containing a phosphate compound represented by the chemical formula MPO, where Mis at least one element that can have a valency of 3 and k is an integer in a range of 2 to 4, and the lithium-containing transition metal oxide contains a group IVA element Mand a group IIA element Mof the periodic table.

For us in nonaqueous electrolyte secondary cells, the invention provides an electrode which comprises a first carbon material serving as a core material, and a second carbon material coating the first carbon material over the surface thereof and containing boron. When used as an active substance for negative electrode to provide a nonaqueous electrolyte secondary cell, the electrode diminishes the reduction of the cell capacity that would result if the cell is allowed to store, giving improved storage characteristics to the cell.

Carbon materials, electrodes and nonaqueous electrolyte secondary cells

A lithium secondary battery according to the present invention includes a positive electrode in which an aluminum foil containing manganese is used as a current collector, a negative electrode, and a non-aqueous electrolyte solution formed by dissolving lithium salt in a non-aqueous solvent wherein divalent manganese salt is added to said non-aqueous electrolyte solution.

The lithium secondary battery of this invention uses a nonaqueous electrolyte including lithium tetrakis(pentafluorophenyl)borate as a part or whole of an electrolytic salt. As a result, the lithium secondary battery exhibits better charge-discharge cycle performance than a lithium secondary battery using a conventional lithium salt as the electrolytic salt.

A nonaqueous electrolyte secondary cell having a rolled-up electrode unit housed in a cell can and comprising a positive electrode and a negative electrode each formed by coating a surface of a striplike current collector with an electrode material. According to a first embodiment, the current collector of at least one of the positive electrode and the negative electrode comprises a plurality of current collector pieces arranged along one direction and a PTC element interconnecting each pair of adjacent current collector pieces Alternatively with a second embodiment, at least one of the positive electrode and the negative electrode comprises a PTC element held between opposed faces of an uncoated portion of the current collector thereof and a base end portion of a current collector tab. The PTC element serves to prevent continuous occurrence of a current in excess of a predetermined value and realizes a high energy density.

Nonaqueous electrolyte secondary cell

The present invention provides a positive electrode of a nonaqueous electrolyte secondary cell which is prepared using an active substance containing a composition of LiNi Co M O (a&plus;b&plus;c&equals;1;0&lE;c&lE;0.5) wherein M is at least one metal selected from among Mn, Fe, Zn, Ti, Cr, Mg, Al, Cu, or Ga and a composition of AlX(SO ) wherein X is at least one material selected from among Na, Rb, Cs, or NH . This enables the secondary cell to diminish the reduction of a cell capacity when allowed to store and thus the storage characteristics of the secondary cell is improved.

Active substances, electrodes, nonaqueous electrolyte secondary cells, and a process for fabricating the active substances

A nonaqueous electrolyte secondary cell having a rolled-up electrode unit housed in a cell can and comprising a positive electrode and a negative electrode each formed by coating a surface of a striplike current collector with an electrode material. According to a first embodiment, the current collector of at least one of the positive electrode and the negative electrode comprises a plurality of current collector pieces,arranged along one direction and a PTC element,interconnecting each pair of adjacent current collector pieces,Alternatively with a second embodiment, at least one of the positive electrode and the negative electrode comprises a PTC element held between opposed faces of an uncoated portion of the current collector thereof and a base end portion of a current collector tab. The PTC element serves to prevent continuous occurrence of a current in excess of a predetermined value and realizes a high energy density.

Nonaqueous electrolyte secondary cell wit PTC current collector tabs

A method is disclosed for manufacturing a nonaqueous battery which includes a negative electrode containing lithium or a material capable of occluding and discharging lithium, a positive electrode containing an oxide of manganese or cobalt, and a nonaqueous electrolyte. In the method the nonaqueous electrolyte is treated with an oxide of the metal of the positive electrode before the nonaqueous electrolyte is assembled into the battery. The method provides a nonaqueous electrolyte battery having an improved self-discharge property.

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Kobe, Japan

Atsushi Yanai