US 7,745,042 B2Granted

Lithium ion secondary battery

AssigneePanasonic Corporation

InventorsAkiko Fujino, Tsumoru Ohata, Tetsuya Hayashi

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Abstract

A lithium ion secondary battery in which an abnormal overheat due to a short circuit of a current collecting portion of one electrode and an electrode material mixture of the other is prevented. The lithium ion secondary battery has: a positive electrode including a core material having a current collecting portion and a material mixture carrying portion and a material mixture layer carried thereon; a negative electrode including a core material having a current collecting portion and a material mixture carrying portion and a material mixture layer carried thereon; a separator and a porous electron-insulating layer including an inorganic oxide filler and a binder both interposed between the positive and negative electrodes; and a non-aqueous electrolyte. The insulating layer is carried on a region including surfaces of the positive electrode current collecting portion and material mixture layer, and/or a region including surfaces of the negative electrode current collecting portion and material mixture layer. The positive and negative electrodes are wound with the separator and the insulating layer interposed therebetween.

Claims16

Dependent claims

A lithium ion secondary battery, comprising:

a pair of electrodes comprising a positive electrode and a negative electrode;
a separator comprising a microporous film;
and a non-aqueous electrolyte,
wherein said positive electrode and said negative electrode are wound with said separator interposed therebetween,
said positive electrode comprises:
a positive electrode core material;
and a positive electrode material mixture layer carried on said positive electrode core material, said positive electrode material mixture layer comprising a composite lithium oxide,
said negative electrode comprises:
a negative electrode core material;
and a negative electrode material mixture layer carried on said negative electrode core material, said negative electrode material mixture layer comprising a negative electrode material capable of absorbing and desorbing lithium,
in the case where the winding direction is in a longitudinal direction, said positive electrode is provided with a positive electrode current collector portion on one end thereof in said longitudinal direction, said positive electrode current collector portion being a protrusion of said positive electrode core material on which said positive electrode material mixture layer is not carried,
a part of a positive electrode lead is welded to said positive electrode current collector portion,
an entire surface of said positive electrode material mixture layer and a part of said positive electrode current collector portion are covered with a porous electron-insulating layer, and
said porous electron-insulating layer contains 50 wt % or more of an inorganic oxide filler and below 50 wt % of a binder.

11 more elements

A lithium ion secondary battery, comprising:

a pair of electrodes comprising a positive electrode and a negative electrode;
a separator comprising a microporous film;
and a non-aqueous electrolyte,
wherein said positive electrode and said negative electrode are wound with said separator interposed therebetween,
said positive electrode comprises:
a positive electrode core material;
and a positive electrode material mixture layer carried on said positive electrode core material, said positive electrode material mixture layer comprising a composite lithium oxide,
said negative electrode comprises:
a negative electrode core material;
and a negative electrode material mixture layer carried on said negative electrode core material, said negative electrode material mixture layer comprising a negative electrode material capable of absorbing and desorbing lithium,
in the case where the winding direction is in a longitudinal direction, said negative electrode is provided with a negative electrode current collector portion on one end thereof in said longitudinal direction, said negative electrode current collector portion being a protrusion of said negative electrode core material on which said negative electrode material mixture layer is not carried,
a part of a negative electrode lead is welded to said negative electrode current collector portion,
an entire surface of said negative, electrode material mixture layer and a part of said negative electrode current collector portion are covered with a porous electron-insulating layer, and
said porous electron-insulating layer contains 50 wt % or more of an inorganic oxide filler and below 50 wt % of a binder.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/577,494Filed 28 Dec 2004
Priority: JP 2004-0038739 Jan 2004
Published: US 2007/0122715 A131 May 2007
Granted: 29 Jun 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H01M 10/052
Accumulators with non-aqueous electrolyte: li-accumulators
H01M 10/02
Secondary cells; Manufacture thereof: details
H01M 50/443
Separators, membranes or diaphragms characterised by the material: particulate material
H01M 50/581
Devices or arrangements for the interruption of current: in response to temperature

Family

US 2007/0122715 A1Pre-grant publication · published 31 May 2007
US 7,745,042 B2This patent

From the US filing history. Foreign family members aren’t listed.

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