Loading patent…
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsShinji Murashige, Naoto Arai
Estimating the term…
A lithium ion secondary battery is so designed as to facilitate the insertion of the top insulator plate and to secure the fixation of the electrode group. This structure can reduce the probability of the electrode group moving around in the battery case to be damaged when the battery is dropped or shocked, thereby maintaining high safety standards even when a high pressure is applied from outside the battery. In a lithium ion secondary battery provided with a safety valve and composed of an electrode group which consists of a band-shaped positive electrode plate and a band-shaped negative electrode plate wound together with a separator disposed therebetween and which is housed in a cylindrical metal battery case with a bottom, together with a top insulator plate, the top insulator plate is designed to be elastic and is provided in its center with a through hole into which a center core member is press-fitted.
A cylindrical lithium ion secondary battery comprising:
A method for fabricating a cylindrical lithium ion secondary battery comprising the steps of:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Backward citations are indexed for grants only.
Battery cases, separators and other inactive parts
Li-accumulators: rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
Construction or manufacture: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes…
Characterised by their shape or physical structure: having curved cross-section, e.g. round or elliptic
Term end not estimated
The present invention relates to a lithium ion secondary battery, and more specifically, to a cylindrical lithium ion secondary battery equipped with a winding type electrode.
In recent years, portable and cordless electronic appliances including AV devices and personal computers are being developed in a rapid pace, and lithium ion secondary batteries are being used as a power supply for driving these appliances because the batteries have characteristics of being small, lightweight and having a high-energy density.
Among the lithium ion secondary batteries, a cylindrical lithium ion secondary battery is disclosed in Japanese Patent Publication No. 3143951 where a metallic center pin in the form of a hollow cylinder is arranged at the center space of the winding type electrode in order to maintain high safety standards even when a high pressure is applied to the battery from outside.
FIG. 1 is a vertical cross-sectional view of the cylindrical lithium ion secondary battery of an example in accordance with the present invention.
FIG. 2 is a perspective view of the hollow cylindrical center core member having a slit of an example in accordance with the present invention.
FIG. 3 is a perspective view of the hollow cylindrical center core member having a slit of another example in accordance with the present invention.
In order to achieve the object, the present invention is related to a cylindrical lithium ion secondary battery comprising: a safety valve; an electrode group comprising a band-shaped positive electrode plate and a band-shaped negative electrode plate which are wound together with a separator disposed therebetween; and a bottomed cylindrical metal battery case accommodating the electrode group together with a top insulator plate, characterized in that the top insulator plate is designed to be elastic and provided in the center thereof with a through hole into which a center core member is press-fitted. This structure enables the winding type electrode group be sandwiched between the inner bottom surface of the battery case and the surface of the top insulator plate, thereby fixing the electrode group to the battery case.
The method for fabricating a cylindrical lithium ion secondary battery in accordance with the present invention comprises the steps of; preparing an electrode group by winding a band-shaped positive electrode plate and a band-shaped negative electrode plate together with a separator disposed therebetween and accommodating the electrode group into a bottomed cylindrical metal battery case; arranging a top insulator plate on the end surface of the electrode group, the top insulator plate being designed to be elastic and provided with a through hole at the center thereof; and press-fitting the center core member into the through hole to fix the electrode group in the metal battery case. Since the top insulator plate is made of an elastic material and designed in a shape of exerting elasticity, it can be easily inserted into the battery case. And, the press-fitting of the center core member into the through hole can make the top insulator plate be propped and fixed between the inner wall of the battery case and the center core member and, as a result, the electrode group can be prevented from moving around in the battery case.
The present invention relates to a cylindrical lithium ion secondary battery comprising: a safety valve; an electrode group comprising a band-shaped positive electrode plate and a band-shaped negative electrode plate which are wound together with a separator disposed therebetween; and a bottomed cylindrical metal batter case accommodating the electrode group together with a top insulator plate, wherein the top insulator plate is designed to be elastic and provided in the center thereof with a through hole into which a center core member is press-fitted.