Matsushita Electric Industrial Co., Ltd.

Tadahiro Tokumoto

Tomomichi Ueda

Katsuhiko Mori

Susumu Kitaoka

Akira Iwase

Ryuichiro Ebi

Norio Suzuki

Gota Asano

Masatoshi Hano

Yoshio Goda

Shoji Yamashita

Kenichi Aoki

Masanori Makino

Yoshio Gohda

Kazuyuki Higashi

Hisashi Komeno

Tokiya Fujimoto

A battery case () has a cutting groove () formed on its elongated side surface (). Between a groove bottom surface of the cutting groove () and an inner surface of the battery case () is provided a thin-walled easily-rupturable portion () designed to rupture at an instant when an internal pressure of the battery case () reaches a predetermined value. Thereby, a safety mechanism for use with a prismatic battery is realized. The manufacture of the safety mechanism is as follows. A cutting blade () rotated at a high speed by a high-speed rotary body () is brought into cutting engagement with the elongated side surface () of the battery case () of the prismatic battery in finished form until it reaches a predetermined depth and is fixed, and subsequently the high-speed rotary body () or the prismatic battery is brought into rectilinear relative movement.

Safety mechanism for rectangular battery and method of manufacturing the same

A prismatic battery case with high dimensional precision is manufactured, while pursuing an improvement in productivity, with a manufacturing method of a prismatic battery case that includes a first step for molding an intermediate cup body () by impact molding a pellet () of prescribed shape, and a second step for molding a prismatic battery case () with a cross section of substantially rectangular shape by DI processing the intermediate cup body (). The DI processing conducts drawing and ironing continuously, in one action.

Square battery container, method of manufacturing the container, and square battery using the container

A battery having a stable internal resistance with a small deviation of internal resistance, and capable of suppressing a change or elevation of internal resistance due to external impact is provided. The battery comprises a battery can having a conductivity, serving also as a negative terminal, and including an opening, a spiral electrode group disposed in the battery can, a positive plate and a negative plate wound around a separator, an electrolyte member disposed in the battery can, and a sealing member serving also as a positive terminal, disposed in the opening of the battery can through an electric insulating member. In the inner wall of the battery can, contacting with the negative electrode positioned on the outermost circumference of the plate group, plural linear bumps vertical to the bottom of the battery can are formed. The height of each linear bump of the plural linear bumps ranges from 0.05 mm to 0.25 mm, and the pitch of the linear bumps ranges from 0.5 mm to 10 mm. The negative electrode member comprises a metal core and a negative electrode material covering the surface of the metal core, and linear bumps are formed on the inner surface of the battery can, and the bumps are contact the surface of the negative electrode material.

Battery

This invention relates to a method to manufacture cell-cans by DI can method, by manufacturing a bottomed cylindrical cup-shaped intermediate product from a sheet material of which both surfaces are nickel plated and annealed in an atmosphere of inert gas making the metal nickel layer thickness and the hardness at predetermined values, then ironing the intermediate product at a predetermined ironing rate, securing a thickness of the metal nickel layer of more than 1.0 .mu.m and a Vickers hardness of more than HV 200 on the side wall of finished cell-cans. By this, conventional defect problems due to the cracks generated on the intermediate product can be solved completely and the problem of hair-lines formed on the surface of finished cell-can can be eliminated.

Method to manufacture cell-cans

Growing community of inventors

Hirakata, Japan

Tadahiro Tokumoto