Sanyo Electric Co., Ltd.

Taishi Maeda

Masaru Kihara

Masao Takee

Takeo Hamamatsu

Kenji Arisawa

Etsuya Fujisaka

Takahiro Endo

Teruhito Nagae

Satoru Kometani

Koji Izumi

A cylindrical type alkaline storage battery includes a cylindrical container having electrical conductivity, and an electrode assembly contained in the container, the electrode assembly being a roll obtained by rolling up a positive electrode plate, a negative electrode plate and a separator together. Provided that the maximum diameter of the container is Dmax and that the number of turns of the positive electrode plate is N, the relationship N&#x2267;[0.5&#xd7;Dmax&#x2212;2.65] is fulfilled (where '[ ]' represents Gauss' notation). Where the battery is of AA size, for example, the number N of turns is four or more. Also, provided the circumferential position of the roll starting end of the positive electrode plate is a reference position, the angle &#x3b8; measured from the circumferential position of the roll terminating end of the positive electrode plate to the reference position ranges from 180&#xb0; to 270&#xb0;.

Cylindrical type alkaline storage battery

A cylindrical alkaline storage battery has a cylindrical case which contains an electrode assembly and an alkaline electrolyte. The assembly is formed by spirally winding a negative plate, a positive plate and a separator. The negative plate has a substrate having through holes and an active material layer which is disposed on the substrate and has an inner layer, an outer layer and a filler filled in the through holes. Each of the inner layer and outer layers has an overlapping portion which overlaps the adjacent positive plate via the separator. The filler has filling portions distributed in an area of the substrate that is covered by the overlapping portion of the inner and outer layers. The total amount of the active material contained in the overlapping portions and the filling portions ranges from 75% of the total amount of the active material in the negative plate to 100%.

Cylindrical alkaline storage battery

A cylindrical alkaline storage battery suitable for increasing capacity thereof and arranged to prevent a short circuit between positive and negative electrodes. The battery has an electrically-conductive cylindrical outer can that accommodates therein an electrode group and an alkaline electrolyte. The electrode group is formed by rolling up a positive electrode, a negative electrode, and a separator. The positive electrode includes a main part and a terminal end part integrally formed to extend from one end of the main part and smaller in thickness than the main part. The terminal end part has an inner face thereof flush with an inner face of the main part. Between the positive electrode and the separator disposed on the outer face side of the positive electrode, an insulating protective piece is disposed at the boundary between the main part and terminal end part of the positive electrode.

A cylindrical alkaline storage battery has a conductive cylindrical case whose outside diameter lies in a range from 13.5 mm to 14.5 mm, and an electrode assembly contained, together with an alkaline electrolyte, in the case. The electrode assembly is formed by spirally winding a belt-like negative plate and a belt-like positive plate with a separator intervened therebetween. The negative plate forms the outermost portion of the electrode assembly which contacts the inner wall of the case. The volume energy density of the battery lies in a range from 340 Wh/l to 450 Wh/l. The ratio of the volume of the positive plate to the characteristic volume of the case is in a range from 48% to 60%.

An alkaline storage battery has a group of spiral electrodes composed of positive and negative electrode plates spirally wound with first and second separators respectively located at the outside of the positive electrode plate and at the inside of the positive electrode plate. The weight per unit area of the first separator is greater than that of the second separator.

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Takasaki, Japan

Taishi Maeda