US-12627014-B2 - Alkaline storage battery

US12627014B2US 12627014 B2US12627014 B2US 12627014B2US-12627014-B2

Abstract

An alkaline storage battery of the present invention includes: an electrode group that includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode, which are stacked on top of each other; an outer can that is bottomed cylindrical shape having an opening at the top; a sealing body that seals the outer can; and a positive terminal electrically connected to the sealing body. The positive electrode includes a positive electrode body and a positive electrode protrusion protruding from a portion of the positive electrode body toward the sealing body to connect electrically to the sealing body. The negative electrode includes a negative electrode body and a negative electrode protrusion protruding from a portion of the negative electrode body toward the sealing body and terminating between the sealing body and the negative electrode body. The positive electrode and the negative electrode have a positive electrode active material and a negative electrode active material, respectively, in portions facing each other with the separator therebetween.

Inventors

Masaru Takasu

Assignees

FDK CORPORATION

Dates

Publication Date: 20260512
Application Date: 20210309
Priority Date: 20200323

Claims (1)

1 . An alkaline storage battery comprising: an electrode group that includes a positive electrode with a belt shape, a negative electrode with a belt shape, and a separator with a belt shape and located between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being stacked on top of each other to wind in a spiral shape such that a negative electrode active material of the negative electrode is exposed on an outermost surface of the electrode group; an outer can with a bottomed cylindrical shape in which the electrode group is housed together with an alkaline electrolyte, the outer can having an opening at its top, wherein the outer can has an inner-side-surface that is electrically connected to the negative electrode by being in direct physical contact with the negative electrode active material exposed on the outermost surface of the electrode group; a sealing body that seals the opening of the outer can; and a positive terminal electrically connected to the sealing body, wherein the positive electrode includes a positive electrode body with a belt shape and a positive electrode protrusion protruding from a portion of the positive electrode body toward the sealing body to connect electrically to the sealing body by being in direct physical contact with the sealing body, the positive electrode body and the positive electrode protrusion both being wound in the spiral shape with the negative electrode and the separator, the negative electrode includes a negative electrode body with a belt shape and a negative electrode protrusion protruding from a portion of the negative electrode body toward the sealing body and terminating between the sealing body and the negative electrode body, the positive electrode and the negative electrode have a positive electrode active material and a negative electrode active material, respectively, in portions facing each other with the separator therebetween, the positive electrode active material is disposed across the entirety of each surface of the positive electrode, including the positive electrode protrusion, that faces the negative electrode with the separator therebetween, the negative electrode active material is disposed across the entirety of each surface of the negative electrode, including the negative electrode protrusion, that faces the positive electrode with the separator therebetween, and the inner-side-surface of the outer can functions as a negative terminal without using a negative lead tab.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is the national phase of PCT Application No. PCT/JP2021/009101 filed on Mar. 9, 2021, which claims priority to Japanese Application No. 2020-051202 filed on Mar. 23, 2020, the contents of which are incorporated herein by reference in their entirety. BACKGROUND Technical Field The present disclosure relates to an alkaline storage battery, particularly to a cylindrical alkaline storage battery. Background Art The alkaline storage battery includes an electrode group having a positive electrode, a negative electrode, and a separator stacked on top of each other. In the electrode group, the separator is located between the positive electrode and the negative electrode. In the alkaline storage battery, for example, the electrode group is wound in a spiral shape and housed with an alkaline electrolyte in a conductive outer can with a bottomed cylindrical shape. In the alkaline storage battery, a predetermined electrochemical reaction occurs between the positive and negative electrodes facing each other with a separator therebetween, thereby causing charge and discharge. As an example of a battery having an electrode group that is wound in a spiral shape, Patent Document 1, for example, discloses a nickel-metal hydride secondary battery in which an electrode body having a positive electrode and a negative electrode stacked on top of each other with a separator therebetween is housed inside a battery container. To be specific, in the nickel-metal hydride secondary battery disclosed in Patent Document 1, the electrode body includes a positive electrode protrusion that is a portion of the positive electrode protruding toward the sealing body. The positive electrode protrusion is directly connected to the sealing body, and the positive electrode protrusion of the positive electrode is not filled with an active material. PRIOR ART DOCUMENT Patent Document Patent Document 1: JP 2015-125869 A SUMMARY In order to increase the capacity of the battery, it is conceivable, for example, to form a thinner separator and increase the amount of active material applied to the positive electrode and negative electrode. However, in the nickel-metal hydride secondary battery disclosed in Patent Document 1, when the separator is made thin and the amounts of positive electrode active material and negative electrode active material are increased, burrs on the positive electrode and negative electrode could break through the separator and cause a short-circuit inside the battery. An object of the present disclosure, which has been made to solve these problems, is to provide an alkaline storage battery that can achieve high capacity while suppressing internal short-circuits. To achieve the aforementioned object, an alkaline storage battery of the present disclosure includes: an electrode group that includes a positive electrode with a belt shape, a negative electrode with a belt shape, and a separator with a belt shape located between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being stacked on top of each other to wind in a spiral shape; an outer can with a bottomed cylindrical shape in which the electrode group is housed together with an alkaline electrolyte, the outer can having an opening at the top; a sealing body that seals the opening of the outer can; and a positive terminal electrically connected to the sealing body. The positive electrode includes a positive electrode body with a belt shape and a positive electrode protrusion protruding from a portion of the positive electrode body toward the sealing body to connect electrically to the sealing body. The negative electrode includes a negative electrode body with a belt shape and a negative electrode protrusion protruding from a portion of the negative electrode body toward the sealing body and terminating between the sealing body and the negative electrode body. The positive electrode and the negative electrode have a positive electrode active material and a negative electrode active material, respectively, in portions facing each other with the separator therebetween. The alkaline storage battery according to an aspect of the present disclosure, further includes a conductive and elastic connection member that is disposed between the sealing body and the positive electrode protrusion. In the alkaline storage battery of the present disclosure, the positive electrode includes a positive electrode body with a belt shape and a positive electrode protrusion protruding from a portion of the positive electrode body toward the sealing body to connect electrically to the sealing body. Further, the negative electrode includes a negative electrode body with a belt shape and a negative electrode protrusion protruding from a portion of the negative electrode body toward the sealing body and terminating between the sealing body and the negative electrode body. Furth