KR-102963362-B1 - BATTERY CASE AND SECONDARY BATTERY INCLUDING THE SAME

KR102963362B1KR 102963362 B1KR102963362 B1KR 102963362B1KR-102963362-B1

Abstract

A battery case according to an embodiment of the present invention may include a receiving portion for receiving an electrode assembly in which a positive electrode and a negative electrode are alternately stacked with a separator in between, wherein the edge portion of the negative electrode protrudes outwardly from the positive electrode. The bottom surface of the receiving portion may include a main region; and a periphery region located around the main region, having a predetermined step difference with respect to the main region, and overlapping with the edge portion of the negative electrode with respect to the stacking direction of the electrode assembly.

Inventors

한현규

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260512
Application Date: 20230922

Claims (17)

A battery case comprising a receiving portion for accommodating an electrode assembly in which a positive electrode and a negative electrode are alternately stacked with a separator in between, wherein the edge portion of the negative electrode protrudes outwardly from the positive electrode, The bottom surface of the above-mentioned receiving portion is, Main area; and A battery case comprising a perimeter region located around the main region, having a predetermined step difference with respect to the main region, and overlapping with the edge portion of the negative electrode with respect to the stacking direction of the electrode assembly.
In Article 1, It further includes a terrace portion connected to the perimeter surface of the above-mentioned receiving portion, and A battery case in which, based on the above terrace portion, the depth of the main area is deeper than the depth of the perimeter area.
In Article 1, The above receiving portion includes a first receiving portion and a second receiving portion facing each other, and The bottom surface of each of the first receiving portion and the second receiving portion is a battery case including the main area and the perimeter area.
In Article 1, The above perimeter area is a battery case having a closed-loop shape.
An electrode assembly in which an anode and a cathode are alternately stacked with a separator in between, wherein the edge portion of the cathode protrudes outwardly more than the anode; and A battery case having a receiving portion for accommodating the electrode assembly, and The bottom surface of the above-mentioned receiving portion is, Main area; and A secondary battery comprising a perimeter region located around the main region, having a predetermined step difference with respect to the main region, and overlapping with the edge portion of the negative electrode with respect to the stacking direction of the electrode assembly.
In Article 5, The width of the above perimeter region corresponds to the width of the edge portion of the above negative electrode in a secondary battery.
In Article 5, The step difference between the main region and the perimeter region corresponds to half the total thickness of the anode included in the electrode assembly, in a secondary battery.
In Article 5, The above perimeter area is, A tab section extending parallel to the side where the cathode tab protrudes from the above cathode; and A secondary battery comprising a side section that extends in a direction perpendicular to the above-mentioned tab section and has a width narrower than the above-mentioned tab section.
An electrode assembly in which an anode and a cathode are alternately stacked with a separator in between, wherein the edge portion of the cathode protrudes outwardly more than the anode; A battery case having a receiving portion for accommodating the electrode assembly; and It includes a pad disposed on at least one side with respect to the stacking direction of the electrode assembly within the above receiving portion, and The above pad is, A secondary battery having a predetermined thickness and including a support portion that overlaps with the edge portion of the negative electrode with respect to the stacking direction of the electrode assembly.
In Article 9, The width of the above support portion corresponds to the width of the edge portion of the above negative electrode in a secondary battery.
In Article 9, The above support member is a secondary battery having a closed-loop shape.
In Article 9, The thickness of the support portion corresponds to the total thickness of the plurality of positive electrodes included in the electrode assembly, in a secondary battery.
In Article 9, The above pad is, A secondary battery further comprising a cover portion located inwardly from the support portion and having a thinner thickness than the support portion.
In Article 13, The difference between the thickness of the cover portion and the thickness of the support portion corresponds to the total thickness of the plurality of positive electrodes included in the electrode assembly, in a secondary battery.
In Article 9, The above pad is a secondary battery that is in close contact with the inner side of the bottom surface of the above receiving portion.
In Article 9, The above receiving portion includes a first receiving portion and a second receiving portion facing each other, and The above pad is, A first pad positioned on one side with respect to the stacking direction of the electrode assembly and located within the first receiving portion; and A secondary battery comprising a second pad positioned on the other side with respect to the stacking direction of the electrode assembly and located within the second receiving portion.
In Article 9, The above support member is, A tab section extending parallel to the side where the cathode tab protrudes from the above cathode; and A secondary battery comprising a side section that extends in a direction perpendicular to the above-mentioned tab section and has a width narrower than the above-mentioned tab section.

Description

Battery case and secondary battery including the same The present invention relates to a battery case accommodating an electrode assembly comprising a positive electrode and a negative electrode larger than the positive electrode, and a secondary battery comprising said electrode assembly and the battery case. Generally, types of secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries, and lithium-ion polymer batteries. These secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and E-bikes, but also in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices and backup power storage devices that store surplus generated power or renewable energy. To manufacture such a secondary battery, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to produce a positive electrode and a negative electrode, and these are stacked on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, and after injecting an electrolyte, it is sealed. Secondary batteries are classified into pouch type and can type depending on the material of the case housing the electrode assembly. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material. The can type, on the other hand, houses the electrode assembly in a case made of materials such as metal or plastic. Generally, a pouch-type battery case is manufactured by performing press processing on a flexible pouch film to form a cup-shaped receiving portion. Then, once the receiving portion is formed, an electrode assembly is housed inside the receiving portion and the sides are sealed to manufacture a secondary battery. Pouch-type battery cases are formed to accommodate insertability by matching the thickness of the electrode assembly. However, there is a size difference between the positive and negative electrodes included in the electrode assembly. More specifically, the negative electrode is generally formed to be larger than the positive electrode. Due to this size difference, a slight difference in thickness occurs between the center and the edges of the electrode assembly. Conventionally, the receiving portion of a pouch-type battery case was formed to a uniform depth without considering these thickness differences, so empty spaces were created within the receiving portion, and there was a possibility of safety issues such as lithium deposition or electrode displacement. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is an exploded perspective view of a secondary battery according to one embodiment of the present invention. Figure 2 is a schematic diagram of the electrode assembly shown in Figure 1. FIG. 3 is a side view of a secondary battery according to one embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating the interior of a secondary battery according to one embodiment of the present invention, with an enlarged view of the perimeter area around the bottom surface of the receiving portion. FIG. 5 is a plan view of a secondary battery according to one embodiment of the present invention. Figure 6 is a plan view of the electrode assembly shown in Figure 1. FIG. 7 is an exploded perspective view of a secondary battery according to another embodiment of the present invention. FIG. 8 is a cross-sectional view illustrating the interior of a secondary battery according to another embodiment of the present invention, with an enlarged view of the area around the support portion of the pad. Fig. 9 is a plan view of the pad shown in Fig. 7. Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments. In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire spe