CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0006230, filed on Jan. 17, 2018 in the Korean Intellectual Property Office (KIPO), the content of which is incorporated herein in its entirety by reference.

BACKGROUND

1. Field

Aspects of embodiments of the present invention relate to a secondary battery.

2. Description of the Related Art

Generally, a secondary battery is designed to be recharged, while a primary battery is not designed to be recharged. Low-capacity secondary batteries having a single secondary battery packaged in the form of a pack are widely used in small, portable electronic equipment, such as mobile phones and camcorders. Large-capacity secondary batteries (e.g., secondary battery modules) having a plurality of secondary batteries assembled in the form of a module are widely used as power sources for, as one example, driving motors of hybrid or electric cars.

Secondary batteries can be configured by housing an electrode assembly, which may be formed by arranging a separator as an insulator between a positive electrode plate and a negative electrode plate, in a case together with an electrolytic solution and installing a cap plate onto the case. As one example, an electrode assembly may be formed in a jelly-roll configuration. The jelly-roll electrode assembly is configured such that a main tab (e.g., an uncoated portion of the positive or negative plate) protrudes upwardly from the electrode assembly or from left and right sides of the electrode assembly and a current collector is connected to the main tab (e.g., the uncoated portion).

The above information disclosed in this Background section is for enhancement of understanding of the background of the described technology, and therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

SUMMARY

Example embodiments of the present invention provide a secondary battery having increased capacity by reducing or minimizing a space occupied by a main tab (e.g., an uncoated portion) between a case and an electrode assembly.

The above and other aspects and features of the present invention will be described in, or will be apparent from, the following description of example embodiments.

According to an embodiment of the present invention, a secondary battery includes: an electrode assembly including a main tab; a current collecting member adjacent the main tab; and a sub-tab electrically connecting the main tab to the current collecting member. The main tab is in and welded to the sub-tab, and the sub-tab and the main tab are bent in the same direction on the current collecting member.

The sub-tab and the main tab may be bent to extend in a direction parallel to the current collecting member.

The electrode assembly may include a plurality of first and second electrode plates and separators stacked on each other and may have a pair of long-side regions and a short-side region extending between the long-side regions. The main tab may extend from the short-side region of the electrode assembly, and the current collecting member may contact the short-side region of the electrode assembly and may have a slit through which the main tab passes.

The current collecting member may include: a first region at one side of the slit and contacting the short-side region of the electrode assembly; a second region at another side of the slit and contacting the short-side region of the electrode assembly; and a third region extending between the first and second regions and contacting the short-side region of the electrode assembly.

The sub-tab may include: a first section welded to the first region of the current collecting member; a second section welded to the second region of the current collecting member; a third section extending from the first section and welded to one surface of the main tab; and a fourth section extending from the second section and welded to another surface of the main tab.

The third and fourth sections of the sub-tab may be bent to extend in a direction parallel to the first region of the current collecting member or the second region of the current collecting member.

Ends of the third and fourth sections of the sub-tab may be coplanar with an end of the main tab.

The sub-tab may further include a fifth section extending between ends of the third and fourth sections of the sub-tab.

The sub-tab may have a greater thickness than the main tab and a smaller thickness than the current collecting member.

The electrode assembly may include a first electrode assembly including a first main tab and a second electrode assembly including a second main tab. The current collecting member may have a first slit through which the first main tab passes and a second slit through which the second main tab passes. The sub-tab may include a first holding part into which the first main tab is inserted and a second holding part into which the second main tab is inserted.

As described above, a secondary battery according to various example embodiments of the present invention may have increased capacity by reducing or minimizing a space between a case and an electrode assembly occupied by a main tab (e.g., an uncoated portion).

According to various example embodiments of the present invention, because the main tab, which extends from the electrode assembly, is close to or is combined with (e.g., contacts) the case when it is bent toward a side portion of the electrode assembly, a space within the case occupied by the main tab of the electrode assembly can be reduced or minimized such that the size of the electrode assembly can be increased, thereby providing a secondary battery having increased capacity.

For example, because a current collecting member, which electrically connects the electrode assembly to a terminal part, is in close contact with the side portion of the electrode assembly, and because the main tab, which passes through the current collecting member to be inserted into and welded to the sub-tab, is then bent to put it in close contact with the current collecting member, a space (e.g., a dead space or dead volume) between the case and the electrode assembly is considerably reduced, thereby providing a secondary battery having increased capacity.

