Secondary battery
Disclosed in the present invention is a secondary battery in which retainers are coupled between a case and the uncoated portions of electrode assemblies so that the electrode assemblies and current collectors can be fixed and prevented from being separated. Disclosed in one embodiment is a secondary battery comprising: a plurality of electrode assemblies of which each has a cathode plate and an anode plate arranged with a separator therebetween, and which includes the uncoated portions of the cathode plate and the anode plate; a case in which the electrode assemblies are embedded; a cap plate coupled to the case; current collectors respectively coupled to the uncoated portions of the plurality of electrode assemblies through a plurality of coupling portions; and retainers inserted and coupled to on one side of the current collectors, wherein the retainers are coupled to the current collectors through protrusion portions having a width greater than that between the coupling portions of the current collectors.
1 . A secondary battery comprising:
a plurality of electrode assemblies of which each has a cathode plate and an anode plate arranged with a separator therebetween, and portions of the cathode plate and the anode plate comprise uncoated portions;
a case in which the plurality of electrode assemblies are accommodated;
a cap plate coupled to the case;
a plurality of current collectors each respectively coupled to the uncoated portions of the plurality of electrode assemblies through a plurality of coupling portions; and
a plurality of retainers, each retainer of the plurality of retainers being coupled to one side of one of the plurality of current collectors, wherein each of the plurality of retainers are coupled to the plurality of current collectors through a first protrusion portion and second protrusion portions, each of the second protrusion portions having a width greater than that between the coupling portions of the plurality of current collectors,
wherein each of the second protrusion portions comprises a central portion contacting the electrode assembly, and a plurality of elastic portions spaced apart from the central portion on opposite sides of the central portion, the plurality of elastic portions contacting the coupling portions of one of the plurality of current collectors,
wherein the second protrusion portions are located on both sides of the first protrusion portion,
wherein the protrusion portions of each of the plurality of retainers protrude from a plate-shaped body portion and are coupled between the coupling portions of one of the plurality of current collectors, and
wherein the elastic portions protrude from one side of the peripheral edge of a cut-out hole provided in the plate-shaped body portion, and are formed to be spaced apart from the central portion.
2 . The secondary battery of claim 1 , wherein the central portion is formed to protrude from the plate-shaped body portion, and the end of a head contacts the electrode assembly.
3 . The secondary battery of claim 1 , wherein a total width of the plurality of elastic portions is larger than a distance between the coupling portions of the one of the plurality of current collectors.
4 . The secondary battery of claim 1 , wherein the first protrusion portion has an empty interior.
5 . The secondary battery of claim 4 , wherein the first protrusion portion has at least one partition wall formed therein.
6 . The secondary battery of claim 1 , wherein the plurality of retainers are formed of polypropylene (PP) or polyethylene (PE).
7 . The secondary battery of claim 4 , wherein the first protrusion portion comprises an air hole.
8 . The secondary battery of claim 1 , wherein a number of the coupling portions and the uncoated portions are the same.