Rechargeable battery

A rechargeable battery including an electrode assembly having first and second electrodes at respective surfaces of a separator; a case that houses the electrode assembly; a cap plate that closes and seals an opening of the case and that is electrically connected to the second electrode; a first electrode terminal that is electrically connected to the first electrode and that is provided at an outer side of the cap plate through a terminal hole in the cap plate; and a second electrode terminal that is directly connected to an outer surface of the cap plate, wherein the second electrode terminal includes a separation portion that is spaced apart from the cap plate; and a support that is connected to the separation portion, the support being supported on the cap plate and including a coupling portion, and wherein the coupling portion is coupled with a corresponding portion of the cap plate.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0026026 filed on Feb. 24, 2015, in the Korean Intellectual Property Office, and entitled “Rechargeable Battery,” is incorporated by reference herein in its entirety.

BACKGROUND

Embodiments relate to a rechargeable battery.

2. Description of the Related Art

A rechargeable battery may be repeatedly charged and discharged, unlike a primary battery. A rechargeable battery of a small capacity may be used for a small portable electronic device (like a mobile phone, a laptop computer, or a camcorder), and a rechargeable battery of a large capacity may be used as a power source for driving a motor of a hybrid vehicle.

A rechargeable battery may include an electrode assembly that is formed by having a positive electrode and a negative electrode at respective surfaces of a separator, a case that houses the electrode assembly, a cap plate that closes and seals an opening of the case, and an electrode terminal that is installed in the cap plate to be electrically connected to the electrode assembly.

SUMMARY

Embodiments are directed to a rechargeable battery.

The embodiments may be realized by providing a rechargeable battery including an electrode assembly having a first electrode and a second electrode at respective surfaces of a separator; a case that houses the electrode assembly; a cap plate that closes and seals an opening of the case and that is electrically connected to the second electrode; a first electrode terminal that is electrically connected to the first electrode and that is provided at an outer side of the cap plate through a terminal hole in the cap plate; and a second electrode terminal that is directly connected to an outer surface of the cap plate, wherein the second electrode terminal includes a separation portion that is spaced apart from the cap plate; and a support that is connected to the separation portion, the support being supported on the cap plate and including a coupling portion, and wherein the coupling portion is coupled with a corresponding portion of the cap plate.

The support may further include a flange adjacent to the cap plate, the flange being bent from the support and contacting the cap plate.

The coupling portion may be a concave groove in the flange, and the corresponding portion may be a protrusion on the cap plate, the corresponding portion being coupled with the concave groove.

The flange may be formed at both sides of the second electrode terminal in a widthwise direction of the second electrode terminal and at both sides of the second electrode terminal in a lengthwise direction of the second electrode terminal.

The concave groove may extend inwardly in the flange in the lengthwise direction of the second electrode terminal at both sides of the second electrode terminal relative to the lengthwise direction of the second electrode terminal.

The protrusion may extend along a widthwise direction of the cap plate at both sides of the second electrode terminal relative to the lengthwise direction of the second electrode terminal.

The concave groove may extend inwardly in the flange in the lengthwise direction at both sides of the second electrode terminal relative to the lengthwise direction of the second electrode terminal and is separated in the widthwise direction of the second electrode terminal to be provided in plural.

The protrusion may be separated in the widthwise direction of the second electrode terminal to be provided in plural and is at both sides of the cap plate relative to the lengthwise direction of the cap plate.

The corresponding portion may be a receiving groove that concavely recedes in the cap plate from the outer surface to an inner surface of the cap plate and is complementary to the flange.

The coupling portion may be a concave groove in the support, and the corresponding portion may be a protrusion on the cap plate and may be coupled with the concave groove.

The second electrode terminal may be produced by performing a press construction method.

DETAILED DESCRIPTION

FIG. 1illustrates a perspective view of a rechargeable battery according to a first exemplary embodiment.FIG. 2illustrates a cross-sectional view of the rechargeable battery taken along line II-II ofFIG. 1.

Referring toFIGS. 1 and 2, a rechargeable battery100according to the first exemplary embodiment may include an electrode assembly10(that performs a charge and discharge operation), a case15(that houses the electrode assembly10), a cap plate20(that closes and seals an opening of the case15), a first electrode terminal21(for convenience, referred to as a “negative electrode terminal”) that is installed in a terminal hole H1of the cap plate20, and a second electrode terminal22(for convenience, referred to as “a positive electrode terminal”) that is directly connected to an outer surface of the cap plate20.

In an implementation, the electrode assembly10may be formed by disposing a first electrode11(for convenience, referred to as a “negative electrode”) and a second electrode12(for convenience, referred to as a “positive electrode”) at respective surfaces of a separator13, which is an insulator, and by spirally-winding the negative electrode11, the separator13, and the positive electrode12in a jelly roll state. In an implementation, the electrode assembly10may be formed by stacking the negative electrode11and the positive electrode12with the separator13therebetween.

The negative electrode11and the positive electrode12may respectively include coated regions11aand12a(at which an active material is applied to a current collector made of, e.g., a metal foil), and uncoated regions11band12b, respectively, (that are formed with an exposed current collector where an active material is not applied thereto).

The uncoated region11bof the negative electrode11may be formed in an end portion of one side of the negative electrode11along the, e.g., spiral-wound, negative electrode11. The uncoated region12bof the positive electrode12may be formed in an end portion of one side of the positive electrode12along the, e.g., spiral-wound, positive electrode12. For example, the uncoated regions11band12bof the negative and positive electrodes11and12may be disposed at opposite ends of the electrode assembly10.

The negative electrode11may be installed or connected in an electrical insulating state in or on the cap plate20through an external short circuit portion40. When an internal pressure of the rechargeable battery100rises, the negative electrode11may be short-circuited from or with the cap plate20by operation of the external short circuit portion40. In contrast, the positive electrode12may be directly electrically connected to the cap plate20. For example, the cap plate20and the case15may have the same polarity and/or may be charged as a positive electrode.

For example, the case15may be formed in an approximate cuboid to set or include a space that houses the electrode assembly10and an electrolyte solution therein. The case15may include an opening that connects the outside and an internal space at one surface of the cuboid. The opening may facilitate the electrode assembly10to be inserted into the case15.

The cap plate20may be coupled with and/or welded to an opening of the case15to close and seal the case15. For example, the cap plate20and the case15may be made of aluminum to be welded to each other. In an implementation, the cap plate20has an electrolyte injection opening201, a vent hole202, and/or a short circuit hole402.

The electrolyte injection opening201may facilitate injection of an electrolyte solution into the case15. After the electrolyte solution is injected, the electrolyte injection opening201may be sealed by a seal stopper203.

The vent hole202may be closed and sealed by a welded vent plate204. When an internal pressure of the rechargeable battery100reaches or exceeds a predetermined pressure, the vent plate204may be cut out or burst to open the vent hole202. The vent plate204may have a notch205that induces or directs cutout.

The negative electrode terminal21may be installed in or through the terminal hole H1of the cap plate20to be electrically connected to the negative electrode11of the electrode assembly10. The negative electrode terminal21may include a rivet terminal21athat is installed in the terminal hole H1of the cap plate20, a flange21bthat is integrally and widely formed in or on the rivet terminal21aat an inside or interior side of the cap plate20, and a plate terminal21cat an outside or exterior side of the cap plate20to be connected to the rivet terminal21aby, e.g., riveting or welding.

A negative electrode gasket36may be inserted between the rivet terminal21aof the negative electrode terminal21and an inner surface of the terminal hole H1to electrically insulate and seal between the rivet terminal21aof the negative electrode terminal21the cap plate20. The negative gasket36may be further extended between the flange21band an inner surface of the cap plate20to electrically insulate and further seal between the flange21band the cap plate20.

A negative electrode lead tab61may electrically connect the negative electrode terminal21to the uncoated region11bof the negative electrode11of the electrode assembly10. For example, the negative electrode lead tab61may include a bent current collecting portion611and connection portion612. The current collecting portion611may be connected by welding to the uncoated region11bof the electrode assembly10, and the connection portion612may be connected to the rivet terminal21a.

For example, by caulking or welding the lower end while coupling the connection portion612of the negative electrode lead tab61to the lower end of the rivet terminal21a, while the connection portion612of the negative electrode lead tab61is supported to the flange21b, the connection portion612may be connected to the lower end of the rivet terminal21ain a conductive structure.

An internal insulator71may be installed between the connection portion612of the negative electrode lead tab61and the cap plate20to electrically insulate the connection portion612of the negative electrode lead tab61and the cap plate20. In an implementation, the internal insulator71may closely contact the cap plate20at one side and may enclose the connection portion612of the negative electrode lead tab61, the rivet terminal21a, and the flange21bat the other side, thereby stabilizing a connection structure thereof.

The negative electrode gasket36may be further extended and inserted between the rivet terminal21aof the negative electrode terminal21and the external short circuit portion40(e.g., a hole of a negative electrode insulator31corresponding to the terminal hole H1). The external short circuit portion40may be formed to maintain a separated state or to short circuit according to an internal pressure of the rechargeable battery100.

The external short circuit portion40may include a membrane43that closes and seals the short circuit hole402that is formed in the cap plate20and that may be inverted according or in response to an internal pressure, and a short circuit tab44that is electrically connected to the negative electrode terminal21to be separately disposed at one side of the membrane43. The membrane43may be welded to the short circuit hole402to close and seal the short circuit hole402. The short circuit tab44may be installed between the negative electrode insulator31and the plate terminal21cto be extended onto the membrane43.

In a state in which the rechargeable battery100normally operates, the short circuit tab44may maintain a separated state from the membrane43. When an internal pressure of the rechargeable battery100rises and reaches and/or exceeds a predetermined pressure, the membrane43may be inverted to be short-circuited with the short circuit tab44. In this way, at the outside of the electrode assembly10, because the membrane43is short-circuited, a current that is charged at the electrode assembly10may be safely discharged at the outside of the electrode assembly10.

In an implementation, the cap plate20may be charged as a positive electrode, and the short circuit tab44of the external short circuit portion40and the rivet terminal21aof the negative electrode terminal21may be installed by interposing the negative electrode insulator31on the cap plate20. The negative electrode insulator31may have holes corresponding to the terminal hole H1and the short circuit hole402to not disturb installation of the rivet terminal21aand inversion of the membrane43.

A positive lead tab62may be electrically connected to the uncoated region12bof the positive electrode12of the electrode assembly10. For example, the positive lead tab62may include a bent current collecting portion621and a connection portion622. The current collecting portion621may be connected to the uncoated region12bof the electrode assembly10by, e.g., welding, and the connection portion622may be welded to an inner surface of the cap plate20.

The positive electrode terminal22may be directly connected to the cap plate20(that is charged as or has a same polarity as a positive electrode). For example, the positive electrode terminal22may be electrically connected to the positive electrode12of the electrode assembly10through the cap plate20and the positive lead tab62. Therefore, the electrode assembly10may be drawn outside of the case15through the negative electrode terminal21and the positive electrode terminal22.

FIG. 3illustrates an exploded perspective view of a cap plate and an electrode terminal ofFIG. 1.FIG. 4illustrates a cross-sectional view of the coupled cap plate and electrode terminal taken along line IV-IV ofFIG. 3.

Referring toFIGS. 3 and 4, the positive electrode terminal22may include a separation portion221(that is separated or spaced apart from the cap plate20), and a support222(that is connected to the separation portion221to be supported on or coupled with the cap plate20). The support222may have a coupling portion223. The support222may be coupled with a corresponding portion210(in or on the cap plate20) by the coupling portion223. Therefore, when welding the positive electrode terminal22to the cap plate20, rotation of the positive electrode terminal22may be reduced and/or prevented, and a location thereof may be stably fixed.

For example, the support222may further include a flange224at a side thereof that is adjacent to the cap plate20, and the flange224may contact the cap plate20. By enlarging a contact area with the cap plate20, the flange224may help stabilize electrical connection and mechanical strength.

For example, the coupling portion223may be formed as or may take the form of a concave groove in the flange224. When forming the positive electrode terminal22by performing a drawing or press construction method, the coupling portion223may be formed, and thus a separate process may not be required. Therefore, production cost of the positive electrode terminal22may be reduced and productivity may be improved.

The corresponding portion210may be formed as or may take the form of a protrusion that protrudes from or on an outer surface of the cap plate20(by, e.g., press processing the cap plate20) to correspond to or complement the concave groove coupling portion223of the positive electrode terminal22. For example, at an inner surface of the cap plate20, a pressing groove211that results from forming the corresponding portion210may be provided. A protrusion of the corresponding portion210may be coupled with the concave groove-shaped coupling portion223in the support222and the flange224.

The flange224may be formed on the positive electrode terminal22at both sides of the positive electrode terminal22relative to a widthwise direction (y-axis direction) of the positive electrode terminal22. For example, the flange224may be formed at both outer sides of the positive electrode terminal22relative to a widthwise direction of the positive electrode terminal22. The flange224may be formed in or on the positive electrode terminal22at both sides of a lengthwise direction (x-axis direction). In an implementation, the concave groove-shaped coupling portion223may be formed at both sides relative to the lengthwise direction (x-axis direction) of the positive electrode terminal22and may be formed by receding or extending inwardly in the lengthwise direction (x-axis direction) at the flange224.

The protruding corresponding portion210may extend along a widthwise direction (y-axis direction of the cap plate20) to correspond to or complement the coupling portion223. For example, the corresponding portion210may be provided at both sides in a lengthwise direction (x-axis direction) of the cap plate20or the positive electrode terminal22. For example, the coupling portion223and the corresponding portion210may be coupled along a widthwise direction (y-axis direction) at both sides relative to a lengthwise direction (x-axis direction) of the cap plate20. When welding the positive electrode terminal22to the cap plate20, a location of the positive electrode terminal22may be stabilized and the positive electrode terminal22may be prevented from rotating. Further, the coupling portion223and the corresponding portion210may be coupled and welded, and electrical connection and mechanical coupling strength of the positive electrode terminal22and the cap plate20may be improved.

Hereinafter, various exemplary embodiments will be described. In the following description, constituent elements identical to or corresponding to those of a first exemplary embodiment may be omitted, and only dissimilar constituent elements may be described.

FIG. 5illustrates an exploded perspective view of a cap plate and an electrode terminal in a rechargeable battery according to a second exemplary embodiment.FIG. 6illustrates a top plan view of a coupled cap plate and electrode terminal ofFIG. 5.

Referring toFIGS. 5 and 6, in a positive electrode terminal32of a rechargeable battery200according to the second exemplary embodiment, a concave groove-shaped coupling portion323may be formed at both sides relative to a lengthwise direction (x-axis direction) of the positive electrode terminal32, may be formed by receding or extending inwardly in a length direction (x-axis direction) in a flange324, and may be separated from one another in a widthwise direction (y-axis direction) to be formed or provided in plural.

A protruding corresponding portion310may be separated in a widthwise direction (y-axis direction) at both sides relative a lengthwise direction (x-axis direction) of the cap plate220or positive electrode terminal32, and may be separated in a widthwise direction (y-axis direction) to be formed or provided in plural.

Therefore, the coupling portion323and the corresponding portion310may be separated, divided, and coupled along a widthwise direction (y-axis direction) at both sides relative to a lengthwise direction (x-axis direction) of the cap plate220or positive electrode terminal32. For example, the coupling portion323and the corresponding portion310may have a complementary structure to facilitate coupling. Thus, when welding the positive electrode terminal32to the cap plate220, the positive electrode terminal32may be prevented from rotating. Further, the coupling portion323and the corresponding portion310may be coupled and welded in plural, and electrical connection and mechanical coupling strength of the positive electrode terminal32and the cap plate220may be further improved.

FIG. 7illustrates an exploded perspective view of a cap plate and an electrode terminal in a rechargeable battery according to a third exemplary embodiment.FIG. 8illustrates a cross-sectional view of the coupled cap plate and electrode terminal taken along line VIII-VIII ofFIG. 7.

Referring toFIGS. 7 and 8, in a rechargeable battery300according to a third exemplary embodiment, a corresponding portion410may be formed as a receiving groove concavely receding inwardly from an outer surface to an inner surface of a cap plate320. The corresponding portion410may correspond to or complement a flange424of a positive electrode terminal42.

For example, the flange424may circumferentially surround the positive electrode terminal42. For example, the flange424and the corresponding portion410may be coupled at both sides relative to a lengthwise direction (x-axis direction) and both sides relative to a widthwise direction (y-axis direction) of the cap plate320. For example, the positive electrode terminal42and the corresponding portion410may have a complementary structure to facilitate coupling. Thus, when welding the positive electrode terminal42to the cap plate320, the positive electrode terminal42may be prevented from rotating.

Compared with the positive electrode terminals22and32of the first exemplary embodiment and the second exemplary embodiment, in the positive electrode terminal42of the third exemplary embodiment, a height (that is set in a z-axis direction) may be reduced, and the positive electrode terminal42may be effectively applied to the rechargeable battery300having a low height.

FIG. 9illustrates an exploded perspective view of a cap plate and an electrode terminal in a rechargeable battery according to a fourth exemplary embodiment. Referring toFIG. 9, in a rechargeable battery400according to the fourth exemplary embodiment, a concave groove-shaped coupling portion523of a positive electrode terminal52may be in the form of a groove receding or extending in a z-axis direction in a support522, e.g., in a direction orthogonal to a plane of the cap plate420. A protruding corresponding portion510of a cap plate420may protrude from the cap plate420to couple with the concave groove-shaped coupling portion523. For example, the coupling portion523and the corresponding portion510may have a complementary structure to facilitate coupling.

Therefore, the coupling portion523and the corresponding portion510may be coupled along a widthwise direction (y-axis direction) at both sides relative to a lengthwise direction (x-axis direction) of the cap plate420and, when welding the positive electrode terminal52to the cap plate420, the positive electrode terminal52may be prevented from rotating.

Compared with the positive electrode terminals22,32, and42of the first exemplary embodiment to the third exemplary embodiment, the positive electrode terminal52of the fourth exemplary embodiment may not have a flange, and production cost of the positive electrode terminal52may be further reduced.

By way of summation and review, an electrode terminal may include a rivet terminal that is connected to an electrode assembly to be installed in a terminal hole of a cap plate, and a plate terminal that is disposed outside of the cap plate to be connected to the rivet terminal. The plate terminal may have a hole to which the rivet terminal is coupled.

For example, the plate terminal may be completed by shaping an outer edge of a plate terminal with a forging process and processing a hole through a cutting process. In this way, when producing the plate terminal, a forging process and a cutting process may be performed, and thus a cost to produce a plate terminal, i.e., an electrode terminal, may increase, and productivity may be deteriorated. This may result in a price increase of a rechargeable battery.

The embodiments may provide a rechargeable battery in which an electrode terminal is electrically connected to a cap plate.

The embodiments may provide a rechargeable battery having advantages of reducing a cost of producing an electrode terminal and improving productivity. The embodiments may provide a rechargeable battery having advantages of improving mechanical strength of an electrode terminal that is connected to a cap plate.

According to an exemplary embodiment, a (second) electrode terminal is formed with a separation portion and a support and a coupling portion that is formed in the support may be coupled to a corresponding portion of the cap plate, and thus production cost of the electrode terminal may be reduced and productivity may be improved.

The support of the electrode terminal may be coupled and welded to the corresponding portion of the cap plate, and mechanical strength of the electrode terminal that is connected to the cap plate may be improved. Further, the coupling portion of the electrode terminal may be coupled to the corresponding portion of the cap plate and, when welding the electrode terminal to the cap plate, the electrode terminal may be prevented from rotating and a location of the electrode terminal before welding can be fixed.

DESCRIPTION OF SYMBOLS