Patent Description:
Lithium (e.g., lithium ion) secondary batteries are utilized as power sources for hybrid or electric vehicles as well as portable electronic devices owing to several features and/or advantages including, for example, high operating voltage and high energy density per unit weight.

The secondary batteries may be classified into cylindrical, prismatic, or pouch types (kinds) in shape. For example, a cylindrical secondary battery generally includes a cylindrical case, a cylindrical electrode assembly coupled to the case, an electrolyte (optional) injected inside the case to enable movement of lithium ions, and a cap assembly coupled to one side of the case to prevent or reduce leakage of electrolyte and to prevent or reduce separation of the electrode assembly.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute prior art.

The present disclosure provides a secondary battery according to claim <NUM>. Aspects of one or more embodiments of the present disclosure are directed towards a cylindrical secondary battery in which a positive electrode terminal and a negative electrode terminal are concurrently (e.g., simultaneously) implemented in a cap assembly.

One or more embodiments of the present disclosure include a secondary battery including: a case including a beading part and a crimping part; an electrode assembly physically coupled to the case and including a first electrode plate and a second electrode plate, the first electrode plate being electrically connected to the case; a first insulating gasket between the beading part and the crimping part; a cap plate coupled between the beading part and the crimping part through the first insulating gasket; a second insulating gasket penetrating (e.g., extending) through and coupled to the cap plate; and a rivet terminal penetrating (e.g., extending) through and physically coupled to the second insulating gasket, and wherein the rivet terminal is electrically connected to the second electrode plate of the electrode assembly.

In one or more embodiments, the crimping part and the cap plate may be connected to each other.

In one or more embodiments, an outer surface of the crimping part and the cap plate may be connected to each other by a conductive adhesive.

In one or more embodiments, an inner surface of the crimping part and the cap plate may be connected to each other by a conductive adhesive.

In one or more embodiments, the crimping part and the cap plate may be connected to each other by a welding region.

In one or more embodiments, the welding region may be provided on a partial region of the crimping part or may be provided on an entire region of the crimping part.

In one or more embodiments, an inner insulator may be on an inner surface of the cap plate.

In one or more embodiments, the cap plate may include: a cap plate-peripheral region coupled between the beading part and the crimping part; a cap plate-inclined region extending from the cap plate-peripheral region and inclined upward; and a cap plate-center region extending from the cap plate-inclined region and coupled to the second insulating gasket and the rivet terminal.

In one or more embodiments, an outer surface of the crimping part and an outer surface of the cap plate-center region may be coplanar.

In one or more embodiments, the case may further include a bottom surface, and the bottom surface may include a safety vent.

In one or more embodiments, the second electrode plate of the electrode assembly may be electrically connected to the rivet terminal through a second lead tab.

In one or more embodiments, the first electrode plate of the electrode assembly may be electrically connected to the safety vent through a first lead tab.

Hereinafter, one or more embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

Examples of the present disclosure are provided to more completely explain the present disclosure to those skilled in the art, and the following examples may be modified in one or more suitable other forms. The present disclosure, however, may be embodied in many different forms and should not be construed as being limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete and will convey the aspects and features of the present disclosure to those skilled in the art. Accordingly, processes, elements, and techniques that are not necessary to those having ordinary skill in the art for a complete understanding of the aspects and features of the present disclosure may not be described.

In addition, in the accompanying drawings, sizes or thicknesses of various components may be exaggerated for brevity and clarity. Like numbers refer to like elements throughout, and duplicative descriptions thereof may not be provided. In addition, it will be understood that when an element A is referred to as being "on," "connected to," or "coupled to" an element B, the element A can be directly on, connected to or coupled to the element B or an intervening element C (or multiple intervening elements) may be present therebetween such that the element A and the element B are indirectly connected to each other. In addition, it will also be understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

It will be further understood that the terms "comprise," "include," "comprising," and "including," when used in this specification, specify the presence of stated features, numbers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. may be used herein to describe one or more suitable members, elements, regions, layers and/or sections, these members, elements, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one member, element, region, layer and/or section from another. Thus, for example, a first member, a first element, a first region, a first layer and/or a first section discussed below could be termed a second member, a second element, a second region, a second layer and/or a second section without departing from the teachings of the present disclosure.

Spatially relative terms, such as "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, when the element or feature in the drawings is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "on" or "above" the other elements or features. The device may be otherwise oriented (e.g., rotated <NUM> degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

<FIG> and <FIG> are a perspective view and a cross-sectional view, respectively, illustrating an example secondary battery <NUM> according to one or more embodiments of the present disclosure. <FIG> is an enlarged cross-sectional view illustrating a cap assembly <NUM> and a structure (e.g., a structure around or a surrounding structure) thereof in the example secondary battery <NUM> according to one or more embodiments of the present disclosure.

As shown in <FIG>, <FIG> and <FIG>, the example secondary battery <NUM> according to one or more embodiments of the present disclosure includes a cylindrical case <NUM>, a cylindrical electrode assembly <NUM>, and a cap assembly <NUM>. In some embodiments, the example secondary battery <NUM> may further include a center pin <NUM> (optional) coupled to the electrode assembly <NUM>.

The cylindrical case <NUM> may include a substantially circular bottom portion <NUM> and a sidewall <NUM> extending a set or predetermined length upward from the bottom portion <NUM>. In some embodiments, the case <NUM> may include or be referred to as a can, an exterior material, or a housing.

During the manufacturing process of the secondary battery <NUM>, the upper portion of the cylindrical case <NUM> may be opened. Accordingly, during the assembling process of the secondary battery <NUM>, the electrode assembly <NUM> may be integrated into one structure and inserted into the cylindrical case <NUM>. Of course, thereafter, an electrolyte (optional or suitable) may be additionally injected into the cylindrical case <NUM>.

The cylindrical case <NUM> may be made of steel, a steel alloy, nickel-plated steel, nickel-plated steel alloy, aluminium, or an aluminium alloy.

In one or more embodiments, in the cylindrical case <NUM>, a beading part <NUM> that is recessed inwardly may be provided at the bottom of the cap assembly <NUM> and a crimping part <NUM> that is bent inward may be provided on the upper portion of the cap assembly <NUM> such that the cap assembly <NUM> is not separated to the outside (e.g., so that the cap assembly <NUM> may not be separated from the secondary battery <NUM> after assembly).

In one or more embodiments, a safety vent <NUM> may be provided at the bottom <NUM> of the cylindrical case <NUM>. In some embodiments, the safety vent <NUM> may be provided in an approximately or substantially circular ring shape or a C shape. In some embodiments, the safety vent <NUM> may include or be referred to as a notch, recess, or groove.

The electrode assembly <NUM> may be accommodated in the cylindrical case <NUM>. The electrode assembly <NUM> may include or be referred to as an electrode, an electrode group, or a jelly roll. The electrode assembly <NUM> may include a negative electrode plate <NUM> coated with a negative electrode active material (e.g., graphite, carbon, etc.), a positive electrode plate <NUM> coated with a positive electrode active material (e.g., transition metal oxide(s) (LiCoO<NUM>, LiNiO<NUM>, LiMn<NUM>O<NUM>, etc.), and a separator <NUM> positioned between the negative electrode plate <NUM> and the positive electrode plate <NUM> to prevent or substantially prevent a short circuit and allow only or substantially or effectively allow only the movement of lithium ions. The negative electrode plate <NUM>, the positive electrode plate <NUM>, and the separator <NUM> may be wound in a substantially cylindrical shape. In some embodiments, the negative electrode plate <NUM> may include copper (Cu) foil, the positive electrode plate <NUM> may include aluminium (Al) foil, and the separator <NUM> may include polyethylene (PE) or polypropylene (PP).

In one or more embodiments, a negative electrode lead tab <NUM> protruding downward by a set or predetermined length may be connected to the negative electrode plate <NUM>, and a positive electrode lead tab <NUM> protruding upward by a set or predetermined length may be connected to the positive electrode plate <NUM>, or vice versa. In some embodiments, the negative electrode lead tab <NUM> may include copper (Cu) or nickel (Ni), and the positive lead tab <NUM> may include aluminium (Al). In one or more embodiments, the negative electrode lead tab <NUM> of the electrode assembly <NUM> may be welded to a bottom portion <NUM> of the cylindrical case <NUM>. Therefore, the cylindrical case <NUM> may operate as a negative electrode. In one or more embodiments, the negative electrode lead tab <NUM> may be welded to the safety vent <NUM> provided on the bottom portion <NUM> of the cylindrical case <NUM>. Of course, in contrast, the positive electrode lead tab <NUM> may be welded to the bottom portion <NUM> of the cylindrical case <NUM>, and in this case, the cylindrical case <NUM> may operate as a positive electrode.

In one or more embodiments, a first insulating plate <NUM> coupled to the cylindrical case <NUM> and having a first hole 126a formed at the center thereof and a second hole 126b formed at the outside thereof may be disposed between the electrode assembly <NUM> and the bottom portion <NUM>. In one or more embodiments, the first insulating plate <NUM> prevents or protects the electrode assembly <NUM> from electrically contacting the bottom portion <NUM> of the cylindrical case <NUM>. In one or more embodiments, the first insulating plate <NUM> prevents or protects the positive electrode plate <NUM> of the electrode assembly <NUM> from electrically contacting the bottom portion <NUM>. In one or more embodiments, when a large amount of gas is generated due to an abnormality in the secondary battery, the first hole 126a allows the gas to rapidly move upward through the center pin <NUM>, and the second hole 126b allows the negative electrode lead tab <NUM> to penetrate (e.g., extend) through and be welded to the bottom portion <NUM>.

In one or more embodiments, a second insulating plate <NUM> coupled to the cylindrical case <NUM> and having a first hole 127a formed at the center thereof and a plurality of second holes 127b formed at the outside thereof may be interposed between the electrode assembly <NUM> and the cap assembly <NUM>. In one or more embodiments, the second insulating plate <NUM> prevents or protects the electrode assembly <NUM> from electrically contacting the cap assembly <NUM>. In one or more embodiments, the second insulating plate <NUM> prevents or protects the negative electrode plate <NUM> of the electrode assembly <NUM> from electrically contacting the cap assembly <NUM>. In one or more embodiments, when a large amount of gas is generated due to an abnormality in the secondary battery, the first hole 127a allows the gas to rapidly move to the cap assembly <NUM>, and the second holes 127b allow the positive electrode lead tab <NUM> to penetrate (e.g., extend) through and be welded to the rivet terminal <NUM>. In one or more embodiments, the remaining second holes 127b serve to allow an electrolyte to quickly flow into the electrode assembly <NUM> in an electrolyte injection process.

In one or more embodiments, the first holes 126a and 127a of the first and second insulating plates <NUM> and <NUM> are formed to have smaller diameters than the center pin <NUM>, thereby preventing or substantially preventing the center pin <NUM> from electrically contacting the bottom portion <NUM> or the cap assembly <NUM> due to an external impact.

The center pin <NUM> has a hollow circular pipe shape, and may be coupled to approximately the center of the electrode assembly <NUM>. The center pin <NUM> may be formed of steel, stainless steel, aluminium, an aluminium alloy, or polybutylene terephthalate, but the present disclosure is not limited thereto. The center pin <NUM> serves to suppress or reduce deformation of the electrode assembly <NUM> during charging and discharging of the battery, and serves as a passage for gas generated inside the secondary battery.

The cap assembly <NUM> includes a first insulating gasket <NUM>, a cap plate <NUM>, a second insulating gasket <NUM>, and a rivet terminal <NUM>. In one or more embodiments, the cap assembly <NUM> may further include an upper insulator <NUM>, a lower insulator <NUM>, and an inner insulator <NUM>. In some embodiments, the cap assembly <NUM> may include or be referred to as a cap, a cap-up, a plate, a cover, a lid, or a shroud.

The first insulating gasket <NUM> is interposed between the beading part <NUM> and the crimping part <NUM> provided in the case <NUM>. In one or more embodiments, the upper end of the first insulating gasket <NUM> may be positioned between the beading part <NUM> and the crimping part <NUM>, and the lower end of the first insulating gasket <NUM> may be positioned inside the beading part <NUM>. In one or more embodiments, the first insulating gasket <NUM> may include an insulator that does not react with an electrolyte. In some embodiments, the first insulating gasket <NUM> may include polypropylene (PP), polyethylene (PE), ethylene propylene diene monomer (EPDM), or nitrile butadiene rubber (NBR). The first insulating gasket <NUM> isolates the inside and outside of the case <NUM> to prevent or substantially prevent an electrolyte contained inside the case from leaking to the outside and/or foreign substances (e.g., moisture or dust) from entering the inside of the case.

The cap plate <NUM> is coupled between the beading part <NUM> and the crimping part <NUM> to be fixed with the first insulating gasket <NUM> interposed therebetween. In one or more embodiments, the cap plate <NUM> may include a cap plate-peripheral region <NUM>, a cap plate-inclined region <NUM>, and a cap plate-center region <NUM>. The cap plate-center region <NUM> may include a terminal hole <NUM> through which the second insulating gasket <NUM> and the rivet terminal <NUM> penetrate (e.g., extend) to be coupled, as discussed in more detail below. In some embodiments, the cap plate <NUM> may include aluminium, copper, nickel, iron, or an alloy thereof. In some embodiments, the cap plate <NUM> may include or be referred to as a cap, a cap-up, a plate, a cover, a lid, or a shroud.

The cap plate-peripheral region <NUM> may be coupled between the beading part <NUM> and the crimping part <NUM>. In one or more embodiments, the side surface and the inner surface (lower surface) of the cap plate-peripheral region <NUM> may be in close contact with the first insulating gasket <NUM>, and the outer surface (upper surface) of the cap plate-peripheral region <NUM> may be in close contact with the crimping part <NUM>. In one or more embodiments, the outer surface of the cap plate-peripheral region <NUM> may be electrically connected to the inner surface of the crimping part <NUM>. Accordingly, the case <NUM> and the cap plate <NUM> may have the same polarity.

The cap plate-inclined region <NUM> may extend from the cap plate-peripheral region <NUM> and may be inclined upward. The cap plate-inclined region <NUM> may connect the cap plate-peripheral region <NUM> and the cap plate-center region <NUM> to each other.

The cap plate-center region <NUM> may extend from the cap plate-inclined region <NUM>. The cap plate-center region <NUM> may include a generally flat outer surface (top surface) and an approximately flat inner surface (bottom surface) opposite the outer surface. The terminal hole <NUM> may penetrate (e.g., extend) through the cap plate-center region <NUM>. In one or more embodiments, the outer surface of the crimping part <NUM> and the outer surface of the cap plate-center region <NUM> may be substantially coplanar.

The second insulating gasket <NUM> may be coupled to the terminal hole <NUM>. In one or more embodiments, the second insulating gasket <NUM> may cover an inner wall of the terminal hole <NUM>, a portion of the outer surface of the cap plate-center region <NUM>, and a portion of the inner surface of the cap plate-center region <NUM>. The material of the second insulating gasket <NUM> may be similar to that of the first insulating gasket <NUM>. The second insulating gasket <NUM> may include or be referred to as a sealing gasket or a sealing insulator.

The rivet terminal <NUM> penetrates (e.g., extends) through and is coupled to the second insulating gasket <NUM>. In other words, the rivet terminal <NUM> may be coupled through the terminal hole <NUM> of the cap plate <NUM>.

The rivet terminal <NUM> may include a rivet head <NUM> positioned on the outer surface of the cap plate <NUM>, a rivet body <NUM> positioned inside the terminal hole <NUM>, and a rivet leg <NUM> positioned on (or adjacent) the inner surface of the cap plate <NUM>. In one or more embodiments, the rivet head <NUM>, the rivet body <NUM>, and the rivet leg <NUM> may be integrally provided, and may have a substantially T-shaped cross-section. In some embodiments, the rivet terminal <NUM> may include aluminium, copper, nickel, iron, or an alloy thereof.

As described above, the positive electrode lead tab <NUM> may be electrically connected to the rivet leg <NUM> of the rivet terminal <NUM>. In one or more embodiments, a positive electrode lead tab <NUM> may be welded to the rivet leg <NUM>. Accordingly, the rivet terminal <NUM> may have a positive electrode characteristic. In one or more embodiments, the cap plate <NUM> may serve as a negative electrode terminal, and the rivet terminal <NUM> may serve as a positive electrode terminal. For example, the cap plate <NUM> may have a negative electrode characteristic by being electrically connected to the crimping part <NUM> of the case <NUM>, and the rivet terminal <NUM> may have a positive electrode characteristic by being electrically connected to the positive electrode lead tab <NUM>. Accordingly, in the present disclosure, two terminals (a positive electrode terminal and a negative electrode terminal) are concurrently (e.g., simultaneously) provided at (e.g., in) the upper region (or portion) of the cylindrical secondary battery <NUM>.

The upper insulator <NUM> may be provided between the rivet terminal <NUM> and the cap plate <NUM>. In one or more embodiments, the upper insulator <NUM> may be interposed between the rivet head <NUM> and the cap plate-center region <NUM>.

The lower insulator <NUM> may be interposed between the rivet body <NUM> and/or the rivet leg <NUM> and the cap plate-center region <NUM>. In one or more embodiments, the lower insulator <NUM> may be interposed between the rivet leg <NUM> and the second insulating gasket <NUM> and/or the inner insulator <NUM>.

An inner insulator <NUM> may be additionally provided on the inner surface of the cap plate <NUM>. In one or more embodiments, the inner insulator <NUM> may be provided in the cap plate-center region <NUM>. In one or more embodiments, the inner insulator <NUM> may be provided on the inner surface of the cap plate-center region <NUM>. In one or more embodiments, the inner insulator <NUM> may be provided from the terminal hole <NUM> provided in the cap plate-center region <NUM> to the cap plate-inclined region <NUM>.

In one or more embodiments, the insulators <NUM>, <NUM>, and <NUM> may include insulators that do not react with an electrolyte. In one or more embodiments, the insulators <NUM>, <NUM>, and <NUM> may include PP, PE, EPDM or NBR. In one or more embodiments, the insulators <NUM>, <NUM>, and <NUM> may be provided by being coated on the cap plate <NUM> in a liquid state and then cured, or may be provided by being separately provided and then assembled to the cap plate <NUM>.

<FIG> is an enlarged cross-sectional view illustrating a cap assembly <NUM> and a structure (e.g., a structure around or a surrounding structure) thereof in the example secondary battery <NUM> according to one or more embodiments of the present disclosure. In the example shown in <FIG>, the cap plate <NUM> and the crimping part <NUM> may be electrically connected to each other by a conductive adhesive 150A. In one or more embodiments, the cap plate-peripheral region <NUM>, the cap plate-inclined region <NUM>, and/or the cap plate-center region <NUM> may be electrically connected to the outer surface of the crimping part <NUM> by the conductive adhesive 150A. In one or more embodiments, the conductive adhesive 150A may include silver-filled epoxy or solder. In some embodiments, the conductive adhesive 150A may include a welding region provided by laser welding, resistance welding, arc welding, and/or the like.

<FIG> is an enlarged cross-sectional view illustrating a cap assembly <NUM> and a structure (e.g., a structure around or a surrounding structure) thereof in the example secondary battery <NUM> according to one or more embodiments of the present disclosure. In the example shown in <FIG>, the cap plate <NUM> and the crimping part <NUM> may be electrically connected to each other by a conductive adhesive 150B. In one or more embodiments, the cap plate-peripheral region <NUM> may be electrically connected to the inner surface of the crimping part <NUM> by the conductive adhesive 150B. In some embodiments, the conductive adhesive 150B may include silver-filled epoxy or solder. In some embodiments, the conductive adhesive 150B may include a welding region provided by laser welding, resistance welding, arc welding, and/or the like.

<FIG> is an enlarged cross-sectional view illustrating a cap assembly <NUM> and a structure (e.g., a structure around or a surrounding structure) thereof in the example secondary battery <NUM> according to one or more embodiments of the present disclosure. In the example shown in <FIG>, the crimping part <NUM> and the cap plate <NUM> may be electrically connected to each other by a welding region 150C. In one or more embodiments, the welding region 150C may be provided by laser beams. In one or more embodiments, as the laser beams are irradiated to the outer surface (upper surface) of the crimping part <NUM>, a partial region of the crimping part <NUM> and a partial region of the cap plate-peripheral region <NUM> are melted and then cooled to provide the welding region 150C, and, by the welding region 150C, the crimping part <NUM> and the cap plate-peripheral region <NUM> may be electrically, mechanically and/or physically connected to each other.

<FIG> and <FIG> are enlarged plan views illustrating a cap assembly <NUM> and a structure (e.g., a structure around or a surrounding structure) thereof in the example secondary battery <NUM> according to one or more embodiments of the present disclosure.

As shown in <FIG>, the welding region 150C provided by the laser beams may be provided at four portions at intervals of approximately <NUM>° from the outer surface of the crimping part <NUM>. In one or more embodiments, at each portion, the welding region 150C may be provided in the form of two lines. In one or more embodiments, each welding region 150C may be provided in the form of an arc.

As shown in <FIG>, the welding region 150C provided by the laser beams may be provided on the entire outer surface of the crimping part <NUM> in the form of a circular ring. In one or more embodiments, the welding region 150C may be provided in the form of two circular rings.

As described above, the present disclosure provides a cylindrical secondary battery in which a negative electrode terminal and a positive electrode terminal are concurrently (e.g., simultaneously) implemented in a cap assembly.

As used herein, the term "substantially," "about", and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. "Substantially" as used herein, is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "substantially" may mean within one or more standard deviations, or within ± <NUM>%, <NUM>%, <NUM>%, <NUM>% of the stated value.

Claim 1:
A secondary battery comprising:
a case comprising a beading part and a crimping part;
an electrode assembly physically coupled to the case and comprising a first electrode plate and a second electrode plate, the first electrode plate being electrically connected to the case;
a first insulating gasket between the beading part and the crimping part;
a cap plate coupled between the beading part and the crimping part through the first insulating gasket;
a second insulating gasket extending through and coupled to the cap plate; and
a rivet terminal extending through and physically coupled to the second insulating gasket, and
wherein the rivet terminal is electrically connected to the second electrode plate of the electrode assembly, and wherein the cap plate comprises
a cap plate-peripheral region coupled between the beading part and the crimping part;
a cap plate-inclined region extending from the cap plate-peripheral region and inclined upward; and
a cap plate-center region extending from the cap plate-inclined region and coupled to the second insulating gasket and the rivet terminal;
wherein the crimping part and the cap plate-peripheral region are electrically connected to each other.