SECONDARY BATTERY

A secondary battery includes: an electrode assembly including: a first electrode plate; a second electrode plate; and a separator between the first electrode plate and the second electrode plate; a case configured to accommodate the electrode assembly; a cap assembly electrically connected to the second electrode plate of the electrode assembly; and an insulator coupled to an upper side of the electrode assembly, wherein the insulator includes: an insulating upper portion configured to cover the upper side of the electrode assembly; an insulating side portion between the case and a side portion of the electrode assembly; and an insulating core portion inserted into a hollow portion of the electrode assembly to support the electrode assembly.

CROSS REFERENCE TO RELATED APPLICATION

The present applications claim priority to and all the benefit of Korean Patent Application No. 10-2023-0095984, filed on Jul. 24, 2023, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

Aspects of some embodiments relate to a secondary battery.

2. Description of the Related Art

A secondary battery is a power storage system that provides excellent energy density to change electrical energy into chemical energy so as to store the chemical energy. In contrast to non-rechargeable primary batteries, secondary batteries are generally rechargeable and may be used for a variety of electronic devices such as smartphones, cellular phones, laptops, tablet PCs, and the like. Recently, interests in electric vehicles have increased to prevent or reduce environmental pollution, and thus, high-capacity secondary batteries are being adopted for the electric vehicles. Such secondary batteries may desirably have characteristics such as high density, high output, and stability.

SUMMARY

Aspects of some embodiments of the present disclosure include a secondary battery in which insulating performance and a shape of an electrode assembly are maintained through components of one insulator.

The characteristics of embodiments according to the present disclosure are not limited to the above-mentioned characteristics, and other characteristics not mentioned herein will be clearly understood by those skilled in the art from this specification and the attached drawings.

According to some embodiments, a secondary battery includes: an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate; a case configured to accommodate the electrode assembly; a cap assembly electrically connected to the second electrode plate of the electrode assembly; and an insulator coupled to an upper side of the electrode assembly, wherein the insulator includes: an insulating upper portion configured to cover the upper side of the electrode assembly; an insulating side portion between the case and a side portion of the electrode assembly; and an insulating core portion inserted into a hollow portion of the electrode assembly to support the electrode assembly.

According to some embodiments, the insulating core portion may have a length greater than that of the insulating side portion.

According to some embodiments, the length of the insulating core portion may be about 5% to about 20% of a length of the electrode assembly.

According to some embodiments, a diameter of a lower end of the insulating core portion may be less than that of the other area of the insulating core portion.

According to some embodiments, the insulating core portion may be inclined with respect to a direction in which the electrode assembly extends.

According to some embodiments, a thickness of a lower end of the insulating core portion may be less than that of the other area of the insulating core portion.

According to some embodiments, each of the insulating side portion, the insulating upper portion, and the insulating core portion may have a thickness of about 0.1 mm to about 1 mm.

According to some embodiments, the insulator may further include a first hole passing between top and bottom surfaces of a center of the insulating core portion.

According to some embodiments, an end of the insulating side portion facing the electrode assembly may be chamfered.

According to some embodiments, the insulator may further include an insulating rib configured to connect the insulating upper portion to the insulating core portion.

According to some embodiments, the insulating rib may have a circular plate shape that connects an outer edge of the insulating core portion to an inner edge of the insulating upper portion.

According to some embodiments, the insulating rib may further include at least one second hole passing between top and bottom surfaces thereof.

According to some embodiments, the insulating rib may be provided in plurality, which are spaced apart from and symmetrical to each other with respect to the insulating core portion.

According to some embodiments, a second hole passing between top and bottom surfaces may be defined between the plurality of insulating ribs and between the insulating core portion and the insulating upper portion.

According to some embodiments, the insulating core portion may further include a support protrusion protruding toward the electrode assembly to support the electrode assembly outside the insulating core portion.

According to some embodiments, a cutoff portion having a slit shape may be further provided in a lower end of the insulating core portion.

According to some embodiments, a cutoff portion having a slit shape may be further provided in a lower end of the insulating side portion.

According to some embodiments, the insulator may include at least one material of polybutylene terephthalate, polypropylene, polystyrene, or polyethylene.

According to some embodiments, the case may include a beading part recessed along a direction, in which the electrode assembly extends, above the electrode assembly.

According to some embodiments, the insulating upper portion of the insulator may be interposed between the beading part and the electrode assembly.

According to some embodiments, the secondary battery may further include a second current collector plate that is in contact with and electrically connected to a non-coating portion of the second electrode plate exposed to an upper side of the electrode assembly.

According to some embodiments, the secondary battery may further include a sub plate having one end that is in contact with and electrically connected to an upper side of the second current collector plate and the other end that is in contact with or electrically connected to a lower portion of the cap assembly by passing through the insulator.

According to some embodiments, the second current collector plate may be integrated with the insulator.

According to some embodiments, the insulating side portion of the insulator may have a length greater than that of the non-coating portion of the second electrode plate of the electrode assembly.

DETAILED DESCRIPTION

Embodiments of the present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that those skilled in the art thoroughly understand the present disclosure. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description, and the same reference numerals in the drawings refer to the same elements. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. In this specification, it will also be understood that if a member A is referred to as being connected to a member B, the member A can be directly connected to the member B or indirectly connected to the member B with a member B therebetween.

The terms used in this specification are for illustrative purposes of the present disclosure only and should not be construed to limit the meaning or the scope of the present disclosure. As used in this specification, a singular form may, unless definitely indicating a particular case in terms of the context, include a plural form. Also, the expressions “comprise/include” and/or “comprising/including” used in this specification neither define the mentioned shapes, numbers, steps, operations, members, elements, and/or groups of these, nor exclude the presence or addition of one or more other different shapes, numbers, steps, operations, members, elements, and/or groups of these, or addition of these. The term “and/or” used herein includes any and all combinations of one or more of the associated listed items.

As used herein, terms such as “first,” “second,” etc. are used to describe various members, components, areas, layers, and/or portions. However, it is obvious that the members, components, areas, layers, and/or portions should not be defined by these terms. The terms do not mean a particular order, up and down, or superiority, and are used only for distinguishing one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion which will be described may also refer to a second member, component, region, layer, or portion, without departing from the teaching of the present disclosure.

Spatially relative terms, such as “below”, “beneath”, “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 figures. These spatially relative terms are intended for easy comprehension of the prevent invention according to various process states or usage states of the prevent invention, and thus, the present disclosure is not limited thereto. For example, an element or feature shown in the drawings is turned inside out, the element or feature described as “beneath” or “below” may change into “above” or “upper”. Thus the term “below” may encompass the term “above” or “below”.

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

FIG.1illustrates a perspective view of a secondary battery according to some embodiments,FIG.2illustrates a cross-sectional view of the secondary battery ofFIG.1, taken along the line II-II ofFIG.1, andFIG.3illustrates an exploded perspective view of the secondary battery according to some embodiments.

Referring toFIGS.1to3, a secondary battery100according to some embodiments may include a case110, an electrode assembly120, a sub plate130, a cap assembly140, an insulating gasket150, a current collector plate160, and an insulator170. However, the components of the secondary battery100are not limited thereto, and other components may be added, or at least one component may be omitted depending on the embodiments.

The case110may accommodate an electrolyte therein. The case110may function as a main body of the secondary battery100to accommodate the electrode assembly120, the cap assembly140, the insulating gasket150, a current collector plate160, and insulator170along with the electrolyte. The case110may be provided in a cylindrical shape, but the shape is not limited thereto. According to some embodiments, the case110may be made of steel, a steel alloy, aluminum, an aluminum alloy, or an equivalent thereof, but the material thereof is not limited thereto.

The electrolyte may be injected into the case110to serve so that lithium ions generated by electrochemical reaction in a first electrode plate121and a second electrode plate122inside the battery during charging and discharging are movable. The electrolyte may be a non-aqueous organic electrolyte that is a mixture of lithium salt and a high-purity organic solvent. Furthermore, the electrolyte may be a polymer using a polymer electrolyte or a solid electrolyte, and the type of the electrolyte is not limited here.

The case110may include a bottom portion111and a side portion112.

The bottom portion111may be a bottom surface of the case110facing a lower side (e.g., −z direction). The bottom portion111may be provided in an overall circular shape.

The side portion112may extend from the bottom portion111to a certain length along a first direction (e.g., z-axis direction). The side portion112may be a sidewall of the case110, which surrounds the electrode assembly120. The first direction may be a direction parallel to a direction in which a height of the secondary battery100increases (e.g., +z direction) or a direction in which the height of the secondary battery100decreases (e.g., −z direction).

According to some embodiments, during the process of manufacturing the secondary battery100, an upper portion (e.g., portion facing the +z direction) of the case110may be opened so that the electrode assembly120is injected into the case together with the electrolyte during the process of assembling the electrode assembly120. According to some embodiments, the cap assembly140, the insulating gasket150, the current collector plate160, and the insulator170may also be inserted into the case110.

The case110may further include a beading part113and a crimping part114.

The beading part113may be provided by inserting the electrode assembly120into the case110and then pressing the electrode assembly120in a second direction (e.g., x-axis direction) crossing the first direction. The beading part113may prevent the electrode assembly120from being separated from the case110. The beading part113may be recessed toward a central portion of the case110. In a state in which the cap assembly140is located at an upper portion (e.g., portion facing +z direction), an edge area of the cap assembly140may be seated on the beading part113.

In the present disclosure, the “central portion” of the component may mean a portion that is equally spaced apart from both surfaces of the component. For example, a center of the case110may mean a central portion of the case110, which is equally spaced apart from the side portions112.

The crimping part114may be located above the beading part113to extend in the second direction. In a state in which the cap assembly140is located at the upper portion (e.g., portion facing +z direction), the edge area of the cap assembly140may be located below the crimping part114. According to some embodiments, the crimping part114may press and fix the edge of the cap assembly1140to seal the inside of the case110. According to some embodiments, the edge area of the cap assembly140may be interposed between the beading part113and the crimping part114. According to some embodiments, the insulating gasket150for electrical insulation may be further interposed between the cap assembly140and the case110.

The electrode assembly120is accommodated in the case110together with the electrolyte.

The electrode assembly120may include the first electrode plate121, the second electrode plate122, and a separator123. According to some embodiments, the first electrode plate121may be a negative electrode plate, and the second electrode plate122may be a positive electrode plate.

The first electrode plate121may be coated with a negative electrode active material such as graphite or carbon on at least one surface of plate-shaped metal foil made of copper (Cu) or nickel (Ni). According to some embodiments, the first electrode plate121may be provided with a negative electrode non-coating portion that is not coated with the negative electrode active material on a lower end (e.g., portion facing −z direction) thereof. The negative electrode non-coating portion may protrude in a downward direction (e.g., −z direction) of the electrode assembly120. According to some embodiments, the negative electrode non-coating portion may further protrude downward than the second electrode plate122and the separator123.

In the second electrode plate122, at least one surface of plate-shaped metal foil made of aluminum (Al) is applied to a positive electrode active material made of transition metal oxide. According to some embodiments, the second electrode plate122may be provided with a positive electrode non-coating portion that is not coated with a positive electrode active material on an upper end (e.g., portion facing +z direction) thereof. The positive electrode non-coating portion may protrude in an upward direction (e.g., +z direction) of the electrode assembly120. According to some embodiments, the positive electrode non-coating portion of the second electrode plate122may further protrude upward than the first electrode plate121and the separator123.

The separator may be located between the first electrode plate121and the second electrode plate122to prevent the first electrode plate121and the second electrode plate122from being electrically short-circuited with each other and to enable lithium ions to move only. The separator123may be made of polyethylene or polypropylene, but the embodiments according to the present disclosure are not limited thereto.

The electrode assembly120may be wound from a winding front end in a substantially cylindrical shape after the first electrode plate121, the second electrode plate122, and the separator123are stacked. According to some embodiments, in the electrode assembly120, the negative electrode non-coating portion that is not coated with the negative electrode active material may protrude downward from the first electrode plate121, and the positive electrode non-coating portion that is not coated with the positive electrode active material may protrude upward from the second electrode plate122.

The electrode assembly120may be provided with a hollow portion125in a core. According to some embodiments, the hollow portion125may serve to allow the electrolyte to quickly flow into the electrode assembly120during a process of injecting the electrolyte. According to some embodiments, the hollow portion125may serve as a passage through which a gas and/or heat generated inside the secondary battery100move to the outside.

The sub plate130may be electrically connected to the current collector plate160. According to some embodiments, the sub plate130may be electrically connected to the second current collector plate162, which will be described in more detail later. The sub plate130may be made of a separate metal plate and may be welded to the top surface of the second current collector plate162. The sub plate130may be aluminum or an aluminum alloy.

The cap assembly140may be coupled to the upper portion (e.g., portion facing the +z direction) of the case110. If the cap assembly140is coupled to the upper portion of the case110, the cap assembly140may cover the upper portion of the electrode assembly120.

The cap assembly140may include a cap-up141having a plurality of openings141d, a safety plate143installed below the cap-up141, a connection ring145installed below the safety plate143, and a cap-down146coupled to the connection ring145and having a gas discharge hole146b. The above-described sub plate130may be coupled to the cap-down146.

The components of the cap assembly140are not limited thereto, and other components may be added, or at least one component may be omitted depending on the embodiments.

One area of the cap-up141may be provided to be convex upward (e.g., in the +z direction) and may be electrically connected to an external circuit. According to some embodiments, the cap-up141may be provided with an opening141dthat provides a path through which the gas generated inside the case110is discharged to the outside. The cap-up141may be electrically connected to the second electrode plate122of the electrode assembly120through the sub plate130, the cap-down146, and the safety plate143. The cap-up141may be a positive electrode terminal.

The cap-up141may include a terminal part141a, a connection part141b, and an extension part141c, which are sequentially arranged outward from the center.

The terminal part141amay be flat (or approximately flat) and may be located at a substantially center of the cap-up141. According to some embodiments, when the terminal part141aconnects a plurality of secondary batteries100in series or in parallel to form a module, a positive electrode pack tab for connecting the plurality of secondary batteries100to each other is welded on a top surface of the terminal part141a.

The connection part141bis provided by being bent downward from an edge of the terminal part141aand includes at least one opening141d. The opening141dmay discharge the gas inside the case110to the outside if a vent part143bof the safety plate143is broken.

According to some embodiments, the extension part141cmay extend outward from a lower end of the connection part141bin a horizontal direction. An edge surface141ccof the extension part141cmay be surrounded by the safety plate143. According to some embodiments, the bottom surface of the extension part141cand a portion of the top surface of the extension part141cmay be in contact with the safety plate143. According to some embodiments, the edge surface may be a surface connecting the bottom surface to the top surface of the extension part.

The cap-up141may be made of any one selected from general aluminum, an aluminum alloy, steel, a steel alloy, nickel, a nickel alloy, and equivalents thereof, and the material thereof is not limited in the present invention.

The safety plate143may include a central area143aand an edge area143bextending outward from the central area143aand having an end interposed between the beading part113and the crimping part114of the case110so as to be coupled to the case110. The center area143amay be concave toward the inside of the case110compared to the edge area143b. According to some embodiments, the safety plate143may be provided with a stepped portion because the edge area143bis located higher than the central area143a. The safety plate143may further include a connection area143cconnecting the center area143ato the edge area143b. The connection area143cmay be provided to be inclined.

The edge area143bof the safety plate143may be arranged to be in close contact with one area (e.g., an outer circumference) of the cap-up141. According to some embodiments, the edge area143bof the safety plate143may be bent and extend in the first direction and the second direction to surround one area (e.g., the outer circumference) of the cap-up141and may be in contact with the one area of the cap-up141. According to some embodiments, the edge of the safety plate143may surround the cap-up141and extend to an upper side of the cap-up141to cover a top surface of the cap-up141.

The safety plate143may include a vent part143d.

The vent part143dmay be provided in the central area143aand may be opened by a preset breaking pressure. According to some embodiments, the preset breaking pressure may be about 25 kgf/cm2to about 50 kgf/cm2.

The vent part143dmay be a notch provided downward from a top surface of the central area143aof the safety plate143. One area of the safety plate143in which the vent part143dis provided may be thinner than the other area of the safety plate143in which the vent part143dis not provided. According to some embodiments, the vent part143dmay be provided to have a ring shape in a plane (or in a plan view). The vent part143dmay be provided on the top surface of the safety plate143through pressing and forging processes.

If ignition occurs in the electrode assembly120, the vent part143dmay be broken to discharge a gas and heat generated during combustion, thereby reducing a risk of rupture. The vent part143dmay be spaced apart from the connection area143c. A thickness of the vent part143dmay be about 0.15 mm to about 0.2 mm.

According to some embodiments, the thickness of the vent part143dmay be a thickness from the lowest point of the notch to the bottom surface of the safety plate143. If the vent part143dlocated in the central area143aof the safety plate143is broken, the gas and heat may be more easily discharged due to an increase in breakage area, thereby preventing thermal runaway and rupture.

According to the secondary battery100according to some embodiments, if a temperature of the cell increases due to an event, or an internal pressure of the case110exceeds an operating pressure of the safety plate143, the vent part143dmay be broken by the preset breakage pressure to disperse the internal pressure due to heat exposure through the vent part143d, thereby preventing the rupture from occurring. According to some embodiments, the secondary battery100according to some embodiments may relatively improve safety in use by providing the vent part143d.

The safety plate143may function to block electric current and discharge the internal gas if an abnormal internal pressure occurs inside the case110.

The safety plate143may be provided as a circular metal plate and be coupled to the cap-up141and then to an upper end of the case110. The safety plate143coupled to the cap-up141may seal the opening in the upper end of the case110. In the process of assembling the secondary battery100, the electrolyte and the electrode assembly120may be inserted through the opening of the case110, and then, the safety plate143coupled to the cap-up141may be coupled to the opened upper end to seal the case110.

The safety plate143may be coupled to the upper end of the case110in a state in which the second gasket150is interposed to be prevented to electrically connected to the case110. The safety plate143may be electrically connected to the second electrode plate of the electrode assembly120through the cap-down146and the sub plate130. The safety plate143may be made of aluminum, an aluminum alloy, or equivalent. The safety plate143may be provided as a metal plate and have a thickness of about 0.7 mm to about 1.2 mm.

A connection ring145may be located between the safety plate143and the cap-down146to insulate edges of the safety plate143and the cap-down146from each other. According to some embodiments, the connection ring145may be located between an outer circumference of the safety plate143and an outer circumference of the cap-down146. The connection ring145may be made of a resin material such as polyethylene, polypropylene, or polyethylene terephthalate.

The cap-down146may be connected to a bottom surface (e.g., surface facing the −z direction) of the connection ring145. The cap-down146may be provided as a circular plate. A center of the top surface of the cap-down146may be in contact with and welded to a bottom surface of the central area143aof the safety vent143. A thickness of the center of the cap-down146may be thinner than that of each of other areas. The cap-down146may be provided with a notch or arc-shaped hole along the outer circumference of the center on the plane.

If the internal pressure of the case110increases due to the notch or hole of the cap-down146, the central area and the edge area may be separated from each other. According to some embodiments, the cap-down146may be reversed upward in the state in which the central portion is in contact with the safety vent143, and thus, the central portion and the edge area may be separated from each other so as to be electrically separated from the safety vent143. A gas discharge hole146bmay be defined at one side of the cap-down146. A sub plate130may be located below the cap-down146. The gas discharge hole146bmay serve to discharge the internal gas if an excessive internal pressure is generated in the cylindrical can110. According to some embodiments, the vent part143dof the safety plate143may be damaged by the gas discharged through the gas discharge hole146b, and as a result, the gas may be discharged to the outside of the secondary battery100.

The insulating gasket150may function to insulate the cap assembly140from the side portion112of the case110.

The insulating gasket150may be installed in the upper opening of the case110. According to some embodiments, the insulating gasket150may be substantially arranged between the beading part113, which is provided on the side portion of the case110, and the crimping part114. For example, the insulating gasket150may be in the compressed form of the beading part113and the crimping part114. According to some embodiments, the insulating gasket150may be assembled to be in close contact between the extension part141cof the cap-up141, the edge area143bof the safety plate143, and the upper end of the case110. Here, the cap-up141coupled to the safety plate143may be fixed to the upper end of the case110in the state in which the insulating gasket150is interposed by the crimping part114located on the upper end of the case110.

The insulating gasket150may be made of a resin material such as polyethylene, polypropylene, polyethylene terephthalate, or the like. The insulating gasket150may prevent the cap assembly140from being separated from case110.

The current collector plate160may include a first current collector plate161and a second current collector plate162. The first current collector plate161may be in contact with and electrically connected to the first electrode plate121, and the second current collector plate162may be in contact with and electrically connected to the second electrode plate122.

The first current collector plate161may be provided as a circular metal plate that has a shape corresponding to the bottom surface (e.g., surface facing the −z direction) of the electrode assembly120. A planar size of the first current collector plate161may be equal to or less than a size of the bottom surface of the electrode assembly120.

The first current collector plate161may be fixed and electrically connected to the first electrode plate121exposed to the lower side of the electrode assembly120through welding in the state in which the top surface of the first current collector plate161is in contact with the bottom surface of the electrode assembly120. The first current collector plate161may be fixed and electrically connected to a bottom part111by welding in a state in which a bottom surface of the first current collector plate161is in contact with the bottom part111of the case110. The first current collector plate161may serve as a path for the current flow between the first electrode plate121of the electrode assembly120and the case110.

The second current collector plate162may be electrically connected to the second electrode plate122. The second current collector plate162may be provided as a circular metal plate that has a shape corresponding to the top surface (e.g., surface facing the +z direction) of the electrode assembly120.

The bottom surface of the second current collector plate162may be in contact with the top surface of the electrode assembly120. The second current collector plate162may be fixed and electrically connected to the second electrode plate122exposed to the upper side of the electrode assembly120.

The insulator170may be interposed between the electrode assembly120and the cap assembly140and between the electrode assembly120and the case110. The insulator170may be coupled to the electrode assembly120at an upper side of the second current collector plate162.

According to some embodiments, the insulator170may be integrated with the second current collector plate162by injection molding or assembly. For example, the second current collector plate162may be in close contact with and fixed to a lower portion of the insulator170. According to some embodiments, a portion of the edge area of the second current collector162may be surrounded by the insulating upper portion171of the insulator170. According to some embodiments, a portion of the upper area of the second current collector plate162may be exposed to an upper side of the insulator170.

The insulator170may insulate the second current collector plate162and the case110from each other and insulate the second electrode plate122of the electrode assembly120and the case110from each other. The insulator170may include an appropriate material to perform an insulating function. The insulator170may include at least one of polybutylene terephthalate, polypropylene, polystyrene, or polyethylene. However, the material of the insulator170is not limited thereto and may include other materials as long as the material performs the insulating function.

A structure of the insulator170may be illustrated inFIG.4, and the structure of the insulator170will be described below with reference toFIG.4. The insulator170may include an insulating upper portion171, an insulating side portion172, and an insulating core portion173. The insulator170may further include an insulating rib174. The insulator170may further include a first hole170aand a second hole170b.

The insulating upper portion171may be located between the second current collector plate162and the beading part113of the case110. The insulating upper portion171may prevent the second current collector plate162and the beading part113from being in contact with each other. The insulating upper portion171may have a circular ring shape covering the edge area of the second current collector plate162.

The insulating side portion172may be located between the side portion112of the case110and the electrode assembly120. The insulating side portion172may extend downward from an outer circumference of the insulating upper portion171. The insulating side portion172may be integrated with the insulating upper portion171. According to some embodiments, the insulating side portion172may cover a portion of an upper side of the sidewall of the electrode assembly120. According to some embodiments, a length of the insulating side portion172in the first direction (z) may be less than that of the electrode assembly120. The length of the insulating side portion172may be greater than that of the non-coating portion of the second electrode plate122, which protrudes upward from the electrode assembly120.

The insulating side portion172may insulate the side portion112of the case110and the second electrode plate122of the electrode assembly120from each other and may insulate the side portion112of the case110and the second current collector plate162from each other. The insulating side portion172may entirely surround an upper sidewall of the electrode assembly120. The insulating side portion172may be interposed between the side portion112of the case110and the electrode assembly120. According to some embodiments, a diameter of the insulating side portion172may be less than an inner diameter of the side portion112of the case100and greater than an outer diameter of the electrode assembly120.

The insulating core portion173may be inserted into the hollow portion130of the electrode assembly120to support the core of the electrode assembly120. The insulating core portion173may have a first hole170aextending downward from a top surface thereof. Because the insulating core portion173has the first hole170a, the electrolyte may be smoothly introduced into the electrode assembly120during the process of injecting the electrolyte into the electrode assembly120. According to some embodiments, the insulating core portion173may support the shape of the core of the electrode assembly120to be maintained.

The insulating core portion173may be located inside the insulating upper portion171and the insulating side portion172on the plane. According to some embodiments, the insulating core portion173may be provided to extend downward from approximately the center of the insulator170on the plane. The insulating core portion173may further protrude downward (e.g., −z direction) than the insulating side portion172. The insulating core portion173may have an overall hollow cylindrical shape. The insulating core portion173may have a smaller diameter at a lower side compared to a diameter at an upper side thereof. According to some embodiments, the insulating core portion173may have a smaller diameter and be inclined toward the lower side compared to the upper side thereof. According to some embodiments, the insulating core portion173may have a uniform thickness. As another example, a diameter of the insulating core portion173may be smaller by chamfering a lower outer surface thereof. This insulating core portion173may be easily inserted into the hollow portion125of the electrode assembly120.

According to some embodiments, a size of an end173aof the insulating core portion173may be less than that of an intermediate portion173bof the insulating core portion173. According to some embodiments, the insulating core portion173may be easily inserted into the hollow portion125. For example, a diameter of the end173aof the insulating core portion173may be less than that of the intermediate portion173bof the insulating core portion173.

The insulating core portion173may be arranged to be inclined with respect to the first direction (+z direction) in which the case110extends. According to some embodiments, the insulating core portion173may gradually decrease in size along a direction from the second current collector plate162toward the electrode assembly120. For example, a diameter173D of the insulating core portion173may gradually decrease toward the lower side (e.g., −z direction). According to some embodiments, the secondary battery100according to some embodiments may have a structure in which the insulating core portion173is easily inserted into the hollow portion125.

The insulating core portion173may be inserted into an opening162aof the second current collector162. The diameter173D of the insulating core portion173may be less than that of the opening162aof the second current collector plate162.

The insulating rib174may connect the insulating upper portion171to the insulating core portion173. The insulating rib174may have a uniform thickness with the insulating upper portion171. The insulating rib174may be interposed between the cap assembly140and the second current collector plate162. All of the insulating rib174, the insulating core portion173, the insulating side portion172, and the insulating upper portion171may be provided in one body. The insulating rib174may be provided in plurality to be symmetrical to each other on the plane with the insulating core portion173as the center.

According to some embodiments, a second hole170bmay be provided between adjacent insulating ribs174. The sub plate130may pass through the insulator170through the second hole170bto electrically connect the second current collector plate162to the cap-down146. For example, one end of the sub plate130may be in contact with and coupled to the top surface of the second current collector plate162, and the other end may be in contact with and coupled to the bottom surface of the cap-down146through the insulator170. The second hole170bmay be defined at the upper side of the insulator170. For example, the second hole170bmay be defined between the insulating upper portion171and the insulating core portion173and between the plurality of insulating ribs174.

The insulator170may maintain a shape of the hollow portion125of the electrode assembly120while insulating the case110and the second current collector plate162from each other and insulating the case110and the second electrode plate122of the electrode assembly120from each other. That is, the secondary battery100may be implemented with a structure that is capable of maintaining the insulation performance and the shape of the electrode assembly120through the components of one insulator170. According to some embodiments, productivity of the secondary battery100may be relatively improved by reducing the number of manufacturing components and manufacturing processes.

The end172aof the insulating side portion172may be chamfered. For example, the end172aof the insulating side portion172may gradually decrease in thickness toward the lower side (e.g., −z direction). According to some embodiments, the insulator170may be easily inserted between the side portion112of the case110and the electrode assembly120through the end172aof the insulating side portion172.

The thickness170dof the insulator170may be about 0.1 mm to about 1 mm. According to some embodiments, the secondary battery100may ensure the insulating function, relatively improve ease of the manufacturing process, and achieve miniaturization.

If the thickness170dof the insulator170is less than about 0.1 mm, the insulator170may be difficult to be manufactured to a uniform thickness because the thickness is too thin during the manufacturing, and thus, the insulating performance may be deteriorated, and shape deformation or distortion may occur.

If the thickness170dof the insulator170exceeds about 1 mm, capacity of the electrode assembly120inserted into the same case110may be reduced due to the unnecessary increase in size. According to some embodiments, in the insulator170, each of the insulating upper portion171, the insulating side portion172, the insulating core portion173, and the insulating rib174may have a thickness of about 0.1 mm to about 1 mm.

According to some embodiments, a length173L of the insulating core portion173may be about 5% to about 20% of the length of the electrode assembly120. If the length173L of the insulating core portion173exceeds about 20% of the length of the electrode assembly120, it may not be easy to insert the insulating core portion173into the hollow portion125. If the length173L of the insulating core portion173is less than about 5% of the length of the electrode assembly120, it may be difficult to prevent the hollow portion125from collapsing.

In the secondary battery100, because the length173L of the insulating core portion173is about 5% to about 20% of the length of the electrode assembly120, the shape of the electrode assembly120may be easily maintained, and the insulating core portion173may be easily inserted into the hollow portion125.

Hereinafter, various embodiments of the insulator170will be sequentially described with reference toFIGS.5to10.

FIG.5Aillustrates a plan view of the insulator including an example of an insulating rib,FIG.5Billustrates a cross-sectional view of the insulator ofFIG.5A, taken along the line A-A′ ofFIG.5A, andFIG.5Cillustrates a side view of the insulator ofFIG.5Awhen viewed from the side.

FIG.6Aillustrates a plan view of the insulator including another example of the insulating rib,FIG.6Billustrates a cross-sectional view of the insulator ofFIG.6A, taken along the line B-B′ ofFIG.6A, andFIG.6Cillustrates a side view of the insulator ofFIG.6Awhen viewed from the side.

Referring toFIGS.5A to6C, the insulator170may include an insulating upper portion171, an insulating side portion172, an insulating core portion173, an insulating rib174, a first hole170a, and a second hole170b. At least one of the components of the insulator170illustrated inFIGS.5A to6Cmay be the same as or similar to at least one (e.g., insulating upper portion) of the components of the insulator170illustrated inFIGS.2to4, and thus, some description of the same or similar elements may be omitted below.

N (N is a natural number of 2 or more) number of insulating ribs174may be arranged along a circumferential direction of the insulating core portion173. Three insulating ribs174are illustrated inFIGS.5A to5C, and four insulating ribs174are illustrated inFIGS.6A to6C.

According to the secondary battery100according to some embodiments, a plurality of insulating ribs174may be arranged to be spaced apart from each other, and thus, sufficient support force connecting the insulating upper portion171to the insulating core portion173may be secured, and a second hole170bthrough which a sub plate130passes may be defined in a space between the insulating ribs174spaced apart from each other. According to some embodiments, the secondary battery100may relatively improve a supporting force between the insulating upper portion171and the insulating core portion173and provide a second hole170bhaving a compact structure.

In a process of manufacturing the secondary battery100according to some embodiments, in a state in which the insulator170is coupled to the electrode assembly120, the insulator170and the electrode assembly120may be inserted together in the case110. According to some embodiments, in the state in which the electrode assembly120inserted into the case110, the insulator170may be coupled between the electrode assembly120and the case110.

FIG.7Aillustrates a plan view of the insulator including further another example of an insulating rib,FIG.7Billustrates a cross-sectional view of the insulator ofFIG.7A, taken along the line C-C′ ofFIG.7A, andFIG.7Cillustrates a side view of the insulator ofFIG.7Awhen viewed from the side;

Referring toFIGS.7A to7C, the insulator170includes an insulating upper portion171, an insulating side portion172, an insulating core portion173, an insulating rib174, and a first hole170a, and a second hole170b. At least one of the components of the insulator170illustrated inFIGS.7A to7Cmay be the same as or similar to at least one (e.g., insulating upper portion) of the components of the insulator170illustrated inFIGS.2to4, and thus, some description of the same or similar elements may be omitted below.

The insulating rib174may be arranged to surround the entire inside of the insulating upper portion171and the entire outside of the insulating core portion173.

According to some embodiments, the insulating rib174may extend from an inner edge of the insulating upper portion171to an upper outer edge of the insulating core portion173. This insulating rib174may be referred to as a portion of the insulating upper portion171. That is, the insulating upper portion171and the insulating rib174may have one circular plate shape connecting an upper end of the insulating core portion173to an upper end of the insulating side portion172. According to some embodiments, a second hole170bthrough which a sub plate passes may be defined in the insulating rib174.

In the secondary battery100, the insulating rib174may be connected to the insulating upper portion171and a front surface of the insulating core portion173to increase in area between the insulating upper portion171and the insulating core portion173. According to some embodiments, the supporting force connecting the insulating upper portion171to the insulating core portion173may be relatively improved. According to some embodiments, the secondary battery100may relatively improve the supporting force between the insulating upper portion171and the insulating core portion173and provide the second hole170bhaving a compact structure.

FIG.8Aillustrates a plan view of the insulator including a support protrusion,FIG.8Billustrates a cross-sectional view of the insulator ofFIG.8A, taken along the line DDA′ ofFIG.8A, andFIG.8Cillustrates a side view of the insulator ofFIG.8Awhen viewed from the side.

Referring toFIGS.8A to8C, the insulator170may include an insulating upper portion171, an insulating side portion172, an insulating core portion173, an insulating rib174, a support protrusion175, a first hole170a, and a second hole170b.

At least one of the components of the insulator170illustrated inFIGS.8A to8Cmay be the same as or similar to at least one (e.g., insulating upper portion) of the components of the insulator170illustrated inFIGS.2to7C, and thus, some description of the same or similar elements may be omitted below.

The support protrusion175may protrude toward the electrode assembly120to support the electrode assembly120. According to some embodiments, the support protrusion175may protrude from the insulating core portion173toward the electrode assembly120to support the electrode assembly120. According to some embodiments, the support protrusion175may be integrated with the insulating core portion173.

The support protrusion175of the insulating core portion173may support the electrode assembly120within a hollow portion125to prevent the insulator170from being separated from the electrode assembly120. According to some embodiments, coupling force between the insulator170and the electrode assembly120may be relatively improved through the support protrusion175of the insulator170.

The support protrusion175may be provided along an outer surface of the insulating core portion173in a circular ring shape or a plurality of arc shapes spaced apart from each other, but the shape is not limited thereto.

FIG.9Aillustrates a plan view of the insulator including an insulating core portion,FIG.9Billustrates a cross-sectional view of the insulator ofFIG.9A, taken along the line E-E′ ofFIG.9A, andFIG.9Cillustrates a side view of the insulator ofFIG.9Awhen viewed from the side.

Referring toFIGS.9A to9C, the insulator170may include an insulating upper portion171, an insulating side portion172, an insulating core portion173, an insulating rib174of an insulating core portion173, a cutoff portion of the insulating core portion173, a first hole170a, and a second hole170b. At least one of the components of the insulator170illustrated inFIGS.9A to9Cmay be the same as or similar to at least one (e.g., insulating upper portion) of the components of the insulator170illustrated inFIGS.2to8C, and thus, some description of the same or similar elements may be omitted below.

The cutoff portion176of the insulating core portion173may be located on one area of the insulating core portion173facing the electrode assembly120. Due to the cutoff portion176, an area occupied by the insulating core portion173may be reduced. The cutoff portion176may be located in a lower end173aof the insulating core portion173. The cut portion176may be in the form of a slit defined along the first direction (e.g., z-axis direction) in the insulating core portion173.

Because the area of the insulating core portion173is reduced through the cutoff portion176, the insulating core portion173may be easily inserted into a hollow. According to some embodiments, ease of assembly between the insulator170and the electrode assembly120may be relatively improved.

FIG.10Aillustrates a plan view of the insulator including a cutoff portion of an insulating side portion,FIG.10Billustrates a cross-sectional view of the insulator ofFIG.10A, taken along the line F-F′ ofFIG.10A, andFIG.10Cillustrates a side view of the insulator ofFIG.10Awhen viewed from the side.

Referring toFIGS.8A to8C, the insulator170may include an insulating upper portion171, an insulating side portion172, an insulating core portion173, an insulating rib174, a cutoff portion177of the insulating side portion172, a first hole170a, and a second hole170b. At least one of the components of the insulator170illustrated inFIGS.10A to10Cmay be the same as or similar to at least one (e.g., insulating upper portion) of the components of the insulator170illustrated inFIGS.2to9C, and thus, some description of the same or similar elements may be omitted below.

The cutoff portion177of the insulating side portion172may be located in an area of the insulating side portion172facing the electrode assembly. Due to the cutoff portion177, an area occupied by the insulating side172may be reduced. The cutoff portion177may be provided in a lower end172aof the insulating side172. The cutoff portion177may be in the form of a slit defined along the first direction (e.g., z-axis direction) in the lower end172aof the insulating side172.

According to the secondary battery100according to some embodiments, a surface area of the insulating side portion172may be reduced through the cutoff portion177, and thus, the insulating side portion172may be easily inserted between the side portion of the case and the electrode assembly. According to some embodiments, ease of assembly between the insulator170and the electrode assembly may be relatively improved.

A secondary battery according to various embodiments of the present disclosure may have the structure in which the insulating performance and the shape of the electrode assembly are maintained through the components of the one insulator to reduce the number of components of the secondary battery and the number of manufacturing processes, thereby relatively improving the productivity and securing the integrity of the secondary battery.

The characteristics of embodiments according to the present disclosure are not limited to the characteristics mentioned above, and other characteristics not mentioned will be more clearly understood by those skilled in the art from the description below.

The description of the above-described embodiments is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of protection of the invention should be determined by the appended claims, and all differences within the equivalent scope of what is stated in the claims should be interpreted as being included in the scope of protection determined by the claims and their equivalents.