Secondary battery

Abstract

The present disclosure relates to a secondary battery. An objective is to provide a secondary battery which is advantageous in terms of electrolyte utilization optimization and safety through minimizing a dead space by inserting a spacer into an empty space between a case and an electrode assembly. To this end, provided in the present disclosure is a secondary battery comprising: an electrode assembly; a case that accommodates the electrode assembly and has at least one opening; a cap assembly coupled through the opening to seal the case; and at least one first spacer contacting one surface of the electrode assembly and one surface of the case and interposed in a space between the electrode assembly and the case, wherein the first spacer is formed in a shape corresponding to the shape of the space between the electrode assembly and the case.

Description

secondary battery

[0001] The present disclosure relates to a secondary battery.

[0002] Secondary batteries, unlike primary batteries, are rechargeable and dischargeable. Low-capacity batteries, each consisting of a single cell packaged in a pack, are used in small, portable electronic devices such as smartphones and digital cameras. Large-capacity batteries, consisting of dozens or hundreds of battery packs connected in a modular form, are used as power sources for motors in hybrid vehicles, electric vehicles, and drones, or as energy storage devices.

[0003] Such a rechargeable secondary battery may be composed of an electrode assembly having a separator interposed between a positive electrode plate and a negative electrode plate, a current collector electrically connected to the electrode assembly, a terminal electrically connected to the current collector plate, a case accommodating the electrode assembly and the current collector plate, and a cap plate sealing the case and having a terminal penetrated therethrough and joined thereto.

[0004] Dead space can form between the electrode assembly and the case. Electrolyte remaining in this dead space within the cell does not participate in electrochemical reactions, reducing its usability. Furthermore, the void volume requires more electrolyte, requiring more electrolyte to be injected. Furthermore, the void space within the cell can cause deformation of the electrode assembly during impacts or vibrations.

[0005] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0006] The present disclosure provides a secondary battery that is advantageous in terms of optimized electrolyte utilization and cell safety by minimizing the empty space between the case and the electrode assembly.

[0007] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0008] According to one embodiment of the present disclosure for solving the above technical problem, a secondary battery includes an electrode assembly, a case that accommodates the electrode assembly and has at least one opening, a cap assembly that is coupled through the opening to seal the case, and at least one first spacer that is in contact with one surface of the electrode assembly and one surface of the case and is interposed in a space between the electrode assembly and the case, wherein the first spacer can be formed in a shape corresponding to the shape of the space between the electrode assembly and the case.

[0009] The electrode assembly includes a first electrode and a second electrode, each including an electrode plate and an electrode non-conductive portion, and the electrode non-conductive portion of the first electrode and the electrode non-conductive portion of the second electrode can protrude in at least one of the direction of the cap assembly and the opposite direction of the cap assembly.

[0010] The first spacer may be formed as a pair on both sides of the electrode assembly where the electrode-free portion of the first electrode and the electrode-free portion of the second electrode do not protrude.

[0011] The above electrode assembly can be formed in multiple pieces.

[0012] It may further include at least one second spacer that is in contact with one surface of the plurality of electrode assemblies and is interposed in a space between the plurality of electrode assemblies.

[0013] The second spacer may be formed in a shape corresponding to the shape of the space between the plurality of electrode assemblies.

[0014] The second spacer may be formed as a pair on both sides of the electrode-free portion of the first electrode and the electrode-free portion of the second electrode, respectively, of the plurality of electrode assemblies, where the two sides do not protrude.

[0015] The plurality of electrode assemblies may have electrode-free portions of each of the first electrodes and electrode-free portions of the second electrodes protruding in the same direction.

[0016] The first spacer and the second spacer may be formed to be separated from each other.

[0017] The first spacer and the second spacer may be formed as an integral part.

[0018] At least one of the first spacer and the second spacer may be formed with an empty space inside.

[0019] At least one of the first spacer and the second spacer can be coupled to the interior of the case.

[0020] It may further include a fixing member that surrounds the side of the plurality of electrode assemblies positioned in series.

[0021] At least one of the first spacer and the second spacer can be coupled to the plurality of electrode assemblies by the fixing member.

[0022] The first spacer and the second spacer may be formed of an insulating material.

[0023] The electrode-free portion of the first electrode and the electrode-free portion of the second electrode are spaced apart from each other and can protrude from the electrode plate toward the cap assembly.

[0024] The above electrode assembly can be wound in a winding type.

[0025] According to embodiments of the present disclosure, by inserting a spacer into the empty space between the case and the electrode assembly to minimize dead space, electrolyte utilization can be optimized, and safety can be enhanced by preventing collisions or deformation caused by the empty space within the cell. Furthermore, the spacer can serve as a guide during cell assembly, thereby enhancing the ease of assembly.

[0026] However, the effects that can be obtained through the present disclosure are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0027] FIG. 1 is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure.

[0028] Figure 2 is an exploded perspective view showing a part of the configuration of the secondary battery of Figure 1.

[0029] Figure 3 is a cross-sectional view taken along line 3-3' of the secondary battery of Figure 1.

[0030] FIG. 4 is a cross-sectional view of a secondary battery including one electrode assembly according to one embodiment.

[0031] FIG. 5 is a cross-sectional view of a secondary battery including a plurality of electrode assemblies according to one embodiment.

[0032] FIG. 6 is a cross-sectional view of a secondary battery including an internally hollow spacer according to one embodiment.

[0033] FIG. 7 is a perspective view illustrating a state in which a spacer of a secondary battery according to one embodiment is coupled to a case.

[0034] FIG. 8 is a perspective view illustrating a state in which a spacer is coupled by a fixing member of a secondary battery according to one embodiment.

[0035] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. Prior to this, it should be noted that terms or words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings, and should be construed with meanings and concepts consistent with the technical spirit of the present disclosure based on the principle that the inventor can appropriately define the concept of a term to best describe his or her invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present disclosure and do not represent all of the technical spirit of the present disclosure. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0036] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0037] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may have exaggerated dimensions. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0038] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0039] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0040] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0041] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0042] Additionally, when a component is described as being "on," "connected to," or "coupled to" another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through other components.

[0043] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" when describing embodiments of the present disclosure refers to "one or more embodiments of the present disclosure." Expressions such as "one or more" and "one or more" preceding a list of elements modify the list as a whole and do not modify individual elements in the list.

[0044] When reference is made throughout the specification to “A and / or B,” this means A, B, or A and B, unless otherwise stated, and when reference is made to “C through D,” this means C or more and D or less, unless otherwise stated.

[0045] When a phrase such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one selected from the group A, B, and C", or "at least one selected from A, B, and C" is used to specify a list of elements A, B, and C, the phrase can refer to any suitable combination.

[0046] The term "use" may be considered synonymous with the term "utilize." As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation rather than degrees, and are intended to take into account inherent variations in measured or calculated values ​​that would be recognized by those skilled in the art.

[0047] Although terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could also be termed a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0048] For ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," and the like may be used herein to describe the relationship of one element or feature to another element(s) or feature(s) as depicted in the drawings. It will be understood that spatially relative positions encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the drawings is turned over, an element described as "beneath" or "lower" another element would be understood to be "above" or "upper" the other element. Thus, the term "beneath" can encompass both the above and below orientations.

[0049] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0050] Hereinafter, in exemplary embodiments of square batteries according to embodiments of the present disclosure, one of the square batteries is selected, and the selected battery is described as having a general structure, and in the case of a generally applicable technology, the general structure of the square battery is described. However, the present disclosure is not limited thereto, and the case may be configured in various shapes such as circular or pouch-shaped. In addition, the case may be configured of a metal such as aluminum, aluminum alloy, nickel-plated steel, or a laminate film or plastic forming a pouch.

[0051] FIG. 1 is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure, and FIG. 2 is an exploded perspective view illustrating a part of the secondary battery of FIG. 1.

[0052] Referring to FIGS. 1 and 2, a secondary battery (100) according to one embodiment may include an electrode assembly (110), a spacer (120, 130), a case (150), and a cap assembly (160).

[0053] The electrode assembly (110) may be formed by winding or laminating a laminate of a first electrode plate, a separator, and a second electrode plate formed in a thin plate shape or film shape. However, in one embodiment, the electrode assembly (110) may be formed by winding. The winding axis of the electrode assembly (110) may be parallel to the longitudinal direction (y) of the case (150). In addition, the electrode assembly (110) may be housed inside the case (150) by stacking one or more electrode assemblies (110) so that their long sides are adjacent to each other, and the number of electrode assemblies (110) is not limited in the present disclosure. Here, the first electrode plate may operate as a first polarity, for example, an anode, and the second electrode plate may operate as a second polarity, for example, a cathode. Of course, the first electrode plate and the second electrode plate may be arranged with different polarities depending on the selection of a person skilled in the art.

[0054] The first electrode plate is formed by applying a first electrode active material such as a transition metal oxide to a first electrode current collector formed of a metal foil such as aluminum or an aluminum alloy, and may include a first electrode non-coated portion (111) which is a region where the first active material is not applied. The first electrode non-coated portion (111) may provide a path for current flow between the first electrode plate and the outside. In addition, the first electrode non-coated portions (111) may be formed to overlap at the same position when the first electrode plate is wound, thereby forming a multi-tap structure. The first electrode non-coated portions (111) are formed to protrude toward one side of the electrode assembly (110), and in some cases, a plurality of them may be welded to each other to form one first current collector tab. These first electrode non-coated portions (111) may be aligned and protrude toward one side of the electrode assembly (110). In some examples, the first electrode portion (111) may protrude from one side of the first electrode plate toward the cap assembly (160).

[0055] The second electrode plate is formed by applying a second electrode active material, such as graphite or carbon, to a second electrode current collector formed of a metal foil, such as copper, a copper alloy, nickel, or a nickel alloy, and may include a second electrode non-coated portion (112), which is an area where the second active material is not applied. The second electrode non-coated portion (112) may provide a path for current flow between the second electrode plate and the outside. In addition, the second electrode non-coated portions (112) may also be formed to overlap at the same position when the second electrode plate is wound, thereby forming a multi-tap structure. The second electrode non-coated portions (112) are formed to protrude from one side of the electrode assembly (110), and in some cases, a plurality of them may be welded to each other to form a single second current collector tab. In some examples, the second electrode non-coated portions (112) may protrude from one side of the second electrode plate toward the cap assembly (160).

[0056] In some examples, the first electrode uncoated portion (111) and the second electrode uncoated portion (112) may protrude parallel to each other from the electrode assembly (110) toward the cap assembly (160). That is, the first electrode uncoated portion (111) and the second electrode uncoated portion (112) in the electrode assembly (110) may be spaced apart from each other with different polarities. In addition, as described above, since the first electrode plate and the second electrode plate are formed by winding or overlapping, the first electrode uncoated portion (111) and the second electrode uncoated portion (112) that are repeatedly formed at each turn may be formed by overlapping a plurality of thin films. When a plurality of thin films are formed in this way, the thin films may be connected to each other by ultrasonic welding to make contact with each other in order to facilitate current flow.

[0057] A separator may be positioned between the first and second electrode plates to prevent short circuits and facilitate the movement of lithium ions. The separator may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene. However, the material used for the separator does not limit the scope of the present invention. In some cases, the separator may be replaced with a solid electrolyte.

[0058] The electrode assembly (110) can be inserted into the case (150) in a direction parallel to the rotation axis. In addition, the electrode assembly (110) can include a first electrode assembly (110a) and a second electrode assembly (110b). At this time, the first electrode assembly (110a) and the second electrode assembly (110b) can be electrically connected. In addition, the first electrode assembly (110a) and the second electrode assembly (110b) can be fixed through a separate fixing member (113) attached to a certain area. The electrode assembly (110) can maintain its shape by the fixing member (113), and can be connected to the electrode assembly (110) at an accurate position thereafter with a current collector (not shown), and can be able to maintain the structure of the electrode assembly (110) even within the final secondary battery structure. Also, in some examples, the spacer (120, 130) described later can be fixed to the electrode assembly (110) by a fixing member (113). Meanwhile, although FIG. 2 illustrates two electrode assemblies (110), this is not limited to the above, and a plurality of electrode assemblies, such as a third electrode assembly (110c) and a fourth electrode assembly (110d), may be provided.

[0059] The electrode assembly (110) can be substantially housed in the case (150) together with an electrolyte. The electrolyte can be composed of a lithium salt such as LiPF6 or LiBF4 in an organic solvent such as EC (ethylene carbonate), PC (propylene carbonate), DEC (diethyl carbonate), EMC (ethyl methyl carbonate), or DMC (dimethyl carbonate). In addition, the electrolyte can be in the form of a liquid, solid, or gel.

[0060] The spacer (120, 130) is interposed between one surface of the electrode assembly (110) and one surface of the case (150) to minimize dead space, which is an empty space inside the case (150). These spacers (120, 130) will be described in more detail below.

[0061] The case (150) may be a roughly rectangular hollow body with an opening formed at the top. Accordingly, the electrode assembly (110) may be inserted into the case (150) through this opening. The case (150) may include a bottom portion, a pair of long sides, and a pair of short sides connecting the pair of long sides, and an opening may be provided facing the bottom portion. A cap plate (161) may be coupled to the opening of the case (150) to seal the case (150). The inner surface of the case (150) is basically insulated to prevent an electrical short circuit from occurring inside. In addition, in some cases, one electrode of the electrode assembly (110) may be electrically connected to the case (150) through the cap plate (161). In this case as well, an electrical short circuit inside the case (150) may be prevented by the insulation treatment inside the case (150). In some examples, the case (150) may be formed of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel, and may be manufactured by a deep drawing process or a bending and welding process.

[0062] The cap assembly (160) can be coupled to the upper portion (opening) of the case (150). Specifically, the cap assembly (160) can include a cap plate (161), an electrolyte injection port (162), a safety vent (163), a first terminal plate (1641), a second terminal plate (1642), a first insulating member (1651), and a second insulating member (1652).

[0063] The cap plate (161) seals the opening of the case (150) and may be formed of the same material as the case (150). The cap plate (161) may be formed of a thin plate in a flat shape. For example, the cap plate (161) may be joined to the case (150) by laser welding. In addition, the cap plate (161) may be electrically independent or, in some cases, electrically connected to a current collector.

[0064] Additionally, an electrolyte injection port (162) for injecting an electrolyte may be formed in the cap plate (161). The electrolyte is injected into the interior of the case (150) through the electrolyte injection port (162), and thereafter, the electrolyte injection port (162) may be sealed by a stopper.

[0065] Additionally, a safety vent (163) formed with a relatively thin thickness compared to other areas may be formed approximately in the center of the cap plate (161). The safety vent (163) can prevent the secondary battery (100) according to one embodiment of the present disclosure from exploding when the pressure inside the case (150) is higher than the set rupture pressure.

[0066] The first terminal plate (1641) and the second terminal plate (1642) can be electrically connected to the first electrode plate and the second electrode plate of the electrode assembly (110) via the current collector plate. That is, the first terminal plate (1641) can operate as a first polarity, for example, an anode, and the second terminal plate (1642) can operate as a second polarity, for example, a cathode. Here, the current collector plate is not shown in the drawing, but can be electrically connected to the first electrode non-conducting portion (111) and the second electrode non-conducting portion (112). The current collector plate can be electrically connected to the first electrode plate and the second electrode plate by coming into contact with the first electrode non-conducting portion (111) and the second electrode non-conducting portion (112) protruding from one end of the electrode assembly (110).

[0067] The first insulating member (1651) and the second insulating member (1652) may be formed between the first terminal plate (1641) and the second terminal plate (1642) and the cap plate (161). The first insulating member (1651) and the second insulating member (1652) may be formed in a form that surrounds the outer side of each of the first terminal plate (1641) and the second terminal plate (1642), and may be formed of an insulating material. In addition, the first insulating member (1651) and the second insulating member (1652) may seal between the first terminal plate (1641) and the second terminal plate (1642), respectively. These first insulating member (1651) and second insulating member (1652) can prevent external moisture from penetrating into the interior of the secondary battery (100) or prevent the electrolyte contained inside the secondary battery (100) from leaking out to the exterior.

[0068] FIG. 3 is a cross-sectional view taken along line 3-3' of the secondary battery of FIG. 1, FIG. 4 is a cross-sectional view of a secondary battery including one electrode assembly according to one embodiment, FIG. 5 is a cross-sectional view of a secondary battery including a plurality of electrode assemblies according to one embodiment, FIG. 6 is a cross-sectional view of a secondary battery including a spacer with an empty interior according to one embodiment, FIG. 7 is a perspective view illustrating a state in which a spacer of a secondary battery is coupled to a case according to one embodiment, and FIG. 8 is a perspective view illustrating a state in which a spacer is coupled by a fixing member of a secondary battery according to one embodiment.

[0069] As described above, in the present disclosure, a winding type electrode assembly (110) may be applied, and a dead space is created inside the case (150) due to the short-side curved portion (1102) of the electrode assembly (110). The electrolyte remaining in this dead space does not participate in the electrochemical reaction, thereby reducing its usability. In addition, since the electrolyte must be injected including the void volume, more electrolyte may be required. In addition, deformation may occur in the electrode assembly (110) due to the empty space inside the case (150) when subjected to a collision or vibration. In other words, due to the characteristics of the winding type electrode assembly (110), it may be difficult to optimize the electrolyte and there may be a problem of reduced cell safety due to the dead space caused by the short-side curved portion (1102).

[0070] Accordingly, referring to FIGS. 3 to 5, in one embodiment of the present disclosure, a spacer (120, 130) is inserted into the empty space inside the case (150) to minimize dead space, thereby reducing the amount of residual electrolyte that does not participate in the electrochemical reaction. In addition, the spacer (120, 130) can serve as a guide during cell assembly, thereby facilitating the assembly process. In addition, in the present disclosure, by filling the empty space inside the case (150) with the spacer (120, 130), the electrode assembly (110) does not move when the battery cell receives an impact, thereby mitigating the physical impact and improving safety. Hereinafter, these spacers (120, 130) will be described in more detail.

[0071] In some examples, the electrode assembly (110) may include a pair of long sides and a pair of short sides connecting the pair of long sides. In addition, the electrode assembly (110) may be formed of a flat portion (1101) and a curved portion (1102), wherein one side of the pair of long sides may be formed of the flat portion (1101), and one side of the pair of short sides may be formed of the curved portion (1102). An empty space is formed between the electrode assembly and the case (150) by the curved portion (1102), and this empty space may be referred to as a first region (A). Regardless of the number of electrode assemblies (110), four regions of the first region (A) may be formed at each corner between the electrode assembly (110) and the case (150). These four first regions (A) may be formed in slightly different shapes depending on the winding shape of the electrode assembly (110), but will be described as having the same shape.

[0072] The first region (A) may be formed by a curved portion formed by the curved portion (1102) of the electrode assembly (110) and a corner portion formed by the corner of the case (150). That is, the shape of the first region (A) may be formed depending on the shape of the curved portion (1102) of the electrode assembly (110) and the corner shape of the case (150).

[0073] In some examples, the first spacer (120) may be interposed in the first region (A). That is, the first spacer (120) may be formed in a shape corresponding to the shape of the first region (A) and may be interposed at each of the four corners. The first spacer (120) may be formed in a slightly different shape, such as the first region (A), but will be described as having the same shape. Since the first spacer (120) is interposed in the first region (A) so that there is no empty space in the first region (A), it may be formed to correspond to the shape of the first region (A). The first spacer (120) may include a first surface (121) that contacts the electrode assembly (110) corresponding to the curved portion of the first region (A), and two second surfaces (122) that contact the corners of the case (150) corresponding to the corners of the first region (A). That is, the first surface (121) of the first spacer (120) may be formed in a curved shape corresponding to the curved portion (1102) of the electrode assembly (110). In addition, the second surface (122) of the first spacer (120) may be formed corresponding to the corner shape of the case (150) because it contacts the corner of the case (150). For example, when the corner is right angled, the two second surfaces (122) of the first spacer (120) may be connected at right angles. That is, the first spacer (120) may be in the shape of a triangular prism in which the first surface (121) is formed as a concave curve. On the other hand, if the corners are formed as gentle curves, the second surface (122) of the first spacer (120) may be connected in two gentle curves.

[0074] Meanwhile, in some examples, when a plurality of electrode assemblies (110) are formed, an empty space may be formed between adjacent electrode assemblies (110a to 110d) by the curved portion (1102) of each electrode assembly (110). This empty space may be referred to as a second region (B). For example, when there are two electrode assemblies (110a, 110b), two second regions (B) may be formed, one on each side of the electrode assemblies (110a, 110b). In addition, when there are four electrode assemblies (110a to 110d), six second regions (B) may be formed, three on each side. These plurality of second regions (B) may be formed somewhat differently depending on the winding shape of the electrode assembly (110), but will be described as having the same shape.

[0075] The second region (B) may be formed by a curved portion formed by the curved portions (1102a, 1102b) of the electrode assemblies (110a, 110b) and a straight portion formed by the case (150). That is, the shape of the second region (B) may be formed according to the shape of the curved portions (1102a, 1102b) of the electrode assemblies (110a, 110b). In addition, if the shape of the inner surface of the case (150) is not a uniform surface but has a pattern formed on it, the shape of the straight portion of the second region (B) may be formed according to the pattern.

[0076] In some examples, the second spacer (130) may be interposed in the second region (B). That is, the second spacer (130) may be formed in a shape corresponding to the shape of the second region (B) and may be interposed between adjacent electrode assemblies (110a, 110b), respectively. The second spacer (130) may be formed in a slightly different shape, such as in the second region (B), but will be described as having the same shape. Since the second spacer (130) is interposed in the second region (B) so that there is no empty space in the second region (B), it may be formed to correspond to the shape of the second region (B). The second spacer (130) may include two first faces (131) that contact the electrode assembly (110a, 110b) corresponding to the curved portion of the second region (B), and a second face (132) that contacts the inner surface of the case (150) corresponding to the straight portion of the second region (B). That is, the first face (131) of the second spacer (130) may be formed in a curved shape corresponding to the curved portions (1102a, 1102b) of the electrode assembly (110a, 110b). In addition, the second face (132) of the second spacer (130) may be formed in a straight shape because it contacts the inner surface of the case (150). For example, the second spacer (130) may have a triangular prism shape in which the two first faces (131) are formed in a concave curve.

[0077] The first spacer (120) and the second spacer (130) may be formed as a pair on opposite sides of the first electrode non-protruding portion (111) and the second electrode non-protruding portion (112) of the electrode assembly (110). In some examples, the same first spacer (120) and the same second spacer (130) may be interposed on the left and right sides of the electrode assembly (110), respectively. Accordingly, in one embodiment of the present disclosure, the first spacer (120) and the second spacer (130) may be interposed in an empty space within the case (150) to eliminate dead space.

[0078] In some examples, the first spacer (120) and the second spacer (130) may be separated from each other. That is, the first spacer (120) and the second spacer (130) may be formed as separate components. However, the present invention is not limited thereto, and the first spacer (120) and the second spacer (130) may also be formed as an integral part. For example, the first spacer (120) and the second spacer (130) may be manufactured as an integral part or may be combined.

[0079] Also, referring to FIG. 6, at least one of the first spacer (120) and the second spacer (130) may be formed with an empty space inside. In some examples, the interiors of all of the first spacers (120) and the second spacers (130) may be formed with an empty space inside, or some of the first spacers (120) and the second spacers (130) may be formed with an empty space inside. Accordingly, in one embodiment of the present disclosure, the weight of the secondary battery (100) may be reduced.

[0080] Meanwhile, referring to FIG. 7, at least one of the first spacer (120) and the second spacer (130) may be coupled to the interior of the case (150). For example, the first spacer (120) and the second spacer (130) may be pre-designed to fit the cell design (electrode assembly thickness, number of electrode assemblies, etc.) and the shape of the case (150) and may be pre-attached to the case (150) before the electrode assembly (110) is inserted into the case (150).

[0081] Also, referring to FIG. 8, in some examples, at least one of the first spacer (120) and the second spacer (130) may be coupled to the plurality of electrode assemblies (110) by the fixing member (113). For example, after assembling the electrode assembly (110) and the cap assembly (160), the first spacer (120) and the second spacer (130) may be fixed by taping the fixing member (113) to both sides of the electrode assembly (110), and may be attached to the electrode assembly (110) before insertion of the case (150).

[0082] These first spacers (120) and second spacers (130) may be formed of an insulating material and may be formed of a material that does not undergo an electrochemical reaction inside the cell. For example, the first spacer (120) and the second spacer (130) may be formed of one or a mixture of two or more selected from the group consisting of polypropylene (PP), polymethylpentene (PMP), polyethyleneterephthalate (PET), polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyetherimide (PEI), polyamideimide, polyethersulfone (PES), polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalene. In some examples, the first spacer (120) and the second spacer (130) may be formed of the same material, but are not limited thereto and may be formed of different materials.

[0083] The above description is only one embodiment for implementing an exemplary secondary battery according to the present disclosure, and the present disclosure is not limited to the above-described embodiment, and as claimed in the following claims, it will be understood that the technical spirit of the present disclosure encompasses a range in which various modifications can be implemented by anyone with ordinary skill in the art to which the present invention pertains without departing from the gist of the present disclosure. In other words, although the present disclosure has been described by limited embodiments and drawings, it is not limited thereto, and it goes without saying that various modifications and variations are possible by a person with ordinary skill in the art to which the present disclosure pertains within the technical idea of ​​the present disclosure and the equivalent scope of the patent claims to be described below.

Claims

1. Electrode assembly; A case accommodating the electrode assembly and having at least one opening; A cap assembly that is coupled through the above opening to seal the case; At least one first spacer is included in the space between the electrode assembly and the case, and is in contact with one surface of the electrode assembly and one surface of the case, A secondary battery wherein the first spacer is formed in a shape corresponding to the shape of the space between the electrode assembly and the case.

2. In paragraph 1, The electrode assembly includes a first electrode and a second electrode, each including an electrode plate and an electrode non-conductive portion, A secondary battery in which the electrode-free portion of the first electrode and the electrode-free portion of the second electrode protrude in at least one of the direction of the cap assembly and the opposite direction of the cap assembly.

3. In paragraph 2, A secondary battery in which the first spacer is formed as a pair on both sides of the electrode assembly where the electrode-free portion of the first electrode and the electrode-free portion of the second electrode do not protrude.

4. In paragraph 3, A secondary battery in which the above electrode assembly is formed in multiple pieces.

5. In paragraph 4, A secondary battery further comprising at least one second spacer interposed in a space between the plurality of electrode assemblies and in contact with one surface of the plurality of electrode assemblies.

6. In paragraph 5, A secondary battery in which the second spacer is formed in a shape corresponding to the shape of the space between the plurality of electrode assemblies.

7. In paragraph 5, A secondary battery in which the second spacer is formed as a pair on both sides of the electrode-free portion of the first electrode and the electrode-free portion of the second electrode, which do not protrude, in each of the plurality of electrode assemblies.

8. In paragraph 4, The above plurality of electrode assemblies are secondary batteries in which the electrode-free portion of each of the first electrodes and the electrode-free portion of each of the second electrodes protrude in the same direction.

9. In paragraph 5, A secondary battery in which the first spacer and the second spacer are formed to be separated from each other.

10. In paragraph 5, A secondary battery in which the first spacer and the second spacer are formed as an integral part.

11. In paragraph 5, A secondary battery in which at least one of the first spacer and the second spacer is formed with an empty space inside.

12. In paragraph 5, A secondary battery, wherein at least one of the first spacer and the second spacer is coupled to the inside of the case.

13. In paragraph 5, A secondary battery further comprising a fixing member that wraps around the side surface of the plurality of electrode assemblies positioned in series.

14. In paragraph 13, A secondary battery, wherein at least one of the first spacer and the second spacer is coupled to the plurality of electrode assemblies by the fixing member.

15. In paragraph 5, A secondary battery wherein the first spacer and the second spacer are formed of an insulating material.

16. In paragraph 2, A secondary battery in which the electrode-free portion of the first electrode and the electrode-free portion of the second electrode are spaced apart from each other and protrude from the electrode plate toward the cap assembly.

17. In paragraph 1, The above electrode assembly is a secondary battery wound in a winding type.

Images