Secondary battery and method for manufacturing secondary battery

Abstract

The invention discloses a secondary battery and a method for manufacturing the same. The secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate having a different polarity from the first electrode plate, and a separator between the first electrode plate and the second electrode plate; a case in which the electrode assembly is accommodated; and a binder applied on at least one surface of the electrode assembly in a predetermined pattern.

Description

TECHNICAL FIELD

[0001] Embodiments relate to a secondary battery and a method for manufacturing a secondary battery. BACKGROUND

[0002] Unlike a primary battery not designed to be (re)charged, a secondary battery (or a rechargeable battery) is a battery designed to be discharged and recharged. Low-capacity secondary batteries are used for portable small electronic devices such as smartphones, feature phones, notebook computers, digital cameras, and camcorders, and high-capacity secondary batteries are widely used as a power source for driving a motor in a hybrid vehicle and an electric vehicle and for storing electric power (e.g., home and / or utility-scale power storage). A secondary battery generally includes an electrode assembly including a positive electrode and a negative electrode, a case accommodating the electrode assembly, and an electrode terminal connected to the electrode assembly.

[0003] According to the shape of the case, a secondary battery can be classified into a cylindrical type, a prismatic type, or a pouch type, and according to the electrolyte used, can be classified into a polymer electrolyte type or a non-aqueous electrolyte type.

[0004] The above-described information disclosed in this BACKGROUND section is for enhancing the understanding of the background of the present disclosure, and as such, it can include information that does not constitute the related art (or the prior art). SUMMARY

[0005] Embodiments include a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate having a different polarity from the first electrode plate, and a separator between the first electrode plate and the second electrode plate; a case accommodating the electrode assembly therein; and an adhesive applied on at least one surface of the electrode assembly in a predetermined pattern.

[0006] The predetermined pattern can include a circular pattern.

[0007] The circular pattern can include a plurality of circles each having a different diameter and a same center.

[0008] The predetermined pattern can include a square pattern.

[0009] The predetermined pattern can include a triangular pattern.

[0010] The melting point of the adhesive can be greater than or equal to 77℃ and less than or equal to 83℃.

[0011] The first electrode plate can include a plurality of positive electrode plates, the second electrode plate can include a plurality of negative electrode plates, and the electrode assembly can be formed by stacking (e.g., can have a stacked structure including) the plurality of positive electrode plates, the plurality of negative electrode plates, the separator zigzag-folded and interposed between the plurality of positive electrode plates and the plurality of negative electrode plates in a thickness direction thereof.

[0012] Any one of the plurality of positive electrode plates can be at the outermost edge of the electrode assembly.

[0013] The adhesive can be applied on both surfaces of the electrode assembly.

[0014] The predetermined pattern can be applied as a single layer.

[0015] The secondary battery can further include a first electrode tab extending from at least one of the first electrode plates in the predetermined direction, and a second electrode tab extending from at least one of the second electrode plates in the predetermined direction, wherein the adhesive is applied on at least one surface of the electrode assembly except for an area corresponding to the first and second tabs.

[0016] The secondary battery can further include a tape covering at least a portion of the electrode assembly, wherein the adhesive is applied on at least one surface of the electrode assembly except for an area corresponding to the tape.

[0017] Embodiments include a method for manufacturing a secondary battery, the method including preparing an electrode assembly and a case, the electrode assembly including first electrode plates, second electrode plates having a different polarity from the first electrode plates, and a separator between the first electrode plates and the second electrode plates; applying an adhesive in a predetermined pattern on at least one surface of the electrode assembly; accommodating the electrode assembly in the case; and pressing the case, the adhesive, and the electrode assembly together.

[0018] The predetermined pattern can include a circular pattern.

[0019] The circular pattern can include a plurality of circles, each of the plurality of circles having a different diameter and a same center.

[0020] The predetermined pattern can include a square pattern.

[0021] The predetermined pattern can include a triangular pattern.

[0022] Applying the adhesive can include applying the adhesive on both surfaces of the electrode assembly.

[0023] Applying the adhesive can include applying the adhesive as a single layer.

[0024] The melting point of the adhesive can be greater than or equal to 77℃ and less than or equal to 83℃.

[0025] However, aspects and features of the present disclosure are not limited to the above-described aspects and features, and other aspects and features not mentioned will be clearly understood by those skilled in the art through the detailed description described below. BRIEF DESCRIPTION OF DRAWINGS

[0026] Features will become apparent to those of ordinary skill in the art upon examination of the following details description of the example embodiments taken in conjunction with the accompanying drawings, of which:

[0027] Figure 1 FIG. 1 is a diagram illustrating an example of a secondary battery according to one or more embodiments of the present disclosure.

[0028] Figure 2 FIG. 2 is a diagram illustrating an example of a secondary battery according to one or more embodiments of the present disclosure, an adhesive being applied on an electrode assembly of the secondary battery;

[0029] Figure 3 FIG. 3 is a diagram for describing a pattern of applying an adhesive according to one or more embodiments of the present disclosure;

[0030] Figure 4 FIG. 4 is a diagram for describing a pattern of applying an adhesive according to one or more embodiments of the present disclosure;

[0031] Figure 5 FIG. 5 is a diagram for describing a pattern of applying an adhesive according to one or more embodiments of the present disclosure;

[0032] Figure 6 FIG. 6 is a diagram for describing an electrode assembly according to one or more embodiments of the present disclosure.

[0033] Figure 7 FIG. 7 is a diagram for describing an application area of an adhesive according to one or more embodiments of the present disclosure;

[0034] Figure 8 FIG. 8 is a diagram for describing an application area of an adhesive according to one or more embodiments of the present disclosure;

[0035] Figure 9 FIG. 9 is a flowchart for describing a method for manufacturing a secondary battery according to one or more embodiments of the present disclosure.

[0036] Figure 10 FIG. 10 is a diagram for describing a step of pressing a case, an adhesive, and an electrode assembly according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0037] Example embodiments will now be described in detail with reference to the accompanying drawings. However, they can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the exemplary embodiments to those skilled in the art.

[0038] In the accompanying drawings, the dimensions of layers and regions may be enlarged for clarity. It should also be understood that when a layer or element is referred to as "on" another layer or substrate, it may be directly on the other layer or substrate, or an intermediary layer may be present. Furthermore, it should be understood that when a layer is referred to as "below" another layer, it may be directly below the other layer, and one or more intermediary layers may be present. Additionally, it should be understood that when a layer is referred to as "between" two layers, it may be the only layer between the two layers, or one or more intermediary layers may be present. The same reference numerals refer to the same elements throughout the drawings.

[0039] The terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical spirit of this disclosure, based on the principle that the inventor can be his / her own lexicographer to properly define the concepts of the terms in order to best interpret his / her embodiments.

[0040] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some embodiments of this disclosure and do not represent all technical ideas, aspects, and features of this disclosure. Accordingly, it should be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0041] It should be understood that when an element or layer is described as being "on" another element or layer, "connected to," or "linked to" another element or layer, it may be directly on, directly connected to, or directly linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is described as being "directly on" another element or layer, "directly connected to," or "directly linked to" another element or layer, then no intermediary element or layer is present. For example, when a first element is described as being "linked" or "connected" to a second element, the first element may be directly linked or directly connected to the second element, or the first element may be indirectly linked or indirectly connected to the second element via one or more intermediary elements.

[0042] In the figures, the dimensions of various elements, layers, etc., may be enlarged for clarity of explanation. The same reference numerals label the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerated items. Furthermore, in describing embodiments of this disclosure, the use of "may" refers to "one or more embodiments of this disclosure." When expressions such as "at least one of..." and "any one of..." precede / follow a list of elements, they modify the entire list of elements and not individual elements within the list. When a list of elements A, B, and C is labeled with phrases 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 of A, B, and C," or "at least one selected from A, B, and C," the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term "use" and its variations may be considered synonymous with the term "utilize" and its variations, respectively. As used herein, the terms “substantially,” “approximately,” and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values ​​that will be recognized by those skilled in the art.

[0043] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, first component, first region, first layer, or first portion discussed below may be referred to as a second element, second component, second region, second layer, or second portion.

[0044] For ease of description, spatial relative terms such as “below,” “below,” “down,” “above,” and “above” are used herein to describe the relationship between one element or feature and another illustrated in the figures. It should be understood that, in addition to the orientation depicted in the figures, the spatial relative terms are intended to also encompass different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as “below” or “below” other elements or features will then be oriented “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or oriented in other directions), and the spatial relative descriptors used herein should be interpreted accordingly.

[0045] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are intended to also include the plural forms. It should be further understood that when the term “comprising” and variations thereof are used in this specification, it specifies the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0046] Furthermore, any numerical range disclosed and / or referenced herein is intended to include all subranges with the same numerical precision contained within the referenced range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and inclusive of) the stated minimum value of 1.0 and the stated maximum value of 10.0, such as a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit set forth herein is intended to include all lower numerical limits contained herein, and all minimum numerical limits set forth herein are intended to include all higher numerical limits contained herein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly define any subranges contained within the range expressly set forth herein.

[0047] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with deviations considered low in the art, such as deviations of less than 5%. Additionally, when a parameter is described as uniform over a given region, it can mean that it is uniform in terms of average value.

[0048] Throughout the instruction manual, unless otherwise stated, each element may be singular or plural.

[0049] Placing any element "above (or below)" or "above (below)" another element can mean that the arbitrary element can be configured to contact the upper (or lower) surface of the element, and the other element can also be located between the element and any element disposed on (or below) the element.

[0050] In addition, it should be understood that when a component is referred to as “connected,” “linked,” or “attached” to another component, these components can be directly “connected,” “linked,” or “attached” to each other, or another component can “intervene” between these components.

[0051] Throughout the specification, unless otherwise stated, when “A and / or B” is mentioned, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the listed items. Unless otherwise stated, when “C to D” is mentioned, it means C and below D.

[0052] Figure 1 This is a diagram illustrating an example of a secondary battery according to one or more embodiments of the present disclosure. For example... Figure 1 As shown, the secondary battery 100 includes an electrode assembly 110 and a housing 130 that houses the electrode assembly 110.

[0053] The electrode assembly 110 includes a negative electrode plate 112 serving as a first electrode plate, a positive electrode plate 114 serving as a second electrode plate, and a diaphragm 116 between the negative electrode plate 112 and the positive electrode plate 114. The negative electrode plate 112 may include a negative electrode tab 122 electrically connected to an uncoated portion of the negative electrode, and the positive electrode plate 114 may include a positive electrode tab 124 electrically connected to an uncoated portion of the positive electrode. The negative electrode tab 122 and the positive electrode tab 124 are respectively soldered to external terminals for electrical connection to the outside of the housing 130 via negative electrode leads 142 and positive electrode leads 144. A tab membrane for insulation from the housing 130 is attached to the negative electrode leads 142 and the positive electrode leads 144.

[0054] With the electrode assembly 110 housed within the housing 130, the sealing portions 132 at the edges of the housing 130 contact each other (e.g., the sealing portions 132 around the outer periphery of the bottom portion of the housing 130 contact the outer periphery of the corresponding top portion (e.g., a cover) of the housing 130) to seal the housing 130. Sealing is performed with the terminal diaphragm disposed between the sealing portions 132. The sealing portions 132 may be made of a heat-fused material and may have a structure that achieves sealing by bonding the heat-fused layers together.

[0055] Figure 2 This is a diagram illustrating an example of a secondary battery according to one or more embodiments of the present disclosure, wherein an adhesive is applied to the electrode assembly of the secondary battery. See also Figure 2 A secondary battery 100 according to one or more embodiments of the present disclosure may include an electrode assembly 110, a housing 130 for housing the electrode assembly 110, and an adhesive 150 applied to the electrode assembly 110.

[0056] In one or more embodiments, adhesive 150 may be applied to at least one surface of electrode assembly 110. In one or more embodiments, the at least one surface of electrode assembly 110 on which adhesive 150 is applied may be an outer surface of electrode assembly 110. For example, when electrode assembly 110 is housed inside housing 130, adhesive 150 may be applied to at least one outward-facing surface of electrode assembly 110. Accordingly, when the top cover of housing 130 covers electrode assembly 110, adhesive 150 applied to at least one surface of electrode assembly 110 may secure electrode assembly 110 and housing 130. In other embodiments, adhesive 150 may be applied to an inner surface of electrode assembly 110. In one or more embodiments, when electrode assembly 110 is housed inside housing 130, adhesive 150 may be applied to at least one inward-facing surface of electrode assembly 110.

[0057] In one or more embodiments, the adhesive 150 may be applied to at least one surface of the electrode assembly 110 in a predetermined pattern. In one or more embodiments, the predetermined pattern may include a circular pattern, a triangular pattern, a square pattern, or a polygonal pattern. By using the configuration of applying the adhesive 150 to at least one surface of the electrode assembly 110 in a predetermined pattern, the adhesive 150 can be uniformly applied to at least one surface of the electrode assembly 110. As a result, the application quality of the adhesive 150 can be improved, and air bubbles that may occur in areas where the adhesive 150 is applied in an overlapping manner can be prevented.

[0058] In one or more embodiments, the adhesive 150 may be applied to one surface or both facing surfaces of the electrode assembly 110. For example, the adhesive 150 may be applied to the outer surface of the electrode assembly 110. As another example, the adhesive 150 may be applied to the inner surface of the electrode assembly 110. As yet another example, the adhesive 150 may be applied to both the outer and inner surfaces of the electrode assembly 110. Compared to the case where the adhesive 150 is applied to at least one surface of the electrode assembly 110, when the adhesive 150 is applied to both surfaces of the electrode assembly 110, the electrode assembly 110 and the housing 130 can be more securely secured.

[0059] In one or more embodiments, the adhesive 150 can be applied so that it does not overlap itself. The adhesive 150 can be applied in a predetermined pattern in a non-overlapping state. Utilizing the configuration of the adhesive 150 not overlapping each other (e.g., a single layer), the adhesive 150 can be applied uniformly to at least one surface of the electrode assembly 110. As a result, the application quality of the adhesive 150 can be improved, and air bubbles that may occur in areas where the adhesive 150 is applied in an overlapping manner can be prevented.

[0060] In one or more embodiments, the melting point of the adhesive 150 may be greater than or equal to 77°C and less than or equal to 83°C, but other melting points are also possible. By applying the adhesive 150 having a melting point within the aforementioned temperature range, the adhesive strength of the adhesive 150 can be maintained even if the temperature of the secondary battery rises during the charging and / or discharging process of the secondary battery 100.

[0061] exist Figure 2 Although the adhesive 150 is illustrated as being applied to a portion of the outer surface of the electrode assembly 110, the adhesive 150 may be applied to the entire outer surface of the electrode assembly 110, or to at least a portion of the front and / or rear surface of the electrode assembly 110. As another example, the adhesive 150 may be applied to at least a portion of the top or bottom of the electrode assembly 110.

[0062] exist Figure 2 Although the adhesive 150 is shown being applied to a square area, the adhesive 150 can be applied to areas with shapes such as polygons, circles, or ellipses.

[0063] exist Figure 2 Although the adhesive 150 is illustrated as being applied to a surface, it can also be applied to at least one surface of the electrode assembly 110 in the form of a dot matrix with a predetermined spacing. Accordingly, the adhesive 150 can be applied from an adhesive application nozzle in dots at predetermined spacing to form lines and / or surfaces. In this disclosure, the adhesive 150 can be applied simultaneously with the formation of a predetermined pattern, and therefore, even when applied in the form of a dot matrix, the adhesive will not form overlapping areas with itself (because the dots are spaced apart by the predetermined spacing).

[0064] Figure 3 It is a diagram used to describe a pattern of applying an adhesive according to one or more embodiments of the present disclosure. Figure 3 The diagram in the middle can correspond to the view from above. Figure 2 A plan view of the electrode assembly 110. See also one or more embodiments. Figure 2 The upper surface of electrode assembly 110 may refer to the surface of electrode assembly 110 on which adhesive is applied. In other embodiments, the upper surface of electrode assembly 110 may refer to the surface of the upper cover facing housing 130.

[0065] See Figure 3The adhesive according to one or more embodiments of the present disclosure can be applied to the upper surface of the electrode assembly 110 in a circular pattern. In one or more embodiments, a circular pattern can refer to a pattern formed by a set of multiple circles (e.g., concentric circles) with different diameters and the same center. Referring to the first example 300a, the adhesive can be applied to at least one surface of the electrode assembly 110 in a first circular pattern 160a. Figure 3 Although the first circular pattern 160a shown in the illustration includes three circles, the number of circles included in the first circular pattern 160a can vary depending on the size of the electrode assembly 110 or the amount of adhesive applied from the nozzle. Figure 3 In the illustration, although the circle is formed by the adhesive applied in the first circular pattern 160a, even if the circle is not a perfect circle, the circle formed by the adhesive applied in the first circular pattern 160a can be formed into a generally circular shape.

[0066] Referring to the second example 300b, the adhesive according to one or more embodiments of this disclosure can be applied to the upper surface of the electrode assembly 110 in a second circular pattern 160b. In one or more embodiments, as Figure 3 As illustrated, the second circular pattern 160b can refer to a pattern in which the starting point of adhesive application and the ending point of adhesive application are connected as one unit and both include a circular pattern. For example, adhesive can be applied continuously from the start of adhesive application to the end of adhesive application. By continuously applying adhesive to at least one surface of the electrode assembly 110 and simultaneously applying adhesive in a circular pattern, the overlap area of ​​the adhesive can be minimized.

[0067] exist Figure 3 In this example, the thickness of the adhesive in the first example 300a and the second example 300b is expressed differently; however, this expression is intended only to indicate the thickness difference based on the physical properties of the adhesive and / or the characteristics of the electrode assembly, and does not imply a difference in the width of the adhesive applied according to the first circular pattern 160a or the second circular pattern 160b. For example, with Figure 3 The thickness of the adhesive applied with the first circular pattern 160a and the thickness of the adhesive applied with the second circular pattern 160b can be the same, or the thickness of the adhesive applied with the first circular pattern 160a can be less than the thickness of the adhesive applied with the second circular pattern 160b.

[0068] With this configuration, the probability of bonding failure of the secondary battery can be reduced because the adhesive can be uniformly applied to at least one surface of the electrode assembly 110. The overlapping area of ​​the adhesive is minimized, and therefore, the phenomenon of increased thickness of the electrode assembly due to adhesive overlap can be prevented. As a result, the energy density of the secondary battery can be improved.

[0069] Figure 4 It is a diagram used to describe a pattern of applying an adhesive according to one or more embodiments of the present disclosure. Figure 4 The diagram in the middle can be compared with Figure 2 The plan view of the electrode assembly 110 viewed from above corresponds to this. See also the following in one or more embodiments: Figure 2 The upper surface of electrode assembly 110 may refer to the surface of electrode assembly 110 on which adhesive is applied. In other embodiments, the upper surface of electrode assembly 110 may refer to the surface of the upper cover facing the housing.

[0070] See Figure 4 The adhesive according to one or more embodiments of this disclosure can be applied to the upper surface of the electrode assembly 110 in a square pattern. In one or more embodiments, the square pattern can refer to a set of patterns formed by a plurality of (concentric) squares. Referring to the first example 400a, the adhesive can be applied to at least one surface of the electrode assembly in a first square pattern 162a. Figure 4 Although the first square pattern 162a is illustrated to include four squares, the number of squares included in the first square pattern 161a can vary depending on the size of the electrode assembly 110 or the amount of adhesive applied from the nozzle. Figure 4 In the illustration, although the square is formed by the adhesive applied with the first square pattern 162a, the square formed by the adhesive applied with the first square pattern 162a can be formed into a generally square shape, in addition to the perfect square.

[0071] Referring to the second example 400b, an adhesive according to one or more embodiments of this disclosure can be applied to the upper surface of the electrode assembly 110 in a second square pattern 162b. In one or more embodiments, the second square pattern 162b may refer to a pattern in which the starting point of adhesive application and the ending point of adhesive application are connected as one, while including, for example... Figure 4 The diagram illustrates a square pattern. For example, adhesive can be applied continuously from the start of adhesive application until the end of adhesive application. By continuously applying the adhesive to at least one surface of the electrode assembly while simultaneously applying the adhesive in a square pattern, the overlap area of ​​the adhesive can be minimized.

[0072] exist Figure 4 In this example, the thickness of the adhesive in the first example 400a and the second example 400b is expressed differently; however, this expression is only intended to express the thickness difference based on the physical properties of the adhesive and / or the characteristics of the electrode assembly, and does not imply a difference in the width of the adhesive applied according to the first square pattern 162a or the second square pattern 162b. For example, withFigure 4 The thickness of the adhesive applied with the first square pattern 162a and the thickness of the adhesive applied with the second square pattern 162b can be the same, or the thickness of the adhesive applied with the first square pattern 162a can be less than the thickness of the adhesive applied with the second square pattern 162b.

[0073] With this configuration, the probability of bonding failure of the secondary battery can be reduced because the adhesive can be uniformly applied to at least one surface of the electrode assembly 110. The overlapping area of ​​the adhesive is minimized, and therefore, the phenomenon of increased thickness of the electrode assembly due to adhesive overlap can be prevented. As a result, the energy density of the secondary battery can be improved.

[0074] Figure 5 It is a diagram used to describe a pattern of applying an adhesive according to one or more embodiments of the present disclosure. Figure 5 The diagram in the middle can be compared with Figure 2 The plan view of the electrode assembly 110 viewed from above corresponds to this.

[0075] See Figure 5 The adhesive according to one or more embodiments of this disclosure can be applied to the upper surface of the electrode assembly 110 in a triangular pattern. In one or more embodiments, the triangular pattern can refer to a pattern formed by a set of multiple (concentric) triangles. Referring to first example 500a, the adhesive can be applied to at least one surface of the electrode assembly in a first triangular pattern 164a. Figure 5 Although the first triangular pattern 164a is shown to include three triangles, the number of triangles included in the first triangular pattern 164a can vary depending on the size of the electrode assembly 110 or the amount of adhesive applied from the nozzle. The first triangular pattern 164a can be an equilateral triangle. In addition to equilateral triangles, the triangles formed by the adhesive applied in the first triangular pattern 164a can include other triangles formed in a generally triangular shape.

[0076] Referring to the second example 500b, an adhesive according to one or more embodiments of this disclosure can be applied to the upper surface of the electrode assembly in a second triangular pattern 164b. In one or more embodiments, the second triangular pattern 164b may refer to a pattern in which the starting point of adhesive application and the ending point of adhesive application are connected as one, while including, for example, Figure 5 The diagram illustrates a triangular pattern. For example, adhesive can be applied continuously from the start of application to the end of application. By continuously applying the adhesive to at least one surface of the electrode assembly while simultaneously applying the adhesive in a triangular pattern, the overlap area of ​​the adhesive can be minimized.

[0077] exist Figure 5 In the examples 500a and 500b, the thickness of the adhesive is expressed differently; however, this expression is intended only to indicate thickness differences based on the physical properties of the adhesive and / or the characteristics of the electrode assembly, and does not imply differences in the width of the adhesive applied according to the first triangular pattern 164a or the second triangular pattern 164b. For example, with Figure 5 The thickness of the adhesive applied in the first triangular pattern 164a and the thickness of the adhesive applied in the second square pattern 164b can be the same, or the thickness of the adhesive applied in the first square pattern 164a can be less than the thickness of the adhesive applied in the second square pattern 164b.

[0078] With this configuration, the probability of bonding failure of the secondary battery can be reduced because the adhesive can be uniformly applied to at least one surface of the electrode assembly 110. The overlapping area of ​​the adhesive is minimized, and therefore, the phenomenon of increased thickness of the electrode assembly due to adhesive overlap can be prevented. As a result, the energy density of the secondary battery can be improved.

[0079] Figure 6 This is a diagram illustrating an electrode assembly according to one or more embodiments of the present disclosure. As illustrated, the electrode assembly 110 may include a plurality of first electrode plates (e.g., a plurality of negative electrode plates 112), a plurality of second electrode plates (e.g., a plurality of positive electrode plates 114), and a zigzag-bent diaphragm 116 between the plurality of negative electrode plates 112 and the plurality of positive electrode plates 114.

[0080] In one or more embodiments, the electrode assembly 110 can be formed by stacking a plurality of negative electrode plates 112, a plurality of positive electrode plates 114, and a zig-bent membrane 116 located between the plurality of negative electrode plates 112 and the plurality of positive electrode plates 114 along the thickness direction of the electrode assembly 110. As illustrated, the membrane 116 can be zig-bent, and the plurality of negative electrode plates 112 and the plurality of positive electrode plates 114 can be alternately inserted and stacked between the bent portions. For example, the plurality of negative electrode plates 112 and the plurality of positive electrode plates 114 can be Figure 6 Insert in the direction of the arrow shown in the diagram.

[0081] In one or more embodiments, any one of the plurality of positive electrode plates 114 may be located at the outermost edge of the electrode assembly 110.

[0082] In one or more embodiments, the negative electrode plate 112 can be formed by applying a negative electrode active material, such as graphite or carbon, to a negative electrode current collector made of a metal foil such as copper, a copper alloy, nickel, or a nickel alloy, and may include a negative electrode tab (or a first uncoated portion), which is a region where no negative electrode active material is applied. The negative electrode tab can serve as a current flow path between the negative electrode plate 112 and the negative electrode terminals. In some examples, the negative electrode tab can be formed by pre-cutting the negative electrode plate 112 to protrude to one side during its manufacture, or it can protrude further to one side than the diaphragm 116 without separate cutting.

[0083] In one or more embodiments, the positive electrode plate 114 may be formed by applying a positive electrode active material, such as a transition metal oxide, to a positive electrode current collector plate made of a metal foil such as aluminum or an aluminum alloy, and may include a positive electrode tab (or a second uncoated portion), which is a region where no positive electrode active material is applied. The positive electrode tab may serve as a path for current flow between the positive electrode plate 114 and the positive electrode terminal. In some examples, the positive electrode tab may be formed by pre-cutting the positive electrode plate 114 during manufacturing to protrude to one side, or may protrude further to one side than the diaphragm 116 without separate cutting.

[0084] Figure 7 and Figure 8 This is a diagram illustrating the application area of ​​the adhesive according to one or more embodiments of this disclosure. See also... Figure 7 The electrode assembly 110 according to one or more embodiments of this disclosure may include a first electrode terminal and a second electrode terminal. See also Figure 8 The electrode assembly 110 according to one or more embodiments of the present disclosure may further include a strip 160 covering at least a portion of the electrode assembly 110.

[0085] In one or more embodiments, a first electrode tab (e.g., negative electrode tab 122) may be configured to extend from at least one of the negative electrode plates in a predetermined direction. Similarly, a second electrode tab (e.g., positive electrode tab 124) may be configured to extend from at least one of the positive electrode plates in a predetermined direction. In one or more embodiments, an adhesive may be applied to at least one surface of the electrode assembly 110, excluding the areas corresponding to the negative electrode tab 122 and the positive electrode tab 124. See, for example, [link to relevant documentation]. Figure 7The illustration shows an area on at least one surface of the electrode assembly 110 where adhesive 150 can be applied. As illustrated, adhesive 150 can be applied to at least one surface of the electrode assembly 110, excluding the areas corresponding to the negative electrode tab 122 and the positive electrode tab 124. Figure 7 Although the area where adhesive 150 is applied is shown to be part of the outer surface of electrode assembly 110, adhesive 150 can be applied to the entire outer surface of electrode assembly 110 and at least a portion of the front and / or rear surfaces of electrode assembly 110, except for the areas corresponding to negative electrode tab 122 and positive electrode tab 124. As another example, adhesive 150 can be applied to at least a portion of the top or bottom of electrode assembly 110. With this configuration, because electrode tabs 122 and 124 do not overlap with adhesive 150, an increase in the thickness of the secondary battery can be prevented.

[0086] In one or more embodiments, the electrode assembly 110 may further include a strip 160 covering at least a portion of the electrode assembly 110. In one or more embodiments, an adhesive 150 may be applied to at least one surface of the electrode assembly 110, excluding the area corresponding to the strip 160. See, for example, [link to relevant documentation]. Figure 8 The illustration shows an area on at least one surface of the electrode assembly 110 where adhesive 150 can be applied. Figure 8 Although the tape 160 is shown to be positioned to cover the side surface of the electrode assembly 110, the tape 160 may be positioned to cover the upper and / or lower surface of the electrode assembly 110, and in one or more embodiments, the adhesive 150 may be applied to at least one surface of the electrode assembly 110 in addition to the area corresponding to the tape 160.

[0087] Figure 9 This is a flowchart describing a method for manufacturing a secondary battery according to one or more embodiments of the present disclosure. See also... Figure 9 The secondary battery manufacturing method S900 may begin with the preparation of an electrode assembly and a housing for accommodating the electrode assembly (S910). In one or more embodiments, the electrode assembly may include a first electrode plate, a second electrode plate having a polarity different from that of the first electrode plate, and a separator between the first electrode plate and the second electrode plate.

[0088] In one or more embodiments, the first electrode plate may include a plurality of positive electrode plates, the second electrode plate may include a plurality of negative electrode plates, and the electrode assembly may be formed by stacking a plurality of positive electrode plates, a plurality of negative electrode plates, and a diaphragm that is zig-bent and located between the plurality of positive electrode plates and the plurality of negative electrode plates in the thickness direction.

[0089] In one or more embodiments, any one of the plurality of positive electrode plates may be disposed on the outermost edge of the electrode assembly.

[0090] Subsequently, the adhesive can be applied to at least one surface of the electrode assembly in a predetermined pattern (S920).

[0091] In one or more embodiments, the predetermined pattern may include a circular pattern. In one or more embodiments, the circular pattern may include a set of multiple circles with different diameters and the same center. In one or more embodiments, the predetermined pattern may include a square pattern. In one or more embodiments, the predetermined pattern may include a triangular pattern.

[0092] In one or more embodiments, the melting point of the adhesive may be greater than or equal to 77°C and less than or equal to 83°C.

[0093] In one or more embodiments, applying an adhesive may include applying the adhesive to at least one or both facing surfaces of the electrode assembly.

[0094] In one or more embodiments, the application of adhesive may include applying the adhesive in a way that does not overlap with each other (e.g., does not overlap itself).

[0095] In one or more embodiments, a first electrode tab may be configured to extend from at least one of the first electrode plates in a predetermined direction, and a second electrode tab may be configured to extend from at least one of the second electrode plates in a predetermined direction. In one or more embodiments, an adhesive may be applied to at least one surface of the electrode assembly, excluding the areas corresponding to the first and second electrode tabs.

[0096] In one or more embodiments, the secondary battery may further include a strip covering at least a portion of the electrode assembly, and an adhesive may be applied to at least one surface of the electrode assembly, except for the area corresponding to the strip.

[0097] Subsequently, the electrode assembly can be accommodated (e.g., inserted) into the housing (S930). Subsequently, the housing, adhesive, and electrode assembly can be pressed together (S940) (e.g., pressing the housing, adhesive, and electrode assembly together).

[0098] By utilizing an adhesive configured in a predetermined pattern that does not overlap with each other (e.g., does not overlap itself), the adhesive can be uniformly applied to at least one surface of the electrode assembly. As a result, the quality of adhesive application can be improved, and air bubbles that may occur in areas where the adhesive is applied in an overlapping manner can be prevented, even if the housing, adhesive, and electrode assembly are pressed together.

[0099] Figure 10This is a diagram illustrating the steps of pressing a housing, adhesive, and electrode assembly according to one or more embodiments of this disclosure. See also... Figure 10 The electrode assembly 110, adhesive 150 and housing 130 can be pressed by supporting mold 211 and hot press fixture 212.

[0100] In one or more embodiments, the electrode assembly 110, the adhesive 150 applied to at least one surface of the electrode assembly 110, and the housing 130 can be pressed by a thermoforming clamp 212 after being placed on a support mold 211. In one or more embodiments, because the adhesive 150 is applied to at least one surface of the electrode assembly 110 in a manner that does not overlap with each other (e.g., does not overlap itself), areas where the adhesive 150 overlaps with each other (e.g., overlaps itself) may not form or may be minimized even when the electrode assembly, adhesive, and housing are pressed by the thermoforming clamp 212. The adhesive 150 may spread when the electrode assembly, adhesive, and housing are pressed by the thermoforming clamp 212. In one or more embodiments, because the blank spaces where no adhesive 150 was applied are filled, the contact area between the electrode assembly 110 and the housing 130 is increased, and the adhesive strength may be improved.

[0101] In one or more embodiments, adhesive 150 may be applied to at least one surface of the electrode assembly 110, excluding the area corresponding to the region where the first electrode tab and / or the second electrode tab are disposed. The thickness of the secondary battery may be increased by the first electrode tab and / or the second electrode tab, but because adhesive 150 is not applied to the area corresponding to the electrode tab, excessive increase in the thickness of the secondary battery can be prevented. Even when the electrode assembly, adhesive, and housing are pressed by the thermoforming clamp 212, localized pressure may not be applied to the area of ​​the electrode assembly 110 corresponding to the electrode tab.

[0102] As the use of rechargeable batteries in mobile devices expands, devices using these batteries are frequently dropped in various environments. As mentioned above, when a product is dropped, the battery installed in the device may be damaged by the impact, potentially causing a short circuit, smoke, or fire. In particular, in the case of polymer batteries, these batteries can be easily deformed because the pouch serves as the outer material. Accordingly, methods may be needed to stably secure the housing and electrode assemblies even when the product is dropped.

[0103] According to some embodiments of this disclosure, by utilizing a configuration in which an adhesive is applied to at least one surface of an electrode assembly in a predetermined pattern, the adhesive can be uniformly applied to at least one surface of the electrode assembly. The adhesive can be applied in a predetermined pattern, and therefore, even if the adhesive is applied in the form of a dot array, overlapping areas may not be formed. As a result, the application quality of the adhesive can be improved, and air bubbles that may occur in areas where the adhesive is applied in an overlapping manner can be prevented.

[0104] According to some embodiments of this disclosure, because the adhesive can be uniformly applied to at least one surface of the electrode assembly, the probability of bonding failure of the secondary battery can be reduced. The overlapping area of ​​the adhesive is minimized, and therefore, the phenomenon of increased thickness of the electrode assembly due to adhesive overlap can be prevented. As a result, the energy density of the secondary battery can be improved.

[0105] Although this disclosure has been described above with respect to its embodiments, it is not limited thereto. Various modifications and variations can be made thereto by those skilled in the art within the spirit of this disclosure and the equivalents of the appended claims.

[0106] Exemplary embodiments have been disclosed herein, and although specific terminology has been used, it is used and interpreted in a general and descriptive sense only and is not intended to be limiting. In some instances, as will be apparent to those skilled in the art at the time of filing this application, unless otherwise specifically indicated, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the following claims.

[0107] Explanation of some figure labels

[0108] 100: Secondary battery

[0109] 110: Electrode assembly

[0110] 112: Negative electrode plate

[0111] 114: Positive electrode plate

[0112] 116: Diaphragm

[0113] 122: Negative electrode connector

[0114] 124: Positive electrode connector

[0115] 130: Casing

[0116] 132: Sealing part

[0117] 142: Negative electrode lead

[0118] 144: Positive electrode lead

Claims

1. A secondary battery comprising: an electrode assembly including a first electrode plate, a second electrode plate having a different polarity from the first electrode plate, and a separator interposed between the first electrode plate and the second electrode plate; a case in which the electrode assembly is accommodated; an adhesive applied in a predetermined pattern on at least one surface of the electrode assembly.

2. The secondary battery according to claim 1, wherein The predetermined pattern includes a circular pattern.

3. The secondary battery according to claim 2, wherein The circular pattern includes a plurality of circles each having a different diameter and a same center.

4. The secondary battery according to claim 1, wherein The predetermined pattern includes a square pattern.

5. The secondary battery according to claim 1, wherein The predetermined pattern includes a triangular pattern.

6. The secondary battery according to claim 1, wherein The adhesive has a melting point of greater than or equal to 77℃ and less than or equal to 83℃. 7.The secondary battery of claim 1, wherein: the first electrode plate includes a plurality of positive electrode plates, the second electrode plate includes a plurality of negative electrode plates, and the electrode assembly has a stacked structure including the plurality of positive electrode plates, the plurality of negative electrode plates, the separator bent in a zigzag shape and interposed between the plurality of positive electrode plates and the plurality of negative electrode plates in a thickness direction of the electrode assembly.

8. The secondary battery according to claim 7, wherein Any one of the plurality of positive electrode plates is at an outermost lateral edge of the electrode assembly.

9. The secondary battery according to any one of claims 1 to 8, wherein The adhesive is applied on both surfaces of the electrode assembly.

10. The secondary battery according to any one of claims 1 to 8, wherein The adhesive is applied as a single layer. 11.The secondary battery of any one of claims 1 to 8, further comprising: a first electrode tab extending in a predetermined direction from at least one of the first electrode plates; and a second electrode tab extending in the predetermined direction from at least one of the second electrode plates, wherein the adhesive is applied on the at least one surface of the electrode assembly except for an area corresponding to the first electrode tab and the second electrode tab. 12.The secondary battery of any one of claims 1 to 8, further comprising: a tape covering at least a portion of the electrode assembly, wherein the adhesive is applied on the at least one surface of the electrode assembly except for an area corresponding to the tape. 13.A method for manufacturing a secondary battery, the method comprising: preparing an electrode assembly and a case, the electrode assembly including a first electrode plate, a second electrode plate having a different polarity from the first electrode plate, and a separator between the first electrode plate and the second electrode plate; applying an adhesive in a predetermined pattern on at least one surface of the electrode assembly; accommodating the electrode assembly in the case; and pressing the case, the adhesive, and the electrode assembly together. The predetermined pattern includes a circular pattern. The circular pattern includes a plurality of circles each having a different diameter and a same center.

14. The method for manufacturing a secondary battery according to claim 13, wherein The predetermined pattern includes a square pattern.

15. The method for manufacturing a secondary battery according to claim 14, wherein The predetermined pattern includes a triangular pattern.

16. The method for manufacturing a secondary battery according to claim 13, wherein Applying the adhesive includes applying the adhesive on both surfaces of the electrode assembly.

17. The method for manufacturing a secondary battery according to claim 13, wherein Applying the adhesive includes applying the adhesive as a single layer.

18. The method for manufacturing a secondary battery according to any one of claims 13 to 17, wherein The adhesive has a melting point of greater than or equal to 77℃ and less than or equal to 83℃.

19. The method for manufacturing a secondary battery according to any one of claims 13 to 17, wherein ​ 20. The method for manufacturing a secondary battery according to any one of claims 13 to 17, wherein ​

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