Battery cell

Abstract

Provided is a battery cell comprising: at least one first electrode plate; at least one second electrode plate having the opposite polarity of the at least one first electrode plate; at least one separator disposed between the at least one first electrode plate and the at least one second electrode plate; and at least one insulation member mounted on the at least one first electrode plate, wherein the at least one insulation member includes a non-adhesive surface in contact with the at least one first electrode plate.

Description

battery cell

[0001] The present invention relates to a battery cell.

[0002] Unlike primary batteries, secondary batteries can be recharged and discharged, making them suitable for a wide range of applications, including digital cameras, mobile phones, laptops, hybrid vehicles, and electric vehicles. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-hydrogen batteries, with lithium-ion batteries becoming increasingly popular.

[0003] In general, a secondary battery (hereinafter referred to as a battery cell), including a lithium ion battery, may have a structure in which an electrode assembly in which one or more positive electrode plates and one or more negative electrode plates are alternately stacked with a separator in between is accommodated inside a case.

[0004] During the charging and discharging process, the internal temperature of a battery cell increases. When the internal temperature exceeds a certain level (e.g., 130°C or higher), the separator separating the anode and cathode frequently shrinks. In this case, as the separator shrinks, the cathode and anode come into contact, creating an electrical short circuit, potentially leading to fire or explosion.

[0005] In particular, in the case of next-generation batteries such as lithium-sulfur batteries (Li-S batteries) or lithium metal batteries (Li-Metal batteries), the negative electrode can be made of lithium metal itself. In this case, there was a problem in that when the separator shrinks, the highly reactive lithium metal comes into contact with the opposite polarity plate, causing a thermal runaway phenomenon in the battery cell.

[0006] The present invention has been devised to solve at least some of the problems of the prior art as described above, and provides a battery cell having a structure in which a negative electrode plate and a positive electrode plate are not mutually short-circuited even when a separator shrinkage phenomenon occurs in a high temperature environment (e.g., 130°C).

[0007] In addition, the present invention provides a battery cell that can solve the problem of the capacity of the battery cell being reduced due to an insulating area formed on an electrode plate.

[0008] To achieve the above object, in embodiments, a battery cell is provided, which includes one or more first electrode plates; one or more second electrode plates having a polarity opposite to that of one or more first electrode plates; one or more separators disposed between the one or more first electrode plates and the one or more second electrode plates; and one or more insulating members mounted on the one or more first electrode plates, wherein the one or more insulating members include a non-adhesive surface that contacts the one or more first electrode plates.

[0009] In embodiments, at least a portion of one or more of the first electrode plates may be made of lithium or an alloy comprising lithium.

[0010] In embodiments, the non-bonded surface of one or more insulating members may be in contact with a portion of one or more first electrode plates made of lithium or an alloy including lithium.

[0011] In embodiments, all portions of one or more insulating members that come into contact with one or more first electrode plates may be formed as non-adhesive surfaces.

[0012] In embodiments, the insulating member may be made of at least one of polyimide, polypropylene, polyvinyl chloride, polyester, polyacetal, polyolefin, and polyethylene.

[0013] In embodiments, one or more first electrode plates include one or more masking portions on which one or more insulating members are mounted; and an exposed portion exposed to the separator, wherein the one or more masking portions can be formed along at least one edge of the one or more first electrode plates.

[0014] In embodiments, one or more insulating members may have a loop-like structure in which a first insulating portion facing one side of one or more first electrode plates and a second insulating portion facing the opposite side of the one side are continuously connected.

[0015] In embodiments, the one or more insulating members may include a first insulating member disposed along a first edge from which an electrode tab protrudes in the first electrode plate; and a second insulating member disposed along a second edge of the first electrode plate opposite the first edge.

[0016] In embodiments, the one or more insulating members further include a third insulating member and a fourth insulating member respectively disposed along a third edge and a fourth edge respectively connected to the first edge and the second edge of the first electrode plate, wherein one end of each of the first to fourth insulating members covers a portion of another insulating member adjacent to the one end, and an opposite end of one end of each of the first to fourth insulating members may be covered by another insulating member adjacent to the opposite end.

[0017] In embodiments, no adhesive material may be applied to a portion of one or more insulating members that comes into contact with one or more masking portions.

[0018] In embodiments, the at least one insulating member includes a fifth insulating member facing one side of the at least one first electrode plate; and a sixth insulating member facing an opposite side of the at least one first electrode plate, wherein the fifth insulating member and the sixth insulating member are separable from each other.

[0019] In embodiments, the fifth insulating member and the sixth insulating member may have a frame-like structure surrounding the periphery of the exposed portion.

[0020] In the embodiments, the first and second electrode plates are arranged to face one side and the opposite side of the one side of the zigzag-folded separator, and one or more insulating members are arranged along each of two edges of the first electrode plate, and the first and second insulating members may be arranged to be spaced apart from each other in the width direction of the separator.

[0021] According to embodiments, a battery cell having a structure in which a negative electrode plate and a positive electrode plate do not short-circuit each other even when a separator shrinkage phenomenon occurs in a high temperature environment (particularly, 130°C) can be implemented.

[0022] In addition, according to embodiments, a battery cell can be provided in which the capacity of the battery cell is not reduced even if a masking portion is formed in at least a portion of the electrode plate to prevent short-circuiting with an electrode plate of opposite polarity.

[0023] Figure 1 is an exploded perspective view of a battery cell according to one embodiment.

[0024] Figure 2 is a reference drawing showing the configuration of an electrode assembly included in a battery cell.

[0025] Fig. 3 is an exemplary cross-sectional view according to part II' of Fig. 2.

[0026] Figure 4 is an exploded perspective view of a first electrode assembly according to one embodiment.

[0027] FIG. 5 is an exploded perspective view of a first electrode assembly according to another embodiment.

[0028] Fig. 6 is a reference drawing showing the configuration of an electrode assembly according to another embodiment.

[0029] Figure 7 is an exploded perspective view of the first electrode assembly illustrated in Figure 6.

[0030] Fig. 8 is a graph showing the temperature change of each electrode assembly when the electrode assembly according to the embodiment and the electrode assembly according to the first comparative example are heated.

[0031] FIG. 9 is a graph showing the results of a capacity performance test of a battery cell including an electrode assembly according to an embodiment and a battery cell including an electrode assembly according to a second comparative example.

[0032] Fig. 10 is a graph showing the temperature change of each electrode assembly when the electrode assembly according to the embodiment and the electrode assembly according to the second comparative example are heated.

[0033] Before going into the detailed description of the present invention, it should be noted that the terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his own invention in the best way. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of this application.

[0034] The same reference numbers or symbols used in each drawing attached to this specification represent parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols may be used in different embodiments. In other words, even if components with the same reference numbers are depicted in multiple drawings, they do not necessarily represent a single embodiment.

[0035] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprises" or "comprises" should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0036] In addition, in the description below, expressions such as top, upper, lower, lower, side, front, and rear are expressed based on the direction shown in the drawing, and it is noted in advance that they may be expressed differently if the direction of the object in question changes.

[0037] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited manner. For example, components associated with these ordinals should not be interpreted in a restricted manner, such as in the order of use or arrangement, based on their numbers. If necessary, each ordinal number may be used interchangeably.

[0038] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, the spirit of the present invention is not limited to the presented embodiments. For example, those skilled in the art who understand the spirit of the present invention may propose other embodiments within the spirit of the present invention by adding, modifying, or deleting components, etc., but such embodiments will also be considered to be within the spirit of the present invention. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0039] First, referring to FIGS. 1 to 3, the configuration of a battery cell according to one embodiment will be described.

[0040] Fig. 1 is an exploded perspective view of a battery cell (1) according to embodiments.

[0041] FIG. 2 is a reference drawing showing an exemplary configuration of an electrode assembly (10) included in a battery cell (1 in FIG. 1).

[0042] Fig. 3 is an exemplary cross-sectional view according to part II' of Fig. 2.

[0043] Referring to FIG. 1, a battery cell (1) according to an embodiment may include an electrode assembly (10) in which a plurality of electrode plates are stacked, a case (30) in which the electrode assembly (10) is accommodated, and a lead tab (20) electrically connected to the electrode assembly (10) and a portion of which is exposed to the outside of the case (30).

[0044] The case (30) may include an electrode receiving portion (33) in which an electrode assembly (10) is received, and a sealing portion (34) arranged along the edge of the electrode receiving portion (33). The electrode receiving portion (33) is formed by joining an upper case (32) and a lower case (31) vertically, and may have an internal space in which the electrode assembly (10) is received. The sealing portion (34) is formed by pressing or heat-welding the edges of the upper case (32) and the lower case (31) along the edge of the electrode receiving portion (33), thereby preventing foreign substances or moisture from outside the case (30) from entering the electrode assembly (10) received inside the electrode receiving portion (33).

[0045] The case (30) may be a pouch-shaped case (30) made of a flexible material. For example, the case (30) may be made of an aluminum laminate sheet. However, the case (30) of the battery cell (1) according to the embodiments may also be made of a square case or a cylindrical case made of a metal material such as aluminum, in addition to the above-described pouch-shaped case (30).

[0046] Referring to FIG. 2, the electrode assembly (10) may have a structure in which a plurality of first electrode plates (110) and a plurality of second electrode plates (200) having opposite polarities are laminated with a separator (300) therebetween. However, those illustrated in FIG. 2 are only a part of the first electrode plates (110), the second electrode plates (200), and the separator (300) included in the electrode assembly (10), and the actual electrode assembly (10) may have a greater number of first electrode plates (110), second electrode plates (200), and separators (300) than those illustrated in FIG. 2.

[0047] The separator (300) may be interposed between the first electrode plate (110) and the second electrode plate (200) to prevent electrical short circuit between the first electrode plate (110) and the second electrode plate (200) and may be configured to be impregnated with an electrolyte so that ions may pass through. The separator (300) may be formed of a porous polymer film or a porous non-woven fabric. However, in addition to the above materials, any material commonly used in lithium secondary batteries may be used as the material for the separator (300) without any particular limitation.

[0048] The first electrode plate (110) and the second electrode plate (200) may each be provided with electrode tabs (112, 210). In the following description, the electrode tab (112) of the first electrode plate (110) is defined as the first electrode tab (112), and the electrode tab (210) of the second electrode plate (200) is defined as the second electrode tab (210).

[0049] In the electrode assembly (10), a plurality of first electrode tabs (112) and second electrode tabs (210) may be provided. The plurality of electrode tabs (112, 210) may be grouped together with the same polarity to form an electrode tab bundle (ET). A lead tab (20) serving as a terminal in a battery cell (1) may be coupled to the electrode tab bundle (ET), and thus the electrode assembly (10) and the lead tab (20) may be electrically connected to each other. Various welding methods including ultrasonic welding or a physical fastening method using rivets or the like may be applied to the coupling between the electrode tab bundle (ET) and the lead tab (20).

[0050] The lead tab (20) may be made of a conductive metal material. For example, the lead tab (20) may be made of nickel (Ni), copper (Cu), nickel-plated copper, aluminum (Al), etc. A sealing member (21) may be placed between the lead tab (20) and the case (30). For example, the sealing member (21) may be made of a material having both insulating and adhesive properties, and may be bonded to the sealing portion (34) of the case (30) while wrapping a portion of the lead tab (20), thereby securing electrical insulation between the lead tab (20) and the case (30) and sealing the area between the lead tab (20) and the sealing portion (34).

[0051] In embodiments, the first electrode plate (110) and the second electrode plate (200) of the electrode assembly (10) may be electrode plates having opposite polarities. For example, when the first electrode plate (110) is a negative electrode plate, the second electrode plate (200) may be a positive electrode plate.

[0052] The positive electrode plate may have a structure in which a positive electrode active material layer (202) is formed on a current collector (201). For example, referring to FIG. 2, the second positive electrode plate (200) may be a positive electrode plate, and may be formed by applying a mixture of a positive electrode active material, a conductive material, and a binder to a current collector (201) made of an aluminum alloy material. At this time, any known material used in a positive electrode plate of a lithium secondary battery may be used as the materials for the positive electrode active material, the binder, the conductive material, and the current collector (201).

[0053] The negative electrode plate of the battery cell (1) according to the embodiments may be formed of a metal sheet formed of lithium or an alloy containing lithium (hereinafter, simply referred to as “lithium metal”), unlike a conventional negative electrode plate.

[0054] In conventional cases, the negative electrode plate may have a structure in which a layer of negative electrode active material is formed on a current collector. For example, the negative electrode plate may be formed by applying a mixture of a negative electrode active material, a conductive agent, and a binder to a current collector made of a copper alloy material.

[0055] In contrast, the negative electrode plate of the battery cell (1) according to the embodiments may have an integrated structure composed of a body portion of a plate made of a lithium metal sheet and an electrode tab arranged on one side of the body portion of the plate. Since the battery cell (1) to which the negative electrode plate made of a lithium metal sheet is applied can omit a conventional negative electrode current collector made of nickel (Ni), aluminum (Al), copper (Cu), etc., it is not only advantageous in reducing the weight of the battery cell (1) but also can have a very high energy density.

[0056] The first electrode plate (110) and the second electrode plate (200) can be separated by a separator (300) and maintained in a state where they do not contact each other.

[0057] However, the separator (300) frequently experiences shrinkage at high temperatures, for example, at temperatures of approximately 130°C, and thus, there is a risk that the first electrode plate (110) and the second electrode plate (200) may come into contact with each other beyond the edge of the shrunken separator (300) and cause a short circuit. If the first electrode plate (110) and the second electrode plate (200) are short-circuited, the temperature of the electrode assembly (10) may rapidly rise, causing a flame to occur, and thus, a thermal runaway phenomenon of the battery cell (1) may occur.

[0058] Accordingly, in order to prevent the first electrode plate (110) and the second electrode plate (200) from contacting each other even when the separator (300) shrinks, the battery cell (1) according to the embodiments may further include one or more insulating members (120) arranged along at least one edge of the first electrode plate (110). For example, referring to FIGS. 2 and 3, the insulating member (120) may be arranged in a state of being sandwiched between the first electrode plate (110) and the separator (300) near at least one edge of the first electrode plate (110).

[0059] The insulating member (120) is made of an insulating material and is placed on the first electrode plate (110) to prevent the first electrode plate (110) and the second electrode plate (200) from contacting each other beyond the edge of the contracted separator (300) and causing a short circuit.

[0060] The insulating member (120) may be made of a polymer film. For example, the insulating member (120) may be made of at least one of polyimide, polypropylene, polyvinyl chloride, polyester, polyacetal, polyolefin, and polyethylene. However, the material of the insulating member (120) is not limited to those described above, and may be made of any material that can be placed between two different electrode plates to electrically insulate them.

[0061] In embodiments, the insulating member (120) may be disposed on the first electrode plate (110) to form a first electrode plate assembly (100) together with the first electrode plate (110). That is, the electrode assembly (10) according to the embodiments may have a structure in which the first electrode plate assembly (100) and the second electrode plate (200) are alternately laminated with a separator (300) interposed therebetween.

[0062] Even in conventional battery cells, an insulating region coated with an insulating material could be formed at the edge of the electrode plates. However, in this case, the insulating region was formed by applying an insulating coating slurry onto the electrode plates or by attaching an insulating film to the electrode plates.

[0063] According to this method of forming an insulating region, there was a problem in that the insulating region of the electrode plate was covered by an adhesive material of a slurry or insulating film containing a binder component, making it difficult to participate in a battery reaction, and thus the capacity of the entire battery cell was reduced.

[0064] In addition, when some of the electrode plates constituting the electrode assembly are made of lithium metal, there was a problem in that it was difficult to apply slurry for an insulating coating layer or to stably attach an insulating film having an adhesive material due to the high reactivity of lithium.

[0065] In contrast, the battery cell (1) according to the embodiments includes an insulating member (120) in which at least a portion of the part in contact with the first electrode plate (110) is formed as a non-adhesive surface, thereby preventing the edge of the first electrode plate (110) from coming into contact with the second electrode plate (200) and solving the above-described problems.

[0066] Hereinafter, with reference to FIG. 4, a first electrode assembly (100) including an insulating member (120) according to an embodiment will be described in more detail.

[0067] Figure 4 is an exploded perspective view of a first electrode assembly (100) according to one embodiment.

[0068] Since the first electrode plate assembly (100) described in FIG. 4 includes all of the features of the first electrode plate assembly (100) described through FIGS. 1 to 3, any description overlapping with FIGS. 1 to 3 may be omitted.

[0069] The first pole plate assembly (100) may include a first pole plate (110) and one or more insulating members (120) arranged on the first pole plate (110).

[0070] The first electrode plate (110) may include a electrode plate body portion (111) facing the second electrode plate (200) with a separator (300) interposed therebetween, and a first electrode tab (112) protruding from the electrode plate body portion (111) and connected to a lead tab (20).

[0071] As previously described with reference to FIGS. 1 to 3, the first electrode plate (110) may be formed of a lithium metal sheet. For example, both the electrode plate body (111) and the first electrode tab (112) of the first electrode plate (110) may be formed of a lithium metal sheet. The technical advantages of the case where the first electrode plate (110) is formed of a lithium metal sheet may be referred to the descriptions with reference to FIGS. 1 to 3.

[0072] The first electrode plate assembly (100) may include one or more insulating members (120) covering a portion of the first electrode plate (110). For example, referring to FIG. 4, the insulating member (120) may be an insulating film provided in a loop-shaped structure so as to surround and cover a portion near one edge of the electrode plate body portion (111). Here, the loop-shaped structure may mean a structure in which a first insulating member (121) facing one side of the electrode plate body portion (111) and a second insulating member (122) facing an opposite side of one side of the electrode plate body portion (111) are continuously connected at both ends in the length direction. For example, the loop-shaped structure may be formed by bending a long strip-shaped insulating film and connecting one end of the insulating film to the other end. Accordingly, the loop-shaped insulating member (120) may have a structure in which a slit or hole into which a first electrode plate (110) can be inserted is provided in a width direction (e.g., in the Y-axis direction based on the first insulating member (120a), or in the X-axis direction based on the third insulating member (120c)) while being continuously connected in a length direction (e.g., in the Y-axis direction based on the first insulating member (120a), or in the X-axis direction based on the third insulating member (120c)).

[0073] Alternatively, the insulating member (120) of the loop-shaped structure may be formed by joining two rectangular sheets of the same shape to each other at both ends in the longitudinal direction, or may be implemented through a process of forming a polymer resin material, which is the raw material of the insulating member (120), into a ring shape.

[0074] However, the shape, structure, and manufacturing method of the insulating member (120) are not limited to the drawings and the above-described description. The insulating member (120) may have any structure as long as it can stably cover a portion of the electrode body portion (111).

[0075] In one first electrode plate assembly (100), a plurality of insulating members (120) may be provided. For example, as shown in FIG. 4, the first electrode plate assembly (100) may include four insulating members (120a, 120b, 120c, and 120d) arranged along the four edges of the electrode plate body portion (111).

[0076] As the insulating member (120) covers a portion of the plate body portion (111), the plate body portion (111) can be divided into a masking portion (111a) covered by the insulating member (120) and an exposed portion (111b) directly exposed to the separator (300) because the insulating member (120) does not cover it.

[0077] The masking portion (111a) may be formed along at least one edge of the plate body portion (111) corresponding to the position where the insulating member (120) is arranged. For example, referring to FIG. 4, as the first to fourth insulating members (120a, 120b, 120c, and 120d) are arranged along the four edges of the plate body portion (111), the masking portion (111a) may be formed along the four edges of the plate body portion (111), and an exposed portion (111b) may be formed therebetween.

[0078] However, the masking portion (111a) is different from the exposed portion (111b) in that it is covered by an insulating material (120), and its material composition may not be different from that of the exposed portion (111b).

[0079] In the insulating member (120), at least a portion of the portion facing the masking portion (111a) may be formed as a non-adhesive surface (NA) where no adhesive material exists. For example, in the loop-shaped insulating member (120) illustrated in FIG. 4, the entire inner surface that comes into contact with the masking portion (111a) of the first electrode plate (110) may be formed as a non-adhesive surface (NA), and accordingly, the insulating member (120) may be placed on the first electrode plate (110) in a state of being in contact with the masking portion (111a) but not being adhered to it.

[0080] In this way, by configuring the part that comes into contact with the first electrode plate (110) as a non-adhesive surface (NA), a separate adhesive material may not exist on the masking portion (111a) of the first electrode plate (110).

[0081] In particular, when the first electrode plate (110) is made of lithium metal having high reactivity, a problem may arise where the adhesive material comes into contact with lithium and prevents lithium in the corresponding region from participating in the battery reaction or contaminates the lithium. However, the insulating member (120) according to the embodiments can prevent such a problem from occurring in advance by settling on the lithium metal of the first electrode plate (110) through the non-adhesive surface (NA).

[0082] That is, the insulating member (120) according to the embodiments is secured to the masking portion (111a) of the first electrode plate (110) through the non-adhesive surface (NA), thereby preventing the first electrode plate (110) and the second electrode plate (200) from being short-circuited due to contact when the separator (300) is contracted, and at the same time, preventing the reactivity of the first electrode plate (110) from being reduced by the insulating member (120). Accordingly, since the entire area of ​​the electrode plate body portion (111) of the first electrode plate (110) can participate in the battery reaction, the capacity of the battery cell (1) can be prevented from being reduced and the energy density of the battery cell (1) can be maximized.

[0083] In addition, since the part of the insulating member (120) that comes into contact with the masking portion (111a) is configured as a non-adhesive surface (NA), the process of assembling the insulating member (120) and the first electrode plate (110) can be performed more quickly and easily than the conventional slurry application or adhesive insulating film attachment process. For example, when the insulating member (120) has a loop-shaped structure as shown in FIG. 4, the masking portion (111a) can be simply formed by simply inserting the insulating member (120) into the edge of the first electrode plate (110) and adjusting the position. In this case, there is also an advantage in that the masking portion (111a) can be easily formed on both sides near one edge of the first electrode plate (110) through one loop-shaped insulating member (120).

[0084] Meanwhile, in the insulating member (120), even if there is no adhesive material in the part that comes into contact with the first electrode plate (110), the insulating member (120) can stably maintain a state of being seated on the masking portion (111a) of the first electrode plate (110) by the lamination pressure formed during the lamination process of the electrode assembly (10).

[0085] When a plurality of insulating members (120) are provided, one insulating member (e.g., 120a) may cover a portion of another insulating member (e.g., 120d). For example, referring to FIGS. 2 and 4 together, the first electrode plate assembly (100) may include a first insulating member (120a) disposed along one edge (hereinafter, referred to as a first edge) from which an electrode tab (112) protrudes in the electrode plate body portion (111), a second insulating member (120b) disposed along an edge opposite to the one edge (hereinafter, referred to as a second edge), and a third insulating member (120c) and a fourth insulating member (120d) disposed along two edges (hereinafter, referred to as a third edge and a fourth edge) that are respectively connected to the first edge and the second edge. At this time, as illustrated in FIG. 2, a plurality of insulating members (120a, 120b, 120c, and 120d) may be arranged to sequentially cover a portion of a surface of another insulating member (120) adjacent to the insulating member in a clockwise (or counterclockwise) direction. That is, the first insulating member (120a) may be arranged to cover a portion of a surface of the fourth insulating member (120d), the fourth insulating member (120d) may be arranged to cover a portion of a surface of the second insulating member (120b), the second insulating member (120b) may be arranged to cover a portion of a surface of the third insulating member (120c), and the third insulating member (120c) may be arranged to cover a portion of a surface of the first insulating member (120a).

[0086] In this way, a structure in which one insulating member (120) covers a part of another adjacent insulating member (120) is defined as a 'cross-placement structure'.

[0087] According to the cross-arrangement structure, each of the insulating members (120) arranged at the four edges of the plate body part (111) can form a stable arrangement structure by crossing and contacting each other. That is, the end of one insulating member (120) covers a part of a surface of another adjacent insulating member (120), thereby preventing the insulating member (120) from being dislodged from its place, and while the electrode assembly (10) is laminated and assembled, the insulating members (120) can stably maintain a state in which they are in contact with each other and cover the masking part (111a). In addition, since the insulating members (120) at the four edges of the plate body part (111) cross each other so that the same structure is repeated in a clockwise direction, the occurrence of structural imbalance as a plurality of first plate assemblies (100) is prevented.

[0088] However, the cross arrangement structure of the insulating member (120) is not limited to that illustrated in FIG. 2. For example, unlike FIG. 2, a counterclockwise cross arrangement structure is also possible, or a cross arrangement structure in which any one of the first to fourth insulating members (120a, 120b, 120c, and 120d) does not cover the other insulating members is also possible.

[0089] Alternatively, in other embodiments, the insulating member may be provided in various other shapes other than the loop-shaped structure described above. Hereinafter, a first electrode plate assembly to which such a different type of insulating member is applied will be described with reference to FIG. 5.

[0090] Figure 5 is an exploded perspective view of a first electrode assembly (100') according to another embodiment.

[0091] In the first electrode plate assembly (100') according to the embodiment described in FIG. 5, other features than the shape of the insulating member (120') are the same as the features of the first electrode plate assembly (100) described above through FIGS. 1 to 4, and thus, redundant descriptions may be omitted.

[0092] The first pole plate assembly (100') may include a plurality of insulating members (120') that are respectively mounted on one side and the other side of the first pole plate (110). For example, as shown in FIG. 5, a fifth insulating member (120e) having a frame-like structure may be disposed on one side of the first pole plate (110), and a sixth insulating member (120f) having a frame-like structure may be disposed on the opposite side of the one side of the first pole plate (110).

[0093] In the process of stacking and assembling the electrode assembly, the fifth insulating member (120e) and the sixth insulating member (120f) are sequentially stacked and assembled so that the first electrode plate (110) is placed between them, and the state of being seated on the masking portion (111a) of the first electrode plate (110) can be maintained by the stacking pressure of the electrode assembly.

[0094] The fifth insulating member (120e) and the sixth insulating member (120f) are different from the first to fourth insulating members (120a, 120b, 120c, and 120d) described above through FIGS. 1 to 4 only in shape, and all other features such as the material and the arrangement of the non-adhesive surface (NA) are the same. For example, at least some of the portions of the fifth insulating member (120e) and the sixth insulating member (120f) that come into contact with the first electrode plate (110) may be formed as non-adhesive surfaces (NA), and the technical effects thereof may be described with reference to FIGS. 1 to 4.

[0095] Meanwhile, in another embodiment, the electrode assembly may have a structure in which the first electrode plate assembly and the second electrode plate are separated from each other by a continuous separator folded in a zigzag shape. Hereinafter, an electrode assembly according to another embodiment will be described with reference to FIGS. 6 and 7.

[0096] Fig. 6 is a reference drawing showing the configuration of an electrode assembly (10") according to another embodiment.

[0097] Figure 7 is an exploded perspective view of the first electrode assembly (100") illustrated in Figure 6.

[0098] Referring to FIG. 6, in the manufacturing process of an electrode assembly (10") according to another embodiment, one or more separators (300") may be continuously supplied and folded multiple times in a zigzag shape, and a first electrode plate assembly (100") or a second electrode plate (200) may be arranged in each folded portion to form an electrode assembly (10).

[0099] In this case, the first electrode plate assembly (100") faces one side of the zigzag separator (300"), and the second electrode plate (200) faces the opposite side of one side of the separator (300"), and accordingly, the first electrode plate assembly (100") and the second electrode plate (200) are stacked without contacting each other with the separator (300") interposed therebetween.

[0100] When the separator (300") has a zigzag structure as described above, the portion where the first electrode plate (110) and the second electrode plate (200) can come into contact with each other as the separator (300") shrinks may be a portion corresponding to the edge in the width direction (e.g., the Y-axis direction of FIG. 6) of the separator (300"). For example, referring to FIG. 6, as the separator (300") is continuously formed, in a situation where the separator (300") shrinks, there is a concern that the edge where the electrode tab (112) protrudes from the first electrode plate (110) and the adjacent area of ​​the edge opposite thereto may come into contact with the second electrode plate (200), but the probability that the remaining edge area will be exposed to the second electrode plate (200) may be somewhat low.

[0101] In this case, unlike FIGS. 1 to 5, the insulating member (120") can sufficiently achieve the intended purpose even if it is placed only on some of the four edges of the first electrode plate (110). That is, the insulating member (120") can be concentratedly placed on a portion of the first electrode plate (110) that is likely to be exposed to the second electrode plate (200) as the separator (300") shrinks. For example, referring to FIGS. 6 and 7, in the first electrode plate assembly (100), the first insulating member (120a) and the second insulating member (120b) can be placed along two edges corresponding to opposite sides of the first electrode plate (110), but spaced apart from each other in the width direction of the separator (300").

[0102] In the embodiment described in FIGS. 6 and 7, other features except for the shape of the separator (300") and the arrangement position of the insulating member (120") may be the same as the features of the battery cell (1) described above through FIGS. 1 to 5. For example, as illustrated in FIG. 7, the insulating member (120") may have a loop-shaped structure so as to cover both sides near one edge of the first electrode plate (110), and the portion in contact with the first electrode plate (110) may be formed as a non-adhesive surface (NA).

[0103] Referring to FIG. 8, it can be confirmed that the stability of the battery cell (1) according to the embodiment is improved compared to a conventional battery cell as the above-described insulating member (120, 120', 120") is arranged.

[0104] Fig. 8 is a graph showing the temperature change of each electrode assembly when the electrode assembly according to the embodiment and the electrode assembly according to the first comparative example are heated.

[0105] The graph (b) of FIG. 8 shows the temperature change of the electrode assembly (10) during a test process of heating the electrode assembly (10) inside a hot box according to the embodiment described in FIGS. 2 to 4.

[0106] The graph (a) of Fig. 8 shows the temperature change of the electrode assembly during a test process of heating the electrode assembly according to the first comparative example inside a hot box. The electrode assembly according to the first comparative example is an electrode assembly (10) according to the embodiment described in Figs. 2 to 4, with the insulating member (120) omitted. That is, the electrode assembly according to the first comparative example has a structure in which a plurality of first electrode plates (110) to which the insulating member (120) is not applied are alternately stacked with a plurality of second electrode plates (200) with a separator (300) interposed therebetween.

[0107] In both graphs, the heating test conditions of the hot box are identical. Specifically, the heating test is performed sequentially by performing the following steps: a first step of increasing the ambient temperature of the electrode assembly placed inside the hot box to 130°C at a rate of 5°C / min, a second step of maintaining the ambient temperature of the electrode assembly at 130°C for 30 minutes, and a third step of increasing the ambient temperature of the electrode assembly to 250°C at a rate of 5°C / min.

[0108] First, referring to graph (a), the electrode assembly according to the first comparative example rapidly increased in temperature and generated flames the moment its temperature reached around 130°C. This is because, as explained above with reference to FIGS. 1 to 7, as the temperature of the battery cell increased, the separator contracted around 130°C, and as a result, the first and second electrode plates contacted and short-circuited each other beyond the edge of the separator.

[0109] On the other hand, referring to graph (b), it can be confirmed that the electrode assembly (10) according to the embodiment maintains a stable state even when heated to around 130°C. This is because, even if a shrinkage phenomenon of the separator (300) occurs around 130°C, the insulating member (120) prevents the first electrode plate (110) and the second electrode plate (200) from making direct contact, thereby preventing a short circuit from occurring.

[0110] That is, according to the test results of FIG. 8, it can be confirmed that the electrode assembly (10, 10") to which the insulating member (120, 120', 120") according to the embodiments is applied can prevent a short circuit phenomenon between the electrode plates due to shrinkage of the separator (300, 300") even when the temperature rises to 130°C or higher. Accordingly, the probability of a thermal runaway phenomenon occurring in the battery cell (1) can be significantly reduced.

[0111] FIG. 9 is a graph showing the results of a capacity performance test of a battery cell including an electrode assembly according to an embodiment and a battery cell including an electrode assembly according to a second comparative example.

[0112] In the graph of FIG. 9, P1 represents a capacity performance test result value of a battery cell including an electrode assembly (10) according to the embodiment described in FIGS. 2 to 4, and P2 represents a capacity performance test result value of a battery cell including an electrode assembly according to the second comparative example.

[0113] Here, the electrode assembly according to the second comparative example is an electrode assembly (10) according to the embodiment described in FIGS. 2 to 4 in which the insulating member is changed to an adhesive insulating tape. That is, in the electrode assembly according to the second comparative example, an insulating tape with an adhesive material applied thereto is attached to the masking portions of the plurality of first electrode plates.

[0114] On the graph, two curves are displayed at P1 and P2, with the curve with increasing voltage value representing the charging result value, and the curve with decreasing voltage value representing the discharging result value.

[0115] As can be seen from the graph, it can be seen that the battery cell including the electrode assembly (10) according to the embodiments in which the masking portion is formed using an insulating member composed of a non-adhesive surface has a charge / discharge capacity that increases by approximately 129% compared to the battery cell including the electrode assembly according to the second comparative example in which an adhesive insulating tape is applied.

[0116] This is because, in the electrode assembly (10) of the embodiment, the battery reaction is smoothly carried out up to the masking portion area in contact with the non-adhesive surface, whereas, in the electrode assembly of the second comparative example, the battery reaction is hindered in the masking portion area due to the adhesive material of the insulating tape.

[0117] According to these test results, it can be confirmed that the electrode assembly to which the insulating member according to the embodiments is applied has a battery cell capacity performance that is superior to that of the electrode assembly to which the conventional adhesive insulating tape is applied.

[0118] Fig. 10 is a graph showing the temperature change of each electrode assembly when the electrode assembly according to the embodiment and the electrode assembly according to the second comparative example are heated.

[0119] In the graph of Fig. 10, P1 represents the temperature change of the electrode assembly (10) during a test process of heating the electrode assembly (10) inside a hot box according to the embodiment described in Figs. 2 to 4. P2 represents the temperature change of the electrode assembly during a test process of heating the electrode assembly according to the second comparative example applied to the test of Fig. 9 inside a hot box.

[0120] In the graph of Fig. 10, the heating test conditions of the hot box are the same as the heating test conditions of the hot box described above through Fig. 8.

[0121] Referring to the P1 and P2 values, it can be confirmed that the electrode assemblies according to the examples and the second comparative example maintain a stable state even when heated to around 130°C. Through this, it was confirmed that the short-circuit prevention effect by the insulating member having a non-adhesive surface is the same as the short-circuit prevention effect by the conventional adhesive insulating tape.

[0122] That is, referring to the test results shown in FIGS. 9 and 10, it can be confirmed that the electrode assembly (10, 10") to which the insulating member (120, 120', 120") according to the embodiments is applied is significantly advantageous in terms of the capacity of the battery cell (1) while maintaining the same short-circuit prevention effect between the electrode plates compared to the one in which the masking portion is formed with a conventional adhesive insulating tape.

[0123] In particular, the insulating member (120, 120', 120") according to the embodiments does not prevent the lithium metal from participating in the battery reaction when the electrode plate constituting the electrode assembly (10, 10") is made of lithium metal, thereby preventing the capacity of the battery cell (1) from being reduced by the formation of the masking portion (111a). In addition, since the inner surface of the insulating member (120, 120', 120") is configured as a non-adhesive surface (NA), the insulating member (120, 120', 120") can be chemically and physically stably disposed on the highly reactive lithium metal electrode plate.

[0124] Meanwhile, the battery cell (1) according to the embodiments can be used as a power source for various electronic devices, and the battery device can be, for example, a laptop computer, a netbook, a tablet PC, a mobile phone, an MP3, a wearable electronic device, a power tool, an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric bicycle (E-bike), an electric scooter (E-scooter), an electric golf cart, or an energy storage system (ESS), but is not limited thereto.

[0125] While various embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations are possible without departing from the technical spirit of the present invention as set forth in the claims. Furthermore, the embodiments described above may be implemented by deleting some components, and the embodiments may be implemented in combination with each other.

[0126] [Explanation of symbols]

[0127] 1... battery cell 10... electrode assembly

[0128] 20... Lead tab 30... Case

[0129] 100... First plate assembly 110... First plate

[0130] 111... plate body part 111a... masking part

[0131] 111b... exposed portion 112... first electrode tab

[0132] 120, 120', 120"... Insulating member NA... Non-adhesive surface

[0133] 200... Second electrode plate 210... Second electrode tab

[0134] 300, 300'... membrane

Claims

1. One or more first electrode plates; At least one second electrode plate having a polarity opposite to that of said at least one first electrode plate; One or more separators disposed between the one or more first electrode plates and the one or more second electrode plates; and comprising one or more insulating members mounted on one or more of the first electrode plates; A battery cell wherein said one or more insulating members include a non-adhesive surface that contacts said one or more first electrode plates.

2. In paragraph 1, A battery cell wherein at least a portion of said one or more first electrode plates is made of lithium or an alloy containing lithium.

3. In paragraph 2, A battery cell wherein the non-adhesive surface of the at least one insulating member is in contact with a portion of the at least one first electrode plate made of lithium or an alloy containing lithium.

4. In paragraph 1, A battery cell in which all of the portions of the one or more insulating members that come into contact with the one or more first electrode plates are formed of the non-adhesive surface.

5. In paragraph 1, A battery cell wherein the insulating material is made of at least one of polyimide, polypropylene, polyvinyl chloride, polyester, polyacetal, polyolefin, and polyethylene.

6. In paragraph 1, The above one or more first electrode plates One or more masking portions on which the one or more insulating members are secured; and Including an exposed portion for the above separator, A battery cell wherein the one or more masking portions are formed along at least one edge of the one or more first electrode plates.

7. In paragraph 6, One or more of the above insulating members A battery cell having a loop-shaped structure in which a first insulating portion facing one side of one or more of the first electrode plates and a second insulating portion facing the opposite side of the one side are continuously connected at both ends in the length direction.

8. In paragraph 6, One or more of the above insulating members A first insulating member arranged along a first edge from which an electrode tab protrudes from the first electrode plate; and A battery cell comprising a second insulating member arranged along a second edge opposite the first edge of the first electrode plate.

9. In paragraph 8, One or more of the above insulating members Further comprising a third insulating member and a fourth insulating member respectively arranged along a third edge and a fourth edge respectively connected to the first edge and the second edge of the first electrode plate, A battery cell wherein one end of each of the first to fourth insulating members covers a portion of another insulating member adjacent to the one end, and the opposite end of each of the first to fourth insulating members is covered by another insulating member adjacent to the opposite end.

10. In Article 6 A battery cell characterized in that no adhesive material is applied to a portion of the one or more insulating members that comes into contact with the one or more masking portions.

11. In paragraph 6, One or more of the above insulating members A fifth insulating member facing one side of the at least one first electrode plate; A sixth insulating member is included, which faces the opposite side of the one or more first electrode plates, The fifth insulating member and the sixth insulating member are battery cells separated from each other.

12. In paragraph 11, A battery cell in which the fifth insulating member and the sixth insulating member have a frame-shaped structure surrounding the periphery of the exposed portion.

13. In paragraph 1, The above first and second electrode plates are arranged to face one side of the zigzag-folded separator and the opposite side of the one side, One or more of the above insulating members A battery cell including a first insulating member and a second insulating member respectively arranged along two edges of the first electrode plate and spaced apart from each other in the width direction of the separator.

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