Battery cell for retarding thermal propagation

Abstract

A battery cell according to an embodiment of the present invention comprises: an electrode assembly including an electrode lead; a cell case having a cell terrace, on which the electrode lead is disposed, on one side and accommodating the electrode assembly; and a heat transfer prevention pad disposed on the cell terrace of the cell case. The battery cell according to an embodiment of the present invention has an effect of retarding thermal propagation to an adjacent cell during thermal runaway by means of the heat transfer prevention pad disposed on the cell terrace.

Description

Battery cells to delay heat transfer

[0001] The present invention relates to a battery cell in which heat transfer is delayed, and more particularly, to a battery cell in which heat transfer to an adjacent cell is delayed when a thermal runaway occurs in a battery module.

[0002] Secondary batteries, unlike primary batteries that cannot be recharged, are batteries that can be charged and discharged. They are used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical power sources.

[0003] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, i.e., unit battery cells, is approximately 2.5 V to 4.6 V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Furthermore, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Therefore, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0004] When configuring a battery pack by connecting multiple battery cells in series or parallel, it is common to first configure a battery module comprising at least one battery cell, preferably multiple battery cells, and then use at least one such battery module and add other components to configure the battery pack. Here, a battery module refers to a component in which multiple battery cells are connected in series or parallel, and a battery pack refers to a component in which multiple battery modules are connected in series or parallel to increase capacity and output, etc.

[0005] Battery modules generate heat during charging or discharging, and if there is overcharging, etc., swelling of the battery cells can cause an explosion or fire, and such explosion or fire can cause greater danger, even leading to casualties.

[0006] The purpose of the present invention is to provide a battery cell and a battery module capable of delaying heat transfer to adjacent cells when a battery cell experiences thermal runaway.

[0007] According to one embodiment of the present invention, a battery cell is characterized by including: an electrode assembly including an electrode lead; a cell case having a cell terrace on one side where the electrode lead is arranged and accommodating the electrode assembly; and a heat transfer prevention pad arranged on the cell terrace of the cell case.

[0008] In addition, the cell terraces are arranged on each side of the cell case, and the heat transfer prevention pads are arranged on each of the cell terraces on each side of the cell case.

[0009] In addition, the heat transfer prevention pad includes a first pad portion arranged on one side of the cell terrace; and a second pad portion arranged on the opposite side of the cell terrace.

[0010] Additionally, the first pad portion and the second pad portion are each attached to the cell terrace using an adhesive tape.

[0011] Additionally, the heat transfer prevention pad further includes a connecting portion connecting the first pad portion and the second pad portion.

[0012] Additionally, in the heat transfer prevention pad, the first pad portion, the second pad portion, and the connecting portion are formed as one piece.

[0013] Additionally, the connecting portion includes a slot.

[0014] Additionally, the cell terrace includes an insertion tab that is inserted into the slot.

[0015] Additionally, the insertion tab inserted into the slot has a bent portion bent toward the heat transfer prevention pad.

[0016] Additionally, the above-mentioned bend may be a U-shaped bend.

[0017] Additionally, the end of the above-mentioned bending portion is placed in contact with the above-mentioned heat transfer prevention pad.

[0018] Additionally, the heat transfer prevention pad includes silicone.

[0019] Additionally, the electrode assembly includes a lead film disposed on the electrode lead.

[0020] Additionally, the heat transfer prevention pad can cover the lead film.

[0021] In addition, the battery cell is characterized in that it is a pouch-type battery cell.

[0022] A battery cell and a battery module according to an embodiment of the present invention have the effect of delaying heat transfer to adjacent cells during thermal runaway.

[0023] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention.

[0024] Figure 2 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0025] Figure 3 is a perspective view of a terminal bus bar in one embodiment of the present invention.

[0026] Figure 4 is a perspective view of an insulating cover and an end plate in one embodiment of the present invention.

[0027] Figure 5 is a plan view of a battery cell in one embodiment of the present invention.

[0028] FIG. 6 is a drawing showing the inside of a pouch-type battery cell in one embodiment of the present invention.

[0029] Figure 7 is a drawing showing an electrode assembly in one embodiment of the present invention.

[0030] Figure 8 is a detailed view of a pouch-type battery cell in one embodiment of the present invention.

[0031] Figure 9 is a perspective view of a heat transfer prevention pad in one embodiment of the present invention.

[0032] Fig. 10 is a detailed view of a portion of the pouch-type battery cell in Fig. 8.

[0033] FIG. 11 is a drawing showing a cell terrace of a pouch-type battery cell before attachment of a heat transfer prevention pad in one embodiment of the present invention.

[0034] FIG. 12 is a drawing illustrating a battery pack according to one embodiment of the present invention.

[0035] FIG. 13 is a perspective view of a vehicle equipped with a battery pack according to one embodiment of the present invention.

[0036] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid ambiguity in the interpretation of the present invention. Like reference numerals refer to like elements throughout the specification.

[0037] In order to clearly represent multiple layers and regions in the drawings, thicknesses may be enlarged. Similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "over" another element, this includes not only the case where it is "directly over" that element, but also the case where there are other elements in between. Conversely, when an element is said to be "directly over" another element, it can mean that there are no other elements in between. Furthermore, when an element such as a layer, film, region, or plate is said to be "under" another element, this includes not only the case where it is "directly under" that element, but also the case where there are other elements in between. Conversely, when an element is said to be "directly under" another element, it can mean that there are no other elements in between.

[0038] A battery cell (110) and a battery module (1000) that delay heat transmission according to a preferred embodiment of the present invention are described in detail with reference to the drawings.

[0039] FIG. 1 is a perspective view of a battery module according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a battery module according to an embodiment of the present invention, FIG. 3 is a perspective view of a terminal bus bar according to an embodiment of the present invention, FIG. 4 is a perspective view of an insulating cover and an end plate according to an embodiment of the present invention, FIG. 5 is a plan view of a battery cell according to an embodiment of the present invention, FIG. 6 is a view showing the inside of a pouch-type battery cell according to an embodiment of the present invention, FIG. 7 is a view showing an electrode assembly according to an embodiment of the present invention, FIG. 8 is a partial detailed view of a pouch-type battery cell according to an embodiment of the present invention, FIG. 9 is a perspective view of a heat transfer prevention pad according to an embodiment of the present invention, FIG. 10 is a partial detailed view of the pouch-type battery cell according to FIG. 8, and FIG. 11 is a view showing a cell terrace of a pouch-type battery cell before attachment of a heat transfer prevention pad according to an embodiment of the present invention.

[0040] A battery module (1000) according to one embodiment of the present invention may include a battery cell stack (100) in which a plurality of battery cells (110) are stacked, a module case (200) that accommodates the battery cell stack (100), a bus bar frame (300) positioned on one side and / or the other side of the battery cell stack (100), an insulating cover (500) positioned on the outside of the bus bar frame (300), and an end plate (400) positioned on the outside of the insulating cover (500).

[0041] The above battery cell stack (100) may be formed by stacking a plurality of battery cells (110) along one direction, and the plurality of battery cells (110) may be electrically connected. The direction in which the plurality of battery cells (110) are stacked may be the X-axis direction (or -X-axis direction) in FIG. 2.

[0042] The direction from the front to the rear of the battery cell stack (100), or the opposite direction, may be defined as the longitudinal direction of the battery cell stack (100), and may be the Y-axis direction in the drawing. In addition, the direction from the upper surface to the lower surface of the battery cell stack (100), or the opposite direction, may be defined as the width direction of the battery cell stack (100), and may be the Z-axis direction in the drawing.

[0043] The longitudinal direction of the battery cell stack (100) may be substantially the same as the longitudinal direction of the battery cell (110). The electrode leads (121, 122) of the battery cell (110) may be positioned on the front and rear sides of the battery cell stack (100), and the bus bars (310, 320) of the battery module (1000) may be positioned close to the front and rear sides of the battery cell stack (100) to easily form an electrical connection with the electrode leads (121, 122). The battery cell (110) will be described later.

[0044] The above module case (200) may be for protecting the battery cell stack (100) and electrical components connected thereto from external physical impact, and the module case (200) may accommodate the battery cell stack (100) and electrical components connected thereto in the internal space of the module case (200).

[0045] The structure of the module case (200) may vary, and for example, the structure of the module case (200) may be a mono-frame structure. Here, the mono-frame may be in the form of a metal plate in which the upper surface, lower surface, and both side surfaces are integrated. The mono-frame may be manufactured by extrusion molding. As another example, the structure of the module case (200) may be a structure in which a U-shaped frame and a top plate (201) are combined. In the case of a structure in which a U-shaped frame and a top plate (201) are combined, the structure of the module case (200) may be formed by combining the top plate (201) on the upper side of a U-shaped frame, which is a metal plate in which a lower plate and both side surfaces are combined or integrated, and each frame or plate may be manufactured by press molding. In addition, the structure of the module case (200) may be provided as an L-shaped frame structure in addition to a mono-frame or a U-shaped frame (210), and may be provided as various structures not described in the above-described examples.

[0046] The structure of the module case (200) may be provided in an open form along the longitudinal direction of the battery cell stack (100). The front and rear sides of the battery cell stack (100) may not be covered by the module case (200). The electrode leads (111, 112) of the battery cells (110) may not be covered by the module case (200). The front and rear sides of the battery cell stack (100) may be covered by a bus bar frame (300), an end plate (400), or bus bars (310, 320) to be described later, and through this, the front and rear sides of the battery cell stack (100) may be protected from external physical impacts, etc.

[0047] A compression pad (150) may be positioned between one side of the inner surface of the battery cell stack (100) and the module case (200).

[0048] The compression pad (150) can be arranged to face the battery cell (110) at the outermost end of the battery cell stack (100) in the X-axis direction in the drawing.

[0049] In addition, a thermally conductive resin may be injected between the inner surface of the battery cell stack (100) and the module case (200), and a thermally conductive resin layer (610) may be formed between one of the inner surfaces of the battery cell stack (100) and the module case (200) by the injected thermally conductive resin. At this time, the thermally conductive resin layer (610) may be positioned on the Z-axis of the battery cell stack (100), and may be formed between the battery cell stack (100) and the lower plate positioned on the -Z-axis of the module case (200).

[0050] The above busbar frame (300) is positioned on one side of the battery cell stack (100), and can cover one side of the battery cell stack (100) and simultaneously guide the connection between the battery cell stack (100) and an external device. Specifically, the busbar frame (300) can be positioned on the front or rear side of the battery cell stack (100) as illustrated, and can also be positioned on the upper side, lower side, or side. At least one of a busbar (310, 320) and a module connector can be mounted on the busbar frame (300). As illustrated in FIG. 2, one side of the busbar frame (300) can be connected to one side or the other side of the battery cell stack (100), and the other side of the busbar frame (300) can be connected to the busbar (310, 320).

[0051] The busbar frame (300) may include an electrically insulating material. The busbar frame (300) may limit contact between the busbars (310, 320) and other parts of the battery cells (110) other than the parts where the busbars are connected to the electrode leads (111, 112), thereby preventing electrical short circuits from occurring.

[0052] The busbar frame (300) may be positioned on one side and the other side of the battery cell stack (100).

[0053] The busbar (310, 320) may be mounted on one side of the busbar frame (300) and may be used to electrically connect the battery cell stack (100) or battery cells (110) and an external device circuit. A plurality of busbars (310, 320) may be arranged, and may be positioned between the battery cell stack (100) or busbar frame (300) and the end plate (400), thereby protecting the battery from external impacts, etc., and minimizing the deterioration of durability due to external moisture, etc.

[0054] The busbar (310, 320) can be electrically connected to the battery cell stack (100) through the electrode leads (121, 122) of the battery cell (110).

[0055] Specifically, the electrode leads (121, 122) of the battery cells (110) can be bent and connected to the bus bars (310, 320) after passing through the lead slits formed in the bus bar frame (300). The battery cells (110) constituting the battery cell stack (100) can be connected in series or in parallel by the bus bars (310, 320).

[0056] The busbars (310, 320) may include terminal busbars (320) for electrically connecting one battery module (100) to another battery module (100). At least a portion of the terminal busbars (320) may be exposed to the outside of the end plate (400) to be connected to another battery module (100), and the end plate (400) may be provided with terminal openings (410) for this purpose.

[0057] The terminal bus bar (320) can have one end (second part (322)) exposed through the opening (510) of the insulating cover (500) and the terminal opening (410) of the end plate (400).

[0058] As illustrated in FIG. 3, the terminal bus bar (320) may include a first portion (321) connected to the electrode leads (111, 112) of the battery cell (110) and a second portion (322) exposed to the outside through a terminal opening (410). In addition, the terminal bus bar (320) may further include a bending portion (323) formed between the first portion (321) and the second portion (322).

[0059] In the terminal bus bar (320), the first part (321) can be connected to the second part (322) through the bending part (323), and one side of the first part (321) and one side of the second part (322) can be perpendicular to each other. That is, by forming a bent bending part (323) in the terminal bus bar (320), the second part (322) can protrude and be seated in the seating part (530) of the insulating cover (500), and the second part (322) can be electrically connected to the inter bus bar (not shown). A joining hole (322a) is formed in the second part (322) constituting one end of the terminal bus bar (320), and the second part (322) of the terminal bus bar (320) is fixed by a fixing pin (not shown) inserted into the joining hole (322a).

[0060] The end plate (400) may be used to protect the battery cell stack (100) and electrical components connected thereto from external physical impact by covering the open surface of the module case (200). To this end, the end plate (400) may be manufactured from a material having a predetermined strength, and for example, the end plate (400) may include a metal such as aluminum or a plastic material.

[0061] A terminal opening (410) may be formed in the end plate (400). The terminal openings (410) may be positioned on each side of the end plate (400), and a portion of the insulating cover (500) and one end (second portion (322)) of the terminal bus bar (320) may be exposed through the terminal openings (410).

[0062] In addition, a connector opening may be located between terminal openings (410) located on both sides of the end plate (400), and a module connector may be exposed to the outside through the connector opening.

[0063] The end plate (400) can be combined with the module case (200) while covering the busbar frame (300) or busbar (310, 320) located on one side of the battery cell stack (100). Each corner of the end plate (400) can be combined with a corresponding corner of the module case (200) by welding, bolting, hooking, or the like.

[0064] The end plate (400) can be positioned on one side and the other side of the module case (200) to cover both sides of the battery cell stack (100). In this embodiment, an example in which the end plate (400) is positioned on the front and rear sides of the module case (200) is shown.

[0065] Additionally, an insulating cover (500) for electrical insulation may be positioned between the end plate (400) and the busbar frame (300). That is, the busbar frame (300), the insulating cover (500), and the end plate (400) may be sequentially positioned outward from the battery cell stack (100). Like the end plate (400), the busbar frame (300) and the insulating cover (500) may each be configured in multiples.

[0066] The insulating cover (500) may include an electrically insulating material and may block the busbar (310, 320) from contacting the end plate (400).

[0067] The insulating cover (500) may include an opening (510) and a mounting portion (530). The openings (510) may be positioned on each of the upper sides of the insulating cover (500), and one end (second portion (322)) of the terminal bus bar (320) may be exposed through the openings (510).

[0068] In addition, a connector opening may be located between the openings (510) located on both sides of the insulating cover (500), and the module connector may be exposed to the outside through the connector opening.

[0069] The insulating cover (500) may be positioned on the inner surface of the end plate (400) and may be in close contact with the inner surface of the end plate (400), but this is not necessarily the case.

[0070] As described above, one end (the second part (322)) of the terminal bus bar (320) can be exposed through the opening (510), and the exposed one end (the second part (322)) of the terminal bus bar (320) can be seated on the mounting portion (530). Accordingly, the mounting portion (530) can be positioned adjacent to the opening (510) and can be positioned on the upper outer surface.

[0071] The mounting portion (530) may have a second portion (322) of the terminal bus bar (320) mounted on its upper surface, and thus the upper surface of the mounting portion (530) may form a mounting surface. In addition, as illustrated in FIG. 4, the mounting portion (530) may include a fixing member (531) for fixing the terminal bus bar (320).

[0072] The fixing member (531) can fix the second part (322) of the terminal bus bar (320) and may include a fixing hole (531a).

[0073] A fixing pin (not shown) can be inserted into the fixing hole (531a) above. A fixing pin (not shown) inserted into a joining hole (322a) formed in a second part (322) of the terminal bus bar (320) is fixed by being coupled to the fixing hole (531a), thereby fixing the second part (322) of the terminal bus bar (320) to the insulating cover (500).

[0074] Accordingly, the second part (322) of the terminal bus bar (320) is seated on the mounting portion (530) of the insulating cover (500), and the second part (322) is seated on the fixing member (531) arranged on the mounting portion (530) and comes into contact with it.

[0075] In addition, a terminal cover portion (not shown) covering one end (second portion (322)) of the exposed terminal bus bar (320) can be placed on the insulating cover (500).

[0076] As illustrated in FIGS. 5 to 7, in the present embodiment, the battery cell (110) may be provided as a pouch-shaped battery cell (110), and the number of pouch-shaped battery cells (110) stacked per unit area may be maximized. However, the battery cell (110) does not necessarily have to be provided in a pouch shape, and may be provided in a square shape, a cylindrical shape, or various other shapes.

[0077] A battery cell (110) provided in a pouch form may include an electrode assembly (120) and a cell case (130) that accommodates the electrode assembly (120).

[0078] The cell case (130) of the battery cell (110) may be a pouch-type cell case (130) for accommodating the electrode assembly (120). The cell case (130) includes a lower case (131) and an upper case (132) covering the lower case (131), and the upper and lower cases (132, 131) may be formed integrally. In addition, as illustrated in FIG. 6, the connecting portions of the upper and lower cases (132, 131) may be formed in a structure in which they are bent and folded. FIG. 6 conveniently illustrates the state in which the upper case (132) is positioned with the upper portion of the lower case (131) open in order to show the inside of the pouch-type battery cell (110). However, in an actual finished product, as in FIG. 5, the upper case (132) may completely cover the lower case (131) and a sealing portion (S) may be formed at the periphery.

[0079] The upper and lower cases (132, 131) can both be formed of a laminate structure including an inner covering layer, a metal layer, and an outer covering layer. The inner covering layer is located on the inside of the cell case (115) based on the metal layer and is in direct contact with the electrode assembly (120), so it must have insulation and electrolytic resistance. In addition, in order to seal it from the outside, it is required to have sealing properties, that is, the sealing portion where the inner layers are thermally bonded must have excellent thermal bonding strength. The material of the inner covering layer can be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and good sealing properties, polyurethane resins, and polyimide resins, and polypropylene (PP) which has excellent mechanical properties such as tensile strength, rigidity, surface hardness, impact resistance, and chemical resistance is preferable.

[0080] The metal layer is located between the inner and outer covering layers and serves as a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside. A preferred material for the metal layer in contact with the inner covering layer is a lightweight aluminum (Al) thin film with excellent formability.

[0081] The outer covering layer is located on the outside of the cell case (130) based on the metal layer, and this outer covering layer can use a heat-resistant polymer with excellent tensile strength, moisture permeability, and air permeability to protect the electrode assembly while ensuring heat resistance and chemical resistance. For example, nylon or polyethylene terephthalate can be used.

[0082] A receiving groove (133) may be formed in each of the upper and lower cases (132, 131), and an electrode assembly may be accommodated in the receiving groove (133) of the upper and lower cases (132, 131).

[0083] The electrode assembly (120) housed in the cell case (130) may be one of a group consisting of a jelly-roll type electrode assembly having a structure in which a separator is interposed between long sheet-shaped positive and negative electrodes and then rolled up, a stack type electrode assembly having unit cells having a structure in which rectangular positive and negative electrodes are stacked with a separator interposed between them, a stack-folding type electrode assembly in which the unit cells are rolled up by a long separating film, and a lamination-stack type electrode assembly in which the unit cells are stacked with a separator interposed between them and attached to each other.

[0084] In the present invention, the electrode assembly (120) may include, for example, an electrode laminate (125) as shown in FIG. 7, and a fixing tape (129) for winding the electrode laminate (125).

[0085] The electrode stack (125) may include an anode (126), a cathode (128), and a separator (127) disposed between the anode (126) and the cathode (128), and may be formed by stacking the anode (126), the separator (127), and the cathode (128). In addition, the electrode stack (125) may be formed in a form in which the length in the longitudinal direction is relatively longer than the length in the transverse direction.

[0086] The positive electrode may include a positive electrode current collector and a first active material layer disposed on the positive electrode current collector, and the first active material layer may be formed by applying an electrode active material to one or both surfaces of the positive electrode current collector.

[0087] The negative electrode may include a negative current collector and a second active material layer disposed on the negative current collector, and the second active material layer may be formed by applying an electrode active material to one or both surfaces of the negative current collector.

[0088] The above fixing tape (129) is for fixing the electrode laminate (125) in which the positive electrode (126), the separator (127), and the negative electrode (128) are laminated, and is fixed by winding the outside of the electrode laminate (125).

[0089] The electrode stack (125) may include a plurality of anodes (126), a plurality of cathodes (128), and a plurality of separators (127).

[0090] Additionally, the electrode assembly (120) may include two electrode tabs (111, 112) and two electrode leads (121, 122).

[0091] The electrode tabs (111, 112) are formed by protruding outward from the electrode laminate (125). One of the two electrode tabs (111, 112) may be a positive electrode tab connected (extended) to the positive electrode (126), and the other electrode tab (112) may be a negative electrode tab connected (extended) to the negative electrode (128).

[0092] The electrode leads (121, 122) are connected to the electrode tabs (111, 112), and can be connected to the electrode tabs (111, 112) by welding, for example. The material of the electrode leads (121, 122) can be used without any particular limitation as long as it is an electrically conductive material. For example, the material of the electrode leads (121, 122) may include at least one of copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), carbon (C), chromium (Cr), and manganese (Mn). However, the electrode leads (121, 122) are not limited to the materials described above, and may be selected in various ways in consideration of mechanical strength, flexibility, and processability.

[0093] A welded portion may be formed by overlapping a certain portion of the electrode leads (121, 122) and the electrode tabs (111, 112) vertically and welding them, and the electrode tabs (111, 112) and the electrode leads (121, 122) may be connected to each other by this welded portion.

[0094] Among the two electrode leads (121, 122), one electrode lead (121) may be a positive lead connected to the positive tab, and the other electrode lead (122) may be a negative lead connected to the negative tab. The positive lead may be made of, for example, aluminum, and the negative lead may be made of, for example, copper or nickel-coated copper, but is not limited thereto.

[0095] As shown in FIGS. 5 to 7, a lead film (113) may be attached to each of the electrode leads (121, 122). The lead film (113) coupled to the electrode leads (121, 122) is positioned between the electrode leads (121, 122) and the cell case (130), thereby preventing a short circuit from occurring between the electrode leads (121, 122) and the cell case (130) and improving the sealing force, thereby preventing leakage of the electrolyte, etc.

[0096] The lead film (113) may be formed in a form in which a pair of lead films (113) are positioned on both sides of each electrode lead (121, 122) and then the portions that do not come into contact with the electrode leads (121, 122) are joined by a method such as heat fusion to wrap the electrode leads (121, 122), and after sealing the cell case (130), a part of the lead film (113) may be formed to protrude and be exposed to the outside of the cell case (130) to be advantageous in preventing short circuits (see FIG. 11).

[0097] The two electrode leads (121, 122) illustrated are shown as being arranged on both sides of the electrode assembly (120), but may be arranged on one side of the electrode assembly (120) depending on the arrangement of the electrode tabs (111, 112). That is, when the two electrode tabs (111, 112) are arranged on one side of the electrode assembly (120), the two electrode leads (121, 122) connected to the electrode tabs (111, 112) may also be formed in the same direction of the electrode assembly (120).

[0098] Meanwhile, in one embodiment of the present invention, a heat transfer prevention pad (140) is attached to a pouch-type battery cell (110).

[0099] In FIG. 5, the cell case (130) of the pouch-shaped battery cell (110) may have a pair of long sides and a pair of short sides at the edge, and a pair of opposite short sides where electrode leads (121, 122) are arranged may be referred to as a cell terrace (135).

[0100] As shown in FIGS. 8 to 10, in the present embodiment, a heat transfer prevention pad (140) can be attached to a cell terrace (135) of a pouch-type battery cell (110).

[0101] The heat transfer prevention pad (140) includes a first pad portion (141) arranged on one side of the cell terrace (135) and a second pad portion (142) arranged on the opposite side of the cell terrace (135). The heat transfer prevention pad (140) may include, for example, silicon or may be made of silicon or the like. That is, the heat transfer prevention pad (140) may be made of a silicon pad.

[0102] As a material for the heat transfer prevention pad (140), silicone has high elasticity (elasticity that allows the shape to change even when the terrace section is deformed), heat resistance, and chemical resistance, which can be advantageous in preventing heat transfer during thermal runaway.

[0103] The first pad portion (141) is disposed on one side of the cell terrace (135), and an adhesive may be applied to the attachment surface with the cell terrace (135) or an adhesive tape may be combined. The first pad portion (141) may be attached to the cell terrace (135) by an adhesive or an adhesive tape (141a) disposed on the attachment surface, which is the rear surface of the first pad portion (141). The adhesive tape (141a) may be a double-sided tape, and in the case of a double-sided tape, the release paper of the double-sided tape may be peeled off and attached to the cell terrace (135).

[0104] The first pad portion (141) may be formed in a shape identical to or similar to the cell terrace (135) so that it can be attached to the maximum area of ​​the cell terrace (135). That is, the edge of the first pad portion (141) may be formed along the edge of the cell terrace (135). In addition, the first pad portion (141) may cover at least a portion or completely the lead film (113). In addition, the first pad portion (141) may cover the cell terrace (135) including the portion covering the lead film (113) in the upper and lower cases (131, 132). The first pad portion (141) may include silicon and may be formed of silicon or the like.

[0105] The second pad portion (142) is disposed on the opposite side of one side of the cell terrace (135) where the first pad portion (141) is disposed, and an adhesive may be applied to the attachment surface with the cell terrace (135) or an adhesive tape may be bonded thereto. The second pad portion (142) may be attached to the cell terrace (135) by an adhesive or an adhesive tape (142a) disposed on the attachment surface, which is the rear surface of the second pad portion (142). The adhesive tape (142a) may be a double-sided tape.

[0106] The second pad portion (142) may be formed in a shape identical to or corresponding to that of the first pad portion (141). That is, the second pad portion (142) may be formed in a shape identical to or similar to that of the cell terrace (135) so that it can be attached to the maximum area of ​​the cell terrace (135) like the first pad portion (141). That is, the edge of the second pad portion (142) may be formed along the edge of the cell terrace (135). In addition, the second pad portion (142) may cover at least a portion or completely the lead film (113). In addition, the second pad portion (142) may cover the cell terrace (135) including the portion covering the lead film (133) in the upper and lower cases (131, 132). The second pad portion (142) may include silicon and may be formed of silicon or the like.

[0107] The first pad portion (141) and the second pad portion (142) of the heat transfer prevention pad (140) can cover 70% or more, or 80% or more (in terms of area) of one surface of the cell terrace (135) to which it is attached.

[0108] The heat transfer prevention pad (140) may additionally include a connecting portion (143) connecting the first pad portion (141) and the second pad portion (142).

[0109] The connecting portion (143) is for connecting the first pad portion (141) and the second pad portion. As shown, one end of the connecting portion (143) is connected to the first pad portion (141) and the other end of the connecting portion (143) is connected to the second pad portion (142).

[0110] In this embodiment, the connecting portion (143) may include a slot (144). The slot (144) may extend along the edge of the cell terrace (135) from the connecting portion (143), and an insertion tab (135a) of the cell terrace (135) may be inserted into the slot (144).

[0111] The first pad portion (141), the second pad portion (142), and the connection portion (143) of the heat transfer prevention pad (140) can be formed as one piece.

[0112] In the manufacturing process of a pouch-type battery cell (110), the upper case (132) covers the lower case (131), and a sealing portion (S) is formed at the periphery, and then the outside of the sealing portion (S) is cut off. In the present embodiment, the insertion tab (135a) is left behind and cut off. Accordingly, as shown in FIG. 11, the insertion tab (135a) is formed to protrude outside the sealing portion (S).

[0113] This insertion tab (135a) can be inserted into the slot (144) of the connecting portion (143). And the insertion tab (135a) inserted into the slot (144) can be exposed to the outside of the heat transfer prevention pad (140). The exposed insertion tab (135a) can be bent toward the heat transfer prevention pad (140) and can have a bent portion (135b) bent toward the heat transfer prevention pad (140). That is, the bent portion (135b) can be a U-shaped bent portion (135b).

[0114] The end of the bending portion (135b) can extend to the edge of the heat transfer prevention pad (140) and can be placed in contact with the connecting portion (143), the first pad portion (141), or the second pad portion (142) of the heat transfer prevention pad (140).

[0115] In this way, in this embodiment, the insertion tab (135a) is inserted into the slot (144) of the connecting portion (143), and the inserted insertion tab (135a) is bent toward the heat transfer prevention pad (140), thereby fixing the heat transfer prevention pad (140).

[0116] The heat transfer prevention pad (140) can be placed on both cell terraces (135) where the electrode leads (121, 122) are placed in the pouch-type battery cell (110).

[0117] In general, when a thermal runaway occurs in a pouch-type battery cell, the flame can easily spread to an adjacent cell through the electrode lead portion. When a thermal runaway occurs in a battery cell, the sealing portion of the electrode lead portion of the battery cell may be peeled off, releasing flames and discharged substances, and this flame may cause heat to spread to an adjacent cell.

[0118] In this embodiment, a heat transfer prevention pad (140) is attached to a cell terrace (135) where electrode leads (121, 122) are arranged in a cell case (130), so that when thermal runaway of a battery cell (110) occurs, peeling of the sealing portion of the electrode leads (121, 122) is prevented, thereby preventing heat transfer to an adjacent cell (110) and delaying the transition of thermal runaway due to heat transfer.

[0119] As described above, one or more battery modules (1000) according to the present invention can form a battery pack. As illustrated in FIG. 12, a battery pack (2000) according to the present invention can accommodate at least one battery module (1000) inside a pack case (2100) and can include various control and protection systems such as a BMS (Battery Management System) and a cooling system.

[0120] The pack case (2100) may include a lower housing (2110) and an upper housing (not shown) coupled to the upper side of the lower housing (2110), and a plurality of battery modules (1000) may be stored in the internal space of the lower housing (2110) and the upper housing.

[0121] Meanwhile, in the embodiment of the present invention, an example is shown in which a plurality of battery modules (1000) are accommodated inside a battery pack (2000), but a plurality of battery cells (110) may be directly arranged inside the battery pack (2000).

[0122] The battery module (1000) and battery pack (2000) according to the present invention, configured as described above, can be applied to various devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, or ESS (Energy Storage Systems), but are not limited thereto and can be applied to various devices capable of using secondary batteries.

[0123] Fig. 13 is a drawing illustrating an electric vehicle (V) equipped with a battery pack (2000). In the electric vehicle (V), the wheels are driven by a motor that receives power from the battery pack (2000) so that the electric vehicle can be driven.

[0124] Although the present invention has been described with reference to preferred embodiments as described above, it is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the invention pertains within a scope that does not depart from the spirit of the present invention.

[0125]

[0126] The present invention can provide a battery cell capable of delaying heat transfer to adjacent cells when a thermal runaway of the battery cell occurs.

Claims

1. An electrode assembly including an electrode lead; A cell case having a cell terrace on one side where the electrode leads are arranged and accommodating the electrode assembly; and A heat transfer prevention pad placed on the cell terrace of the cell case; A battery cell characterized by including:

2. In paragraph 1, The above cell terraces are arranged on each side of the cell case, The above heat transfer prevention pads are battery cells each placed on the cell terraces on both sides of the cell case.

3. In paragraph 1, The above heat transfer prevention pad A first pad portion arranged on one side of the cell terrace; and A second pad portion arranged on the opposite side of the cell terrace; A battery cell comprising:

4. In paragraph 3, A battery cell in which the first pad portion and the second pad portion are each attached to the cell terrace by including an adhesive tape.

5. In paragraph 3, A battery cell wherein the heat transfer prevention pad further includes a connecting portion connecting the first pad portion and the second pad portion.

6. In paragraph 5, A battery cell in which the first pad portion, the second pad portion, and the connecting portion of the heat transfer prevention pad are formed as one body.

7. In paragraph 5, The above connecting part is a battery cell including a slot.

8. In paragraph 7, The above cell terrace is a battery cell including an insertion tab that is inserted into the slot.

9. In paragraph 8, A battery cell having an insert tab inserted into the above slot and a bend portion bent toward the heat transfer prevention pad.

10. In paragraph 9, The above-mentioned folded part is a battery cell having a U-shaped folded part.

11. In paragraph 9, A battery cell in which the end of the above-mentioned bending portion is placed in contact with the above-mentioned heat transfer prevention pad.

12. In paragraph 1, The above heat transfer prevention pad is a battery cell containing silicon.

13. In paragraph 1, The above electrode assembly is a battery cell including a lead film disposed on the electrode lead.

14. In paragraph 13, The above heat transfer prevention pad is a battery cell covering the lead film.

15. In paragraph 1, A battery cell characterized in that the above battery cell is a pouch-type battery cell.

16. A battery module comprising a plurality of battery cells according to paragraph 1.

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