Cap plate assembly and battery cell having the same

Abstract

The present invention comprises a cap plate formed to cover a cell case of a secondary battery, wherein the cap plate has a first receiving hole formed therein that is penetrated at least a portion so as to communicate with the inside and outside of the cell case; and a first electrode portion coupled to the first penetration hole at the upper and lower portions of the top plate; wherein the first electrode portion may include a first terminal plate installed by being seated on the upper portion of the top plate; a first sealing portion formed to separate the first terminal plate from the top plate; a first electrode terminal inserted into and coupled to the first penetration hole so as to conduct current from the inside of the cell case to the first terminal plate; and a first sub-plate connected to the lower portion of the first electrode terminal.

Description

Technology Field

[0001] The present invention relates to a cap plate and a battery cell, and more specifically, to a cap plate used in a secondary battery and a battery cell including the same. Background Technology

[0002] Generally, secondary batteries used in electric and hybrid vehicles, which consume a large amount of power, require long-term operation and high power operation. Accordingly, they are used in the form of battery modules in which multiple batteries are electrically connected using bus bars and bundled into a single unit. Additionally, depending on the type of external device to which they are applied, such as mobile devices or uninterruptible power supplies, they can be used in the form of a single battery.

[0003] Fuel cells used in electric vehicles, hybrid vehicles, etc., prefer battery modules due to issues with output and capacity, and battery modules can increase output voltage or output current depending on the number of built-in cells.

[0004] The output of fuel cell charging systems is continuously increasing, and accordingly, safety regulations for battery systems are also being strengthened. However, when risks arise due to short circuits, high heat, or overcurrents in batteries, the materials of battery components fail to maintain flame-retardant performance, leading to rapid ignition or explosion.

[0005] Accordingly, there is a trend toward using materials with excellent flame retardancy and reducing the amount of carbon added. The problem to be solved

[0006] The present invention aims to solve various problems, including those mentioned above, by providing a cap plate and a battery cell including the same, which use a conductive plastic material to have high electrical conductivity stability, sufficient mechanical strength, high mechanical and thermal shock resistance, and good injection moldability. However, these problems are exemplary and the scope of the present invention is not limited by them. means of solving the problem

[0007] According to one embodiment of the present invention, a cap plate is provided. The cap plate is a cap plate formed to cover a cell case of a secondary battery, comprising: a top plate having a first receiving hole formed therein with at least a portion penetrating so as to communicate with the inside and outside of the cell case; and a first electrode portion coupled to the first receiving hole at the upper and lower portions of the top plate; wherein the first electrode portion comprises: a first terminal plate installed on the upper portion of the top plate to be connected to a bus bar for connecting a plurality of cells on the outside of the cell case; a first sealing portion formed of a polymer composite material including a carbon nanotube, having a first terminal mounting portion formed thereon on which the first terminal plate is mounted, a first penetrating hole formed inside the first receiving hole, and formed to space the first terminal plate from the top plate; and a first electrode terminal inserted into and coupled to the first penetrating hole to conduct current from the inside of the cell case to the first terminal plate. and may include a first sub-plate connected to the first electrode terminal to conduct electricity and connected to the lower part of the first electrode terminal.

[0008] According to one embodiment of the present invention, the first seal may be formed of a polymer composite material comprising 0.3 to 3 vol% of carbon nanotubes.

[0009] According to one embodiment of the present invention, the first seal may be formed by insert injection molding on the top plate and the first terminal plate so as to be formed between the top plate and the first terminal plate.

[0010] According to one embodiment of the present invention, the first electrode terminal may be formed by laminating a first material having the same main component as the first terminal plate and a second material having the same main component as the first sub-plate in the width or length direction of the top plate.

[0011] According to one embodiment of the present invention, the first electrode terminal may include: a core portion formed of the first material and having an upper surface joined to the first terminal plate; and a clad portion formed of the second material, formed to surround the outer surface of the core portion and having a lower surface joined to the first sub-plate.

[0012] According to one embodiment of the present invention, the first electrode terminal may be formed by stacking an upper laminated portion formed of a first material having the same main component as the first terminal plate and a lower laminated portion formed of a second material having the same main component as the first sub-plate in the height direction of the cap plate.

[0013] According to one embodiment of the present invention, a third sealing member formed by being coupled to the lower part of the top plate to support the first subplate may be included.

[0014] According to one embodiment of the present invention, a battery cell is provided. The battery cell comprises: an electrode assembly having a first electrode and a second electrode formed on both sides of a separator; a cell case having an electrode receiving portion formed inside to house the electrode assembly; and a cap plate formed to cover the upper part of the cell case and having a first electrode portion connected to the first electrode installed in a conductive state on a top plate having a first receiving hole formed to communicate the inside and outside of the cell case, and a second electrode portion connected to the second electrode installed in an insulated state on a second receiving hole formed on the top plate; wherein the first electrode portion comprises a first terminal plate seated and installed on the upper part of the top plate to be connected to a bus bar for connecting a plurality of cells on the outside of the cell case; It may include: a first terminal seating portion formed on the upper part where the first terminal plate is seated, a first through hole formed inside the first receiving hole, and formed to separate the first terminal plate from the top plate, and a first sealing portion formed of a polymer composite material including carbon nanotubes; a first electrode terminal inserted into and coupled to the first through hole so as to conduct electricity from the inside of the cell case to the first terminal plate; and a first sub-plate connected to conduct electricity with the first electrode terminal and connected to the lower part of the first electrode terminal.

[0015] According to one embodiment of the present invention, the first seal may be formed of a polymer composite material comprising 0.3 to 3 vol% of carbon nanotubes.

[0016] According to one embodiment of the present invention, the second electrode portion may include: a second terminal plate installed on the upper part of the top plate so as to be connected to the bus bar; a second terminal seating portion formed on the upper part where the second terminal plate is seated, a second through hole formed inside the second receiving hole, and a second sealing portion formed to separate the second terminal plate from the top plate; a second electrode terminal inserted into the second through hole and coupled so as to conduct electricity from the inside of the cell case to the second terminal plate; and a second sub-plate connected to conduct electricity with the second electrode terminal and connected to the lower part of the second electrode terminal.

[0017] According to one embodiment of the present invention, the second electrode terminal may be formed by laminating a first material having the same main component as the second terminal plate and a second material having the same main component as the second sub-plate in the width or length direction of the top plate.

[0018] According to one embodiment of the present invention, the second electrode terminal may include: a core portion formed of the first material and having an upper surface joined to the second terminal plate; and a clad portion formed of the second material, formed to surround the outer surface of the core portion and having a lower surface joined to the second sub-plate.

[0019] According to one embodiment of the present invention, the second electrode terminal may be formed by stacking an upper laminated portion formed of a first material having the same main component as the second terminal plate and a lower laminated portion formed of a second material having the same main component as the second sub-plate in the height direction of the cap plate. Effects of the invention

[0020] According to one embodiment of the present invention as described above, by manufacturing a battery component with a new conductive plastic material, the electrical conductivity stability of the battery cell is high, the mechanical strength is sufficient, and the mechanical and thermal shock resistance can be increased. In addition, flame retardant performance is maintained for a sufficient period of time in the event of a risk caused by a short circuit, high heat, or overcurrent inside the battery, thereby securing sufficient time for the user to respond and take action.

[0021] In addition, the top plate and the electrode terminal are joined by insert injection molding, which effectively prevents electrolyte leakage between the top plate and the electrode terminal; simplifies the manufacturing process for joining sealing members such as gaskets; improves production efficiency and reduces manufacturing and processing costs; and enables the realization of a cap plate and a battery cell including the same, which increases the bonding area between each component by using a laminate and lowers the resistance between dissimilar materials from the electrode assembly to the bus bar, thereby increasing power transfer efficiency. Of course, the scope of the present invention is not limited by these effects. Brief explanation of the drawing

[0022] FIG. 1 is a perspective view showing a cap plate according to one embodiment of the present invention. FIG. 2 is an exploded perspective view showing a cap plate according to one embodiment of the present invention. FIG. 3 is a cross-sectional view showing a cap plate according to one embodiment of the present invention. FIGS. 4 and FIGS. 5 are perspective views showing various embodiments of the first electrode terminal of a cap plate according to the present invention. FIG. 6 is a cross-sectional view showing a battery cell according to one embodiment of the present invention. Specific details for implementing the invention

[0023] Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0024] The embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, and the following embodiments may be modified in various different forms, and the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided to make the disclosure more faithful and complete and to fully convey the spirit of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of explanation.

[0025] Hereinafter, embodiments of the present invention are described with reference to drawings that schematically illustrate ideal embodiments of the present invention. In the drawings, variations of the illustrated shapes may be expected, for example, depending on manufacturing techniques and / or tolerances. Accordingly, embodiments of the inventive concept should not be interpreted as being limited to specific shapes of the areas illustrated herein, but should include, for example, variations in shape resulting from manufacturing.

[0026] FIG. 1 is a perspective view showing a cap plate according to one embodiment of the present invention, FIG. 2 is an exploded perspective view showing a cap plate according to one embodiment of the present invention, FIG. 3 is a cross-sectional view showing a cap plate according to one embodiment of the present invention, and FIG. 4 and FIG. 5 are perspective views showing various embodiments of the first electrode terminal of the cap plate according to the present invention.

[0027] First, a cap plate (1000) according to one embodiment of the present invention may largely include a top plate (1100) and a first electrode portion (1200), as shown in FIG. 1.

[0028] The top plate (1100) is formed to cover the upper part of the cell case of the secondary battery, and a first receiving hole (1110) may be formed with at least a portion penetrating so that the inside and outside of the cell case are in communication.

[0029] The top plate (1100) can seal the cell case by being installed in the opening of the cell case of the battery cell. For example, the cell case and the top plate (1100) can be formed from a first material and welded together, and the first material may include aluminum, aluminum alloy, etc.

[0030] Additionally, the top plate (1100) may include an electrolyte inlet, a vent hole, and a terminal hole. The electrolyte inlet (not shown) is an inlet that allows the electrolyte to be injected into the interior of the cell case after the top plate (1100) is attached to the cell case. After the electrolyte is injected, the electrolyte inlet may be sealed with a sealing plug (not shown).

[0031] As shown in FIGS. 2 and 3, the top plate (1100) may have a first receiving hole (1110) formed therein, which is penetrated vertically in at least a portion.

[0032] Specifically, the first receiving hole (1110) is a hole formed by penetrating the top plate (1100) so as to connect the lower and upper parts of the top plate (1100). The inner surface of the first receiving hole (1110), along with the periphery of the first receiving hole (1110), may be surrounded by the first sealing part (1240) to be described later.

[0033] Additionally, the top plate (1100) may further have a first support hole formed therein that penetrates at least a portion vertically.

[0034] The first electrode portion (1200) is a coupling structure formed to connect a bus bar connected to the inside and outside of a sealed battery cell.

[0035] The first electrode portion (1200) may include a positive terminal installed in a conductive state on the cap plate (1100), or a negative terminal installed in an insulated state on the cap plate (1100).

[0036] The first electrode portion (1200) can be coupled to the first receiving hole (1110) at the upper and lower parts of the top plate (1100).

[0037] Specifically, the first electrode portion (1200) may include a first terminal plate (1210), a first sealing portion (1240), a first electrode terminal (1220), and a first sub-plate (1230).

[0038] As shown in FIGS. 2 and 3, the first terminal plate (1210) can be installed by being seated on the upper part of the top plate (1100) so as to be connected to a bus bar for connecting a plurality of cells on the outside of the cell case.

[0039] The upper surface of the first terminal plate (1210) can be formed in a shape corresponding to the shape of the bus bar so as to be combined with the bus bar, and can be surface-treated to increase the current conduction efficiency when in contact with the bus bar.

[0040] A protrusion may be formed on the side of the first terminal plate (1210). The protrusion may be formed by welding at least a portion of the perimeter of the first terminal plate (1210), and may be formed as a stepped portion with a lower portion protruding more than the upper portion of the side of the first terminal plate (1210).

[0041] The first terminal plate (1210) may be formed from a first material, and the first material may include aluminum, aluminum alloy, etc. Additionally, if the bus bar is formed from copper, copper alloy, nickel, nickel alloy, etc., the first terminal plate (1210) may be formed in the same way.

[0042] As illustrated in FIGS. 2 and 3, the first sealing part (1240) may have a first terminal mounting part (1241) formed on its upper side, on which a first terminal plate (1210) is mounted.

[0043] The first sealing part (1240) may be formed such that the first terminal plate (1210) is installed in the first terminal seating part (1241) so that the first terminal plate (1210) can be fixed to the first sealing part (1240), and a fixing groove into which the protrusion is inserted may be formed.

[0044] The above fixed groove may be formed in a shape corresponding to the above protrusion at a position corresponding to the circumference of the first terminal plate (1210) in the first sealing portion (1240).

[0045] The first sealing portion (1240) may be formed such that at least a portion is formed on the upper part of the top plate (1100), and the first terminal seating portion (1241) is formed on the opposite side in contact with the top plate (1100) to separate the first terminal plate (1210) from the top plate (1100).

[0046] The first sealing part (1240) may have a first through hole (1242) formed inside the first receiving hole (1110). Specifically, at least a portion of the first sealing part (1240) may be formed on the inner side of the first receiving hole (1110) so that the inner surface of the first receiving hole (1110) is blocked from the outside.

[0047] At this time, the first receiving hole (1110) is not filled with the first sealing part (1240), and a first through hole (1242) smaller than the first receiving hole (1110) is formed inside the first receiving hole (1110), and at least a part of the first electrode part (1200) can be inserted through the first through hole (1242).

[0048] The first receiving hole (1110) can be formed by penetrating through a hole of various shapes such as a circle, ellipse, or square.

[0049] The first sealing part (1240) is formed to surround the first receiving hole (1110) of the top plate (1100) and can be formed to secure the first terminal plate (1210).

[0050] Specifically, the first seal (1240) can be formed by insert injection molding with the top plate (1100) and the first terminal plate (1210).

[0051] That is, a first sealing part (1240) can be formed by injecting molten material around the first receiving hole (1110) of the top plate (1100) and between the top plate (1100) and the first terminal plate (1210) in a mold in which the top plate (1100) and the first terminal plate (1210) are fixed.

[0052] The first sealing part (1240) is insert-molded between the top plate (1100) and the first terminal plate (1210), so that they can be easily combined without performing individual assembly processes for each of the top plate (1100), the first sealing part (1240), and the first terminal plate (1210).

[0053] In addition, the first terminal plate (1210) and the first sealing part (1240) can be easily fixed, and the space between the first terminal plate (1210) and the first sealing part (1240) can be sealed without a sealing such as a gasket.

[0054] The first sealing portion (1240) may be formed from a polymer composite material containing carbon nanotubes. The polymer composite material may have a microstructure in which carbon nanotubes, which are an electrically conductive material, are dispersed in a matrix made of a polymer material.

[0055] The above-mentioned polymeric material may include one or more of polyphenylene sulfide, polybutylene terephthalate, liquid crystal polymer, polyether ether ketone, polyphthalamide, polyamide, and polycarbonates.

[0056] For example, the first seal (1240) may be formed of a polymer composite material containing 0.3 to 3 vol% of carbon nanotubes.

[0057] Compared to carbon black, carbon nanotubes exhibit higher electrical conductivity, mechanical strength, mechanical-thermal shock resistance, and injection moldability. Furthermore, carbon nanotubes demonstrate higher electrical conductivity, mechanical-thermal shock resistance, and injection moldability even when compared to carbon fiber.

[0058] When comparing the electrical conductivity of carbon nanotubes, carbon black, and carbon fiber, the electrical resistance value is 1000–2000Ω when 1 vol% of carbon nanotubes are included in the polymer resin. On the other hand, when 30 vol% of carbon black is included in the polymer resin, the electrical resistance value is 1000–10000Ω, and when 8 vol% of carbon fiber is included in the polymer resin, the electrical resistance value is 1000–5000Ω.

[0059] In other words, to achieve a minimum electrical resistance of approximately 1000Ω, carbon black must be added at 30 vol% of the polymer resin, and carbon fiber must be added at 8 vol%. On the other hand, carbon nanotubes can achieve the same electrical resistance value with the addition of 1 vol%, and accordingly, flame retardancy is significantly increased.

[0060] The above polymer composite material can be manufactured by adding carbon nanotubes and a dispersant to a polymer material in a liquid state, stirring, and then solidifying. At this time, the dispersant may be added in a range of 10 to 40 wt% of the carbon nanotubes.

[0061] The liquid polymer material containing the dispersant and carbon nanotubes is injected through an insert injection machine and then solidified to form the first sealing part (1240).

[0062] As illustrated in FIGS. 2 and 3, the first subplate (1230) can be connected to the lower part of the first electrode terminal (1220) so as to be electrically connected to the first electrode terminal (1220). For example, the first subplate (1230) is formed in a flat shape, so that one side is joined to the first electrode terminal (1220) and the other side is joined to a tab portion inside the cell case, so that electrically connected from the tab portion to the first electrode terminal (1220).

[0063] The first electrode terminal (1220) can be inserted into and coupled to the first through hole (1242) so as to conduct current from the first sub-plate (1230) formed inside the cell case (3000) to the first terminal plate (1210).

[0064] The first subplate (1230) may be formed from a first material having the same main component as the first terminal plate (1210), and the material of the first subplate (1230) may be selectively formed according to the polarity of the first electrode portion (1200).

[0065] For example, when the first electrode part (1200) is an anode, the first subplate (1230) may be a metal having aluminum, an aluminum alloy, etc. as the main component, and when the first electrode part (1200) is a cathode, the first subplate (1230) may be a metal formed from copper, a copper alloy, nickel, a nickel alloy, etc.

[0066] More specifically, for example, when the first electrode portion (1200) is a positive electrode, the first terminal plate (1210) and the first sub-plate (1230) may be formed of the same main component material, and the first electrode terminal (1220) connecting the first terminal plate (1210) and the first sub-plate (1230) may also be formed of the same main component material.

[0067] When the first electrode portion (1200) is a negative electrode, the first terminal plate (1210) may be formed from a first material, and the first sub-plate (1230) may be formed from a second material different from the first material.

[0068] In another embodiment, when the first electrode portion (1200) is a positive electrode, the bus bar is formed of a different material from the first sub-plate (1230), for example, the first sub-plate (1230) is formed of a first material, and the first terminal plate (1210) connected to the bus bar can be formed of a second material different from the first material.

[0069] In order to allow the first terminal plate (1210) and the first sub-plate (1230) formed of different materials to be energized, a first electrode terminal (1220) formed by stacking the first material and the second material is installed between the first terminal plate (1210) and the first sub-plate (1230), so that the main components can be bonded to the same material.

[0070] For example, as shown in FIG. 4, the first electrode terminal (1220) may be formed by laminating a first material having the same main component as the first terminal plate (1210) and a second material having the same main component as the first sub-plate (1230) in the width or length direction of the top plate (1100).

[0071] More specifically, for example, the first electrode terminal (1220) may include a core portion (1221) and a clad portion (1222).

[0072] The core portion (1221) can be formed in various shapes such as circular, elliptical, and square.

[0073] The core portion (1221) is formed from a first material, and the first material may include aluminum, aluminum alloy, etc.

[0074] The clad portion (1222) may be formed to surround the outer surface of the core portion (1221). For example, the clad portion (1222) may be formed to surround the direction perpendicular to the axial direction of the core portion (1221).

[0075] The clad portion (1222) is formed from a second material, and the second material may include copper, copper alloy, nickel, nickel alloy, etc.

[0076] The clad portion (1222) and the core portion (1221) are a laminate of heterogeneous materials that are bonded together through bonding and stabilization, in which the mutual structure of the contact surfaces of the clad portion (1222) and the core portion (1221) is destroyed due to strong heat and pressure.

[0077] By forming a clad portion (1222) on the outer surface of the core portion (1221), corrosion and damage to the core portion (1221) can be protected even if the electrolyte contained inside the cell case flows into the first electrode terminal (1220).

[0078] The upper surface of the first electrode terminal (1220) may be joined to the first terminal plate (1210), and the lower surface of the first electrode terminal (1220) may be joined to the first sub-plate (1230).

[0079] Specifically, the upper surface of the core portion (1221) of the first electrode terminal (1220) may be joined to the first terminal plate (1210), and for example, the first terminal plate (1210) and the core portion (1221) may be joined by welding above the first terminal plate (1210).

[0080] The clad portion (1222) of the first electrode terminal (1220) can have its lower surface joined to the first subplate (1230), for example, the clad portion (1222) and the first subplate (1230) can be joined by direct bonding on the lower surface of the clad portion (1222). Additionally, the clad portion (1222) and the first subplate (1230) can be joined by various methods such as welding or laser welding.

[0081] That is, the core portion (1221) of the first electrode terminal (1220) and the first terminal plate (1210) are joined, and the clad portion (1222) of the first electrode terminal (1220) and the first sub-plate (1230) are joined, so that the configuration formed of the same main component is joined, thereby lowering the resistance from inside the cell case to the bus bar and increasing the power transfer efficiency.

[0082] As another example, as illustrated in FIG. 5, the first electrode terminal (1220) may be formed by stacking an upper laminate (1223) formed of a first material having the same main component as the first terminal plate (1210) and a lower laminate (1224) formed of a second material having the same main component as the first sub-plate (1230) in the height direction of the cap plate (1000).

[0083] Specifically, for example, the upper laminate (1223) is formed from a first material and may include aluminum, aluminum alloy, etc., and the lower laminate (1224) is formed from a second material and may include copper, copper alloy, nickel, nickel alloy, etc.

[0084] The upper laminate (1223) and the lower laminate (1224) are a laminate of heterogeneous materials that are bonded together through bonding and stabilization, in which the mutual structure of the surfaces where the upper laminate (1223) and the lower laminate (1224) come into contact is destroyed due to strong heat and pressure.

[0085] That is, the first electrode terminal (1220) is heterogeneously joined with an upper stacked portion (1223) and a lower stacked portion (1224) formed of different materials, so that the first electrode terminal (1220) can be easily joined to the upper stacked portion (1223) and the first subplate (1230) can be easily joined to the lower stacked portion (1224), and by joining a configuration formed of the same main component, the resistance from inside the cell case to the bus bar can be lowered and the power transfer efficiency can be increased.

[0086] A cap plate according to some embodiments of the present invention may further include a third sealing portion (1250).

[0087] The third seal (1250) may be formed by being coupled to the lower part of the top plate (1100) to support the first sub-plate (1230).

[0088] As shown in FIGS. 2 and 3, the third seal (1250) is formed in a flat plate shape, and an opening that penetrates vertically may be formed in at least a portion.

[0089] The upper surface of the third sealing part (1250) is installed by being coupled to the lower surface of the top plate (1100), and the lower surface of the third sealing part (1250) can be coupled to the upper surface of the first sub-plate (1230). At this time, the first electrode terminal (1220) joined to the first sub-plate (1230) through the opening can be inserted.

[0090] The third seal (1250) is formed between the first subplate (1230) and the top plate (1100) so as to separate the first subplate (1230) from the top plate (1100).

[0091] FIG. 6 is a cross-sectional view showing a battery cell according to one embodiment of the present invention.

[0092] A battery cell according to one embodiment of the present invention may include an electrode assembly (2000), a cell case (3000), and a cap plate (1000), as shown in FIG. 6.

[0093] As illustrated in FIG. 6, the electrode assembly (2000) is a structure in which a first electrode (2200) and a second electrode (2300) are formed on both sides of a separator (2100). Specifically, the first electrode (2200) and the second electrode (2300), which are each formed as a single plate with the separator (2100) in between, can be assembled by stacking them, or the separator (2100), the first electrode (2200), and the second electrode (2300) can be assembled by folding them in a zigzag shape and stacking them.

[0094] The cell case (3000) is a case that houses an electrode assembly (2000) and has an electrode receiving portion formed inside, and has an opening formed on one side to allow the electrode assembly (2000) to be connected, and the opening can be sealed with a cap plate (1000) to accommodate the electrode assembly (2000) and electrolyte inside.

[0095] A cap plate (1000) is formed to cover the upper part of a cell case (3000), and a first electrode part (1200) and a second electrode part (1300) may be respectively installed on a top plate (1100) in which a first receiving hole and a second receiving hole are formed so as to communicate the inside and outside of the cell case (3000).

[0096] The first electrode portion (1200) may include a positive terminal installed in a conductive state on the top plate (1100), and the second electrode portion (1300) may include a negative terminal installed in an insulated state on the top plate (1100). At this time, the top plate (1100) and the cell case (3000) may be charged in a positive state.

[0097] The first electrode part (1200) is coupled to the first receiving hole at the upper and lower parts of the top plate (1100) and can be installed in a conductive state on the top plate (1100) and connected to the first electrode (2200).

[0098] Specifically, as illustrated in FIG. 6, the first electrode portion (1200) may include a first terminal plate (1210), a first sealing portion (1240), a first electrode terminal (1220), and a first sub-plate (1230).

[0099] The first terminal plate (1210) can be installed by being seated on the upper part of the top plate (1100) so as to be connected to a bus bar for connecting multiple cells on the outside of the cell case (3000).

[0100] The upper surface of the first terminal plate (1210) can be formed in a shape corresponding to the shape of the bus bar so as to be combined with the bus bar, and can be surface-treated to increase the current conduction efficiency when in contact with the bus bar.

[0101] A protrusion may be formed on the side of the first terminal plate (1210). The protrusion may be formed by welding at least a portion of the perimeter of the first terminal plate (1210), and may be formed as a stepped portion with a lower portion protruding more than the upper portion of the side of the first terminal plate (1210).

[0102] The first terminal plate (1210) may be formed from a first material and may include aluminum, aluminum alloy, etc.

[0103] The first sealing part (1240) may have a first terminal seating part formed on the upper part where the first terminal plate (1240) is seated.

[0104] The first sealing part (1240) may be formed such that the first terminal plate (1210) is installed in the first terminal seating part (1241) so that the first terminal plate (1210) can be fixed to the first sealing part (1240), and a fixing groove into which the protrusion is inserted may be formed.

[0105] The above fixed groove may be formed in a shape corresponding to the above protrusion at a position corresponding to the circumference of the first terminal plate (1210) in the first sealing portion (1240).

[0106] The first sealing portion (1240) may be formed such that at least a portion is formed on the upper part of the top plate (1100), and the first terminal seating portion is formed on the opposite side in contact with the top plate (1100) to separate the first terminal plate (1210) from the top plate (1100).

[0107] The first sealing part (1240) may have a first through hole formed inside the first receiving hole. Specifically, at least a portion of the first sealing part (1240) may be formed on the inner side of the first receiving hole so that the inner surface of the first receiving hole is blocked from the outside.

[0108] The first sealing part (1240) can be formed by insert injection molding with the top plate (1100) and the first terminal plate (1210).

[0109] The first sealing part (1240) is insert-molded between the top plate (1100) and the first terminal plate (1210), so that they can be easily combined without performing individual assembly processes for each of the top plate (1100), the first sealing part (1240), and the first terminal plate (1210).

[0110] The first sealing part (1240) may include a conductive polymer resin.

[0111] For example, the first seal (1240) may be formed of a polymer composite material including carbon nanotubes.

[0112] For example, the first seal (1240) may be formed of a polymer composite material containing 0.3 to 3 vol% of carbon nanotubes.

[0113] Compared to carbon black, carbon nanotubes exhibit higher electrical conductivity, mechanical strength, mechanical-thermal shock resistance, and injection moldability. Furthermore, carbon nanotubes demonstrate superior electrical conductivity, mechanical-thermal shock resistance, and injection moldability even when compared to carbon fiber. Additionally, carbon nanotubes can achieve electrical resistance values ​​similar to carbon black and carbon fiber even with low additive amounts, resulting in a significant increase in flame retardancy.

[0114] The first sub-plate (1230) is formed from a second material and connected to the first electrode terminal (1220) to conduct electricity, and can be connected to the lower part of the first electrode terminal (1220). For example, the first sub-plate (1230) is formed in a flat shape, so that one side is joined to the first electrode terminal (1220) and the other side is joined to a tab portion inside the cell case, so that electricity can be conducted from the tab portion to the first electrode terminal (1220).

[0115] The first electrode terminal (1220) can be inserted into the first through hole and coupled so as to conduct electricity from the inside of the cell case (3000) to the first terminal plate (1210).

[0116] The second electrode terminal (1320) is formed from a first material including aluminum, aluminum alloy, etc., and can be formed as a single body. Thus, the first sub-plate (1230), the first electrode terminal (1220), and the first terminal plate (1210) can be formed from the same material as the main component, thereby increasing power transfer efficiency.

[0117] The first terminal plate (1210), the first seal (1240), the first electrode terminal (1220), and the first sub-plate (1230) may include various embodiments as illustrated in FIGS. 2 to 5, and are identical to those described above.

[0118] The cap plate (1000) may include a second electrode part (1300) that is installed in an insulated state in the second through hole formed in the top plate (1100) and connected to the second electrode (2300).

[0119] Specifically, as illustrated in FIG. 6, the second electrode portion (1300) may include a second terminal plate (1310), a second sealing portion (1340), a second electrode terminal (1320), and a second sub-plate (1330).

[0120] The second terminal plate (1310) can be installed to be seated on the top plate (1100) so as to be connected to the bus bar.

[0121] The upper surface of the second terminal plate (1310) can be formed in a shape corresponding to the shape of the bus bar so as to be combined with the bus bar, and can be surface-treated to increase the current conduction efficiency when in contact with the bus bar.

[0122] A protrusion may be formed on the side of the second terminal plate (1310). The protrusion may be formed by welding at least a portion of the perimeter of the second terminal plate (1310), and may be formed as a stepped portion with the lower part protruding more than the upper part of the side of the second terminal plate (1310).

[0123] The second terminal plate (1310) may be formed from a second material and may include copper, copper alloy, nickel, nickel alloy, etc.

[0124] The second sealing part (1340) may have a second terminal seating part formed on the upper part where the second terminal plate (1310) is seated.

[0125] The second sealing part (1340) is formed such that the second terminal plate (1310) is installed in the second terminal seating part (1341) so that the second terminal plate (1310) can be fixed to the second sealing part (1340), and a fixing groove into which the protrusion is inserted can be formed.

[0126] The above fixed groove may be formed in a shape corresponding to the above protrusion at a position corresponding to the circumference of the second terminal plate (1310) in the second sealing part (1340).

[0127] The second sealing portion (1340) may be formed such that at least a portion is formed on the upper part of the top plate (1100), and a second terminal seating portion (1341) is formed on the opposite side in contact with the top plate (1100) to separate the second terminal plate (1310) from the top plate (1100).

[0128] The second sealing part (1340) may have a second through hole formed inside the second receiving hole. Specifically, at least a portion of the second sealing part (1340) may be formed on the inner side of the second receiving hole so that the inner surface of the second receiving hole is blocked from the outside.

[0129] At this time, the second receiving hole is not filled with the second sealing part (1340), and a second through hole smaller than the second receiving hole is formed inside the second receiving hole, and at least a part of the second electrode part (1300) can be inserted through the second through hole.

[0130] The second receiving hole mentioned above can be formed by penetrating through a hole portion of various shapes, such as a circle, ellipse, or square.

[0131] The second sealing part (1340) is formed to surround the second receiving hole (1130) of the top plate (1100) and can be formed to secure the second terminal plate (1310).

[0132] Specifically, the second seal (1340) can be formed by insert injection molding with the top plate (1100) and the second terminal plate (1310).

[0133] That is, a second sealing part (1340) can be formed by injecting molten material around the second receiving hole (1130) of the top plate (1100) and between the top plate (1100) and the second terminal plate (1310) in a mold in which the top plate (1100) and the second terminal plate (1310) are fixed.

[0134] The second sealing part (1340) is insert-molded between the top plate (1100) and the second terminal plate (1310), so that they can be easily combined without performing individual assembly processes for each of the top plate (1100), the second sealing part (1340), and the second terminal plate (1310).

[0135] In addition, the second terminal plate (1310) and the second sealing part (1340) can be easily fixed, and the space between the second terminal plate (1310) and the second sealing part (1340) can be sealed without a sealing such as a gasket.

[0136] The second sub-plate (1330) is connected to the second electrode terminal (1320) to conduct electricity and can be connected to the lower part of the second electrode terminal (1320). For example, the second sub-plate (1330) is formed in a flat shape, so that one side is joined to the second electrode terminal (1320) and the other side is joined to a tab portion inside the cell case, so that electricity can be conducted from the tab portion to the second electrode terminal (1320).

[0137] The second electrode terminal (1320) can be inserted into the second through hole and coupled so as to conduct electricity from the inside of the cell case (3000) to the second terminal plate (1310).

[0138] For example, the second terminal plate (1310) may be formed from a first material, and the second sub-plate (1330) may be formed from a second material different from the first material. That is, in order to allow current to be supplied to the second terminal plate (1310) and the second sub-plate (1330) formed from different materials, a second electrode terminal (1320) formed by stacking the first material and the second material may be installed between the second terminal plate (1310) and the second sub-plate (1330), so that the main components may be bonded to the same material.

[0139] According to some embodiments, the second electrode terminal (1320) may be formed by laminating a first material having the same main component as the second terminal plate (1310) and a second material having the same main component as the second sub-plate (1330) in the width or length direction of the top plate (1100).

[0140] Specifically, for example, the second electrode terminal (1320) may include a core portion formed of a first material and having its upper surface bonded to a second terminal plate (1310), and a clad portion formed of a second material, having its lower surface bonded to a second sub-plate (1330) and having its outer surface surrounded by the core portion.

[0141] According to some other embodiments, the second electrode terminal (1320) may be formed by stacking an upper laminate formed of a first material having the same main component as the second terminal plate (1310) and a lower laminate formed of a second material having the same main component as the second sub-plate (1330) in the height direction of the cap plate (1000).

[0142] According to various embodiments of the present invention, the cap plate and the battery cell including the same are manufactured with a new conductive plastic material to ensure high stability of electrical conductivity of the battery cell, sufficient mechanical strength, and increased mechanical and thermal shock resistance, and can achieve a low electrical resistance value with a small amount of additive, thereby increasing flame retardancy.

[0143] Accordingly, in the event of a risk caused by a short circuit, high heat, or overcurrent inside the battery, flame retardant performance is maintained for a sufficient period of time, thereby providing the user with sufficient time to respond and take action.

[0144] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0145] 1000: Cap plate 1100: Top Plate 1200: First electrode part 1210: 1st terminal plate 1220: First electrode terminal 1221: Core section 1222: Cladbu 1230: 1st subplate 1240: 1st Confidential Department 1250: Third Secret Division 1300: Second electrode part 2000: Electrode assembly 3000: Cell case

Claims

Claim 1 A cap plate formed to cover a cell case of a secondary battery, comprising: a top plate having a first receiving hole formed therein with at least a portion penetrating so as to communicate with the inside and outside of the cell case; and a first electrode portion coupled to the first receiving hole at the upper and lower portions of the top plate; wherein the first electrode portion comprises: a first terminal plate installed on the upper portion of the top plate to be connected to a bus bar for connecting a plurality of cells on the outside of the cell case; a first sealing portion formed of a polymer composite material including carbon nanotubes, having a first terminal mounting portion formed on the upper portion on which the first terminal plate is mounted, a first through hole formed inside the first receiving hole, and formed to space the first terminal plate from the top plate; and a first electrode terminal inserted into and coupled to the first through hole to conduct electricity from the inside of the cell case to the first terminal plate. A cap plate comprising: a first subplate connected to conduct electricity with the first electrode terminal and connected to the lower part of the first electrode terminal; wherein the polymer composite material is formed in a structure in which carbon nanotubes, which are an electrically conductive material, are dispersed in a matrix made of a polymer material. Claim 2 In claim 1, the first sealing portion is a cap plate formed of a polymer composite material comprising 0.3 to 3 vol% carbon nanotubes. Claim 3 In claim 1, the first sealing portion is formed by insert injection molding on the top plate and the first terminal plate so as to be formed between the top plate and the first terminal plate, a cap plate. Claim 4 In claim 1, the first electrode terminal is a cap plate formed by laminating a first material having the same main component as the first terminal plate and a second material having the same main component as the first sub-plate in the width or length direction of the top plate. Claim 5 In claim 4, the first electrode terminal comprises: a core portion formed of the first material and having an upper surface joined to the first terminal plate; and a clad portion formed of the second material, formed to surround the outer surface of the core portion and having a lower surface joined to the first sub-plate; a cap plate. Claim 6 In claim 1, the first electrode terminal is a cap plate formed by stacking an upper laminated portion formed of a first material having the same main component as the first terminal plate and a lower laminated portion formed of a second material having the same main component as the first sub-plate in the height direction of the cap plate. Claim 7 A cap plate comprising: a third sealing portion formed by being coupled to the lower part of the top plate to support the first subplate in claim 1. Claim 8 An electrode assembly having a first electrode and a second electrode formed on both sides of a separator; a cell case having an electrode receiving portion formed inside to house the electrode assembly; The apparatus comprises: a cap plate formed to cover the upper portion of the cell case and having a first electrode portion installed in a conductive state and connected to the first electrode, wherein a first receiving hole is formed to communicate the inside and outside of the cell case, and a second electrode portion installed in an insulated state and connected to the second electrode, wherein the first electrode portion comprises: a first terminal plate installed on the upper portion of the top plate to be connected to a bus bar for connecting a plurality of cells on the outside of the cell case; a first sealing portion formed of a polymer composite material including carbon nanotubes, wherein a first terminal seating portion is formed on the upper portion on which the first terminal plate is seated, a first through hole is formed inside the first receiving hole, and the first terminal plate is formed to be spaced apart from the top plate; and a first electrode terminal inserted into and coupled to the first through hole to conduct electricity from the inside of the cell case to the first terminal plate. A battery cell comprising: a first subplate connected to conduct electricity with the first electrode terminal and connected to the lower portion of the first electrode terminal; wherein the polymer composite material is formed in a structure in which carbon nanotubes, which are an electrically conductive material, are dispersed in a matrix made of a polymer material. Claim 9 In claim 8, the first seal is formed of a polymer composite material comprising 0.3 to 3 vol% carbon nanotubes, forming a battery cell. Claim 10 In claim 8, the battery cell comprises: a second terminal plate installed on the upper part of the top plate so as to be connected to the bus bar; a second terminal mounting portion formed on the upper part where the second terminal plate is mounted, a second through hole formed inside the second receiving hole, and a second sealing portion formed to separate the second terminal plate from the top plate; a second electrode terminal inserted into the second through hole and coupled so as to conduct electricity from the inside of the cell case to the second terminal plate; and a second sub-plate connected to conduct electricity with the second electrode terminal and connected to the lower part of the second electrode terminal. Claim 11 In claim 10, the battery cell wherein the second electrode terminal is formed by laminating a first material having the same main component as the second terminal plate and a second material having the same main component as the second sub-plate in the width or length direction of the top plate. Claim 12 A battery cell according to claim 11, wherein the second electrode terminal comprises: a core portion formed of the first material and having an upper surface bonded to the second terminal plate; and a clad portion formed of the second material, formed to surround the outer surface of the core portion, and having a lower surface bonded to the second sub-plate. Claim 13 In claim 10, the battery cell is formed such that the second electrode terminal is formed by stacking an upper laminated portion formed of a first material having the same main component as the second terminal plate and a lower laminated portion formed of a second material having the same main component as the second sub-plate in the height direction of the cap plate.

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