Welding heat shielding member, damage prevention structure for electrode assemblies to which it is applied, and battery cell to which it is applied

Abstract

Embodiments of the present invention provide a battery cell comprising a can including a bottom member and a side wall member, a cap covering the opening of the can, and an electrode assembly housed inside the can. A current collector plate is connected to electrode tabs provided at the second end of the electrode assembly, which is located on the open end side of the can, of the first and second ends, which are respectively located on both sides in the axial direction of the electrode assembly. The current collector plate includes an electrode tab connecting portion that contacts the electrode tab and is electrically connected to the electrode tab, a can connecting portion provided radially outside the electrode tab connecting portion and contacting the can and being electrically connected to the can, and a conductive connecting portion that electrically connects the can connecting portion and the electrode tab connecting portion. The periphery of one side end of the side wall member and the outer edge of the cap in the radial direction are seam-welded along the outer circumference, and at least a portion of a heat insulating member is interposed between the current collector plate and the electrode assembly in the axial direction.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0083012 filed on June 27, 2023, and Korean Patent Application No. 10-2024-0069583 filed on May 28, 2024, and all the content disclosed in the specifications and drawings of the said applications is incorporated into this application.

[0002] The present invention relates to a welding heat shielding member applied to prevent damage to the separator of an electrode assembly caused by welding heat generated during the welding process of a battery can, a damage prevention structure of an electrode assembly to which the same is applied, and a battery cell to which the same is applied.

Background Art

[0003] The process of manufacturing a battery cell applying a cylindrical can includes deep drawing a metal sheet to form a circular bottom and a circular tubular side wall member connected to the bottom member, accommodating an electrode assembly therein, and then covering and sealing the open end of the side wall member with a cap or a lid. Hereinafter, for convenience of explanation, the cap or the lid is collectively referred to as a cap.

[0004] On the other hand, a current collector plate that is in contact with and electrically connected to the electrode tab of the electrode assembly is provided at an end of the electrode assembly facing the open end in the axial direction. The current collector plate is connected to the cap or the side wall member by a method such as welding so as to be in contact with and electrically connected to the cap or the side wall member.

[0005] A cylindrical lithium-ion battery requires excellent sealing performance to prevent performance degradation due to leakage of an electrolytic solution and ignition due to contact with air or moisture. Therefore, seam welding using a laser has been developed in the process of assembling a cylindrical can and a cap.

[0006] Laser seam welding is known to provide excellent airtightness and mechanical strength by using a laser to melt and join cans and caps. However, lasers are a high-energy-density heat source, and welding heat can be transferred outside the weld during welding. This can damage other parts surrounding the weld.

[0007] In particular, the separation membrane of electrode assemblies made of fine porous polymer films is more susceptible to damage such as thermal deformation, burning, and melting compared to the steel, aluminum, and copper materials that make up the electrode assemblies and other components. However, using a low-energy-density laser to prevent this can reduce the width and penetration depth of the weld bit, potentially lowering the airtightness and mechanical strength of the welded area. In other words, there is a trade-off between the possibility of damage to the separation membrane due to laser power and airtightness.

[0008] These characteristics make it difficult to optimize laser process variables. Furthermore, they can narrow the process window during mass production, potentially reducing product yield.

[0009] Therefore, there is a need for a method that can prevent damage to the separation membrane due to welding heat, even when using a high-energy-density laser during laser seam welding. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The present invention was devised to solve the above-mentioned problems, and aims to provide a method that can prevent welding heat generated during the seam welding process of a battery can from damaging surrounding components.

[0011] Furthermore, the present invention aims to provide a method for seam welding battery cans with a high-energy-density laser to ensure welding quality while preventing the resulting welding heat from damaging surrounding components.

[0012] Furthermore, the present invention aims to provide a solution that can increase the yield by expanding the process window for seam welding of battery cans.

[0013] Furthermore, the present invention aims to provide a method for ensuring a process margin in laser seam welding of battery cans.

[0014] The technical problems of the present invention are not limited to those described above, and other problems and advantages can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, the problems and advantages of the present invention can be realized by the means and combinations thereof shown in the claims. [Means for solving the problem]

[0015] One aspect of the present invention for solving the above-mentioned problems is applied to a battery cell comprising an electrode assembly, a current collector plate electrically connected to the electrode assembly, and a can housing the electrode assembly and the current collector plate.

[0016] The can includes a bottom member, a side wall member connected to the bottom member and extending to one side in the axial direction, and a cap that covers an open end provided at one end of the side wall member in the axial direction.

[0017] The peripheral edge of the one end of the side wall member and the radial peripheral edge of the cap are seam-welded along the outer circumference.

[0018] The electrode assembly may be in the form of a jelly roll wound around a predetermined axis.

[0019] Electrode tabs are provided at both ends of the electrode assembly in the axial direction, at the ends facing the open end, and the current collector plate can be connected to the electrode tabs.

[0020] The current collector plate may include an electrode tab connecting portion that contacts and electrically connects to the electrode tab.

[0021] The current collector plate may include a can connecting portion that contacts the can and is electrically connected thereto.

[0022] The current collector plate may include a conductive connecting portion that connects the can connecting portion and the electrode tab connecting portion therebetween.

[0023] The can connecting portion and the electrode tab connecting portion may be electrically connected to each other by the conductive connecting portion.

[0024] The current collector plate may include an inner ring.

[0025] The inner ring may define a hole facing the core hollow portion of the electrode assembly.

[0026] The current collector plate may further include an outer ring that extends in a form surrounding the inner ring on the radially outer side of the inner ring.

[0027] The current collector plate may further include at least one first spoke (spoke) that is connected to the inner ring and extends radially outward from the inner ring, and at least one second spoke.

[0028] The first spoke may extend radially outward from a first position in the outer circumferential direction of the inner ring.

[0029] The second spoke may extend radially outward from a second position in the outer circumferential direction of the inner ring that does not overlap with the first position.

[0030] The first spoke and the second spoke may be arranged spaced apart from each other in the outer circumferential direction.

[0031] The outer ring may be arranged spaced apart from the first spoke and connected to the second spoke.

[0032] The outer ring may be positioned radially outward from the radially outer end of the first spoke.

[0033] The outer ring may be connected to the radially outer end of the second spoke.

[0034] The inner ring may have a closed-loop or open-loop shape.

[0035] The outer ring may have a closed-loop or open-loop shape.

[0036] Preferably, the outer ring may have a closed-loop shape.

[0037] The electrode tab connecting portion may be positioned at least on the first spoke.

[0038] The electrode tab connecting portion may also be positioned at a first position in the outer circumference direction of the inner ring.

[0039] The can connecting portion may be positioned in the outer ring.

[0040] The conductive connecting portion may be arranged at least on the second spoke.

[0041] The conductive connecting portion may also be positioned at a second position in the outer circumference direction of the inner ring.

[0042] The conductive connecting portion may also be positioned at a third position located between the first position and the second position in the outer circumference direction of the inner ring.

[0043] The conductive connecting portion may be further positioned at a first position in the outer circumference direction of the inner ring.

[0044] The battery cell includes a heat insulating member that suppresses the transfer of heat generated during the seam welding process between the side wall member and the cap to the electrode assembly.

[0045] At least a portion of the heat insulating member is interposed between the current collector plate and the electrode assembly in the axial direction.

[0046] The heat insulating member may be positioned outside the space between the electrode tab connecting portion and the electrode assembly in the axial direction.

[0047] The heat insulating member may be positioned outside the space between the first spoke and the electrode assembly in the axial direction.

[0048] The avoidance groove provided in the heat insulating member prevents the heat insulating member from being interposed between the electrode tab connecting portion and the electrode assembly in the axial direction.

[0049] At least a portion of the heat insulating member may be positioned between the can connecting portion and the electrode assembly in the axial direction.

[0050] At least a portion of the thermal insulation member may be positioned between the outer ring and the electrode assembly in the axial direction.

[0051] At least a portion of the heat insulating member may be positioned between the second spoke and the electrode assembly in the axial direction.

[0052] At least a portion of the heat insulating member may be positioned between the second position on the outer circumference of the inner ring and the electrode assembly in the axial direction.

[0053] At least a portion of the heat insulating member may be positioned between the third position on the outer circumference of the inner ring and the electrode assembly in the axial direction.

[0054] At least a portion of the heat insulating member may be positioned between the first position on the outer circumference of the inner ring and the electrode assembly in the axial direction.

[0055] At least a portion of the thermal insulation member may be positioned outside the electrode tab connecting portion in the radial direction.

[0056] At least a portion of the heat insulating member may be positioned outside the first spoke in the radial direction.

[0057] At least a portion of the thermal insulation member may be positioned between two adjacent electrode tab connecting portions in the outer peripheral direction.

[0058] At least a portion of the heat insulating member may be arranged between the first spokes in the outer peripheral direction.

[0059] The heat insulating member can cover the space between the electrode tab connecting portion and the can connecting portion in the radial direction.

[0060] The heat insulating member can cover the space between the first spoke and the outer ring in the radial direction.

[0061] The heat insulating member can cover the space between the inner ring and the outer ring in the radial direction.

[0062] The heat insulating member can cover the space between the electrode tab connecting portion and the conductive connecting portion in the outer peripheral direction.

[0063] The heat insulating member can cover the space between the first spoke and the second spoke in the outer peripheral direction.

[0064] The heat insulating member can cover the separation space between the electrode tab connecting portion and the can connecting portion in the radial and / or outer peripheral directions.

[0065] The aforementioned heat insulating member may include a high heat-resistant polymer material.

[0066] The aforementioned heat insulating material may be made of a material that is substantially inactive with the electrolyte.

[0067] The heat insulating member may be substantially chemically stable with respect to the electrolyte injected into the can.

[0068] The aforementioned heat insulating material may include at least one of the following: polycarbonate (PC), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), and polyethylene terephthalate (PET).

[0069] The can connecting portion or outer ring may include a first portion that contacts the side wall member and a second portion that contacts the cap.

[0070] The first portion and the side wall member can be joined by welding.

[0071] The second part and the cap can be joined by welding.

[0072] The first and second parts can be welded together in a single process.

[0073] The welding may be laser welding.

[0074] The first portion may be a can connecting portion or an outer ring outer surface that faces and contacts the inner circumferential surface of the side wall member in the radial direction.

[0075] The second portion may be the axial outer surface of the outer ring that faces and contacts the axial inner surface of the cap in the axial direction.

[0076] The cap may include an outer circumferential surface that faces and contacts the inner circumferential surface of the side wall member in the radial direction.

[0077] The battery cell may include a welded portion formed by welding together the inner circumferential surface of the side wall member, the outer circumferential surface of the cap, and the can connecting portion of the current collector plate or the first and second portions of the outer ring.

[0078] The outer circumferential surface of the cap and the outer circumferential surface of the can connecting portion or outer ring can each come into contact with the inner circumferential surface of the side wall member.

[0079] The axial ends of the outer circumferential surface of the cap and the inner circumferential surface of the side wall member, which are in contact in the radial direction, may be exposed to the outside in the axial direction.

[0080] The welded portion can be formed by a laser irradiated from the axial outside of the battery cell to the outer circumferential surface of the cap and the axial end of the inner circumferential surface of the side wall member.

[0081] The thermal conductivity of the current collector plate may be higher than that of the side wall member. This allows welding heat to be dispersed to the electrode assembly through the current collector plate.

[0082] As the welding heat is conducted through the current collector plate, the temperature may gradually decrease. Therefore, it is preferable that the insulating member be interposed between the current collector plate and the electrode assembly, at least in the portion corresponding to the initial path through which the welding heat is conducted.

[0083] In the current collector plate, the position where welding heat is first conducted may be the outer ring. The welding heat can be conducted in the current collector plate in the order of outer ring, second spoke, inner ring and first spoke, or in the order of can connection, conductive connection and electrode tab connection.

[0084] Therefore, the heat insulating member may be placed at least between the can connection portion or outer ring of the current collector plate and the electrode assembly. Preferably, the heat insulating member may be further placed between the conductive connection portion or second spoke of the current collector plate and the electrode assembly.

[0085] Additionally, the heat insulating member may be further positioned between at least a portion of the inner ring and the electrode assembly.

[0086] Furthermore, the welding heat can also be transferred to the electrode assembly by radiation.

[0087] Therefore, preferably, the heat insulating member can cover the separation space between the electrode tab connecting portion and the can connecting portion, or the separation space between the outer ring, the inner ring, the first spoke, and the second spoke, in the radial and / or circumferential direction. Specifically, the heat insulating member can cover the electrode assembly so that it is not exposed through the separation space.

[0088] Laser seam welding may be performed circumferentially along the periphery of the current collector plate. Therefore, preferably, the heat insulating member may include a ring shape that extends radially inward by a predetermined distance from the periphery of the current collector plate.

[0089] In this case, the heat insulating member may have a shape in which at least the portion corresponding to the electrode tab connecting portion or the first spoke of the current collector plate has been removed. [Effects of the Invention]

[0090] According to one aspect of the present invention, the influence of welding heat on the electrode assembly can be minimized by applying a welding heat shielding member. This makes it possible to perform seam welding using a high-energy-density laser.

[0091] According to one aspect of the present invention, the influence of welding heat on the electrode assembly can be minimized while ensuring sufficient width and penetration depth of the welding bit. This makes it possible to prevent damage to the separation membrane while ensuring sufficient sealing ability and mechanical strength of the welded joint.

[0092] According to one aspect of the present invention, it is possible to easily optimize the laser process variables, expand the process window during mass production, and secure process margins to increase the production yield of products.

[0093] Along with the effects described above, the specific effects of the present invention will be explained together with the specific matters for carrying out the invention, which will be described later. [Brief explanation of the drawing]

[0094] [Figure 1] This is a perspective view of a cylindrical battery cell according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the electrode assembly housed inside the can before winding. [Figure 3] Figure 2 is a perspective view of the electrode assembly in its stacked state before winding. [Figure 4] Figure 3 is a perspective view showing the laminated material wound up to form a cylindrical jelly-roll type electrode assembly. [Figure 5] This is a perspective view showing the state in which the first current collector plate is joined to the electrode tab of the first electrode of the electrode assembly. [Figure 6] This is a perspective view showing the process of joining the second current collector plate to the electrode tab of the second electrode of the electrode assembly with an insulating material interposed therebetween. [Figure 7] This is a perspective view showing the state in which the second current collector plate is joined to the electrode tab of the second electrode of the electrode assembly with an insulating material interposed therebetween. [Figure 8] This is a cross-sectional view showing the process of housing the electrode assembly, to which the current collector plates are joined, inside the can. [Figure 9] This is a cross-sectional view showing the joining process between the first current collector plate and the first electrode terminal of the electrode assembly housed in a can. [Figure 10] This is a cross-sectional view showing the process of covering the open end of a can containing an electrode assembly with a cap. [Figure 11] This is a cross-sectional view showing the open end of the can containing the electrode assembly covered with a cap. [Figure 12] This is a cross-sectional view showing the process of pouring electrolyte through the cap's filling port after seam welding the cap to the can's side wall member. [Figure 13] This is a cross-sectional view showing the state after the electrolyte solution has been injected and the injection port of the cap has been sealed with a stopper. [Figure 14] Figure 11 is a magnified view of the side wall member, current collector plate, and cap of the battery cell where welding takes place. [Figure 15]Figure 14 shows the process of welding the side wall member, current collector plate, and cap together to form a welded joint. [Figure 16] This is a plan view of the second current collector plate. [Figure 17] This is a plan view of the insulation material. [Figure 18] This is a plan view showing the second current collector plate with an insulating material superimposed on it. [Figure 19] This is a cross-sectional view along line XIX-XIX in Figure 18. [Figure 20] This is a cross-sectional view along the line XX-XX in Figure 18. [Figure 21] This is a flowchart of a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 22] This is a flowchart of a method for manufacturing a battery cell according to a modified embodiment of the present invention. [Figure 23] This figure shows a battery pack to which a battery cell of one embodiment has been applied. [Figure 24] Figure 23 shows a car equipped with a battery pack. [Modes for carrying out the invention]

[0095] The aforementioned problems, features, and advantages will be described in detail later with reference to the attached drawings. This will enable a person with ordinary skill in the art to which the present invention pertains to be able to easily implement the technical idea of ​​the present invention. In the description of the present invention, if it is determined that a specific description of the relevant prior art may obscure the gist of the present invention, such detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0096] Furthermore, while terms such as "first," "second," etc., are used to indicate various components, these components are not limited by these terms. These terms are used to distinguish one component from another, and unless otherwise specified, the first component may be the second component.

[0097] Throughout the specification, unless otherwise specified, each component may be singular or plural.

[0098] Furthermore, the placement of any configuration "above (or below)" or "above (or below)" a component means not only that the configuration is placed in contact with the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed above (or below) it.

[0099] Furthermore, when one component is described as being "connected," "joined," or "linked" to another component, this includes not only cases where the components are directly connected to or linked to each other, but also cases where other components are "interposed" between each component, or where each component is "connected," "joined," or "linked" through other components.

[0100] As used herein, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “composed of” or “including” are not to be interpreted as including all of the various components or stages described herein, but rather as not including some of the components or stages, or including additional components or stages.

[0101] Throughout this specification, "A and / or B" means A or B, or A and B, unless otherwise specified, and "C to D" means C to D unless otherwise specified.

[0102] In the description of the embodiments, the axial direction refers to the direction in which the axis forming the winding center of the jelly roll-type electrode assembly extends, the radial direction refers to the direction that is closer to (centripetal) or further away from (centrifugal) the axis, and the outer circumference (circumferential) direction refers to the direction that surrounds the axis.

[0103] Hereinafter, an embodiment of a battery cell to which the welding heat shielding member, i.e., the heat insulating member, of the present invention is applied will be described in detail with reference to Figures 1 to 20.

[0104] One embodiment of a battery cell may be a cylindrical battery cell in which the form factor ratio (defined as the ratio of the diameter to the height of a cylindrical battery cell, i.e., the ratio of height (H) to relative diameter (Φ)) is greater than approximately 0.4.

[0105] Here, form factor refers to a value that indicates the diameter and height of a cylindrical battery cell. Cylindrical battery cells can be, for example, 46110 cells, 48750 cells, 48110 cells, 48800 cells, or 46800 cells. In the numerical value indicating the form factor, the first two digits indicate the diameter of the cell, the following two digits indicate the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0106] The battery cell may be a cylindrical battery cell that is roughly cylindrical in shape, with a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0107] A battery cell according to another embodiment may be a cylindrical battery cell that is substantially cylindrical, with a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0108] Furthermore, a battery cell according to another embodiment may be a cylindrical battery cell that is substantially cylindrical, with a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0109] Furthermore, a battery cell according to another embodiment may be a cylindrical battery cell that is substantially cylindrical, with a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0110] Furthermore, a battery cell according to another embodiment may be a cylindrical battery cell that is substantially cylindrical in shape, with a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0111] The present invention can, of course, also be applied to battery cells with a form factor ratio of approximately 0.4 or less, such as 18650 cells and 21700 cells. In the case of an 18650 cell, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. In the case of a 21700 cell, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0112] One embodiment of the battery cell includes an electrode assembly 20, current collector plates 31 and 32 electrically connected to the electrode assembly 20, and a can 10 that houses the electrode assembly 20 and the current collector plates 31 and 32.

[0113] The can 10 includes a bottom member 12, a side wall member 11 connected to the bottom member 12 and extending in the axial direction, and a cap 16 that covers an open end provided at one axial end of the side wall member 11.

[0114] The bottom member 12 is a disc shape with a hole formed in the center, and the side wall member 11 may be a circular tube.

[0115] The bottom member 12 and the side wall member 11 can be manufactured by forming a metal sheet with nickel plating on the surface of steel using a deep drawing process, and then trimming the tip of the side wall member 11 with a punch while holding it in a blank holder. Of course, the material of the can 10 is not limited to this.

[0116] A first electrode terminal 13 can be fitted into the hole. The first electrode terminal 13 can be fixed to the bottom member 12 by riveting with a gasket 14 in between. The gasket 14 is interposed between the first electrode terminal 13 and the bottom member 12 to seal the inside and outside of the can 10, prevent leakage of the electrolyte, and electrically insulate the first electrode terminal 13 from the bottom member 12.

[0117] However, the method of connecting the first electrode terminal 13 and the bottom member 12 is not limited to this. For example, as long as the structure can seal the space between the first electrode terminal 13 and the bottom member 12 and electrically insulate the first electrode terminal 13 and the bottom member 12, a variety of other fixing methods can be applied, such as a bolt-nut connection method, a glass seal method, or a chrome coating & PP-MAH thermal bonding method.

[0118] The first electrode terminal 13 has a first polarity, and the can 10 may have a second polarity. That is, the bottom member 12 of the can 10, the side wall member 11 connected to the bottom member 12, and the cap 16, which will be described later and connected to the side wall member 11, may all have a second polarity.

[0119] As a result, the battery cell can have both the first electrode terminal 13 and the second electrode terminal 15 located at the axial end where the bottom member 12 is provided, i.e., at the closed end. Then, the battery cell can have both the busbar connected to the first electrode terminal 13 and the busbar connected to the second electrode terminal 15 located at the top of the battery cell.

[0120] For example, the first electrode terminal 13 may be the positive terminal and the second electrode terminal 15 may be the negative terminal. Of course, the opposite may also be true.

[0121] The electrode assembly 20 is housed inside the can 10. As shown in Figure 2, the electrode assembly 20 is prepared by preparing a first electrode 21, a second electrode 22, and a separation membrane 28 that have a predetermined width and extend in the longitudinal direction. As shown in Figure 3, a laminate is formed by stacking the first electrode 21, separation membrane 28, second electrode 22, and separation membrane 28 in that order, and then, as shown in Figure 4, it is manufactured in the form of a jelly roll by winding it around a core shaft.

[0122] The first electrode 21 can be the positive electrode, and the second electrode 22 can be the negative electrode. Of course, the opposite is also possible.

[0123] The first electrode 21 and the second electrode 22 are manufactured in sheet form. The electrode sheet is manufactured in a form in which an active material layer 24 is coated on the surface of a metal foil 23. The electrode sheet has a textured area 25 on which the active material layer 24 is coated and a plain area 26 on which the active material layer 24 is not coated. The positive electrode sheet has a plain area 26 on one side in the width direction, and the negative electrode sheet has a plain area 26 on the other side in the width direction.

[0124] The plain area 26 is exposed or protrudes from the laminate in the width direction. The plain area 26 functions as an electrode tab 27 itself.

[0125] Notches can be formed at predetermined intervals in the plain section 26 to create a plurality of flag-shaped notched tabs 27.

[0126] In this embodiment, the multiple notching tabs 27 are exemplified as being in the shape of an equilateral trapezoid. However, these shapes may be a variety of shapes such as semicircular, semielliptical, triangular, rectangular, or parallelogram.

[0127] Furthermore, in the embodiment, an example is shown in which the notching tabs 27 arranged along the longitudinal direction have the same width. However, the width of the multiple notching tabs may be such that they gradually or stepwise increase from the core side to the outer circumference side.

[0128] Furthermore, in the embodiment, a configuration is shown in which the height of the notching tab 27 increases in stages from the core side to the outer circumference side. However, the height of such multiple notching tabs may be constant or gradually decrease.

[0129] Furthermore, in the embodiment, a structure is exemplified in which the notching tab 27 is removed from a predetermined section at the centripetal end and a predetermined section at the centrifugal end of the plain portion 26. However, the notching tab may not be removed from the centripetal end of the plain portion, or it may not be removed from the centrifugal end of the plain portion.

[0130] In the jelly roll-type electrode assembly 20, the notching tab 27 can be bent radially and flattened, as shown in Figure 4. The notching tab 27 can be bent radially inward or outward. In this embodiment, a structure in which the notching tab 27 is bent radially inward is illustrated.

[0131] The notching tabs 27 can be bent one by one during the process of winding the laminate to form the jelly roll-type electrode assembly 20. Alternatively, the notching tabs 27 may be bent all at once after the laminate has been wound to form the jelly roll-type electrode assembly.

[0132] The multiple notched tabs 27 of the first electrode 21 and the multiple notched tabs 27 of the second electrode 22, which are folded radially and overlapped in this manner, can each provide a plane substantially perpendicular to the axial direction at both axial ends of the electrode assembly 20.

[0133] The notched tabs 27 exposed at both axial ends of the electrode assembly 20 are bent to provide a substantially flat surface, which can then be bonded to the first current collector plate 31 and the second current collector plate 32, respectively, as shown in Figures 5 and 6.

[0134] In the embodiment, the first current collector plate 31 is a positive electrode current collector plate, and the second current collector plate 32 is a negative electrode current collector plate. The first current collector plate 31 may be made of aluminum, and the second current collector plate 32 may be made of copper.

[0135] The current collector plates 31 and 32 may be manufactured by punching, trimming, piercing, and / or bending a metal sheet.

[0136] Referring to Figure 5, the first current collector plate 31 includes a terminal connecting portion 312 extending radially from the center, a ring portion 313 connecting the centrifugal periphery of the terminal connecting portion 312 in the circumferential direction, and an electrode connecting portion 314 extending centripetally from the ring portion 313 and not connected to the terminal connecting portion 312. The central part of the terminal connecting portion 312 covers at least a portion of the hollow core of the electrode assembly 20.

[0137] The electrode connecting portion 314 is joined to the notched tab 27 of the first electrode 21 of the electrode assembly 20 by a method such as laser welding before the electrode assembly 20 is placed in the can 10. The laser welding line may extend radially.

[0138] Referring to Figures 6, 7, and 16, the second current collector plate 32 includes an inner ring 321 that defines a hole 322 corresponding to the hollow portion of the core of the electrode assembly 20 and is provided in a manner that surrounds the hollow portion of the core, a first spoke 326 extending radially from the inner ring 321, a second spoke 327 extending radially from the inner ring 321, and an outer ring 328 positioned centrifugal to the first spoke 326 and connected to the centrifugal end of the second spoke 327. The first spoke 326 and the second spoke 327 are connected to first and second positions, respectively, which are different positions on the inner ring 321 in the outer circumference direction. The first spoke 326 and the second spoke 327 are also positioned spaced apart from each other in the outer circumference direction. Furthermore, the outer ring 328 is concentric with the inner ring 321 and is positioned radially outward from the inner ring 321 and the first spoke 326.

[0139] In this embodiment, the inner ring 321 and the outer ring 328 are shown to be in a closed-loop shape, but their shapes are not necessarily limited to this. For example, the inner ring 321 may be C-shaped, and the outer ring 328 may be a plurality of arc shapes formed intermittently and arranged along the outer circumference.

[0140] The second current collector plate 32 includes an electrode tab connecting portion 323 that is joined to and electrically connected to the electrode tab 27 of the second electrode 22 of the electrode assembly 20, a can connecting portion 324 that is joined to and electrically connected to the can 10, and a conductive connecting portion 325 that electrically connects the electrode tab connecting portion 323 and the can connecting portion 324 to each other.

[0141] In the embodiment, the electrode tab connector 323 is exemplified as being located on the first spoke 326, but the arrangement of the electrode tab connector 323 is not limited thereto. For example, the electrode tab connector 323 may be further located on the inner ring 321, specifically at a first position on its outer circumference.

[0142] In the embodiment, the can connector 324 is exemplified as being arranged on the outer ring 328, and the can connector 324 is exemplified as being arranged along the entire outer circumference of the outer ring 328. However, the can connector 324 is not necessarily arranged along the entire outer circumference. For example, the can connector 324 may be arranged intermittently along the outer circumference of the outer ring 328.

[0143] According to the embodiment, the conductive connecting portion 325 is positioned on the second spoke 327. However, the conductive connecting portion 325 may be further positioned on the inner ring 321, specifically at a second position in its outer circumference, in conjunction with the arrangement of the electrode tab connecting portion 323, or at a third position between the first and second positions in its outer circumference.

[0144] In this embodiment, it is illustrated that four first spokes 326 and four second spokes 327 are alternately arranged at 90° intervals. That is, the multiple spokes (first spokes 326, second spokes 327) can be arranged at 45° intervals. On the other hand, this results in four electrode tab connecting portions 323 being provided at 90° intervals.

[0145] The can connection portion 324 is positioned radially outward from the electrode tab connection portion 323.

[0146] The electrode tab connecting portion 323 and the can connecting portion 324 are spaced apart in the radial direction. Also, the electrode tab connecting portion 323 and the conductive connecting portion 325 are spaced apart in the circumferential direction. Specifically, the first spoke 326 and the outer ring 328 are spaced apart in the radial direction, and the first spoke 326 and the second spoke 327 are spaced apart in the circumferential direction.

[0147] Such a separation portion may define a U-shaped separation space 329.

[0148] As a result, the current transfer path in the second current collector plate 32 may be in the order of electrode tab connecting portion 323, conductive connecting portion 325 and can connecting portion 324, in the order of first spoke 326, inner ring 321, second spoke 327 and outer ring 328, or in the reverse order thereof.

[0149] Similarly, the path of welding heat transfer by conduction in the second current collector plate 32 may be in the order of can connection portion 324, conductive connection portion 325 and electrode tab connection portion 323, or in the order of outer ring 328, second spoke 327, inner ring 321 and first spoke 326.

[0150] The electrode tab connecting portion 323 of the second current collector plate 32 may be joined to the notched tab 27 of the second electrode 22 of the electrode assembly 20 by a method such as laser welding before the electrode assembly 20 is housed in the can 10. The laser welding line may extend radially.

[0151] According to one embodiment, a welding heat shielding member may be interposed between the second current collector plate 32 and the electrode assembly 20 to prevent the welding heat between the side wall member 11 and the cap 16 (described later) from affecting the separation membrane 28 of the electrode assembly 20. The welding heat shielding member may be a heat insulating member 18.

[0152] The heat insulating member 18 is preferably made of a material that does not react with the electrolyte and is also highly heat resistant. The heat insulating member 18 may be a polymer material. This may be polycarbonate, polyethylene naphthalate, polyetheretherketone, or polyethylene terephthalate.

[0153] Referring to Figures 6, 7, and 16-20, the heat insulating member 18 is interposed in the axial direction between the second current collector plate 32 and the electrode assembly 20.

[0154] The heat insulating member 18 may include an outer ring portion 181 and a centered extending portion 182 that extends radially inward from the outer ring portion 181.

[0155] The centered extension portion 182 may extend inward by a predetermined distance d from the radial outer edge of the heat insulating member 18.

[0156] The heat insulating member 18 may be provided with avoidance grooves 185 in which the portion corresponding to the electrode tab connecting portion 323 of the second current collector plate 32 has been removed. In this embodiment, four avoidance grooves 185 may be provided at 90° intervals to correspond to the second current collector plate.

[0157] With the heat insulating member 18 interposed between the second current collector plate 32 and the electrode assembly 20, the outer ring portion 181 of the heat insulating member 18 covers the outer ring 328 and a portion of the separation space 329 of the second current collector plate 32, and the centered extension portion 182 of the heat insulating member 18 covers the second spoke 327 of the second current collector plate 32 and the remaining portion of the separation space 329.

[0158] If the portion of the heat insulating member 18 that covers the outer ring 328 of the second current collector plate 32 is defined as the circumferentially extended cover portion 186, then the circumferentially extended cover portion 186 can be defined by a part of the outer ring portion 181.

[0159] Furthermore, if the portion of the heat insulating member 18 that covers the second spoke 327 of the second current collector plate 32 is defined as the radially extending cover portion 184, then the radially extending cover portion 184 can be defined by a part of the centrifugal extending portion 182.

[0160] Furthermore, if the portion of the heat insulating member 18 that covers the separation space 329 of the second current collector plate 32 is defined as the separation space cover portion 183, then the separation space cover portion 183 may be defined by the remaining portion of the outer ring portion 181 and the remaining portion of the centered extension portion 182.

[0161] In other words, the outer ring 328 of the second current collector plate 32 is covered by the outer ring portion 181 of the heat insulating member 18, the second spoke 327 of the second current collector plate 32 is covered by the centered extension portion 182 of the heat insulating member 18, and the separation space 329 of the second current collector plate 32 is covered by the outer ring portion 181 and the centered extension portion 182 of the heat insulating member 18.

[0162] The heat insulating member 18 is interposed axially between the second current collector plate 32 and the electrode assembly 20, and with the avoidance groove 185 of the heat insulating member 18 aligned with the first spoke 326 or electrode tab connecting portion 323 of the second current collector plate 32, the first spoke 326 or electrode tab connecting portion 323 of the second current collector plate 32 is joined to the electrode tab 27 of the second electrode 22 of the electrode assembly 20. Such joining can be performed by irradiating the surface of the electrode tab connecting portion 323 with a laser, and the laser may be irradiated in a radial scanning manner. The laser scan may be performed multiple times at multiple points spaced apart along the outer circumference.

[0163] When welding the electrode tab connecting portion 323, the welding is performed with the first spoke 326 pressed against the electrode tab 27, so that the first spoke 326 can be elastically deformed axially from the inner ring 321 and come into close contact with the electrode tab 27. As a result, the first spoke 326 or the electrode tab connecting portion 323 can be fitted into the avoidance groove 185 of the heat insulating member 18.

[0164] As a result, the peripheral surface of the first spoke 326 interferes with the peripheral surface of the avoidance groove 185, and with the electrode tab connecting portion 323 and the electrode tab 27 of the electrode assembly 20 welded together, the position of the heat insulating member 18 is restricted as shown in Figure 7.

[0165] As shown in Figures 9 and 10, the electrode assembly 20 is housed in the can 10 with the first current collector plate 31 aligned toward the bottom member 12 of the can 10. At this time, an insulator 19 is interposed between the first current collector plate 31 and the bottom member 12 of the can 10 to electrically insulate the first current collector plate 31 from the bottom member 12.

[0166] The terminal connection portion 312 of the first current collector plate 31 is joined to the first electrode terminal 13 fixed to the can 10 by resistance welding, ultrasonic welding, or laser welding. The welding apparatus for welding the first current collector plate 31 and the first electrode terminal 13 can be positioned to approach the back surface of the center of the terminal connection portion 312 of the first current collector plate 31 from the open end of the can 10, through the hollow core of the electrode assembly 20, and perform the welding. Of course, the first current collector plate 31 and the first electrode terminal 13 may also be joined by other methods such as brazing or soldering. In other words, a variety of methods are applicable as long as they are coupling methods that electrically connect and mutually fix the first current collector plate 31 and the first electrode terminal 13.

[0167] With the electrode assembly 20 housed inside the can 10 and the first current collector plate 31 and the first electrode terminal 13 joined, the electrode tab 27 of the second electrode 22 and the second current collector plate 32 are positioned facing the open end of the side wall member 11.

[0168] In this state, as shown in Figures 10 to 12, the open end of the can 10 is covered with the cap 16, and the periphery of the cap 16 is welded to the periphery of the side wall member 11 and the second current collector plate 32. Then, the electrolyte is injected into the can 10 through the liquid injection port 162 of the cap 16.

[0169] After injecting the electrolyte, the battery cell assembly is completed by covering and sealing the electrolyte inlet 162 of the cap 16 with the stopper 164, as shown in Figure 13.

[0170] Unlike the illustrated embodiment, in a structure where the cap 16 does not have a liquid filling port, the electrolyte may be injected into the can 10 before covering the open end of the can 10 with the cap 16, then the open end of the can 10 may be covered with the cap 16, and the periphery of the cap 16 may be welded to the periphery of the side wall member 11 and the second current collector plate 32 to complete the assembly of the battery cell.

[0171] As shown in Figure 14, the contact area between the periphery of the side wall member 11 and the periphery of the cap 16 is exposed outward in the axial direction. A laser for seam welding this area can be irradiated onto the area where the periphery of the side wall member 11 and the periphery of the cap 16 contact in the axial direction. The area irradiated by the laser can then move relative to the area along the circumferential direction of the can 10, continuously forming the welded area W.

[0172] In the battery cell, the welded portion W is formed at the contact point between the side wall member 11, the cap 16, and the second current collector plate 32.

[0173] As shown in Figure 15, during the process of forming the weld W, the welding heat is conducted along the side wall member 11 and further conducted along the second current collector plate 32.

[0174] The second current collector plate 32 may contain a material with a higher thermal conductivity than the side wall member 11, such as copper. The second current collector plate 32 is in contact with the side wall member 11. Therefore, when the welding heat generated on the side wall member 11 by the laser is conducted along the axial direction of the side wall member 11, the welding heat is dispersed to the electrode assembly 20 through the second current collector plate 32. This prevents the welding heat from being conducted axially along the side wall member 11 and transmitted to the separation membrane 28 portion of the outer circumferential surface of the electrode assembly 20 facing the inner circumferential surface of the side wall member 11, thereby damaging the separation membrane 28 in that portion.

[0175] Furthermore, the welding heat conducted to the second current collector plate 32 moves along the outer ring 328, second spoke 327, inner ring 321, and electrode tab connecting portion 323 of the second current collector plate 32. As the welding heat moves, its temperature gradually decreases. At this time, since the insulating member 18 is interposed between the outer ring 328 and second spoke 327 portions of the second current collector plate 32, which are relatively hotter, and the electrode assembly 20, it is possible to prevent high-temperature heat from being transmitted to the inside of the electrode assembly 20 through the electrode tab 27 and affecting the axial tip of the separation membrane 28.

[0176] According to this embodiment, the heat insulating member 18 extends a predetermined distance d from the radial outer edge, so the inner ring 321 is not covered. Furthermore, the avoidance groove 185 prevents the heat insulating member 18 from covering the electrode tab connecting portion 323. Since the temperature of the welding heat that reaches the inner ring 321 and the electrode tab connecting portion 323 by conduction is relatively low, the heat transferred from these to the electrode assembly 20 is unlikely to damage the separation membrane 28.

[0177] On the other hand, the heat insulating member 18 covers the separation space 329 of the second current collector plate 32 between the second current collector plate 32 and the electrode assembly 20. As a result, the portion of the electrode assembly 20 corresponding to the separation space 329 is covered by the heat insulating member 18.

[0178] Because the outer ring 328 of the second current collector plate 32 is very close to the area where welding heat is generated, there is a risk that the heat radiated from the heated outer ring 328 may be transmitted through the separation space 329 to the corresponding area of ​​the electrode assembly 20.

[0179] However, according to the embodiment, since the heat insulating member 18 covers the portion of the electrode assembly 20 corresponding to the separation space 329, it is possible to shield the radiant heat so that it does not damage the separation membrane 28 of the electrode assembly 20.

[0180] The manufacturing method for the battery cells described above will be explained below with reference to Figure 21.

[0181] According to the battery cell manufacturing method, first, a can 10 is prepared with a first electrode terminal 13 fixed to a bottom member 12, and an electrode assembly 20 is prepared by joining a first current collector plate 31 and a second current collector plate 32 to both ends in the axial direction, respectively. At this time, a heat insulating member 18 is interposed between the second current collector plate 32 and the electrode assembly 20.

[0182] Then, the electrode assembly 20 is inserted and housed in the can 10 so that the first current collector plate 31 faces the bottom member 12. As a result, the second current collector plate 32 is positioned on the open end side of the can 10. In this process of housing the electrode assembly 20 in the can 10, the radial outer edge of the second current collector plate 32 is brought into contact with the inner circumferential surface of the side wall member 11.

[0183] Next, the first current collector plate 31 and the first electrode terminal 13 are joined together.

[0184] Then, while covering the open end of the side wall member 11 with the cap 16, the periphery of the cap 16 is brought into contact with the inner circumferential surface of the side wall member 11 and the upper end of the periphery of the second current collector plate 32.

[0185] Next, a laser is irradiated onto the contact area between the inner surface of the side wall member 11 and the outer surface of the cap 16, welding the side wall member 11, the cap 16, and the can connecting portion 324 of the second current collector plate 32 together. As a result, the welded portion W joins the side wall member 11, the cap 16, and the second current collector plate 32 together.

[0186] In this case, the overhang portion 117 of the side wall member 11, which protrudes further outward in the axial direction than the cap 16, can be melted into the welding area between the inner surface of the side wall member 11 and the outer surface of the cap 16, thereby ensuring a sufficient welding pool.

[0187] Even with a high laser energy density, the second current collector plate 32 has an even higher thermal conductivity, preventing high-temperature heat from being transferred to the separation membrane 28 on the outer circumference of the electrode assembly 20 through the side wall member 11 and damaging the separation membrane 28. Furthermore, because the heat insulating member 18 covers the electrode assembly 20, welding heat transferred through the second current collector plate 32 cannot affect the separation membrane 28 of the electrode assembly 20.

[0188] After the seam welding is completed in this manner, the electrolyte is injected into the can 10 through the liquid injection port 162 of the cap 16.

[0189] Furthermore, after the electrolyte injection is complete, the injection port 162 of the cap 16 is covered and sealed with a stopper 164. Since known techniques can be applied to sealing the stopper 164, a detailed explanation is omitted.

[0190] On the other hand, other embodiments of the battery cell manufacturing method described above will be explained below with reference to Figure 22.

[0191] First, a can 10 is prepared with a first electrode terminal 13 fixed to the bottom member 12, and an electrode assembly 20 is prepared by joining a first current collector plate 31 and a second current collector plate 32 to both ends in the axial direction, respectively. At this time, a heat insulating member 18 is interposed between the second current collector plate 32 and the electrode assembly 20.

[0192] Then, the electrode assembly 20 is inserted and housed in the can 10 so that the first current collector plate 31 faces the bottom member 12. As a result, the second current collector plate 32 is positioned on the open end side of the can 10. In this process of housing the electrode assembly 20 in the can 10, the radial outer edge of the second current collector plate 32 is brought into contact with the inner circumferential surface of the side wall member 11.

[0193] Next, the first current collector plate 31 and the first electrode terminal 13 are joined together.

[0194] In this state, the electrolyte is poured into the inside of can 10 through the open end of can 10.

[0195] After the liquid injection is complete, the open end of the side wall member 11 is covered with the cap 16, and the periphery of the cap 16 is brought into contact with the inner circumferential surface of the side wall member 11 and the upper end of the periphery of the second current collector plate 32.

[0196] Next, a laser is irradiated onto the contact area between the inner surface of the side wall member 11 and the outer surface of the cap 16, welding the side wall member 11, the cap 16, and the can connecting portion 324 of the second current collector plate 32 together. As a result, the welded portion W joins the side wall member 11, the cap 16, and the second current collector plate 32 together.

[0197] The battery cells 72 produced through the welded structure and welding process described above can be housed in the housing 71 of the battery pack 70, as shown in Figure 23. The battery pack 70 may be constructed using battery modules, which are an intermediate form of assembly, or the battery pack 70 may be constructed directly without battery modules, as shown.

[0198] Because the aforementioned battery cell 72 has a large volume, the battery pack 70 can be easily realized without using an intermediate structure such as a battery module. Furthermore, the battery cell 72 has low internal resistance and an even higher energy density. As a result, the battery pack 70 equipped with the battery cell 72 can achieve an even higher energy density.

[0199] By increasing the energy density in this way, the battery pack 70 can reduce its volume and weight while storing the same amount of energy. Therefore, if a battery pack 70 incorporating such battery cells 72 is installed in a vehicle such as an automobile 80 that uses electricity as an energy source, as shown in Figure 24, the vehicle's driving range relative to its energy can be further expanded.

[0200] It should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated more by the claims described below than by the detailed description above. Furthermore, the meaning and scope of the claims described below, as well as all modifiable forms derived from their equivalent concepts, are to be interpreted as being included within the scope of the present invention.

[0201] As described above, the present invention has been explained with reference to the embodiments and drawings, but it is obvious that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications are possible by an ordinary person within the scope of the technical concept of the present invention. Furthermore, it goes without saying that even if the effects of the configuration of the present invention are not explicitly stated in the description of the embodiments of the present invention, the effects that can be predicted by such configuration should also be recognized. [Explanation of symbols]

[0202] 10: Can, 11: Side wall member, 117: Overhang section, 12: Bottom member, 13: First electrode terminal (positive electrode terminal), 14: Gasket, 15: Second electrode terminal, 16: Cap, 162: Injection port, 164: Stopper, 18: Heat insulating member (welding heat shielding member), 181: Outer ring section, 182: Centered extension section, 183: Separation space cover section, 184: Radially extending cover section, 185: Avoidance groove 1, 86: Circumferential extension cover section, 19: Insulator, 20: Electrode assembly, 21: First electrode, 22: Second electrode, 23: Metal foil, 24: Active material layer 25: Textured part, 26: Untextured part, 27: Electrode tab (notching tab), 28: Separation membrane, 31: First current collector plate (positive electrode current collector plate), 312: Terminal connection part, 313: Ring part, 314: Electrode connection part, 32: Second current collector plate (negative electrode current collector plate), 321: Inner ring, 322: Hole, 323: Electrode tab connection part, 324: Can connection part, 325: Conductive connection part, 326: First spoke, 327: Second spoke, 328: Outer ring, 329: Separation space, W: Welded part, 70: Battery pack, 71: Housing, 72: Battery cell, 80: Automobile

Claims

1. A battery cell comprising a can including a bottom member, a side wall member connected to the bottom member and extending axially from the bottom member to one side, and a cap covering an open end provided at one end of the side wall member in the axial direction, and an electrode assembly housed inside the can, A current collector plate is connected to the electrode tab provided at the second end, which is located on the open end side of the can, of the first and second ends, which are arranged on both sides in the axial direction of the electrode assembly. The aforementioned current collector plate is An electrode tab connecting portion that contacts the electrode tab and is electrically connected to the electrode tab, A can connecting portion is provided radially outside the electrode tab connecting portion, and is in contact with the can and electrically connected to the can, Includes a conductive connecting portion that electrically connects the can connecting portion and the electrode tab connecting portion, The peripheral edge of the one end of the side wall member and the outer edge of the cap in the radial direction are seam-welded along the outer circumference. A battery cell in which at least a portion of a heat insulating material is interposed between the current collector plate and the electrode assembly in the axial direction.

2. The battery cell according to claim 1, wherein at least a portion of the heat insulating member is arranged outside the electrode tab connecting portion in the radial direction.

3. The battery cell according to claim 1 or 2, wherein at least a portion of the heat insulating member is arranged between two adjacent electrode tab connecting portions in the outer peripheral direction.

4. The battery cell according to claim 1 or 2, wherein at least a portion of the heat insulating member is disposed between the can connecting portion and the electrode assembly in the axial direction.

5. The battery cell according to claim 1 or 2, wherein the heat insulating member covers the space between the electrode tab connecting portion and the can connecting portion in the radial direction.

6. The battery cell according to claim 1 or 2, wherein the heat insulating member covers the space between the electrode tab connecting portion and the conductive connecting portion in the outer peripheral direction.

7. The battery cell according to claim 1 or 2, wherein the heat insulating member is positioned outside the space between the electrode tab connecting portion and the electrode assembly in the axial direction.

8. The aforementioned current collector plate is A hole facing the hollow portion of the core of the electrode assembly is defined, and an inner ring surrounds the hollow portion of the core, The inner ring extends radially outward from the inner ring and is arranged to be spaced apart from each other in the circumferential direction, and the at least one first spoke and at least one second spoke are provided. It includes an outer ring that extends radially outward from the inner ring and surrounds the inner ring, The battery cell according to claim 1 or 2, wherein the outer ring is positioned at a distance from the first spoke and connected to the second spoke.

9. The battery cell according to claim 8, wherein the outer ring has a closed-loop shape.

10. The electrode tab connecting portion is arranged at least on the first spoke, The conductive connecting portion is arranged at least on the second spoke, The battery cell according to claim 8, wherein the can connecting portion is arranged on the outer ring.

11. The battery cell according to claim 8, wherein at least a portion of the heat insulating member is positioned outside the first spoke in the radial direction.

12. The battery cell according to claim 8, wherein at least a portion of the heat insulating member is arranged between the first spokes in the outer peripheral direction.

13. The battery cell according to claim 8, wherein at least a portion of the heat insulating member is disposed between the second spoke and the electrode assembly in the axial direction.

14. The battery cell according to claim 8, wherein at least a portion of the heat insulating member is disposed between the outer ring and the electrode assembly in the axial direction.

15. The battery cell according to claim 8, wherein the heat insulating member is positioned outside the space between the first spoke and the electrode assembly in the axial direction.

16. The battery cell according to claim 8, wherein the heat insulating member covers the space between the first spoke and the outer ring in the radial direction.

17. The battery cell according to claim 8, wherein the heat insulating member covers the space between the first spoke and the second spoke in the outer peripheral direction.

18. The battery cell according to claim 8, wherein the heat insulating member covers the space between the inner ring and the outer ring in the radial direction.

19. The battery cell according to claim 1, wherein the heat insulating member includes a high heat-resistant polymer material.

20. The battery cell according to claim 19, wherein the heat insulating member is substantially chemically stable with respect to the electrolyte injected into the can.

21. The battery cell according to claim 19, wherein the heat insulating member is substantially unreactive to the electrolyte.

22. The battery cell according to claim 19, wherein the heat insulating member comprises at least one of polycarbonate (PC), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), and polyethylene terephthalate (PET).

Images