Unit cell, secondary battery including the same, and battery module including the same

Abstract

The present disclosure relates to a unit cell, a secondary battery including the unit cell, and a battery module including the secondary battery, the unit cell according to the present disclosure including: an electrode stack in which a first electrode, a separator, and a second electrode are alternately stacked; a first electrode tab extending from the first electrode; and a second electrode tab extending from the second electrode, wherein the first electrode and the second electrode are formed to have a length greater than a width, the first electrode tab and the second electrode tab extend in a width direction of the first electrode and the second electrode, and two or more first electrode tabs are provided on the first electrode.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2023-0131839, filed in Korea on October 4, 2023, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to a single-cell battery, a secondary battery including the single-cell battery, and a battery module including the secondary battery. Background Technology

[0004] Unlike primary batteries, secondary batteries are rechargeable and have been extensively researched and developed in recent years due to their potential for miniaturization and high capacity. With the technological advancements and increasing demands on mobile devices, the need for secondary batteries as an energy source is rapidly growing.

[0005] Rechargeable batteries are attracting attention not only as a power source for mobile devices such as mobile phones, digital cameras, and laptops, but also as a power source for electric bicycles, electric vehicles, and hybrid electric vehicles. Small battery modules containing a single cell are used in small devices such as mobile phones and cameras, while battery modules with two or more cells connected in parallel and / or series are used in medium and large devices such as laptops and electric vehicles.

[0006] Based on the shape of the battery casing, secondary batteries are classified into button batteries, cylindrical batteries, prismatic batteries, and pouch batteries. A secondary battery houses electrode components and an electrolyte solution. In a secondary battery, the electrode components installed inside the battery casing are rechargeable and dischargeable power-generating elements that utilize a stacked structure of electrodes and separators.

[0007] Electrode assemblies can be broadly classified into: jelly-roll type electrode assemblies, in which sheet-shaped positive and negative electrodes coated with active materials and having a separator between them are wound; stacked type electrode assemblies, in which multiple positive and negative electrodes are stacked sequentially and have a separator between them; and stacked / folded type electrode assemblies, in which stacked cell cells are wound with a long separator.

[0008] Recently, pouch cells, which have a structure in which stacked or stacked / folded electrode assemblies are built into a pouch cell case made of aluminum laminate, have attracted much attention due to their low manufacturing cost, light weight, and easy deformation, and are gradually being used more and more.

[0009] Conventional pouch cells have terminals on both sides. However, a problem exists: the terminals are relatively narrow compared to the cell's width, causing current density to concentrate, increasing heat generation and leading to the cell's highest temperature. Furthermore, while increasing the terminal width reduces current density, this is limited by the cell's narrow width. Additionally, increasing the distance between the positive and negative terminals increases the distance electrons need to travel, increasing resistance and heat generation, resulting in increased cell temperature and delayed fast charging. Summary of the Invention

[0010] Technical issues

[0011] This disclosure aims to provide a cell that can improve the maximum temperature and temperature deviation of the cell, a secondary cell including the cell, and a battery module including the secondary cell.

[0012] Technical solution

[0013] A cell according to an embodiment of the present disclosure may include: an electrode stack having a first electrode, a separator, and a second electrode alternately stacked; a first electrode tab extending from the first electrode; and a second electrode tab extending from the second electrode, wherein the first electrode and the second electrode may be formed to have a length greater than the width, the first electrode tab and the second electrode tab may extend in the width direction of the first electrode and the second electrode, and two or more first electrode tabs may be provided on the first electrode.

[0014] Additionally, the secondary battery according to embodiments of this disclosure may include: an electrode assembly having multiple cell batteries according to embodiments of this disclosure stacked on top of each other; a pouch housing the electrode assembly; a first electrode lead having one end connected to a first electrode tab and another end extending to the outside of the pouch; and a second electrode lead having one end connected to a second electrode tab and another end extending to the outside of the pouch, wherein the ends of the first electrode tabs and the second electrode tabs of the multiple stacked cell batteries may each be configured as tab bundles.

[0015] Furthermore, the battery module according to the embodiments of this disclosure may include: a battery stack having a plurality of secondary batteries according to the embodiments of this disclosure stacked along a third direction, the third direction being the stacking direction of the electrode stack; and a cooling unit disposed in a portion of the battery stack to cool the secondary batteries, wherein the portion may be located on the side opposite to the side where the first electrode terminal piece and the second electrode terminal piece are disposed, with reference to the secondary batteries.

[0016] Beneficial effects

[0017] According to this disclosure, the first electrode terminal piece and the second electrode terminal piece extend in the width direction of the first and second electrodes, which are formed with a length greater than their width, and two or more first electrode terminal pieces are provided on the first electrode, thereby shortening the distance between the terminal pieces, reducing resistance, and suppressing temperature rise. Therefore, the first electrode terminal piece and the second electrode terminal piece extending in the width direction of the first and second electrodes can form a large terminal piece width, thereby reducing current density and resistance.

[0018] In addition, multiple first electrode terminals and multiple second electrode terminals protrude in parallel directions on one of the four sides of the electrode stack in which the first electrode, separator and second electrode are alternately stacked, so that the current inside the cell flows in at least three directions, thereby significantly reducing the current density and significantly reducing the resistance inside the cell, thereby significantly reducing the heating value and the temperature of the cell.

[0019] In addition, multiple first electrode terminals and multiple second electrode terminals are alternately arranged along one of the four sides of the electrode stack, which makes the resistance in the cell more significantly reduced, thereby significantly reducing the heating value and the cell temperature. Attached Figure Description

[0020] Figure 1 This is a plan view showing a cell according to an embodiment of the present disclosure.

[0021] Figure 2 This is an exploded perspective view showing a cell according to an embodiment of the present disclosure.

[0022] Figure 3 This is a side sectional view showing the main parts of a secondary battery according to an embodiment of the present disclosure.

[0023] Figure 4 This is a plan view showing a secondary battery according to an embodiment of the present disclosure.

[0024] Figure 5 This is a plan view showing a battery module according to an embodiment of the present disclosure.

[0025] Figure 6 This is a perspective view showing a battery module according to an embodiment of the present disclosure.

[0026] Figure 7 This is an image showing the experimental results of the temperature distribution based on resistance in the cell according to manufacturing Example 1.

[0027] Figure 8 This is an image showing the experimental results of temperature distribution based on resistance in a cell according to manufacturing Example 2.

[0028] Figure 9 This is an image showing the experimental results of temperature distribution based on resistance in a single cell according to Comparative Example 1.

[0029] Figure 10 This is an image showing the experimental results of temperature distribution based on resistance in a unit cell according to Comparative Example 2. Detailed Implementation

[0030] The objects, specific advantages, and novel features of this disclosure will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. It should be noted that, when affixing reference numerals to elements in each of the drawings in this specification, they are affixed to the same elements as far as possible, even if the same reference numerals are shown in different drawings. Furthermore, this disclosure may be embodied in many different forms and is not limited to the embodiments described herein. In addition, detailed descriptions of related known techniques that may unnecessarily obscure the essence of this disclosure will be omitted in the description of this disclosure.

[0031] Figure 1 This is a plan view showing a cell according to an embodiment of the present disclosure. Figure 2 This is an exploded perspective view showing a cell according to an embodiment of the present disclosure.

[0032] Reference Figure 1 and Figure 2 According to an embodiment of the present disclosure, the cell 10 includes: an electrode stack S, on which a first electrode 11, a separator 13, and a second electrode 12 are alternately stacked; a first electrode terminal piece 11a extending from the first electrode 11; and a second electrode terminal piece 11b extending from the second electrode 12, wherein the first electrode 11 and the second electrode 12 are formed to have lengths L1 and L2 that are greater than widths W1 and W2, and the first electrode terminal piece 11a and the second electrode terminal piece 12a extend in the width direction of the first electrode 11 and the second electrode 12.

[0033] In the electrode stack S, at least one first electrode 11, at least one diaphragm 13, and at least one second electrode 12 are alternately stacked. In this case, in the electrode stack S, the first electrode 11, the diaphragm 13, and the second electrode 12 can be sequentially stacked corresponding to each other in the third direction Z, which is the stacking direction.

[0034] Alternatively, the electrode stack S can be formed in a rectangular shape on a plane. The electrode stack S is formed to have a length L greater than the width W.

[0035] Here, the first electrode 11 and the second electrode 12 can be positive and negative electrodes or negative and positive electrodes.

[0036] The first electrode 11 is formed to have a length L2 that is greater than the width W1. In this case, the first electrode 11 can be formed, for example, in a rectangular shape.

[0037] In addition, the first electrode 11 may include a first electrode current collector and a first electrode active material laminated on one or both surfaces of the first electrode current collector.

[0038] The first electrode terminal piece 11a extends from the first electrode 11 along the width direction of the first electrode 11.

[0039] In this case, the width direction of the first electrode 11 can be a first direction X, and the length direction of the first electrode 11 can be a second direction Y. Here, the first direction X and the second direction Y can be perpendicular to each other in a plane.

[0040] Additionally, the first electrode contact 11a may protrude in, for example, a quadrilateral shape. That is, the first electrode contact 11a may protrude from the first electrode 11 in the width direction of the first electrode 11.

[0041] Alternatively, multiple first electrode terminals 11a can be provided on the first electrode 11. That is, two or more first electrode terminals 11a can be provided on the first electrode 11. In this case, for example, two first electrode terminals 11a can be provided on the first electrode 11.

[0042] Furthermore, the first electrode terminal 11a can be formed of the same material as the first electrode current collector of the first electrode 11.

[0043] The second electrode 12 is formed to have a length L2 greater than the width W2. In this case, the second electrode 12 can be formed, for example, in a rectangular shape.

[0044] In addition, the second electrode 12 may include a second electrode current collector and a second electrode active material laminated on one or both surfaces of the second electrode current collector.

[0045] The second electrode terminal piece 11b extends from the second electrode 12 along the width direction of the second electrode 12.

[0046] In this case, the width direction of the second electrode 12 can be the first direction X, and the length direction of the second electrode 12 can be the second direction Y. Here, the first direction X and the second direction Y can be perpendicular to each other in a plane.

[0047] Additionally, the second electrode contact 11b may protrude in, for example, a quadrilateral shape. That is, the second electrode contact 11b may protrude from the second electrode 12 in the width direction of the second electrode 12.

[0048] Alternatively, multiple second electrode terminals 12a can be provided on the second electrode 12. That is, two or more second electrode terminals 12a can be provided on the second electrode 12. In this case, for example, two second electrode terminals 12a can be provided on the second electrode 12.

[0049] Furthermore, the second electrode terminal 11b can be formed of the same material as the second electrode current collector of the second electrode 12.

[0050] The first electrode connector 11a and the second electrode connector 12a can protrude from one of the four sides S1 of the electrode stack S in a direction parallel to each other.

[0051] Multiple first electrode terminals 11a and multiple second electrode terminals 12a can be alternately arranged along one of the four sides S1 of the electrode stack S.

[0052] Any one of the multiple first electrode terminals 11a can be disposed at one end of one side of the four sides of the electrode stack S, and any one of the multiple second electrode terminals 12a can be disposed at the other end of one side of the four sides of the electrode stack S, S1.

[0053] The plurality of first electrode terminals 11a and the plurality of second electrode terminals 12a can be configured to be spaced apart from each other at a fixed interval D. In this case, the plurality of first electrode terminals 11a and the plurality of second electrode terminals 12a can be configured to be spaced apart from each other at the same interval D.

[0054] The first electrode terminal 11a and the second electrode terminal 12a may have the same length L1-1 and L2-1 protruding along the first direction X, where the first direction X is the width direction of the electrode stack S. The widths W1-1 and W2-1 formed by the first electrode terminal 11a and the second electrode terminal 12a in the second direction Y may be the same, where the second direction Y is the length direction of the electrode stack S.

[0055] Meanwhile, for example, the ratio of the lengths L1 and L2 of the first electrode 11 to the widths W1 and W2 of the second electrode 12 can be 1.3 or more. Therefore, by forming the ratio of the lengths L1 and L2 of the first electrode 11 and the second electrode 12 to the widths W1 and W2 to be 1.3 or more, it has the effect of reducing temperature and resistance. Furthermore, specifically, for example, the ratio of the lengths L1 and L2 of the first electrode 11 and the widths W1 and W2 of the second electrode 12 can be from 1.3 to 5.4.

[0056] In the plan view, the ratio of the width W1-1 of the first electrode terminal piece 11a in the second direction Y perpendicular to the first direction X to the width W1 of the first electrode 11 in the first direction X, and the ratio of the width W2-1 of the second electrode terminal piece 12a in the second direction Y perpendicular to the first direction X to the width W2 of the second electrode 12 in the first direction X, can each be from 0.05 to 0.15.

[0057] Therefore, the ratios of the widths W1-1 of the first electrode contact 11a and W2-1 of the second electrode contact 12a in the second direction Y perpendicular to the first direction X to the widths W1 and W2 of the first electrode 11 and the second electrode 12 in the first direction X are respectively set to be equal to or greater than the minimum value of 0.05, thereby reducing resistance and temperature. Furthermore, the ratios of the widths W1-1 of the first electrode contact 11a and W2-1 of the second electrode contact 12a in the second direction Y perpendicular to the first direction X to the widths W1 and W2 of the first electrode 11 and the second electrode 12 in the first direction X are respectively set to be equal to or less than the maximum value of 0.15, thereby preventing interference between the electrode contacts.

[0058] Meanwhile, the number of multiple first electrode terminals 11a and multiple second electrode terminals 12a extending from the first electrode 11 and the second electrode 12 can be the same. In this case, for example, the number of multiple first electrode terminals 11a and multiple second electrode terminals 12a can each be two. Therefore, by alternately arranging one type of cell, direct connection can be achieved.

[0059] In the cell 10 according to the embodiment of the present disclosure configured as described above, the first electrode terminal piece 11a and the second electrode terminal piece 12a extend in the width direction of the first electrode 11 and the second electrode 12, which are formed to have lengths L1 and L2 greater than widths W1 and W2. Furthermore, two or more first electrode terminal pieces 11a are provided on the first electrode 11, thereby shortening the distance between the terminal pieces, reducing resistance, and suppressing temperature rise. Therefore, the extension of the first electrode terminal piece 11a and the second electrode terminal piece 12a in the width direction of the first electrode 11 and the second electrode 12 can form a large terminal piece width, thereby reducing current density and resistance.

[0060] Furthermore, in the cell 10 according to the embodiments of the present disclosure, a plurality of first electrode terminals 11a and a plurality of second electrode terminals 12a protrude in a direction parallel to each other on one of the four sides S1 of the electrode stack S in which the first electrode 11, the separator 13 and the second electrode 12 are alternately stacked, so that the current inside the cell 10 flows in at least three directions, thereby significantly reducing the current density and significantly reducing the resistance inside the cell 10, thereby significantly reducing the heating value and the cell temperature.

[0061] Furthermore, in the cell 10 according to the embodiments of this disclosure, a plurality of first electrode terminals 11a and a plurality of second electrode terminals 12a are alternately arranged along one of the four sides S1 of the electrode stack S, so that the resistance within the cell 10 can be reduced more significantly, thereby reducing the heating value and the cell temperature more significantly.

[0062] The secondary battery according to an embodiment of this disclosure will be described below.

[0063] Figure 3 This is a side sectional view showing the main parts of a secondary battery according to an embodiment of the present disclosure. Figure 4 This is a plan view showing a secondary battery according to an embodiment of the present disclosure.

[0064] Reference Figure 3 and Figure 4 The secondary battery 100 according to an embodiment of the present disclosure includes: an electrode assembly 110 having a plurality of cell batteries 10 stacked thereon; a pouch 120 for housing the electrode assembly 110; a first electrode lead 131 having one end connected to a first electrode tab 11a and another end extending to the outside of the pouch 120; and a second electrode lead 132 having one end connected to a second electrode tab 11b and another end extending to the outside of the pouch 120.

[0065] The secondary battery 100 according to the embodiments of this disclosure relates to a secondary battery 100 including the unit battery 10 according to the above embodiments. Therefore, this embodiment is described by omitting or briefly describing the content overlapping with the above embodiments and focusing on the differences.

[0066] More specifically, refer to Figures 2 to 4 In the secondary battery 100 according to the embodiments of the present disclosure, the electrode assembly 110 is a rechargeable power generation element having multiple unit batteries 10 stacked on top of each other.

[0067] The cell 10 includes: an electrode stack S, on which at least one first electrode 11, at least one separator 13, and at least one second electrode 12 are alternately stacked; a first electrode tab 11a extending from the first electrode 11; and a second electrode tab 11b extending from the second electrode 12, wherein the first electrode 11 and the second electrode 12 are formed to have lengths L1 and L2 greater than widths W1 and W2, and the first electrode tab 11a and the second electrode tab 12a extend in the width direction of the first electrode 11 and the second electrode 12 (see [reference]). Figure 1 ).

[0068] Multiple first electrode terminals 11a can be provided on the first electrode 11. That is, more than two first electrode terminals 11a can be provided on the first electrode 11. In this case, for example, two first electrode terminals 11a can be provided on the first electrode 11.

[0069] Multiple second electrode terminals 12a can be provided on the second electrode 12. That is, more than two second electrode terminals 12a can be provided on the second electrode 12. In this case, for example, two second electrode terminals 12a can be provided on the second electrode 12.

[0070] Meanwhile, the ends of the first electrode terminals 11a and the second electrode terminals 11b of the multiple stacked unit cells 10 can each be configured as terminals bundles.

[0071] The flexible package 120 can be formed as a receiving portion for accommodating the electrode assembly 110. The flexible package 120 may include, for example, an aluminum sheet and resin layers coated on both surfaces of the aluminum sheet.

[0072] The first electrode lead 131 may have one end connected to the first electrode tab 11a and another end extending to the outside of the flexible package 120. Alternatively, the first electrode lead 131 may be soldered to the end of the first electrode tab 11a disposed in the tab bundle. The width W1-1 of the first electrode tab 11a and the width W3 of the first electrode lead 131 may be the same.

[0073] The second electrode lead 132 may have one end connected to the second electrode tab 11b and another end extending to the outside of the flexible package 120. Alternatively, the second electrode lead 132 may be soldered to the end of the second electrode tab 11b disposed in the tab bundle. The width W2-1 of the second electrode tab 11b and the width W4 of the second electrode lead 132 may be the same.

[0074] The battery module according to an embodiment of the present disclosure will be described below.

[0075] Figure 5This is a plan view showing a battery module according to an embodiment of the present disclosure. Figure 6 This is a perspective view showing a battery module according to an embodiment of the present disclosure.

[0076] Reference Figure 5 and Figure 6 According to an embodiment of the present disclosure, the battery module 1000 includes: a battery stack 1100 having a plurality of secondary batteries 100 stacked in a third direction Z; and a cooling unit 1200 disposed in a portion of the battery stack 1100 to cool the secondary batteries 100.

[0077] The battery module 1000 according to the embodiments of this disclosure relates to a battery module 1000 including the secondary battery 100 according to the above embodiments. Therefore, this embodiment is described by omitting or briefly describing the content that overlaps with the above embodiments and focusing on the differences.

[0078] More specifically, refer to Figure 2 , Figure 5 and Figure 6 In the battery module 1000 according to an embodiment of the present disclosure, a plurality of secondary batteries 100 are stacked in a battery stack 1100 along a third direction Z, where the third direction Z is the stacking direction of the electrode stack S. Here, the third direction Z can be the stacking direction of the electrode stack S in which a first electrode 11, a separator 13, and a second electrode 12 are alternately stacked.

[0079] The secondary battery 100 may include: an electrode assembly 110 having multiple cell batteries 10 stacked on top of each other; a pouch 120 for housing the electrode assembly 110; a first electrode lead 131 having one end connected to a first electrode tab 11a and another end extending to the outside of the pouch 120; and a second electrode lead 132 having one end connected to a second electrode tab 11b and another end extending to the outside of the pouch 120.

[0080] The cell 10 includes: an electrode stack S, on which at least one first electrode 11, at least one separator 13, and at least one second electrode 12 are alternately stacked; a first electrode tab 11a extending from the first electrode 11; and a second electrode tab 11b extending from the second electrode 12, wherein the first electrode 11 and the second electrode 12 are formed to have lengths L1 and L2 greater than widths W1 and W2, and the first electrode tab 11a and the second electrode tab 12a extend in the width direction of the first electrode 11 and the second electrode 12 (see [reference]). Figure 1 ).

[0081] Multiple first electrode terminals 11a can be provided on the first electrode 11. That is, more than two first electrode terminals 11a can be provided on the first electrode 11. In this case, for example, two first electrode terminals 11a can be provided on the first electrode 11.

[0082] Multiple second electrode terminals 12a can be provided on the second electrode 12. That is, more than two second electrode terminals 12a can be provided on the second electrode 12. In this case, for example, two second electrode terminals 12a can be provided on the second electrode 12.

[0083] Cooling unit 1200 may be disposed in a portion of battery stack 1100 to cool secondary battery 100.

[0084] Here, a portion of the battery stack 1100 may be located on the side opposite to the side where the first electrode terminal 11a and the second electrode terminal 12a are provided, with reference to the secondary battery 100. In this case, the first electrode terminal 11a and the second electrode terminal 12a may be provided on the upper side with reference to the secondary battery 100, and the cooling unit 1200 may be provided on the lower side.

[0085] The cooling unit 1200 may include a cooling plate disposed on the lower side of the battery stack 1100.

[0086] Furthermore, the battery module 1000 according to the embodiments of this disclosure may further include a module housing accommodating the battery stack 1100 and the cooling unit 1200. Additionally, the battery module 1000 according to the embodiments of this disclosure may be configured to further include a busbar electrically connecting a plurality of secondary batteries 100 stacked on top of each other, as well as first electrode leads 131 and second electrode leads 132 of the plurality of secondary batteries 100.

[0087] <Manufacturing Example 1>

[0088] Manufacturing a cell includes: an electrode stack having alternating layers of a positive electrode, a separator, and a negative electrode; a positive electrode terminal extending from the positive electrode; and a negative electrode terminal extending from the negative electrode.

[0089] Furthermore, the positive and negative electrodes are formed with a length greater than their width. Two positive electrode contacts are formed on the positive electrode, and two negative electrode contacts are formed on the negative electrode. The positive and negative electrode contacts are formed to protrude from one of the four sides of the electrode stack in a direction parallel to each other.

[0090] In addition, two positive terminal contacts are located on the left side of one of the four sides of the electrode stack, and two negative terminal contacts are located on the right side of one of the four sides of the electrode stack.

[0091] <Manufacturing Example 2>

[0092] Except that the two positive terminal pieces and the two negative terminal pieces are alternately arranged along one of the four sides of the electrode stack, the cell is manufactured in the same manner as in Manufacturing Example 1.

[0093] <Comparative Example 1>

[0094] Except for one positive terminal and one negative terminal provided on both sides of the electrode stack along its length, the cell is manufactured in the same manner as in Manufacturing Example 1.

[0095] <Comparative Example 2>

[0096] Except that two positive electrode terminals and two negative electrode terminals are disposed on both sides of the electrode stack along its length, the cell is manufactured in the same manner as in Manufacturing Example 1.

[0097] <Experimental Example 1>

[0098] Figure 7 This is an image showing the experimental results of temperature distribution based on resistance in a unit cell according to Manufacturing Example 1. Figure 8 This is an image showing the experimental results of temperature distribution based on resistance in the cell according to manufacturing Example 2. Figure 9 This is an image showing the experimental results based on the temperature distribution of resistance in the unit cell of Comparative Example 1. Figure 10 This is an image showing the experimental results based on the temperature distribution according to resistance in the unit cell of Comparative Example 2. Here, Figures 7 to 10 The experimental results are simulation analysis results.

[0099] Based on the temperature distribution of the unit cells in Manufacturing Example 1, Manufacturing Example 2, Comparative Example 1, and Comparative Example 2, as follows: Figures 7 to 10 As shown in the image. At this time, in Figures 7 to 10 In the temperature distribution images of Manufacturing Example 1 and Manufacturing Example 2, as well as Comparative Example 1 and Comparative Example 2, the high-temperature areas are shown as dark colors, and the low-temperature areas are shown as light colors, presenting a contrast between light and dark.

[0100] The cell was charged at a 3C rate for 600 seconds, and the lower part of the cell was cooled. The experiment was conducted under conditions of an initial temperature of 25°C, a cooling temperature of 25°C, and a cooling heat transfer coefficient of 500 W / mK. The results were... Figures 7 to 10 As shown in the image.

[0101] It can be seen that, Figure 7 Manufacturing Example 1 and shown Figure 8 The temperature distribution in manufacturing example 2 shown is uniform and the temperature is relatively low, while Figure 9 Comparative Example 1 and 2 shown Figure 10The temperature distribution in Comparative Example 2 shown is uneven and the temperature is high. Therefore, it can be seen that, compared with Comparative Examples 1 and 2 where the positive and negative terminals are located on both sides of the length direction, the current density and resistance are reduced in Manufacturing Examples 1 and 2 where the positive and negative terminals are located on both sides of the width direction.

[0102] Furthermore, it can be seen that, Figure 8 The temperature distribution shown in manufacturing example 2 indicates a difference compared to... Figure 7 The manufacturing example 1 shown is more uniform and has a lower temperature. Therefore, it can be seen that, compared with manufacturing example 1, where the two positive terminals are located on the left side of one of the four sides of the electrode stack and the two negative terminals are located on the right side of one of the four sides of the electrode stack, the current density is reduced and the resistance is decreased in manufacturing example 2, where the two positive terminals and the two negative terminals are alternately arranged along one of the four sides of the electrode stack.

[0103] Specifically, in the electrode stack of positive and negative electrodes with a stack length greater than its width, it can be seen that in Manufacturing Example 2, where multiple first electrode terminals and multiple second electrode terminals extending in the width direction are alternately arranged along one of the four sides of the electrode stack, the current density and resistance are significantly reduced.

[0104] <Experimental Example 2>

[0105] A current was applied to the cell batteries according to Manufacturing Example 1, Manufacturing Example 2, Comparative Example 1, and Comparative Example 2, and the resistance was measured after 10 seconds, as shown in Table 1. The initial temperature, cooling temperature, cooling heat exchange coefficient, etc., were applied in the same manner as in Experimental Example 1. Table 1 shows the resistance of the electrode current collector portion in the cell battery electrodes, with average values ​​displayed. The resistances listed in Table 1 are the ohmic resistances of the electrode current collector (foil).

[0106] [Table 1]

[0107] The resistance of Comparative Example 1 is 0.47 mΩ, and the resistance of Comparative Example 2 is 0.46 mΩ, which are relatively high. In contrast, the resistance of Manufacturing Example 1 is 0.2 mΩ, and the resistance of Manufacturing Example 2 is 0.11 mΩ, which are relatively low. Therefore, in electrode stacks where the length of the positive and negative electrodes is greater than the width, it can be seen that, compared to Comparative Examples 1 and 2 where the positive and negative electrodes are located on opposite sides of the length direction, the resistance is reduced in Manufacturing Examples 1 and 2 where the positive and negative electrodes are located along the width direction. Furthermore, it can be seen that the resistance of Manufacturing Example 2 is lower than that of Manufacturing Example 1. Therefore, it can be seen that, compared to Manufacturing Example 1 where the two positive electrodes and two negative electrodes are alternately arranged along one of the four sides of the electrode stack, the resistance is reduced in Manufacturing Example 2 where the two positive electrodes and two negative electrodes are alternately arranged along one of the four sides of the electrode stack.

[0108] Specifically, in an electrode stack with a stack length greater than its width for both positive and negative electrodes, it can be seen that in Manufacturing Example 2, where multiple first electrode terminals and multiple second electrode terminals extending in the width direction are alternately arranged along one of the four sides of the electrode stack, the resistance is significantly reduced.

[0109] The present disclosure has been described in detail above with reference to specific embodiments; however, this is intended to specifically describe the present disclosure, and the present disclosure is not limited thereto. It should be understood that various modifications and variations can be made by those skilled in the art within the technical concept of the present disclosure.

[0110] Furthermore, the specific scope of protection of this disclosure will become clear through the appended claims of this patent.

[0111] [List of reference numerals]

[0112] 10: Cell battery

[0113] 11: First electrode

[0114] 11a: First electrode connector

[0115] 12: Second electrode

[0116] 12a: Second electrode connector

[0117] 13: Diaphragm

[0118] 100: Secondary battery

[0119] 110: Electrode assembly

[0120] 120: Soft Pack

[0121] 131: First electrode lead

[0122] 132: Second electrode lead

[0123] 1000: Battery Module

[0124] 1100: Battery stack

[0125] 1200: Cooling unit

[0126] S: Electrode laminate

[0127] X: First direction

[0128] Y: Second direction

[0129] Z: Third-party direction

Claims

1. A single-cell battery, comprising: An electrode stack, in which a first electrode, a diaphragm and a second electrode are alternately stacked; A first electrode terminal piece extends from the first electrode; as well as The second electrode terminal extends from the second electrode. The first electrode and the second electrode are formed to have a length greater than their width. The first electrode terminal and the second electrode terminal extend in the width direction of the first electrode and the second electrode, respectively, and Two or more first electrode terminals are provided on the first electrode.

2. The cell battery according to claim 1, wherein, The first electrode tab and the second electrode tab protrude from one of the four sides of the electrode stack in a direction parallel to each other.

3. The unit cell according to claim 2, wherein, The electrode stack is formed in a rectangular shape, and The first electrode terminal and the second electrode terminal protrude in a quadrilateral shape.

4. The unit cell according to claim 2, wherein, The first electrode connector and the second electrode connector are each configured in multiple ways.

5. The cell battery according to claim 4, wherein, Multiple first electrode terminals and multiple second electrode terminals are alternately arranged along one of the four sides of the electrode stack.

6. The cell battery according to claim 5, wherein, Any one of the plurality of first electrode terminals is disposed at one end of one of the four sides of the electrode stack, and any one of the plurality of second electrode terminals is disposed at the other end of one of the four sides of the electrode stack.

7. The cell battery according to claim 5, wherein, The plurality of first electrode terminals and the plurality of second electrode terminals are configured to be spaced apart from each other at a fixed interval.

8. The cell battery according to claim 5, wherein, The first electrode tab and the second electrode tab protrude by the same length in a first direction, where the first direction is the width direction of the electrode stack. The first electrode terminal and the second electrode terminal have the same width in a second direction, which is the length direction of the electrode stack.

9. The cell battery according to claim 8, wherein, In the plan view, the ratio of the width of the first electrode contact in the second direction perpendicular to the first direction to the width of the first electrode in the first direction, and the ratio of the width of the second electrode contact in the second direction perpendicular to the first direction to the width of the second electrode in the first direction, are each between 0.05 and 0.

15.

10. A secondary battery, comprising: An electrode assembly having multiple unit cells as described in any one of claims 1 to 9 stacked on top of it; A soft package is provided to house the electrode assembly; The first electrode lead has one end connected to the first electrode tab and another end extending to the outside of the soft package; as well as The second electrode lead has one end connected to the second electrode tab and another end extending to the outside of the soft package. In this configuration, the ends of the first electrode terminals and the second electrode terminals of the multiple stacked cell units are each arranged in the form of a terminal bundle.

11. The secondary battery according to claim 10, wherein, The first electrode tab and the first electrode lead are configured to have the same width, and The second electrode tab and the second electrode lead are configured to have the same width.

12. A battery module, comprising: A battery stack having multiple secondary batteries as described in claim 10 stacked along a third direction, wherein the third direction is the stacking direction of the electrode stack; as well as A cooling unit is disposed in a portion of the battery stack to cool the secondary battery. The portion of the battery is located on the side opposite to the side where the first electrode terminal and the second electrode terminal are located, with the secondary battery as a reference.

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