Electrode, electrode assembly, and secondary battery

Abstract

The electrode assembly according to the present invention comprises: a first electrode; and a second electrode which is stacked with the first electrode in a stacking direction and has a polarity different from that of the first electrode, wherein the first electrode comprises a first current collector comprising a first current collector body in which an active material layer is positioned and a first electrode tab protruding from the first current collector body; the second electrode comprises a second current collector comprising a second current collector body and a second electrode tab to correspond to the first electrode; and the first electrode tab and the second electrode tab are configured such that the distance by which charges move from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector bodies.

Description

Electrodes, electrode assemblies, and secondary batteries

[0001] [Cross-reference with related applications]

[0002] This application claims the benefit of priority based on Korean patent application 10-2024-0193274 filed December 20, 2024, and all contents disclosed in the literature of said Korean patent applications are incorporated herein as part of this specification.

[0003] [Technology Field]

[0004] The present invention relates to an electrode, an electrode assembly, and a secondary battery. More specifically, it relates to an electrode that mitigates voltage drop, an electrode assembly including the same, and a secondary battery including the same.

[0005] A secondary battery configured to generate electricity includes an electrode comprising an active material layer and a current collector combined with the active material layer. The electrode can generate electricity by forming a positive electrode and a negative electrode, respectively, with an opposing electrode.

[0006] Electric charge can be transferred between a pair of opposing electrodes. In this case, the transfer of charge can occur through a current collector. The current collector is composed of a conductor, such as metal, to facilitate the transfer of electric charge.

[0007] However, even if the current collector is a conductor, since it is a resistive component, a problem may arise where voltage—electrical energy—drops as electric charges move through the collector. The energy loss caused by this voltage drop can manifest as heat generation. In the case of secondary batteries, voltage drop itself can lead to electrical energy loss. Additionally, since the heat generated by voltage drop affects the safety of the secondary battery, voltage drop caused by the movement of electric charges can cause problems.

[0008] The aforementioned background technology is one that the inventor possessed or acquired in the process of deriving the contents of the disclosure of the present application, and it cannot be considered as prior art disclosed to the general public prior to the filing of this application.

[0009] The present invention has been devised to solve the above problems, and the objective of the present invention is to provide an electrode, an electrode assembly, and a secondary battery that reduce the voltage drop due to the movement of electric charge.

[0010] The technical problems to be solved in this document are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below.

[0011] An electrode assembly according to one embodiment of the present invention comprises a first electrode and a second electrode that is stacked in a stacking direction with respect to the first electrode and has a polarity different from that of the first electrode. The first electrode comprises a first current collector including a first current collector body on which an active material layer is located and a first electrode tab protruding from the first current collector body. The second electrode comprises a second current collector including a second current collector body and a second electrode tab so as to correspond to the first electrode. The first electrode tab and the second electrode tab are configured such that the distance over which charge travels from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector body.

[0012] The charge is transferred from the first electrode tab to the second electrode tab through the first current collector body and the second current collector body, and the first current collector body and the second current collector body may be configured to lower the voltage of the charge in proportion to the distance the charge is transferred while the charge is transferred from the first electrode tab to the second electrode tab.

[0013] The charge is transferred from the first electrode tab to the second electrode tab through the first current collector body and the second current collector body, and the first current collector body and the second current collector body may be configured to generate heat in proportion to the distance the charge is transferred while the charge is transferred from the first electrode tab to the second electrode tab.

[0014] The first electrode tab can be located on the opposite side of the second electrode tab.

[0015] The first current collector body has a long side and a short side, and the second current collector body has a long side and a short side corresponding to the first current collector body, and the first electrode tab can extend from the long side of the first current collector body, and the second electrode tab can extend from the long side of the second current collector body.

[0016] The distance the charge travels from the first electrode tab to the second electrode tab may correspond to the length of the short side of the first current collector body or the second current collector body.

[0017] The width of the first electrode tab can correspond to the length of the long side of the first current collector body.

[0018] The first electrode tab and the second electrode tab can be located on the same side.

[0019] The first current collector body has a long side and a short side, and the second current collector body has a long side and a short side corresponding to the first current collector body, and the first electrode tab can be extended from the short side of the first current collector body, and the second electrode tab can be extended from the short side of the second current collector body.

[0020] The first electrode tab may have a width smaller than the length of the short side of the first current collector body.

[0021] The first current collector body has a pair of short sides located on opposite sides, and the first electrode tabs can be provided as a pair extending from each of the pair of short sides of the first current collector body.

[0022] The first electrode tab can be positioned so as to prevent overlap with the second electrode tab in the stacking direction.

[0023] The first electrode tab and the second electrode tab may be configured so that charge is transferred from the first electrode tab to the second electrode tab from the center of either the first current collector body or the second current collector body to the center of the other.

[0024] The first electrode tab and the second electrode tab may be configured such that the distance the charge travels from the first electrode tab to the second electrode tab corresponds to the long side of the first current collector body or the long side of the second current collector body.

[0025] It may further include a separator located between the first electrode and the second electrode.

[0026] A secondary battery according to one embodiment of the present invention comprises an electrode assembly and a battery case that accommodates the electrode assembly, wherein the electrode assembly comprises a first electrode and a second electrode that is stacked in a stacking direction with respect to the first electrode and has a polarity different from that of the first electrode, the first electrode comprises a first current collector body on which an active material layer is located and a first electrode tab protruding from the first current collector body, and the second electrode comprises a second current collector body and a second electrode tab so as to correspond to the first electrode, and the first electrode tab and the second electrode tab are configured such that the distance over which charge travels from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector body.

[0027] The charge is transferred from the first electrode tab to the second electrode tab through the first current collector body and the second current collector body, and the first current collector body and the second current collector body may be configured to lower the voltage of the charge in proportion to the distance the charge is transferred while the charge is transferred from the first electrode tab to the second electrode tab.

[0028] The charge is transferred from the first electrode tab to the second electrode tab through the first current collector body and the second current collector body, and the first current collector body and the second current collector body may be configured to generate heat in proportion to the distance the charge is transferred while the charge is transferred from the first electrode tab to the second electrode tab.

[0029] The first electrode tab can be located on the opposite side of the second electrode tab.

[0030] An electrode according to one embodiment of the present invention comprises a current collector including an active material layer, a current collector body configured to have the active material layer positioned thereon, and an electrode tab extending from the current collector body, wherein the current collector body includes a long side and a short side, and the electrode tab extends from the long side of the current collector body.

[0031] An electrode assembly according to one embodiment of the present invention can minimize the voltage drop of a charge by reducing the distance traveled by the charge.

[0032] An electrode assembly according to one embodiment of the present invention is configured such that the distance over which a charge travels from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector body, thereby reducing the distance of charge travel.

[0033] An electrode assembly according to one embodiment of the present invention is configured such that an electrode tab is formed on the long side of a current collector body, thereby reducing the charge travel distance to correspond to the length of the short side.

[0034] An electrode assembly according to one embodiment of the present invention can reduce the distance of charge movement to correspond to the length of the long side by forming electrode tabs on both short sides.

[0035] The effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0036] FIG. 1 is an assembly diagram of a secondary battery according to a first embodiment of the present invention.

[0037] FIG. 2 is a plan view illustrating the manufacture of an electrode according to a first comparative example of the present invention corresponding to the electrode included in the electrode assembly shown in FIG. 1.

[0038] FIG. 3 is a cross-sectional view of an electrode assembly according to the first comparative example of the present invention.

[0039] FIG. 4 is a cross-sectional view of an electrode assembly according to a second comparative example of the present invention.

[0040] FIG. 5 is a circuit diagram illustrating the distribution of resistance of the first comparative example or the second comparative example of the present invention.

[0041] Figure 6 is an exploded view showing a part of the electrode assembly shown in Figure 1 disassembled.

[0042] Figure 7 is a cross-sectional view of the electrode assembly shown in Figure 6.

[0043] Figure 8 is a circuit diagram of the electrode assembly shown in Figure 7.

[0044] FIG. 9 is an exploded view illustrating a part of an electrode assembly according to a second embodiment of the present invention.

[0045] FIG. 10 is a cross-sectional view of the electrode assembly shown in FIG. 9.

[0046] Figure 11 is a circuit diagram of the electrode assembly shown in Figure 10.

[0047] FIG. 12 is a conceptual diagram illustrating a first electrode and a second electrode according to a third embodiment of the present invention.

[0048] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0049] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0050] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0051] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments.

[0052] In relation to the description of the drawings, similar reference numerals may be used for similar or related components.

[0053] The singular form of the noun corresponding to the item may include one or multiple items, unless the relevant context clearly indicates otherwise.

[0054] In this document, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0055] The term "and / or" includes a combination of multiple related described components or any of the multiple related described components.

[0056] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish a component from another corresponding component and do not limit the components in other aspects (e.g., importance or order).

[0057] Where any (e.g., 1st) component is referred to as "coupled" or "connected" to another (e.g., 2nd) component, with or without the terms "functionally" or "communicationly," it means that said any component may be connected to said other component directly (e.g., via a wire), wirelessly, or through a third component.

[0058] Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this document, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0059] When it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0060] When it is said that a component is located "on" another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0061] Meanwhile, terms such as "up-and-down direction," "downward side," and "front-backward direction" used in the following description are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0062] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0063] First embodiment

[0064] FIG. 1 is an assembly diagram of a secondary battery (B) according to a first embodiment of the present invention.

[0065] A secondary battery (B) may be provided to generate electricity. In the first embodiment, the secondary battery (B) is described assuming a pouch-type secondary battery (B), but the secondary battery (B) may be cylindrical or prismatic as needed. As shown in FIG. 1, the secondary battery (B) may include a battery case (200) and an electrode assembly (EA).

[0066] A battery case (200) may be formed from a pouch film. A receiving portion (210) may be provided in a part of the pouch film by stretching the pouch film by a press. An electrode receiving space (210S) in which an electrode assembly (EA) is received may be formed in the receiving portion (210). Furthermore, a side portion (220) extending from the receiving portion (210) may be formed on the outer side of the receiving portion (210). In other words, the battery case (200) may include the receiving portion (210) and the side portion (220). As shown in FIG. 1, the receiving portion (210) may be provided in pairs and arranged to face each other. However, the receiving portion (210) may be provided as a single unit if necessary.

[0067] A folding portion (223) may be provided to be folded between a pair of receiving portions (210). By folding the folding portion (223), the pair of receiving portions (210) may face each other. That is, the side portion (220) may include a folding portion (223) located between the pair of receiving portions (210). In addition to the folding portion (223), the side portion (220) may include a lead sealing portion (221) and a degas sealing portion (222). The lead sealing portion (221) may be a portion extending from an edge that overlaps with the electrode (100) lead with respect to the receiving portion (210). The lead sealing portion (221) may face another corresponding lead sealing portion (221) as the pair of receiving portions (210) are positioned to face each other. A lead film may be positioned between a pair of facing lead sealing portions (221). A degas sealing portion (222) may extend from the corner where the lead sealing portion (221) and the folding portion (223) are not formed with respect to the receiving portion (210). The degas sealing portion (222) may face another corresponding degas sealing portion (222) as the pair of receiving portions (210) are positioned to face each other. Each of the facing side portions (220) may fuse together when heat and pressure are applied to seal the receiving portion (210).

[0068] The electrode assembly (EA) may include a plurality of electrodes (100), a separator (300) interposed between the plurality of electrodes (100), and / or an electrode (100) lead coupled to the plurality of electrodes (100). The electrode (100) lead may be positioned between a pair of lead sealing portions (221). Furthermore, a lead film may be coupled to the electrode (100) lead to be coupled to the lead sealing portion (221). The electrode (100) lead may be made of a metal material, the inner side of the lead sealing portion (221) may be made of a polymer material, and the lead film may be made of a polymer material. Since the affinity between the lead film and the lead sealing portion (221) is higher than the affinity between the electrode (100) lead and the lead sealing portion (221), the lead film can enhance the sealing effect between the electrode (100) lead and the lead sealing portion (221).

[0069] Regarding the electrode assembly (EA), the transfer of charge is described while explaining the electrode assembly (EA) according to the following comparative example.

[0070] FIG. 2 is a plan view illustrating the manufacture of an electrode (100-01) according to a first comparative example of the present invention corresponding to an electrode (100) included in an electrode assembly (EA) illustrated in FIG. 1. FIG. 3 is a cross-sectional view of an electrode assembly (EA-01) according to a first comparative example of the present invention. FIG. 4 is a cross-sectional view of an electrode assembly (EA-02) according to a second comparative example of the present invention. FIG. 5 is a circuit diagram illustrating the distribution of resistance of a first comparative example or a second comparative example of the present invention.

[0071] Referring to FIGS. 2 to 5, electrode assemblies (EA-01, EA-02) according to comparative examples of the present invention will be described.

[0072] The electrode assembly (EA-01, EA-02) may include an electrode (100-01). The electrode (100-01) may be formed as shown in FIG. 2. More specifically, as shown in the leftmost drawing of FIG. 2, an active material layer (102-01) is applied to a metal film extending in one direction, and then, as shown in the center drawing of FIG. 2, it is slit to have a predetermined width, and then, as shown in the rightmost drawing of FIG. 2, the electrode (100-01) may be formed by further reducing the width of the side where the active material layer (102-01) is not applied.

[0073] Such electrodes (100-01) are provided in multiple quantities and can be stacked in a stacking direction as shown in FIG. 3. The stacking method of the electrodes (100-01) can be classified into the type of a first comparative example as shown in FIG. 3 and a second comparative example as shown in FIG. 4. First, the first comparative example will be described.

[0074] As illustrated in FIG. 3, the electrode (100-01) may include a first electrode (100a-01) and a second electrode (100b-01) having different polarities. Based on FIG. 3, the first electrode (100a-01) may point to the electrode (100-01) located on the upper side, and the second electrode (100b-01) may point to the electrode (100-01) located on the lower side. A separator (300-01) is positioned between the first electrode (100a-01) and the second electrode (100b-01) to prevent the first electrode (100a-01) and the second electrode (100b-01) from coming into direct contact and causing a short circuit. At this time, the first electrode (100a-01) may form a positive electrode, and the second electrode (100b-01) may form a negative electrode. However, as needed, the electrodes (100-01) forming the positive and negative electrodes may be swapped with each other.

[0075] The first electrode tab (120a-01) formed on the first electrode (100a-01) and the second electrode tab (120b-01) formed on the second electrode (100b-01) can be located on opposite sides. The distribution of this type of electrode tab (120-01) allows the current to be dispersed, thereby enabling a uniform distribution of the internal current density of the secondary battery (B-01). Since this type of electrode (100-01) disperses the current density, it can also be advantageous in terms of thermal management. Therefore, this type can be a structure advantageous for a high-output secondary battery (B-01).

[0076] As indicated by the arrows in FIG. 3, electric charge can be moved. The electric charge can be moved from the second electrode (100b-01) to the first electrode (100a-01). In particular, the electric charge can be moved from the second electrode tab (120b-01) located at the end of the second electrode (100b-01) to the first electrode tab (120a-01) formed at the end of the first electrode (100a-01). The electric charge can be moved through the current collector (101). Since the current collector (101) is a passage through which electricity is moved, it can be composed of a conductor. However, since the current collector (101) itself has resistance, the voltage may drop as the electric charge moves through the current collector (101). Energy loss due to the voltage drop may manifest as heat generation. Therefore, it is necessary to reduce the distance the electric charge travels through the current collector (101).

[0077] Furthermore, in the first comparative example, as illustrated in FIG. 5, the mismatch in resistance at the location where the charge is transferred may be large. Generally, since the electrode tab (120-01) is where electricity enters and exits, the resistance may be the lowest. Also, the location on the opposite side of the electrode tab (120-01) may have the highest resistance. However, as illustrated in FIG. 3, the location where the charge is transferred is a place close to the second electrode tab (120b-01) relative to the second current collector (110b-01), so the charge is transferred at a place with low resistance, and a place far from the first electrode tab (120a-01) relative to the first current collector (110a-01), so the charge is transferred at a place with high resistance. As the charge is transferred, a large energy loss may occur because the difference in resistance is large.

[0078] Furthermore, since the resistance is low at the first electrode tab (120a-01) of the first electrode (100a-01), the oxidation of lithium, which is an example of an active material, occurs most effectively; conversely, since the resistance is high on the opposite side of the second electrode tab (120b-01) of the second electrode (100b-01), the reduction of lithium ions may not occur effectively. Consequently, lithium precipitation occurs at the first electrode tab (120a-01), which may result in a loss of available lithium. This leads to a decrease in the capacity of the secondary battery (B-01), which can cause a reduction in cell lifespan. Furthermore, it may cause stability problems due to lithium precipitation.

[0079] In particular, when the length is increased relative to the width in order to increase the capacity of the secondary battery (B-01), this problem may become even more pronounced. For example, the length of such a secondary battery (B-01) may be more than three times the width. Since such a secondary battery (B-01) uses a high current density, a difference in voltage can directly lead to a decrease in lifespan.

[0080] To solve this, methods such as increasing the content of the conductive material in the active material layer (102-01) to improve current conductivity or increasing the thickness of the current collector (101) may be considered. However, increasing the content of the conductive material in the active material layer (102-01) may result in a problem of reduced capacity due to a decrease in the content of the active material, and increasing the thickness of the current collector (101) may result in a problem of reduced energy density due to an increase in the thickness of the secondary battery (B-01).

[0081] Additionally, as illustrated in FIG. 4, a secondary battery (B-02) such as the second comparative example may be provided with an electrode (100-02) such that an electrode tab (120-02) is positioned on the same side. This type may have the advantage of being easy to design and manufacture with a simpler design compared to the first comparative example, and may result in reduced costs. However, since the current is concentrated on one side, it may be disadvantageous in terms of thermal management. Nevertheless, since the amount of heat generated is relatively low, it may be suitable for a secondary battery (B-02) that requires a small capacity.

[0082] In the case of the second comparative example, the problem of resistance mismatch is small, but since the charge travel distance is long, it may be difficult to avoid the problem of voltage drop.

[0083] In other words, considering that the charge is transferred from the first electrode tab (120a-02) to the second electrode tab (120b-02) through the first current collector body (101a-02) and the second current collector body (101b-02), and that the first current collector body (101a-02) and the second current collector body (101b-02) can be configured to lower the voltage of the charge in proportion to the distance the charge travels while the charge travels from the first electrode tab (120a-02) to the second electrode tab (120b-02), and furthermore, that the first current collector body (101a-02) and the second current collector body (101b-02) can be configured to generate heat in proportion to the distance the charge travels while the charge travels from the first electrode tab (120a-02) to the second electrode tab (120b-02), the distance the charge travels There is a need to reduce it.

[0084] To this end, the following embodiments can be configured such that the first electrode tab (120a) and the second electrode tab (120b) are configured such that the distance over which charge travels from the first electrode tab (120a) to the second electrode tab (120b) is shorter than twice the length of the current collector (101).

[0085] An electrode assembly (EA) according to the first embodiment of the present invention may be provided to solve the above problems. The first embodiment of the present invention will be described further below.

[0086] FIG. 6 is an exploded view showing a part of the electrode assembly (EA) shown in FIG. 1. FIG. 7 is a cross-sectional view of the electrode assembly (EA) shown in FIG. 6. FIG. 8 is a circuit diagram of the electrode assembly (EA) shown in FIG. 7.

[0087] Referring to FIGS. 6 to 8, an electrode assembly (EA) according to a first embodiment of the present invention will be described. It may be helpful to understand the first embodiment as corresponding to the first comparative example above.

[0088] As illustrated in FIG. 6, the electrode assembly (EA) may include a first electrode (100a) and a second electrode (100b) that is stacked in a stacking direction with respect to the first electrode (100a) and has a polarity different from that of the first electrode (100a). Furthermore, it may further include a separator (300) positioned between the first electrode (100a) and the second electrode (100b). Furthermore, the first electrode (100a) may include a first current collector (110a) comprising a first current collector body (101a) on which an active material layer (102) is located and a first electrode tab (120a) protruding from the first current collector body (101a), and the second electrode (100b) may include a second current collector (110b) comprising a second current collector body (101b) and a second electrode tab (120b) so as to correspond to the first electrode (100a).

[0089] The first electrode tab (120a) may be located on the opposite side from the second electrode tab (120b).

[0090] At this time, the first current collector body (101a) may have a long side (111L) and a short side (112L), and the second current collector body (101b) may have a long side (111L) and a short side (112L) corresponding to the first current collector body (101a). The first electrode tab (120a) may extend from the long side (111L) of the first current collector body (101a), and the second electrode tab (120b) may extend from the long side (111L) of the second current collector body (101b).

[0091] Accordingly, the distance the charge travels from the first electrode tab (120a) to the second electrode tab (120b) may correspond to the length of the short side (112L) of the first current collector body (101a) or the second current collector body (101b).

[0092] In the case of the first embodiment, although it may be difficult to prevent the mismatch of resistance itself, the degree of mismatch of resistance can be reduced because the region where voltage drop occurs is short.

[0093] At this time, the width of the first electrode tab (120a) is formed to correspond to the length of the long side (111L) of the first current collector body (101a), so that a process of further reducing the width of the electrode tab (120) as shown in FIG. 2 can be avoided.

[0094] The first embodiment and other embodiments are described below. Content common to the first embodiment will be omitted as much as possible, and the other embodiments will be described focusing on the differences. In other words, it is obvious that if content not explained in the other embodiments is necessary, it can be supplemented through the content of the first embodiment.

[0095] 2nd embodiment

[0096] FIG. 9 is an exploded view showing a part of an electrode assembly (EA-1) according to a second embodiment of the present invention. FIG. 10 is a cross-sectional view of the electrode assembly (EA-1) shown in FIG. 9. FIG. 11 is a circuit diagram of the electrode assembly (EA-1) shown in FIG. 10.

[0097] Referring to FIGS. 9 to 11, an electrode assembly (EA-1) according to a second embodiment of the present invention will be described.

[0098] The first electrode tab (120a-1) and the second electrode tab (120b-1) may be located on the same side. The first current collector body (101a-1) may have a long side (111L-1) and a short side (112L-1), and the second current collector body (101b-1) may have a long side (111L-1) and a short side (112L-1) corresponding to the first current collector body (101a-1). The first electrode tab (120a-1) may extend from the short side (112L-1) of the first current collector body (101a-1), and the second electrode tab (120b-1) may extend from the short side (112L-1) of the second current collector body (101b-1).

[0099] The first current collector body (101a-1) has a pair of short sides (112L-1) located on opposite sides, and the first electrode tab (120a-1) can be provided as a pair extending from each of the pair of short sides (112L-1) of the first current collector body (101a-1).

[0100] In this case, unlike the second comparative example, the charge may be moved from the center rather than from the end of the current collector (101-1). In other words, the first electrode tab (120a-1) and the second electrode tab (120b-1) may be configured so that the charge moves from the center of the first current collector body (101a-1) to the center of the other electrode tab (120b-1). More specifically, the first electrode tab (120a-1) and the second electrode tab (120b-1) can be configured such that the distance the charge travels from the first electrode tab (120a-1) to the second electrode tab (120b-1) corresponds to the long side (111L-1) of the first current collector body (101a-1) or the long side (111L-1) of the second current collector body (101b-1). Referring to FIG. 11, since the movement from the second electrode tab (120b-1) to the first electrode tab (120a-1) occurs at the center of the current collector (101-1), the distance the charge travels is shortened, thereby minimizing the voltage drop.

[0101] The first electrode tab (120a-1) may have a width smaller than the length of the short side (112L-1) of the first current collector body (101a-1). More specifically, the first electrode tab (120a-1) may have a width less than half the width of the first current collector body (101a-1). Furthermore, the first electrode tab (120a-1) may be positioned so as to prevent overlapping with the second electrode tab (120b-1) in the stacking direction. The first electrode tab (120a-1) may be provided in multiple numbers and may be joined together. Since the second electrode tab (120b-1) and the first electrode tab (120a-1) have different polarities, it is necessary to prevent them from being joined or coming into contact with each other. According to the second embodiment of the present invention, the first electrode tab (120a-1) and the second electrode tab (120b-1) do not overlap in the stacking direction, so even if the first electrode tabs (120a-1) or the second electrode tabs (120b-1) are combined in the stacking direction, contact between them can be prevented.

[0102] Third embodiment

[0103] FIG. 12 is a conceptual diagram illustrating a first electrode (100a-2) and a second electrode (100b-2) according to a third embodiment of the present invention.

[0104] Referring to FIG. 12, the first electrode (100a-2) and the second electrode (100b-2) according to the third embodiment of the present invention will be described.

[0105] The third embodiment may be a combination of the first embodiment and the second embodiment.

[0106] In other words, the first electrode tab (120a-2) and the second electrode tab (120b-2) can be formed to extend from the long side (111L-2) of the first current collector body (101a-2) and the second current collector body (101b-2), respectively, so as not to overlap each other with respect to the stacking direction.

[0107] Unless explicitly stated otherwise, the embodiments described above may be combined with other embodiments. Alternatively, unless explicitly limited in the combination of any embodiment with another, it should be considered that combinations between embodiments are possible. Any combination of any embodiment with another embodiment is deemed to be disclosed herein.

[0108] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0109] [Explanation of the symbol]

[0110] B, B-01, B-02: Secondary battery

[0111] 200: Battery case

[0112] 210: Reception Department

[0113] 210S: Electrode receiving space

[0114] 220: Side

[0115] 221: Lead sealing part

[0116] 222: Digas sealing section

[0117] 223: Folding section

[0118] EA, EA-01, EA-02, EA-1: Electrode assembly

[0119] 100, 100-01, 100-02: Electrode

[0120] 100a, 100a-01, 100a-1, 100a-2: First electrode

[0121] 100b, 100b-01, 100b-1, 100b-2: Second electrode

[0122] 101, 101-1: Whole house

[0123] 110a, 110a-01, 110a-02, 110a-1, 110a-2: First entire collection

[0124] 110b, 110b-01, 110b-02, 110b-1, 110b-2: Second entire house

[0125] 101a, 101a-01, 101a-02: First whole body

[0126] 101b, 101b-01, 101b-02: The entire body of the second house

[0127] 102, 102-01, 102-1: Active material layer

[0128] 111L, 111L-01, 111L-1: Long side

[0129] 112L, 112L-01, 112L-1: Single variable

[0130] 120, 120-01, 120-02: Electrode tabs

[0131] 120a, 120a-01, 120a-02, 120a-1, 120a-2: First electrode tab

[0132] 120b, 120b-01, 120b-02, 120b-1, 120b-2: Second electrode tab

[0133] 300, 300-01: Separator

Claims

1. First electrode; and It includes a second electrode that is stacked in the stacking direction with the first electrode and has a polarity different from that of the first electrode, The first electrode comprises a first current collector including a first current collector body on which an active material layer is located and a first electrode tab protruding from the first current collector body. The second electrode comprises a second current collector including a second current collector body and a second electrode tab so as to correspond to the first electrode, and The electrode assembly is configured such that the first electrode tab and the second electrode tab are configured such that the distance over which charge travels from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector body.

2. In Paragraph 1, It is moved through a first current collector body and a second current collector body that transmit from the first electrode tab to the second electrode tab, and The electrode assembly is configured such that the first current collector body and the second current collector body lower the voltage of the charge in proportion to the distance the charge travels while the charge travels from the first electrode tab to the second electrode tab.

3. In Paragraph 1, It is moved through a first current collector body and a second current collector body that transmit from the first electrode tab to the second electrode tab, and The electrode assembly is configured such that the first current collector body and the second current collector body generate heat in proportion to the distance the charge travels while the charge travels from the first electrode tab to the second electrode tab.

4. In Paragraph 1, The first electrode tab is an electrode assembly located on the opposite side of the second electrode tab.

5. In Paragraph 1, The above-mentioned first current collector body has a long side and a short side, The second current collector body has a long side and a short side corresponding to the first current collector body, The first electrode tab extends from the long side of the first current collector body, and The second electrode tab is an electrode assembly extending from the long side of the second current collector body.

6. In Paragraph 5, The electrode assembly in which the distance of charge travel from the first electrode tab to the second electrode tab corresponds to the length of the short side of the first current collector body or the second current collector body.

7. In Paragraph 5, The width of the first electrode tab corresponds to the length of the long side of the first current collector body, forming an electrode assembly.

8. In Paragraph 1, The first electrode tab and the second electrode tab are electrode assemblies located on the same side.

9. In Paragraph 1, The above-mentioned first current collector body has a long side and a short side, The second current collector body has a long side and a short side corresponding to the first current collector body, The first electrode tab extends from the short side of the first current collector body, and The second electrode tab is an electrode assembly extending from the short side of the second current collector body.

10. In Paragraph 9, The first electrode tab is an electrode assembly having a width smaller than the length of the short side of the first current collector body.

11. In Paragraph 9, The above-mentioned first current collector body has a pair of short sides located on opposite sides, The first electrode tab is an electrode assembly provided in pairs so as to extend from each of the pair of short sides of the first current collector body.

12. In Paragraph 9, The first electrode tab is an electrode assembly positioned such that it is not overlapped with the second electrode tab in the stacking direction.

13. In Paragraph 1, The first electrode tab and the second electrode tab are an electrode assembly configured such that charge is transferred from the first electrode tab to the second electrode tab from the center of either the first current collector body or the second current collector body to the center of the other.

14. In Paragraph 9, The electrode assembly is configured such that the distance of charge travel from the first electrode tab to the second electrode tab corresponds to the long side of the first current collector body or the long side of the second current collector body.

15. In Paragraph 1, An electrode assembly further comprising a separator located between the first electrode and the second electrode.

16. Electrode assembly; and It includes a battery case that accommodates the above electrode assembly, The above electrode assembly is, First electrode; and It includes a second electrode that is stacked in the stacking direction with the first electrode and has a polarity different from that of the first electrode, The first electrode comprises a first current collector including a first current collector body on which an active material layer is located and a first electrode tab protruding from the first current collector body. The second electrode comprises a second current collector including a second current collector body and a second electrode tab so as to correspond to the first electrode, and A secondary battery configured such that the first electrode tab and the second electrode tab are configured such that the distance over which charge travels from the first electrode tab to the second electrode tab is shorter than twice the length of the current collector body.

17. In Paragraph 16, It is moved through a first current collector body and a second current collector body that transmit from the first electrode tab to the second electrode tab, and A secondary battery configured such that the first current collector body and the second current collector body lower the voltage of the charge in proportion to the distance the charge travels while the charge travels from the first electrode tab to the second electrode tab.

18. In Paragraph 16, It is moved through a first current collector body and a second current collector body that transmit from the first electrode tab to the second electrode tab, and A secondary battery configured such that the first current collector body and the second current collector body generate heat in proportion to the distance the charge travels while the charge travels from the first electrode tab to the second electrode tab.

19. In Paragraph 16, The first electrode tab is a secondary battery located on the opposite side of the second electrode tab.

20. Active material layer; and A current collector comprising a current collector body configured to have the above-mentioned active material layer positioned thereon and an electrode tab extending from the current collector body, and The above-mentioned entire body includes a long side and a short side, and The electrode tab is an electrode extending from the long side of the current collector body.

Images