Lithium secondary battery

Abstract

The present invention relates to a lithium secondary battery, which includes a stacked electrode assembly including a plurality of electrode leads, and has an advantage of extremely low resistance inside the battery. In addition, the lithium secondary battery has an advantage of being easy to change the positions of the electrode terminals and having a high degree of freedom in designing a battery module, since one or more first and second electrode terminals can be selectively disposed on the top surface of the upper cap and / or the side surface of the cap.

Description

[Technical field]

[0001] The present invention relates to a lithium secondary battery, and more particularly to a prismatic lithium secondary battery having low internal resistance and allowing high degree of freedom in designing a battery module.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0105337 dated August 23, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries, which can be charged and discharged, have been actively researched for application in various cutting-edge fields, and have been commercialized and widely used.

[0004] In particular, in recent years, large-capacity, high-power secondary batteries using non-aqueous electrolytes with high energy density have been developed, and the above-mentioned large-capacity, high-power secondary batteries are generally configured in the form of high-power battery modules by connecting a large number of battery cells in series and parallel so that they can be used for power storage or in devices requiring large power.

[0005] Meanwhile, such battery cells are manufactured in various shapes, representative shapes being cylindrical, square, pouch, etc. In particular, for medium to large modules that require high output, cylindrical and square batteries are generally used, since it is relatively easy to ensure high capacity.

[0006] The battery cell is constructed by housing an electrode assembly formed by interposing a separator between a positive electrode and a negative electrode and an electrolyte in a case and installing a cap plate on the case, and a positive electrode terminal and a negative electrode terminal are connected to the electrode assembly and protrude to the outside through the cap plate.

[0007] When a medium- or large-sized battery module is formed by electrically connecting the battery cells configured in this way, the electrode terminals are fixed in one direction in the conventional structure, so a separate space is required to connect the terminals. Therefore, the volume of the battery module becomes large, and the circuit configuration of the battery module must be arranged on the upper part where the electrode terminals are located, which reduces the flexibility in configuring the battery module and greatly limits the user's options. In addition, when the battery cells with the electrode terminals protruding from the upper part of the battery cells are arranged in a row to configure the module, the height of the battery module becomes high, which is a problem when applied to an electric vehicle, as it has no choice but to increase the height of the vehicle body.

[0008] 1 is a perspective view showing the structure of a conventional cylindrical and prismatic battery, and the electrode assembly applied to the battery is a jelly-roll type. The jelly-roll type electrode assembly has a structural restriction that only one positive electrode lead and one negative electrode lead can protrude to the outside, so there is a limitation that the resistance generated inside the battery is larger than when multiple electrode leads are introduced.

[0009] Therefore, there is a demand for the development of a secondary battery that can reduce the internal resistance of the battery, while allowing easy repositioning of the electrode terminals and providing a high degree of design freedom when constructing a battery module. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2016-0148316 [Patent Document 2] Korean Patent Publication No. 10-2018-0137991 Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a secondary battery that can reduce the internal resistance of the battery, while allowing easy change of the positions of the electrode terminals and providing high design freedom in constructing a battery module. [Means for solving the problem]

[0012] To solve the above-mentioned problems, In one embodiment, the present invention comprises: A laminated electrode assembly including a first electrode, a second electrode, and a separator; and a case for housing the laminated electrode assembly, The above case is A main body including a main body side portion to which one ends of the first side surface to the fourth side surface are sequentially coupled, and a bottom surface portion coupled to a bottom end of the main body side surface portion; a cap side portion to which one ends of A side to D side are sequentially coupled to correspond to the first side to fourth side of the body, and an upper surface portion coupled to an upper end of the cap side portion, and an upper cap coupled to an open upper end of the body, The upper cap has a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal are provided on at least one of the top surface portion and the cap side surface portion, respectively.

[0013] As one example, the upper cap may include the first electrode terminal and the second electrode terminal on the upper surface portion, and the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively, or may include only the second electrode terminal on side A or side C of the cap side portion.

[0014] As another example, the upper cap may include the first electrode terminal on the top surface portion, and the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively, or may include only the second electrode terminal on side A or side C of the cap side portion.

[0015] The total number of the first electrode terminals and the second electrode terminals included in the upper cap may be three or more.

[0016] The main body may also include lead through-portions at an upper portion thereof for exposing the first electrode lead and the second electrode lead on the first side surface and the third side surface, respectively.

[0017] The lead through portion may be formed from a point that is 1 / 2 to 4 / 5 of the height based on the lower end of the first side and the third side to the upper end.

[0018] The electrode pad may further include a sealing portion interposed between an outer periphery of the first electrode lead and the second electrode lead and an inner periphery of the lead through portion.

[0019] Moreover, the A-side and C-side surfaces of the upper cap may have a structure that covers the lead penetrating portion of the main body.

[0020] In addition, the stacked electrode assembly has a stacked structure in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separation membrane interposed between the first electrodes and the second electrodes, and each of the first electrodes and the second electrodes may include one or more first electrode leads and one or more second electrode leads on one side located at the open upper end of the body when inserted into the case and on an adjacent side thereto.

[0021] In this case, each of the first electrode and the second electrode may include an electrode active layer, and the electrode active layer may be located at a height lower than the lead through portion when inserted into the main body. Effect of the Invention

[0022] The lithium secondary battery according to the present invention includes a stacked electrode assembly including a plurality of electrode leads, and has an advantage of extremely low resistance inside the battery. In addition, the lithium secondary battery has one or more first and second electrode terminals that can be selectively disposed on the top surface of the upper cap and / or the side surface of the cap, which allows easy positioning of the electrode terminals and provides a high degree of freedom in designing the battery module. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view showing the structure of a conventional lithium secondary battery. [Diagram 2] 1 is a perspective view showing a structure of a lithium secondary battery according to the present invention. [Diagram 3] FIG. 4 is a schematic diagram showing the positions of a first electrode terminal and a second electrode terminal provided on the upper cap. [Figure 4] 11A and 11B are structural diagrams showing the shape of a sealing part depending on whether or not an electrode lead of an electrode assembly is present; [Diagram 5] 11A and 11B are structural diagrams showing the shape of a sealing part depending on whether or not an electrode lead of an electrode assembly is present; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments are described in detail in the detailed description.

[0025] However, this is not intended to limit the invention to the particular embodiments, but should be understood to include all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0026] In the present invention, the terms "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but should be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] In addition, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion in between. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion in between. In addition, in the present application, being "on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0028] The present invention will now be described in more detail.

[0029] <Lithium secondary battery> In one embodiment, the present invention comprises: A laminated electrode assembly including a first electrode, a second electrode, and a separator; and a case for housing the electrode assembly, The case includes a main body including a main body side portion to which one ends of first to fourth side surfaces are sequentially coupled, and a bottom surface portion coupled to the bottom ends of the side surfaces; an upper cap including a cap side portion to which one ends of A to D side surfaces are sequentially coupled so as to correspond to the first to fourth side surfaces of the main body, and a top surface portion coupled to the top ends of the side surfaces, and coupled to the open top end of the main body; The upper cap has a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal are provided on at least one of the top surface portion and the cap side surface portion, respectively.

[0030] The lithium secondary battery according to the present invention has a structure including an electrode assembly including a first electrode, a second electrode, and a separator, and a case containing an electrolyte, and in this case, the electrode assembly can lower the resistance inside the battery by introducing a plurality of at least one of the first electrode lead and the second electrode lead into the stacked electrode assembly. In addition, since the plurality of electrode leads can be electrically connected to electrode terminals provided on the upper or side surface of the battery, it is easy to change the position of the electrode terminals, and there is an advantage that there is a high degree of freedom in designing the battery module when constructing the battery module.

[0031] FIG. 2 is a perspective view that illustrates a schematic structure of a lithium secondary battery according to the present invention, and the lithium secondary battery will be described in detail with reference to FIG.

[0032] First, the lithium secondary battery 100 according to the present invention includes an electrode assembly 120 in which a plurality of first electrodes 121 and a plurality of second electrodes 122 are alternately stacked with a separator interposed therebetween.

[0033] The first electrode 121 and the second electrode 122 may be positive or negative, and may be understood as negative or positive, respectively, depending on the circumstances. Here, the positive electrode includes a positive active layer including a positive active material on at least one surface of a positive current collector including aluminum, and includes a positive tab extending from a non-coated portion of the positive current collector where the positive active layer is not formed. Also, the negative electrode includes a negative active layer including a negative active material on at least one surface of a negative current collector including copper, and includes a negative tab extending from a non-coated portion of the negative current collector where the negative active layer is not formed. The positive electrode tabs and the negative electrode tabs may be welded to each other to form a positive electrode lead and a negative electrode lead, respectively. Also, the separator is made of a porous thin film, and may be made of, for example, a polyolefin-based resin.

[0034] In addition, the electrode assembly 120 may include one or more first electrode leads 121a, 121b and one or more second electrode leads 122a, 122b.

[0035] Specifically, the electrode assembly 120 may have first electrode leads 121a, 121b and second electrode leads 122a, 122b arranged on one side located at the upper end of the case body 110 when inserted into the case and on the adjacent side, and there may be one or more first electrode leads 121a, 121b and one or more second electrode leads 122a, 122b arranged in this manner.

[0036] As one example, the electrode assembly 120 may include a first electrode lead 121a and a second electrode lead 122a on one side of the electrode assembly 120 that is located at the upper end of the case body 110 when inserted into the case, and may further include a first electrode lead 121b and / or a second electrode lead 122b on both adjacent sides of the one side (i.e., at the position of the first side 111a and the position of the third side 111c of the body 110).

[0037] As another example, the electrode assembly 120 may include a first electrode lead 121a or a second electrode lead 122a on one side of the electrode assembly 120 that is located at the upper end of the case body 110 when inserted into the case, and may further include a first electrode lead 121b and / or a second electrode lead 122b on both adjacent side surfaces of the one side (i.e., the position of the first side surface 111a and the position of the third side surface 111c of the body 110).

[0038] Here, when the electrode assembly 120 includes one electrode lead 121b or 122b on both side surfaces (i.e., the position of the first side surface 111a and the position of the third side surface 111c of the body 110) adjacent to one side surface of the electrode assembly 120 located at the upper end of the case body 110 when inserted into the case, the two electrode leads included in the electrode assembly 120 may be different electrode leads. Specifically, when the electrode assembly 120 includes a first electrode lead 121a on one side surface located at the upper end of the body 110 when inserted into the case, the electrode assembly 120 may include a second electrode lead 122b on a surface adjacent to the one side surface. Also, when the electrode assembly 120 includes a second electrode lead 122a on one side surface located at the upper end of the body 110 when inserted into the case, the electrode assembly 120 may include a first electrode lead 121b on a surface adjacent to the one side surface.

[0039] The present invention can significantly reduce the resistance inside the battery during charging and discharging by introducing one or more electrode leads each for the first electrode 121 and the second electrode 122 into the electrode assembly 120, specifically, by introducing the total number of first electrode leads and second electrode leads into the electrode assembly so that the total number is three or more.

[0040] In addition, the lithium secondary battery 100 according to the present invention includes an electrode assembly 120 and a case for housing the electrode assembly 120. The case may be a battery can having various shapes such as a cylindrical shape or a square shape. As one example, the case may be a square battery can.

[0041] Here, the case includes a body 110 and an upper cap 130, which are manufactured by a deep drawing method or assembled according to a design drawing, and the upper cap 130 may be stacked on the outside of the open upper end of the body 110 and may seal the inside by ultrasonic welding or laser welding.

[0042] More specifically, the body 110 is a rectangular structure having a shape corresponding to an open upper end for accommodating the electrode assembly 120 and an electrolyte (not shown), and has a structure including a body side portion 111 formed by sequentially connecting one end of a first side surface 111a to a fourth side surface 111d, and a lower surface portion (not shown) connected to the lower end of the body side portion 111.

[0043] Also, the body 110 may have a lead through portion 112 at the top for exposing the first electrode lead 121b and the second electrode lead 122b to the first side surface 111a and the third side surface 111c, respectively. Specifically, in the electrode assembly 120 described above, the first electrode leads 121a, 121b and the second electrode leads 122a, 122b are located at one or more of a side surface located at the open upper end of the body 110 and a surface adjacent thereto, i.e., the first side surface 111a and the third side surface 111c of the body, in order to reduce resistance inside the battery. In this case, the first side surface 111a and the third side surface 111c may have a lead through portion 112 for exposing the first electrode lead 121b and the second electrode lead 122b located at one or more of these surfaces.

[0044] The lead through portion 112 may be located at the upper portion of the first side surface 111a and the third side surface 111c. More specifically, the lead through portion 112 may be formed from a point at which the height is equal to or greater than the middle of the lower ends of the first side surface 111a and the third side surface 111c, for example, a point at which the height is 1 / 2 to 4 / 5 of the lower ends of the first side surface 111a and the third side surface 111c, specifically, a point at which the height is 3 / 5 to 4 / 5 of the lower ends of the first side surface 111a and the third side surface 111c, to the upper end.

[0045] By controlling the position of the lead through portion 112 as described above, the present invention can prevent the electrolyte contained inside the main body 110 from leaking to the outside, and at the same time, can improve the shortcomings of the circuit configuration of the battery module due to the low height of the electrode terminals arranged on the side when the battery module is constructed.

[0046] Also, the lead through portion 112 may include a sealing portion 113. Specifically, as shown in Fig. 4, when the electrode lead is provided on one side corresponding to the first side 111a and the third side 111c of the body when the electrode assembly 120 is inserted into the case, the sealing portion 113 may be provided to fill a gap between an outer periphery of the electrode lead (e.g., the first electrode lead and / or the second electrode lead) and an inner periphery of the lead through portion in order to more firmly fix the electrode lead. In this case, the sealing portion 113 may have a structure in which an incision is made from the upper end surface of the body 110 along the lead through portion 112 so that the electrode lead is inserted in the middle, and the electrode lead may be inserted along the incision line 114.

[0047] In addition, as shown in FIG. 5, when an electrode lead is not provided on one side corresponding to the first side 111a and the third side 111c of the body when the electrode assembly 120 is inserted into the case, the sealing portion 113 may be provided in a form that fills the entire inner periphery of the lead through portion 112 in order to primarily prevent leakage of the electrolyte contained in the body 110.

[0048] The sealing part 130 may be made of an elastic material to firmly fix the electrode lead without damaging it when the electrode lead is inserted, and to seal the lead penetration part 112 when the electrode lead is not inserted. Such an elastic material is not particularly limited as long as it is a material commonly used in the art, and specifically, it may be made of one or more resins selected from the group consisting of epoxy, silicone, silicone-based rubber, styrene-based rubber, butadiene-based rubber, polyurethane, soft PVC, and polypropylene copolymer.

[0049] Furthermore, the upper cap, which is coupled to the open upper end of the body 110 to seal the case, includes a cap side portion and a top portion. The cap side portions 130a to 130d include A side 130a to D side 130d, one ends of which are sequentially coupled to positions corresponding to the first side 111a to fourth side 111d of the body, and the top portion is coupled to the upper ends of the cap side portions.

[0050] Here, the upper cap 130 may have a structure in which the A side 130a and the C side 130c of the upper cap cover the lead through portion 112 of the body 110 located on the inner surface. In this manner, the upper cap 130 may be welded in a state in which the lead through portion is covered by the A side 130a and the C side 130c of the upper cap, thereby completely sealing the inside.

[0051] Also, the upper cap 130 may include first electrode terminals 161a, 161b and second electrode terminals 162a, 162b to correspond to the positions of the first electrode lead 121a and the second electrode lead 121b of the electrode assembly 120 housed in the case body 110. In this case, the first electrode terminals 161a, 161b and the second electrode terminals 162a, 162b are provided on at least one of the top surface portion and the cap side surface portion, respectively.

[0052] 3, the electrode assembly 120 may include first electrode terminals 161a, 161b and second electrode terminals 162a, 162b electrically connected to the first electrode leads 121a, 121b and the second electrode leads 122a, 122b, respectively, of the electrode assembly 120 inserted into the body 110. Here, the first electrode terminals 161a, 161b and the second electrode terminals 162a, 162b may be provided on at least one of an upper surface portion and a side surface portion of the upper cap 130 where the electrode leads are located, so as to correspond to the positions of the first electrode leads 121a, 121b and the second electrode leads 122a, 122b, respectively. In the above-described electrode assembly 120, in order to reduce resistance inside the battery, the first electrode leads 121a, 121b and the second electrode leads 122a, 122b are located on one or more of a side surface located at the open upper end of the body 110 when inserted into the case and an adjacent surface thereto, i.e., the first side surface 111a and the third side surface 111c of the body, and first electrode terminals 161a, 161b and second electrode terminals 162a, 162b to which the first electrode leads 121a, 121b and the second electrode leads 122a, 122b are provided.

[0053] As one example, the upper cap may include a first electrode terminal 161a and a second electrode terminal 162a on the upper surface, and may also include a first electrode terminal 161b and a second electrode terminal 162b on sides A and C of the cap side portion, respectively, as shown in (A) and (B) of Figures 3, or may only include the second electrode terminal 162b on sides A or C of the cap side portion.

[0054] In this case, since the upper cap basically includes the first electrode terminal 161 a and the second electrode terminal 162 a on the upper surface, the battery circuit module can be applied in the same manner as a conventional lithium secondary battery using a rectangular battery can, and the resistance inside the battery can be reduced by providing an additional electrode terminal on the side surface.

[0055] As another example, the upper cap 130 may include a first electrode terminal 161a on the upper surface portion, and may also include a first electrode terminal 161b and a second electrode terminal 162b on the A side 130a and C side 130c of the cap side portion, respectively, as shown in (C) and (D) of Figures 3, or may only include the second electrode terminal 162b on the A side 130a or C side 130c of the cap side portion.

[0056] In this case, the upper cap 130 has a structure including one electrode terminal on the upper surface and an electrode terminal on the side surface having an electric charge corresponding to the electrode terminal on the upper surface, which has an advantage of providing a higher structural freedom in designing the battery module compared to a case where both the first electrode terminal 161a and the second electrode terminal 162a are provided on the upper surface.

[0057] In addition, the upper cap 130 may include three or more first electrode terminals and second electrode terminals. In this case, the secondary battery including the upper cap 130 may significantly reduce the resistance inside the battery during charging and discharging, thereby improving the charging and discharging performance of the secondary battery and improving the heat generation phenomenon caused by the internal resistance.

[0058] Meanwhile, the body 110 and the upper cap 130 may be made of a lightweight conductive metal material such as aluminum, nickel, stainless steel, or an alloy thereof.

[0059] In addition, the body 110 and the upper cap 130 may include a coating layer that exhibits insulating properties while sealing the electrolyte inside the conductive metal material. Specifically, the coating layer may be a coating layer including fluorine resin.

[0060] In addition, the cap plate 140 includes terminal through-holes 141a, 141b, 142a, and 142b and an electrolyte injection hole 143, and is welded to an upper end opening of the upper cap 130 to seal the upper cap 130. The terminal through-holes 141a, 141b, 142a, and 142b are formed at 1 / 3 positions based on both sides of the cap plate 140, and electrode terminals 161a, 161b, 162a, and 162b insulated by gasket tubes 151a, 151b, 152a, and 152b are inserted into the terminal through-holes 141a, 141b, 142a, and 142b. The electrolyte injection hole 143 is formed on one side of the cap plate 140 and is sealed by a ball (not shown). In this case, the electrolyte injection hole 143 may be formed to have a circular planar shape as shown in FIG. 2. Although not shown, the electrolyte injection port 143 may have a planar shape of an ellipse, a rectangle, or the like, and this is not a limitation on the planar shape of the electrolyte injection port 143. The electrolyte injection port 143 may have a vertical cross-sectional shape of a Y-shape. Although not shown, the electrolyte injection port 143 may have a vertical cross-sectional shape of an 11-shape, and this is not a limitation on the vertical cross-sectional shape of the electrolyte injection port 143.

[0061] The lithium secondary battery according to the present invention has the above-mentioned configuration, and thus has the advantages of not only low resistance inside the battery, but also ease of changing the positions of the electrode terminals, and high design freedom when configuring the battery module.

[0062] The present invention will now be described in more detail with reference to examples and experimental examples.

[0063] However, the following examples and experimental examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples and experimental examples.

[0064] <Example> First, 40 positive and negative electrodes were prepared, and 81 porous polyethylene separators (9.5 cm wide x 34.5 cm long, average thickness of about 20 μm) that were wider than the positive and negative electrodes were prepared as separators. The prepared positive and negative electrodes were alternately stacked, and separators were placed between them and on the outermost surface to prepare a stacked electrode assembly. The electrode assembly was then inserted into a square case (10 cm wide x 35 cm long x 1.6 cm thick) and electrolyte was injected to prepare a lithium secondary battery.

[0065] In this case, the electrolyte used was a liquid electrolyte in which LiPF6 was added as a lithium salt at a concentration of 1M to an organic solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 3:7. The height of the electrolyte was injected so that the active layer of each electrode was sufficiently impregnated, and was adjusted to be lower than the lead penetration part of the square case.

[0066] In addition, the square case used had the structure of FIG. 2 and was adjusted as shown in FIG. 3, and the electrode terminals of each case were electrically connected to the first and second electrode leads of the corresponding electrode assembly.

[0067] [Table 1]

[0068] <Comparative Example 1> A lithium secondary battery was fabricated in the same manner as in Example 1, except that a square case having the structure of Fig. 1 was used, including a jelly-roll type electrode assembly. However, the composition (components and content) and loading amount of the active material layers provided in the negative and positive electrodes of the electrode assembly were adjusted to be the same as in Example 1.

[0069] <Experimental Example> In order to evaluate the battery resistance of the lithium secondary battery according to the present invention, each of the lithium secondary batteries manufactured in the examples and comparative examples was fully charged to SOC 100% under a voltage condition of 4.25 V. Thereafter, the DC resistance of each fully charged lithium secondary battery was measured, and the DC resistance deviation rate of each lithium secondary battery was calculated based on the DC resistance value of the lithium secondary battery of Comparative Example 1. The results are shown in Table 2 below.

[0070] [Table 2]

[0071] As shown in Table 2, the lithium secondary battery according to the present invention has low internal resistance, which means that the resistance generated during charging and discharging is reduced by including a stacked electrode assembly having a plurality of electrode tabs.

[0072] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art or those having ordinary knowledge in the art that the present invention can be modified and changed in various ways without departing from the spirit and technical scope of the present invention as described in the claims below.

[0073] Therefore, the technical scope of the present invention should not be limited to the contents described in the Summary of the Invention of the specification, but should be defined by the claims. [Explanation of symbols]

[0074] 1: Conventional lithium secondary batteries 10: Case 21: First electrode lead 22: Second electrode lead 30: Top cap 31: Hole for first electrode lead 32: Hole for second electrode lead 33: Electrolyte injection hole 40: Cap plate 41:Terminal hole 42: Electrolyte inlet 50: Gasket tube 60: Electrode terminal 100: Lithium secondary battery according to the present invention 110: Main unit 111a, 111b, 111c, 111d: 1st side, 2nd side, 3rd side, 4th side 112: Lead penetration 113: Sealing part 114: Incision line 120: Electrode assembly 121: 1st electrode 121a, 121b: first electrode lead 122:Second electrode 122a, 122b: second electrode lead 130: Upper cap 130a, 130b, 130c, 130d: A side, B side, C side, D side 131: Hole for first electrode lead 132: Hole for second electrode lead 133: Electrolyte injection hole 140: Cap plate 141a, 141b: Through hole for first electrode terminal 142a, 142b: Through hole for second electrode terminal 143: Electrolyte inlet 151a, 151b: gasket tube for first electrode terminal 152a, 152b: Gasket tube for second electrode terminal 161a, 161b: 1st electrode terminal 162a, 162b: 2nd electrode terminal

Claims

1. a stacked electrode assembly including a first electrode, a second electrode, and a separator; and a case for housing the stacked electrode assembly, The case is a main body including a main body side portion to which one ends of a first side surface to a fourth side surface are sequentially coupled, and a bottom surface portion coupled to a bottom end of the main body side portion; an upper cap including a cap side portion to which one ends of A side to D side are sequentially coupled to correspond to the first side to fourth side of the body, and an upper surface portion coupled to an upper end of the cap side portion, and coupled to an open upper end of the body; The upper cap has a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal are each provided on at least one of a top surface portion and a cap side surface portion.

2. The upper cap is the first electrode terminal and the second electrode terminal are included on the upper surface portion; The lithium secondary battery according to claim 1 , further comprising the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively.

3. The upper cap is the first electrode terminal and the second electrode terminal are included on the upper surface portion; The lithium secondary battery according to claim 1 , wherein only the second electrode terminal is provided on side A or side C of the cap side portion.

4. The upper cap is The first electrode terminal is included on the upper surface portion. The lithium secondary battery according to claim 1 , further comprising the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively.

5. The upper cap is The first electrode terminal is included on the upper surface portion. The lithium secondary battery according to claim 1 , wherein only the second electrode terminal is provided on side A or side C of the cap side portion.

6. The lithium secondary battery according to claim 1 , wherein a total number of the first electrode terminals and the second electrode terminals is three or more.

7. The lithium secondary battery according to any one of claims 1 to 6, wherein the body has a lead through portion at an upper portion thereof for exposing the first electrode lead and the second electrode lead on the first side surface and the third side surface, respectively.

8. 8. The lithium secondary battery of claim 7, wherein the lead through portion is formed from a point that is 1 / 2 to 4 / 5 of the height of the lower end of the first side and the third side to the upper end.

9. The lithium secondary battery of claim 7 , further comprising a sealing portion interposed between an outer periphery of the first electrode lead and the second electrode lead and an inner periphery of the lead through portion.

10. 8. The lithium secondary battery according to claim 7, wherein the side A and side C of the upper cap have a structure for covering the lead-through portion of the main body.

11. The stacked electrode assembly has a stacked structure in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked and a separation film is interposed between the first electrodes and the second electrodes, 2. The lithium secondary battery of claim 1, wherein each of the first electrode and the second electrode includes at least one first electrode lead and at least one second electrode lead on a side surface that is located at the open top end of the body when inserted into the case and on a surface adjacent thereto.

12. The lithium secondary battery according to claim 7 , wherein the first electrode and the second electrode each include an electrode active layer, and the electrode active layer is located at a height lower than the lead penetration portion when inserted into the main body.

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