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 that has low internal resistance and allows for a 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, filed on August 23, 2022, and all contents disclosed in the documents of this 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 amounts of power.

[0005] Meanwhile, such battery cells are manufactured in a variety of shapes, typical shapes being cylindrical, prismatic, pouch, etc. In particular, for medium to large modules that require high output, cylindrical and prismatic batteries are commonly used, as they are relatively easy to secure high capacity.

[0006] The battery cell is constructed by housing an electrode assembly formed between a positive electrode and a negative electrode with a separator interposed therebetween as an insulator, together with an electrolyte, in a case, and installing a cap plate on the case. At this time, a positive electrode terminal and a negative electrode terminal are connected to the electrode assembly, and these terminals are formed to protrude to the outside through the cap plate.

[0007] When a medium- to large-sized battery module is formed by electrically connecting battery cells configured in this manner, the electrode terminals in the conventional structure are fixed in one direction, requiring additional space for connecting the terminals. As a result, the volume of the battery module increases, and the circuit configuration of the battery module must be arranged above the electrode terminals, resulting in reduced flexibility in configuring the battery module and significantly limited user options. Furthermore, when a module is formed by arranging battery cells in a row with electrode terminals protruding above the battery cells as described above, the height of the battery module increases, which results in an increase in the height of the vehicle when applied to an electric vehicle.

[0008] Furthermore, Figure 1 is a perspective view showing the structure of conventional cylindrical and prismatic batteries, and the electrode assembly used in these batteries is a jelly-roll type. Due to structural limitations, the jelly-roll type electrode assembly only allows one positive electrode lead and one negative electrode lead to protrude to the outside, which has the limitation that the resistance generated inside the battery is higher 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, allows easy repositioning of the electrode terminals, and provides a high degree of freedom in designing the battery module configuration. [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, that allows easy repositioning of electrode terminals, and that offers a high degree of freedom in design when constructing a battery module. [Means for solving the problem]

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

[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 surface portion, respectively, or may include only the second electrode terminal on side A or side C of the cap side surface 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 have lead penetrations at its upper portion 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 where the height is 1 / 2 to 4 / 5 of the height from the lower end of the first side surface and the third side surface to the upper end.

[0018] The device may also 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 penetration portion.

[0019] Furthermore, the A and C side faces of the upper cap may have a structure that covers the lead penetration 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 film 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 surface located at the open upper end of the body when inserted into the case and on an adjacent surface thereof.

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

[0022] The lithium secondary battery according to the present invention includes a stacked electrode assembly including a plurality of electrode leads, which has the advantage of significantly lowering the internal resistance of the battery. Furthermore, the lithium secondary battery can selectively arrange one or more first and second electrode terminals on the top surface and / or side surface of the upper cap, which allows for easy repositioning of the electrode terminals and provides greater design flexibility when constructing a battery module. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view showing the structure of a conventional lithium secondary battery. [Figure 2] 1 is a perspective view showing the structure of a lithium secondary battery according to the present invention. [Figure 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] 10A and 10B are structural diagrams showing the shape of a sealing part depending on whether or not an electrode lead of an electrode assembly is present; [Figure 5] 10A and 10B 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 INVENTION

[0024] Because the present invention is susceptible to various modifications 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 any particular embodiment, 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, and should be understood as not precluding the presence or possibility of addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0027] Furthermore, 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 therebetween. 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 therebetween. Furthermore, in this application, being "located 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 stacked 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 lower surface portion coupled to lower 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 an upper surface portion coupled to upper ends of the side surfaces, and coupled to an open upper 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 respectively provided on at least one of the top surface portion and the side surface portion of the cap.

[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 the electrode assembly may further reduce the internal resistance of the battery by introducing a plurality of first electrode leads and / or second electrode leads into a stacked electrode assembly. Furthermore, the plurality of electrode leads may be electrically connected to electrode terminals provided on the top or side of the battery, which allows for easy repositioning of the electrode terminals and provides greater design flexibility when constructing a battery module.

[0031] FIG. 2 is a perspective view that schematically shows the 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 electrodes, respectively, and may be considered negative or positive electrodes, respectively, in some cases. The positive electrode includes a positive electrode active layer including a positive electrode active material on at least one surface of a positive electrode current collector made of aluminum or the like, and a positive electrode tab extending from an uncoated portion of the positive electrode current collector where the positive electrode active layer is not formed. The negative electrode includes a negative electrode active layer including a negative electrode active material on at least one surface of a negative electrode current collector made of copper or the like, and a negative electrode tab extending from an uncoated portion of the negative electrode current collector where the negative electrode active layer is not formed. The positive electrode tabs and the negative electrode tabs may be welded to each other to form positive and negative electrode leads, respectively. The separator is made of a porous thin film, for example, a polyolefin-based resin.

[0034] The electrode assembly 120 may include one or more first electrode leads 121a and 121b and one or more second electrode leads 122a and 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 thereof, 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 also 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 also include a first electrode lead 121b and / or a second electrode lead 122b on both adjacent sides of the one side (i.e., the position of the first side 111a and the position of the third side 111c of the body 110).

[0038] Here, when the electrode assembly 120 includes one electrode lead 121b or 122b on both side surfaces adjacent to one side surface of the electrode assembly 120 located at the top end of the case body 110 when inserted into the case (i.e., the position of the first side surface 111a and the position of the third side surface 111c of the body 110), 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 top end of the body 110 when inserted into the case, the electrode assembly 120 may include a second electrode lead 122b on the 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 top end of the body 110 when inserted into the case, the electrode assembly 120 may include a first electrode lead 121b on the 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 for each of the first electrode 121 and the second electrode 122 into the electrode assembly 120, specifically, by introducing a total of three or more first electrode leads and second electrode leads into the electrode assembly.

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

[0041] Here, the case includes a main 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 top end of the main body 110 and seal the inside by ultrasonic welding or laser welding.

[0042] More specifically, the main 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 main 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 main body side portion 111.

[0043] The body 110 may also have lead through-holes 112 at its upper portion to expose the first electrode lead 121b and the second electrode lead 122b from the first side surface 111a and the third side surface 111c, respectively. Specifically, in order to reduce resistance inside the battery, the electrode assembly 120 has the first electrode leads 121a, 121b and the second electrode leads 122a, 122b positioned on at least one side surface located at the open top end of the body 110 when inserted into the case and the adjacent side surface, i.e., the first side surface 111a and the third side surface 111c of the body. In this case, the first side surface 111a and the third side surface 111c may have lead through-holes 112 to expose the first electrode lead 121b and the second electrode lead 122b positioned on at least one of these sides.

[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 height equal to or greater than the middle of the lower end portions of the first side surface 111a and the third side surface 111c, for example, from a point where the height is 1 / 2 to 4 / 5 of the height of the lower end portions of the first side surface 111a and the third side surface 111c, specifically, from a point where the height is 3 / 5 to 4 / 5 of the height of the lower end portions of the first side surface 111a and the third side surface 111c, to the upper end.

[0045] By controlling the position of the lead penetration 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] 4, when the electrode leads are provided on one side of the body corresponding to the first side 111a and the third side 111c when the electrode assembly 120 is inserted into the case, the sealing portion 113 may fill the gap between the outer periphery of the electrode leads (e.g., the first electrode lead and / or the second electrode lead) and the inner periphery of the lead through portion in order to more firmly fix the electrode leads. 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 leads can be inserted therein, and the electrode leads can be inserted along the incision line 114.

[0047] In addition, as shown in FIG. 5, when the electrode assembly 120 is inserted into the case, if no electrode lead is provided on one side corresponding to the first side 111a and the third side 111c of the body, the sealing portion 113 may be provided in a form that completely fills the 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 end of which is coupled sequentially at positions corresponding to the first side 111a to fourth side 111d of the body, and the top portion is coupled to the upper end of the cap side portion.

[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 penetration part 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 penetration part is covered by the A side 130a and the C side 130c of the upper cap, thereby completely sealing the inside.

[0051] The upper cap 130 may include first electrode terminals 161a and 161b and second electrode terminals 162a and 162b corresponding 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 and 161b and the second electrode terminals 162a and 162b are provided on at least one of the top surface and the side surface of the cap, 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 one or more of the top surface and side surface 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 order to reduce resistance inside the battery, the above-described electrode assembly 120 has first electrode leads 121a, 121b and second electrode leads 122a, 122b located on one side located at the open top end of the body 110 when inserted into the case and one or more of the adjacent sides, i.e., the first side 111a and the third side 111c of the body, and first electrode terminals 161a, 161b and second electrode terminals 162a, 162b provided with the first electrode leads 121a, 121b and 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, as shown in (A) and (B) of Figures 3, 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, or may include only the second electrode terminal 162b on sides A or C of the cap side portion.

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

[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 the 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 the C side 130c of the cap side portion.

[0056] In this case, the upper cap 130 has a structure in which one electrode terminal is provided on the upper surface and an electrode terminal having a charge corresponding to the electrode terminal provided on the upper surface is provided on the side surface, which has the advantage of providing a higher structural freedom in designing the battery module compared to a case in which 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 three or more second electrode terminals. In this case, the secondary battery including the upper cap 130 may significantly reduce the internal resistance of the battery during charging and discharging, thereby improving the charging and discharging performance of the secondary battery and reducing heat generation caused by 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 a fluorine resin.

[0060] The cap plate 140 includes terminal through-holes 141a, 141b, 142a, and 142b and an electrolyte injection hole 143, and is welded to the upper opening of the top cap 130 to seal the top cap 130. The terminal through-holes 141a, 141b, 142a, and 142b are formed at points that are one-third of the way along 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). The electrolyte injection hole 143 may have a circular planar shape as shown in FIG. 2. Although not shown, the electrolyte injection hole 143 may have a planar shape such as an ellipse or a rectangle, and the planar shape of the electrolyte injection hole 143 is not limited thereto. The electrolyte injection hole 143 may have a vertical cross-sectional shape such as a Y-shape, and although not shown, the vertical cross-sectional shape of the electrolyte injection hole 143 may have a vertical cross-sectional shape such as an 11-shape, and the vertical cross-sectional shape of the electrolyte injection hole 143 is not limited thereto.

[0061] The lithium secondary battery according to the present invention has the above-described configuration, which not only reduces the internal resistance of the battery, but also allows for easy repositioning of the electrode terminals, thereby offering the advantage of high design freedom when configuring the battery module.

[0062] The present invention will be described in more detail below 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 electrodes and 40 negative electrodes were prepared, and 81 porous polyethylene separators (9.5 cm wide x 34.5 cm long, approximately 20 μm thick on average) were prepared as separators. The positive and negative electrodes were alternately stacked, and separators were placed between them and on the outermost surface to fabricate stacked electrode assemblies. The electrode assemblies were then inserted into a rectangular case (10 cm wide x 35 cm long x 1.6 cm thick) and filled with electrolyte to fabricate lithium secondary batteries.

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

[0066] The square case used had the structure shown in 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 jelly-roll type electrode assembly was used and a square case having the structure of Figure 1 was used. 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> To evaluate the battery resistance of the lithium secondary batteries according to the present invention, each of the lithium secondary batteries fabricated in the Examples and Comparative Examples was fully charged to an SOC of 100% under a voltage condition of 4.25 V. The DC resistance of each fully charged lithium secondary battery was then 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 multiple 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 with ordinary knowledge in the art that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the present invention as set forth in the claims below.

[0073] Therefore, the technical scope of the present invention should not be limited to the content 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 battery 10: Case 21: First electrode lead 22: Second electrode lead 30: Upper 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 body 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 leads 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 accommodating the stacked electrode assembly, The case is a main body including a main body side portion to which one ends of the first side to fourth side surfaces are sequentially coupled, and a bottom 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 to D sides are sequentially coupled to correspond to the first to fourth sides of the body, and an upper surface portion coupled to the upper ends of the cap side portions, and coupled to the open upper end of the body; The upper cap is The upper surface portion includes a first electrode terminal and a second electrode terminal, The lithium secondary battery includes the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively.

2. A laminated electrode assembly including a first electrode, a second electrode, and a separation membrane, and a case for housing the laminated electrode assembly, The case is a main body including a main body side portion to which one ends of the first side to fourth side surfaces are sequentially coupled, and a bottom 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 to D sides are sequentially coupled to correspond to the first to fourth sides of the body, and an upper surface portion coupled to the upper ends of the cap side portions, and coupled to the open upper end of the body; The upper cap is The upper surface portion includes a first electrode terminal and a second electrode terminal, A lithium secondary battery including only the second electrode terminal on side A or C of the cap side portion.

3. A laminated electrode assembly including a first electrode, a second electrode, and a separation membrane, and a case for housing the laminated electrode assembly, The case is a main body including a main body side portion to which one ends of the first side to fourth side surfaces are sequentially coupled, and a bottom 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 to D sides are sequentially coupled to correspond to the first to fourth sides of the body, and an upper surface portion coupled to the upper ends of the cap side portions, and coupled to the open upper end of the body; The upper cap is a first electrode terminal on the top surface; The lithium secondary battery includes the first electrode terminal and the second electrode terminal on side A and side C of the cap side portion, respectively.

4. a stacked electrode assembly including a first electrode, a second electrode, and a separator; and a case for accommodating the stacked electrode assembly, The case is a main body including a main body side portion to which one ends of the first side to fourth side surfaces are sequentially coupled, and a bottom 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 to D sides are sequentially coupled to correspond to the first to fourth sides of the body, and an upper surface portion coupled to the upper ends of the cap side portions, and coupled to the open upper end of the body; The upper cap is a first electrode terminal on the top surface; The lithium secondary battery includes only the second electrode terminal on the side A or C of the cap side portion.

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

6. 6. The lithium secondary battery according to claim 1, wherein the body has lead penetration 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.

7. The lithium secondary battery of claim 6, wherein the lead-through portion is formed from a point that is ½ to ¾ of the height of the lower end of the first side surface and the third side surface to the upper end.

8. The lithium secondary battery of claim 6 , 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 penetration portion.

9. A laminated electrode assembly including a first electrode, a second electrode, and a separation membrane, and a case for housing the laminated electrode assembly, The case is a main body including a main body side portion to which one ends of the first side to fourth side surfaces are sequentially coupled, and a bottom 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 to D sides are sequentially coupled to correspond to the first to fourth sides of the body, and an upper surface portion coupled to the upper ends of the cap side portions, and coupled to the open upper end of the body; the upper cap includes a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal are respectively provided on at least one of the top surface portion and the cap side surface portion; the main body has lead penetration portions at an upper portion thereof for exposing a first electrode lead and a second electrode lead on a first side surface and a third side surface, respectively; The lithium secondary battery has a structure in which side A and side C of the upper cap cover the lead-through portion of the main body.

10. 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 one or more first electrode leads and one or more second electrode leads on a side surface that is located at the open top end of the body when inserted into the case and a side surface adjacent thereto.

11. The lithium secondary battery according to claim 6 , 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-through portion when inserted into the main body.

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