Secondary battery

Abstract

A secondary battery according to the present disclosure includes: an electrode assembly including a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode from each other; a battery case having an accommodating space accommodating the electrode assembly, and including at least one opening; a cap plate coupled to the battery case to close the opening, and provided with an electrolyte injection port into which an electrolyte is injected; and an elastic support body in close contact with at least a portion of a lower end edge of the electrode assembly and mounted on an inner bottom surface of the battery case to elastically support the electrode assembly in a vertical direction.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a secondary battery capable of charging and discharging. BACKGROUND

[0002] A secondary battery is one of energy storage devices capable of charging and discharging, and is widely used in various devices using electric power as a power source from small devices such as mobile phones, notebook computers, tablet computers, etc. to large devices such as vehicles, aircraft, etc., and in particular, in recent years, the application of a secondary battery as a power source for vehicles is being actively explored.

[0003] A secondary battery can be classified into a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-ion battery, etc. according to electrode materials, etc., and a secondary battery can be appropriately selected according to design capacity, use environment, etc. Among them, a lithium-ion battery can achieve a relatively high voltage and capacity compared to other secondary batteries, and thus, a lithium-ion battery can be widely used in the field requiring a high-density energy storage device such as a battery pack for a vehicle.

[0004] A secondary battery such as a lithium-ion battery includes a positive electrode, a negative electrode, a separator, an electrolyte, etc. The positive electrode and the negative electrode are disposed apart by a separator made of an insulating material, and charging or discharging can be achieved by the movement of ions in the electrolyte. SUMMARY

[0005] (1) Technical problem to be solved

[0006] As shown in FIG. 1, a secondary battery of the related art can include an electrode assembly 10, a case 15, a cover plate 20, and a bottom fixer 70. Figures 1 to 4 The electrode assembly 10 includes a first electrode 11 (11a, 11b), a second electrode 12 (12a, 12b), and a separator 13 interposed between the first electrode 11 and the second electrode 12.

[0007] The upper end of the case 15 is formed with an opening, and the inside of the case 15 is formed with a space in which the electrode assembly is accommodated.

[0008] The cover plate 20 seals the opening of the case 15, is connected to the first electrode 11 and the second electrode 12, respectively, and first and second electrode terminals 21 and 22 are formed apart from each other in a first direction.

[0009] The bottom fixer 70 is formed of an insulating member and is located inside the bottom surface of the case 15, and the bottom fixer 70 is provided with a support portion 71 supporting the electrode assembly 10 and at least one contact portion 72 in contact with the bottom surface of the case 15.

[0010]

[0011] ​The support portion 71 has a flat plate shape, at least a portion of the edge of the support portion 71 has a corrugated shape, and is formed apart from the electrode assembly.

[0012] In addition, the support portion 71 is formed with a hole 73 in a closed form at a position apart from the edge thereof, and at least a portion of the edge of the hole 73 has a corrugated shape.

[0013] Every two contact portions 72 are formed adjacent to each other apart from the support portion 71 in the first direction, and the adjacent contact portions 72 are formed inclined in a direction in which they are apart from each other in the first direction from the support portion 71 toward the bottom surface of the case 15.

[0014] In addition, the contact portion 72 is provided with an inclined portion 72a extending inclined from the support portion 71 toward the bottom surface of the case and a horizontal portion 72b formed parallel to the bottom surface of the case at the end of the inclined portion, and is formed extending from one region of the lower surface of the support portion 71 toward the bottom surface of the case.

[0015] Every two inclined portions 72a are formed adjacent to each other, and the adjacent inclined portions 72a are formed inclined in a direction in which they are apart from each other more as they go down.

[0016] The support portion 71 and the contact portion 72 are alternately formed, and the vertical cross section of the bottom holder contacting the long side surface of the case becomes a corrugated form.

[0017] In the existing secondary battery having the above-described configuration, the bottom surface of the electrode assembly accommodated inside the case is elastically supported in the vertical direction by the bottom holder, but the side surface of the electrode assembly is not supported, and thus the stability against external impact load and the like generated by vehicle operation and the like is poor.

[0018] In addition, since the bottom surface of the case is flat, not only the compression or bending stability against external impact load and the like cannot be ensured, but also the stability of uniform flow of electrolyte cannot be ensured.

[0019] The present disclosure is proposed to solve the problems of the above-described related art, and according to one aspect, it is possible to provide a secondary battery capable of improving the stability of an electrode assembly against external impact load and the like generated by vehicle operation and the like.

[0020] According to one aspect of the present disclosure, it is possible to provide a secondary battery capable of improving the compression or bending stability of a battery case against external impact load and the like.

[0021] According to one aspect of the present disclosure, it is possible to provide a secondary battery capable of improving the stability of uniform flow of electrolyte.

[0022] The secondary battery of the present disclosure can be widely applied to electric vehicles, battery charging stations, other green technology fields using batteries such as solar power generation, wind power generation, etc. In addition, the secondary battery of the present disclosure can be used for eco-friendly electric vehicles, hybrid vehicles, etc. that prevent climate change by suppressing atmospheric pollution and greenhouse gas emissions.

[0023] (II) TECHNICAL SOLUTION

[0024] To achieve the above technical problems of the present disclosure, the secondary battery according to the present disclosure can include an electrode assembly including a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode from each other; a battery case having an accommodation space accommodating the electrode assembly, and including at least one opening; a cover plate coupled to the battery case to close the opening, and provided with an electrolyte injection port into which an electrolyte is injected; and an elastic support body adhering to at least a portion of a lower end edge of the electrode assembly, and installed on an inner bottom surface of the battery case to elastically support the electrode assembly in a vertical direction.

[0025] According to one embodiment, a bottom surface of the battery case can be formed with a concave-convex portion to increase lateral rigidity of the bottom surface of the battery case and to make the flow of the electrolyte uniform or smooth. A concave portion of the concave-convex portion can be configured to uniformly disperse the electrolyte in a lateral direction of the bottom surface when the electrolyte injected into the inside of the battery case through the electrolyte injection port formed inside the cover plate starts to accumulate and fill at the bottom surface. The concave portion can be configured to make arc debris generated in the electrode assembly when repeatedly charged and discharged fall down without contacting the bottom surface of the electrode assembly when the arc debris falls down.

[0026] According to one embodiment, the elastic support may include a base plate, on which protrusions and grooves are alternately and repeatedly formed at predetermined intervals and facing each other on two long sides and two short sides facing each other. An inflow hole may be formed on the base plate through which the electrolyte flows in. Additionally, the elastic support may further include an upwardly extending long-side elastic support piece, which is connected to and upwardly formed with the protrusions on the two facing long sides of the base plate. The upwardly extending long-side elastic support piece may include: a mating portion perpendicularly connected to the protrusion; an extension portion extending obliquely upward from the mating portion; and an end portion extending vertically from the extension portion. Furthermore, the elastic support may further include an upwardly extending short-side elastic support piece, which is connected to and upwardly formed with the protrusions on the two facing short sides of the base plate. The upwardly extending short-side elastic support piece may include: a mating portion perpendicularly connected to the protrusion; an extension portion extending obliquely upward from the mating portion; and an end portion extending vertically from the extension portion. Additionally, the elastic support may further include a downward-facing long-side elastic support piece, which is connected to and formed downwards by grooves created on two opposing long sides of the base plate. The downward-facing long-side elastic support piece may include: an extension portion obliquely connected to the grooves; and a support portion extending horizontally from the extension portion. Furthermore, the elastic support may further include a downward-facing short-side elastic support piece, which is connected to and formed downwards by grooves created on two opposing short sides of the base plate. The downward-facing short-side elastic support piece may include: an extension portion obliquely connected to the grooves; and a support portion extending horizontally from the extension portion.

[0027] (III) Beneficial Effects

[0028] According to one embodiment of the secondary battery of the present disclosure, since the lower end of the electrode assembly is surrounded by a bottom elastic support, the stability of the electrode assembly to external impact loads such as those generated by vehicle operation can be greatly improved.

[0029] Furthermore, in a secondary battery according to an embodiment of the present disclosure, since the bottom surface of the battery casing has irregularities, the compression or bending stability of the battery casing against external impact loads can be improved.

[0030] Furthermore, in a secondary battery according to an embodiment of the present disclosure, since the bottom surface of the battery casing is formed with irregularities, the stability of the uniform flow of electrolyte accumulated on the bottom surface can be greatly improved. Attached Figure Description

[0031] Figure 1 This is a perspective view showing a prior art secondary battery.

[0032] Figure 2 is a cross-sectional view taken along Figure 1 A-A' of FIG. 1.

[0033] Figure 3 is a perspective view showing a bottom holder of Figure 1 FIG. 1.

[0034] Figure 4 is a cross-sectional view taken along Figure 3 B-B' of FIG. 1.

[0035] Figure 5 is an exploded perspective view of a secondary battery according to one embodiment.

[0036] Figure 6 is a partial enlarged view of a battery case of Figure 5 FIG. 1.

[0037] Figure 7 is an enlarged perspective view of an elastic support of Figure 5 FIG. 1.

[0038] Figure 8 is an enlarged perspective view of a modified embodiment of an elastic support of Figure 5 FIG. 1.

[0039] Figure 9 is an enlarged perspective view of another modified embodiment of an elastic support of Figure 5 FIG. 1.

[0040] Figure 10 is an enlarged perspective view of still another modified embodiment of an elastic support of Figure 5 FIG. 1.

[0041] Figure 11a and Figure 11b are diagrams for explaining the interaction between a battery case, an electrode assembly, and an elastic support of Figure 5 FIG. 1.

[0042] BRIEF DESCRIPTION OF DRAWINGS

[0043] 100: secondary battery 110: electrode assembly

[0044] 111: positive electrode tab 113: negative electrode tab

[0045] 130: cover plate 131: exhaust port

[0046] 133: positive electrode terminal 135: negative electrode terminal

[0047] 137: electrolyte injection port 150: battery case

[0048] 151: opening 153: concavo-convex portion

[0049] 153a: recess

[0050] 170, 270, 370, 470: elastic support

[0051] 171, 271, 371, 471: bottom plate

[0052] 171a, 271a, 371a, 471a: protrusion

[0053] 171b, 271b, 371b, 471b: groove

[0054] 171c, 271c, 371c, 471c: inflow hole

[0055] 173, 273, 373: upward long-side elastic support piece

[0056] 173a, 273a, 373a, 475a: close-contact portion

[0057] 173b, 273b, 373b, 475b: expansion portion

[0058] 173c, 273c, 373c, 475c: end portion

[0059] 175, 275, 475: upward short-side elastic support piece

[0060] 175a, 275a: close-contact portion 175b, 275b: expansion portion

[0061] 175c, 275c: end portion

[0062] 177, 277, 377, 477: downward long-side elastic support piece

[0063] 177a, 277a, 377a, 477a: expansion portion

[0064] 177b, 277b, 377b, 477b: bracket portion

[0065] 179: downward short-side elastic support piece 179a: expansion portion

[0066] 179b: bracket portion DETAILED DESCRIPTION

[0067] Hereinafter, a secondary battery having improved safety according to an embodiment will be described with reference to the accompanying drawings.

[0068] First, a secondary battery 100 according to one embodiment will be described with reference to FIG. 1. Figures 5 to 7 A secondary battery 100 according to one embodiment will be described with reference to FIG. 1. Figure 5 is an exploded perspective view of a secondary battery according to one embodiment, Figure 6 isFigure 5 A magnified view of a portion of the battery casing. Figure 7 yes Figure 5 An enlarged 3D view of the elastic support.

[0069] like Figures 5 to 7 As shown, the secondary battery 100 in this embodiment may include an electrode assembly 110, a cover plate 130, a battery casing 150, and an elastic support 170.

[0070] Although not shown, electrode assembly 110 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 110 is primarily formed by a structure called a "jelly roll," in which the positive electrode, negative electrode, and separator are wound around a longitudinal or transverse axis, but is not limited thereto.

[0071] The positive electrode can include a positive current collector and a positive active material. The positive current collector can include aluminum, aluminum alloys, etc., and the positive active material can include lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium iron phosphate, etc.

[0072] A portion of the surface of the positive current collector can be coated with a positive active material, while the remaining portion of the surface uncoated with the positive active material can serve as the positive electrode tab 111. Multiple positive electrode tabs 111 can be provided, and some or all of the multiple positive electrode tabs 111 can be joined to each other.

[0073] The negative electrode includes a negative current collector and a negative active material. The negative current collector may contain copper, copper alloys, nickel, nickel alloys, etc., while the negative active material may contain carbon, silicon, etc.

[0074] A portion of the surface of the negative current collector may be coated with a negative active material, while the remaining portion of the negative current collector without the negative active material coating may serve as the negative electrode tab 113. Multiple negative electrode tabs 113 may be provided, and some or all of the multiple negative electrode tabs 113 may be connected to each other.

[0075] The membrane is positioned between the positive and negative electrodes, which can limit the physical contact between the positive and negative electrodes and provide a channel for ion movement.

[0076] In addition, the diaphragm can contain polymer materials such as polyethylene and polypropylene. The diaphragm can include dry diaphragms and wet diaphragms, and can include coatings such as ceramic coatings.

[0077] A vent 131 can be provided at the center of the cover plate 130, and a positive terminal 133 and a negative terminal 135 can be provided on both sides of the cover plate 130, respectively. An electrolyte injection port 137 is formed between the vent 131 and the positive terminal 133 in the cover plate 130. Here, the positive terminal 133 and the negative terminal 135 can be interchanged, and the positions of the vent 131 and the electrolyte injection port 137 can also be changed.

[0078] The vent 131 is configured to open in response to internal pressure in the battery housing 150 to release the internal pressure to the outside, thereby stabilizing the internal components of the battery housing 150.

[0079] The positive terminal 133 is positioned to be electrically connected to the positive electrode tab 111 of the electrode assembly 110, and the negative terminal 135 is positioned to be electrically connected to the negative electrode tab 113 of the electrode assembly 110. When the positions of the positive terminal 133 and the negative terminal 135 are interchanged, the positions of the positive electrode tab 111 and the negative electrode tab 113 will also be interchanged accordingly.

[0080] The electrolyte injection port 137 is used to inject electrolyte into the internal space of the battery casing 150. In this embodiment, the electrolyte injection port 137 is arranged adjacent to the vent port 131, but the position of the electrolyte injection port 137 can be changed in various ways. Furthermore, after electrolyte injection and formation processes, the electrolyte injection port 137 can be appropriately sealed. The electrolyte injection port 137 can be sealed by pressing in a spherical sealing component made of polymer resin.

[0081] The battery housing 150 provides internal space to accommodate the electrode assembly 110 and the electrolyte, and the upper end of the battery housing 150 is open to form an opening 151. The electrolyte can be formed from an organic solvent containing a lithium salt, such as lithium hexafluorophosphate (LiPF6) or lithium tetrafluoroborate (LiBF4) in liquid or gel form. The organic solvent can contain cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC), or linear carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC).

[0082] The opening 151 of the battery casing 150 can be completely closed by the cover plate 130. For this purpose, the shape and size of the opening 151 of the battery casing 150 and the cover plate 130 correspond to each other, and in order to completely close the casing, the cover plate 130 can be welded to the upper end of the battery casing 150 by ultrasonic welding, laser welding or the like.

[0083] The bottom surface of the battery casing 150 may have irregularities 153 to ensure uniform or smooth flow of the electrolyte.

[0084] like Figure 6 As shown in the enlarged view, the concave-convex portion 153 has a concave-convex cross section.

[0085] In addition, the protrusions 153 can increase the lateral rigidity of the bottom surface of the battery housing 150, thereby greatly increasing the compression or bending stability of the battery housing 150 against external impact loads, etc.

[0086] The recess 153a can function as a path for uniformly dispersing the electrolyte in the lateral direction of the bottom surface as the electrolyte injected into the inside of the battery case 150 through the electrolyte injection port 137 formed in the cover plate 130 starts to accumulate and fill in the bottom surface.

[0087] In addition, the recess 153a can function as a space for accumulating the arc debris generated in the electrode assembly 110 when the arc debris falls down as the charging and discharging are repeated, without the arc debris contacting the bottom surface of the electrode assembly 110.

[0088] The elastic support body 170 is installed at the inner bottom of the battery case 150 to elastically support the electrode assembly 110 in the vertical direction, and as shown in Figure 7 enlarged in the middle, the elastic support body 170 can include a bottom plate 171, an upward long-side elastic support piece 173, an upward short-side elastic support piece 175, a downward long-side elastic support piece 177, and a downward short-side elastic support piece 179.

[0089] The bottom plate 171 has a rectangular shape the same as that of the bottom surface of the battery case 150, and the size of the bottom plate 171 is smaller than that of the bottom surface of the battery case 150.

[0090] Quadrangular protrusions 171a and groove portions 171b are repeatedly formed in a predetermined interval alternately and facing each other on both long sides facing each other and both short sides facing each other of the bottom plate 171. An inflow hole 171c can be formed in the bottom plate 171 so that the electrolyte accumulated on the bottom surface flows into the bottom surface of the electrode assembly 110 through the inflow hole 171c. As shown in the drawing, the inflow hole 171c can be formed in a circular shape, a polygonal shape such as a square or a rectangle.

[0091] The upward long-side elastic support piece 173 can be connected together with the protrusions 171a formed on both long sides facing each other of the bottom plate 171 and formed upward. The upward long-side elastic support piece 173 can include a close portion 173a connected perpendicularly with the protrusion 171a, an extension portion 173b extending upwardly inclined from the close portion 173a, and a terminal portion 173c extending perpendicularly from the extension portion 173b.

[0092] The upward short-side elastic support piece 175 can be connected together with the protrusions 171a formed on both short sides facing each other of the bottom plate 171 and formed upward. The upward short-side elastic support piece 175 can include a close portion 175a connected perpendicularly with the protrusion 171a, an extension portion 175b extending upwardly inclined from the close portion 175a, and a terminal portion 175c extending perpendicularly from the extension portion 175b.

[0093] The downward long-side elastic support piece 177 can be connected together with the groove portions 171b formed on the two long sides of the bottom plate 171 facing each other and formed downward. The downward long-side elastic support piece 177 can include an extension portion 177a connected obliquely with the groove portion 171b and a bracket portion 177b extended horizontally from the extension portion 177a.

[0094] The downward short-side elastic support piece 179 can be connected together with the groove portions 171b formed on the two short sides of the bottom plate 171 facing each other and formed downward. The downward short-side elastic support piece 179 can include an extension portion 179a connected obliquely with the groove portion 171b and a bracket portion 179b extended horizontally from the extension portion 179a.

[0095] Next, the elastic support body according to a modified embodiment will be described with reference to Figure 8 The elastic support body according to a modified embodiment will be described with reference to

[0096] The elastic support body 270 according to the present embodiment is installed at the inner bottom of the battery case 150 to elastically support the electrode assembly 110 in the vertical direction, and can include a bottom plate 271, an upward long-side elastic support piece 273, an upward short-side elastic support piece 275, and a downward long-side elastic support piece 277.

[0097] The bottom plate 271 has a rectangular shape the same as that of the bottom surface of the battery case 150, and the size of the bottom plate 271 can be smaller than that of the bottom surface of the battery case 150.

[0098] The quadrangular protrusion portions 271a and the groove portions 271b are repeatedly formed in a predetermined interval alternately and facing each other on the two long sides and the two short sides of the bottom plate 271 facing each other. The inflow hole 271c can be formed on the bottom plate 271 so that the electrolyte accumulated on the bottom surface flows into the bottom surface of the electrode assembly 110 through the inflow hole 271c. As shown, the inflow hole 271c can be formed in a circular shape, a polygonal shape such as a square or a rectangle.

[0099] The upward long-side elastic support piece 273 can be connected together with the protrusion portions 271a formed on the two long sides of the bottom plate 271 facing each other and formed upward. The upward long-side elastic support piece 273 can include a close-contact portion 273a connected perpendicularly with the protrusion portion 271a, an extension portion 273b extended obliquely upward from the close-contact portion 273a, and a terminal portion 273c extended perpendicularly from the extension portion 273b.

[0100] The upward short-side elastic support piece 275 can be connected together with the protrusions 271a formed on the two short sides of the bottom plate 271 facing each other and formed upward. The upward short-side elastic support piece 275 can include a close portion 275a connected perpendicularly with the protrusions 271a, an extension portion 275b extending upwardly inclined from the close portion 275a, and a terminal portion 275c extending perpendicularly from the extension portion 275b.

[0101] The downward long-side elastic support piece 277 can be connected together with the groove portions 271b formed on the two long sides of the bottom plate 271 facing each other and formed downward. The downward long-side elastic support piece 277 can include an extension portion 277a connected inclinedly with the groove portions 271b, and a bracket portion 277b extending horizontally from the extension portion 277a.

[0102] Next, the elastic support body according to another modified embodiment will be described with reference to Figure 9

[0103] The elastic support body 370 according to the present embodiment is installed at the inner bottom of the battery case 150 to elastically support the electrode assembly 110 in the vertical direction, and can include a bottom plate 371, an upward long-side elastic support piece 373, and a downward long-side elastic support piece 377.

[0104] The bottom plate 371 has a rectangular shape the same as that of the bottom surface of the battery case 150, and the size of the bottom plate 371 can be smaller than that of the bottom surface of the battery case 150.

[0105] The quadrangular protrusions 371a and the groove portions 371b are repeatedly formed in a predetermined interval alternately and facing each other on the two long sides and the two short sides of the bottom plate 371 facing each other. The inflow holes 371c can be formed on the bottom plate 371 so that the electrolyte accumulated on the bottom surface flows into the bottom surface of the electrode assembly 110 through the inflow holes 371c. As shown in the drawing, the inflow holes 371c can be formed in a circular shape, a polygonal shape such as a square or a rectangle.

[0106] The upward long-side elastic support piece 373 can be connected together with the protrusions 371a formed on the two long sides of the bottom plate 371 facing each other and formed upward. The upward long-side elastic support piece 373 can include a close portion 373a connected perpendicularly with the protrusions 371a, an extension portion 373b extending upwardly inclined from the close portion 373a, and a terminal portion 373c extending perpendicularly from the extension portion 373b.

[0107] ​The downward long-side elastic support piece 377 can be connected together with the groove portions 371b formed on the two long sides of the bottom plate 371 facing each other and formed downward. The downward long-side elastic support piece 377 can include an extension portion 377a connected obliquely with the groove portions 371b and a bracket portion 377b extended horizontally from the extension portion 377a.

[0108] Next, the interaction between the battery case 150, the electrode assembly 110, and the elastic support body 170 according to another modified embodiment will be described with reference to FIGS. 13 and 14. Figure 10 An elastic support body according to still another modified embodiment will be described.

[0109] The elastic support body 470 according to still another embodiment is installed at the inner bottom of the battery case 150 to elastically support the electrode assembly 110 in the vertical direction, and can include a bottom plate 471, upward short-side elastic support pieces 475, and downward long-side elastic support pieces 477.

[0110] The bottom plate 471 has a rectangular shape the same as the bottom surface of the battery case 150, and the size of the bottom plate 471 can be smaller than the bottom surface of the battery case 150.

[0111] The quadrangular protrusion portions 471a and the groove portions 471b are alternately and repeatedly formed at predetermined intervals on the two long sides of the bottom plate 471 facing each other and the two short sides facing each other. The inflow holes 471c can be formed on the bottom plate 471 so that the electrolyte accumulated on the bottom surface flows into the bottom surface of the electrode assembly 110 through the inflow holes 471c. As illustrated, the inflow holes 471c can be formed in a circular shape, a polygonal shape such as a square or a rectangle.

[0112] The upward short-side elastic support pieces 475 can be connected together with the protrusion portions 471a formed on the two short sides of the bottom plate 471 facing each other and formed upward. The upward short-side elastic support pieces 475 can include a close portion 475a connected perpendicularly with the protrusion portions 471a, an extension portion 475b extended obliquely upward from the close portion 475a, and a terminal portion 475c extended perpendicularly from the extension portion 475b.

[0113] The downward long-side elastic support pieces 477 can be connected together with the groove portions 471b formed on the two long sides of the bottom plate 471 facing each other and formed downward. The downward long-side elastic support pieces 477 can include an extension portion 477a connected obliquely with the groove portions 471b and a bracket portion 477b extended horizontally from the extension portion 477a.

[0114] Next, the interaction between the battery case 150, the electrode assembly 110, and the elastic support body 170 according to another modified embodiment will be described with reference to FIGS. 13 and 14. Figure 11a and Figure 11b the elastic support body 170 according to another modified embodiment will be described. Figure 5 Figure 11a ​The state in which the electrode assembly 110 is inserted into the inside of the battery case 150 in the state where it is mounted on the elastic support 170 is shown, Figure 11b The state in which the insertion of the electrode assembly 110 is completed is shown. Although the explanation is omitted, the function of the elastic support 270, 370, 470 according to the modified embodiment of the elastic support can be similar to the function to be described later.

[0115] As Figure 11a shown, when the electrode assembly 110 is inserted into the inside of the battery case 150 in the state where it is mounted on the elastic support 170 in the short arrow direction, the abutting portion 173a of the upward long-side elastic support piece 173 abuts against a portion of the lower end of the electrode assembly 110, and the terminal portion 173c abuts against the inner wall of the battery case 150. However, the support portion 177b of the downward long-side elastic support piece 177 does not come into contact with the inner wall of the battery case 150.

[0116] On the other hand, as Figure 11b shown, when the insertion of the electrode assembly 110 into the inside of the battery case 150 is completed in the state where it is mounted on the elastic support 170 in the long arrow direction, the abutting portion 173a of the upward long-side elastic support piece 173 abuts against a portion of the lower end of the electrode assembly 110, and the terminal portion 173c abuts against the inner wall of the battery case 150. The support portion 177b of the downward long-side elastic support piece 177 also comes into contact with the inner wall of the battery case 150.

[0117] At this time, the force of pressing the electrode assembly 110 elastically spreads the extension portion 177a in the horizontal arrow direction in the lateral direction, so that the support portion 177b connected to the end portion of the extension portion 177a comes into contact with the inner wall of the battery case 150.

[0118] Although the secondary battery with improved safety has been explained above with reference to the embodiment of the present disclosure, it will be apparent to those skilled in the art that various changes, modifications or alterations can be made without departing from the scope of the idea of the present disclosure.

Claims

1. A secondary battery, characterized in that, include: An electrode assembly includes a positive electrode, a negative electrode, and a diaphragm that separates the positive electrode and the negative electrode from each other; The battery casing has a receiving space for accommodating the electrode assembly and includes at least one opening; A cover plate is attached to the battery housing to close the opening, and is provided with an electrolyte injection port for injecting electrolyte; as well as An elastic support is attached to at least a portion of the lower edge of the electrode assembly and mounted on the inner bottom surface of the battery housing to elastically support the electrode assembly in the vertical direction.

2. The secondary battery according to claim 1, characterized in that, The bottom surface of the battery casing has irregularities to increase the lateral rigidity of the bottom surface of the battery casing and to make the electrolyte flow uniform or smooth.

3. The secondary battery according to claim 2, characterized in that, The recess of the protrusion is configured to uniformly disperse the electrolyte laterally along the bottom surface when the electrolyte injected into the battery housing through the electrolyte injection port formed in the cover plate begins to accumulate and fill the bottom surface.

4. The secondary battery according to claim 3, characterized in that, The recess is configured to prevent arc debris generated in the electrode assembly during repeated charging and discharging from accumulating on the bottom surface of the electrode assembly.

5. The secondary battery according to claim 1, characterized in that, The elastic support includes a base plate on which protrusions and grooves are alternately and repeatedly formed at predetermined intervals on two long sides and two short sides facing each other. An inflow hole is formed on the base plate through which the electrolyte flows in.

6. The secondary battery according to claim 5, characterized in that, The inlet hole is formed as a circle, a polygon such as a square or a rectangle.

7. The secondary battery according to claim 5, characterized in that, The elastic support further includes an upward long-side elastic support piece, which is connected to and formed upwards by protrusions on two facing long sides of the base plate.

8. The secondary battery according to claim 7, characterized in that, The upward-facing long-side elastic support piece includes: The close-fitting portion is perpendicularly connected to the protrusion. Extension portion; extending obliquely upward from the attached portion; and The end portion extends vertically from the extension portion.

9. The secondary battery according to claim 5, characterized in that, The elastic support further includes an upward short-side elastic support piece, which is connected to and formed upwards by protrusions on two facing short sides of the base plate.

10. The secondary battery according to claim 9, characterized in that, The upward short-side elastic support piece includes: The close-fitting portion is perpendicularly connected to the protrusion. Extension portion; extending obliquely upward from the attached portion; and The end portion extends vertically from the extension portion.

11. The secondary battery according to claim 5, characterized in that, The elastic support further includes a downward long-side elastic support piece, which is connected to and formed downwards by grooves formed on two facing long sides of the base plate.

12. The secondary battery according to claim 11, characterized in that, The downward long-side elastic support piece includes: An extension portion, obliquely connected to the groove portion; and The support portion extends horizontally from the extension portion.

13. The secondary battery according to claim 5, characterized in that, The elastic support further includes a downward short-side elastic support piece, which is connected to and formed downwards by grooves formed on two opposing short sides of the base plate.

14. The secondary battery according to claim 13, characterized in that, The downward short-side elastic support piece includes: An extension portion, obliquely connected to the groove portion; and The support portion extends horizontally from the extension portion.

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