KR20070067780A - Lithium rechargeable battery and method of making the same - Google Patents

Abstract

Provided is a lithium rechargeable battery, wherein an electrolytic solution is easily infiltrated into an electrode assembly by generating convection current in the electrolytic solution through heating. The lithium rechargeable battery comprises an electrode assembly(220), a can(210) for accommodating the electrode assembly(220), and a cap assembly which seals the top opening of the can(210). An insulating plate(212) is inserted between the lower part of the electrode assembly(220) and the can(210). Grooves are formed on the surface of the insulating plate(212). The manufacturing method of a lithium rechargeable battery comprises the steps of: inserting the insulating plate(212) into the can(210); inserting the electrode assembly(220) into the can(210); injecting an electrolytic solution(290) into the can(210); and heating the can(210).

Description

Lithium rechargeable battery and method of manufacturing the same {Lithium rechargeable battery and method of making the same}

1 is a vertical cross-sectional view of a typical lithium secondary battery

2 is a vertical cross-sectional view of a lithium secondary battery according to an embodiment of the present invention.

Figure 3a is a perspective view of an insulating plate according to an embodiment of the present invention

3B is a cross-sectional view taken along the line A-A of FIG. 3A

Figure 4a is a perspective view of an insulating plate according to another embodiment of the present invention

4B is a top view of FIG. 4A

Figure 5a is a perspective view showing an example of a method of manufacturing a lithium secondary battery according to an embodiment of the present invention

FIG. 5B is a schematic sectional view of FIG. 5A

6 is a perspective view showing another example of a method of manufacturing a lithium secondary battery according to an embodiment of the present invention;

<Description of Symbols for Major Parts of Drawings>

200-Lithium Secondary Battery 210-Can

212, 312-insulation plates 214, 314-groove

220-electrode assembly 230-cap assembly

290-electrolyte

The present invention relates to a lithium secondary battery and a method for manufacturing the same, and more particularly, by injecting an electrolyte solution and heating the lower surface or side surface of the can to generate convection in the electrolyte solution so that the electrolyte solution can easily be impregnated into the electrode assembly. The present invention relates to a lithium secondary battery and a method of manufacturing the same, by forming a flow path through which an electrolyte flows on a surface of an insulating plate positioned at the bottom of the can to help the flow of the electrolyte and to easily moisten the electrolyte.

In general, as the light weight and high functionality of portable wireless devices such as a video camera, a portable telephone, a portable computer, and the like progress, a lot of researches have been conducted on secondary batteries used as driving power. Such secondary batteries include, for example, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries are rechargeable, compact, and large-capacity, and are widely used in advanced electronic devices because of their high operating voltage and high energy density per unit weight.

1 is a vertical cross-sectional view of a general lithium secondary battery.

Referring to FIG. 1, the lithium secondary battery 100 stores the electrode assembly 120 including the positive electrode plate 123, the negative electrode plate 125, and the separator 124 together with an electrolyte in the can 110. The upper end opening of the can 110 is formed by sealing the cap assembly 130.

The can 110 is generally formed of aluminum or an alloy thereof, and manufactured by a deep drawing method. The bottom of the can 110 is generally formed in a substantially planar shape.

The electrode assembly 120 is formed by winding a separator 124 between the positive electrode plate 123 and the negative electrode plate 125. The positive electrode tab 126 is coupled to the positive electrode plate 123 to protrude to the upper end of the electrode assembly 120, and the negative electrode tab 127 is coupled to the negative electrode plate 125 to protrude to the upper end of the electrode assembly 120. In the electrode assembly 120, the positive electrode tab 126 and the negative electrode tab 127 are formed to be electrically separated from each other by a predetermined distance. The positive electrode tab 126 and the negative electrode tab 127 are generally formed of nickel metal.

The cap assembly 130 includes a cap plate 140, an insulating plate 150, a terminal plate 160, and an electrode terminal 135. Cap assembly 130 is coupled to a separate insulating case 170 is coupled to the upper opening of the can 110 to seal the can 110.

The cap plate 140 is formed of a metal plate having a size and shape corresponding to the top opening of the can 110. A terminal through hole 1 having a predetermined size is formed in the center of the cap plate 140, and when inserted into the terminal through hole 1, a tubular shape is formed on an outer surface of the electrode terminal 135 to insulate the electrode terminal 135 from the cap plate 140. The gasket tube 146 is combined and inserted together. On the other hand, one side of the cap plate 140 is the electrolyte injection hole 142 is formed to a predetermined size. After the cap assembly 130 is assembled to the upper opening of the can 110, the electrolyte is injected through the electrolyte inlet 142, and the electrolyte inlet 142 is sealed by a ball 180, which is a separate sealed end. . In addition, a safety vent (not shown) may be formed in a predetermined size on the other side of the cap plate 140. The safety vent is thinner than other portions of the cap plate 140 and is damaged when the pressure inside the battery rises above the threshold.

The electrode terminal 135 is connected to the negative electrode tab 127 of the negative electrode plate 125 or the positive electrode tab 126 of the positive electrode plate 123 to act as a negative electrode terminal or a positive electrode terminal.

The insulating plate 150 is formed of an insulating material such as a gasket and is coupled to the bottom surface of the cap plate 140. The insulating plate 150 has a terminal through-hole 2 through which the electrode terminal 135 is inserted at a position corresponding to the terminal through-hole 1 of the cap plate 140. A mounting groove corresponding to the size of the terminal plate 160 is formed on the bottom surface of the insulating plate 150 so that the terminal plate 160 is seated.

The terminal plate 160 is generally formed of a nickel alloy, and is mounted on the bottom surface of the insulating plate 150. The terminal plate 160 has a terminal through hole 3 through which the electrode terminal 135 is inserted at a position corresponding to the terminal through hole 1 of the cap plate 140, and the electrode terminal 135 has the gasket tube 146. By being insulated by) and coupled through the terminal through hole 1 of the cap plate 140, the terminal plate 160 is electrically insulated from the cap plate 140 and electrically connected to the electrode terminal 135.

The negative electrode tab 127 coupled to the negative electrode plate 125 is welded to one side of the terminal plate 160, and the positive electrode tab 126 coupled to the positive electrode plate 123 is welded to the other side of the cap plate 140. . Resistance welding, laser welding, or the like is used as a welding method for coupling the negative electrode tab 127 and the positive electrode tab 126, and resistance welding is generally used.

The insulating case 170 is responsible for the insulation between the cap assembly 130 and the electrode assembly 120, the positive electrode tab hole and the negative electrode tab hole is formed.

In general, a lithium secondary battery is injected into the can inside the electrolyte and allowed to stand for a period of time so that the electrolyte injected therein is impregnated into the electrode assembly. On the other hand, between the inner surface and the electrode assembly of the can of the lithium secondary battery, between the bottom surface and the electrode assembly of the can, and between the electrode plate and the separator of the electrode assembly is formed to be in close contact with a considerable pressure. Therefore, the electrolyte solution injected into the can is not only very hard to be impregnated smoothly into the electrode assembly, but also has a problem that it is difficult to sufficiently moisten the inside of the electrode assembly having almost no gap even when left for a long time.

The present invention has been made to solve the above problems, in particular, by heating the lower surface or side of the can after the injection of the electrolyte to generate convection in the electrolyte so that the electrolyte can be easily moistened into the electrode assembly, An object of the present invention is to provide a lithium secondary battery and a method of manufacturing the same, by forming a flow path through which an electrolyte flows on a surface of an insulating plate located at the bottom to help the flow of the electrolyte, and to easily impregnate the electrolyte.

In the lithium secondary battery of the present invention devised to solve the above problems, in the lithium secondary battery having an electrode assembly, a can containing the electrode assembly, and a cap assembly for sealing the top opening of the can, An insulating plate is inserted between the lower part of the electrode assembly and the can, and a groove is formed on the surface of the insulating plate.

In this case, the insulating plate may be formed with the groove on the upper surface in contact with the electrode assembly. In addition, the groove may be formed in a matrix shape or a radial shape.

In addition, the lithium secondary battery manufacturing method according to the present invention is an insulating plate insertion step of inserting an insulating plate in the can; An electrode assembly insertion step of inserting the electrode assembly into the can; An electrolyte injection step of injecting an electrolyte solution into the can; And it characterized in that it comprises a heating step of heating the can.

In addition, the insulating plate insertion step may be performed after the groove forming step of forming a groove so that the flow path of the electrolyte is formed on the surface of the insulating plate.

In addition, the heating step may be to heat the bottom or side of the can. In addition, the heating step may be to heat to a temperature at least 10 ℃ higher than the temperature of the electrolyte solution. In addition, the heating step may be to heat so that the Rayleigh number of the electrolyte solution (10 ⁴ to 10 ⁵ ).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the rectangular lithium secondary battery has been described as an example, but the present invention may be applied to a cylindrical lithium secondary battery.

First, a lithium secondary battery according to an embodiment of the present invention will be described.

2 is a vertical cross-sectional view of a rechargeable lithium battery according to one embodiment of the present invention. 3A illustrates a perspective view of an insulating plate according to an embodiment of the present invention, and FIG. 3B illustrates a cross-sectional view taken along line A-A of FIG. 3A.

In the lithium secondary battery 200 according to an embodiment of the present invention, referring to FIG. 2, the electrode assembly 220 including the positive electrode plate 223, the negative electrode plate 225, and the separator 224 may be filled with an electrolyte ( And the upper end opening of the can 210 is sealed by the cap assembly 230. In addition, the lithium secondary battery 200 has an insulating plate 212 is inserted to insulate between the electrode assembly 220 and the can 210. The lithium secondary battery 200 includes a long side and a front surface and a rear surface formed to face each other, a short side, and both sides formed to face each other, a top surface on which the cap plate 240 is located and a bottom surface facing the top surface. It is made, including.

The electrode assembly 220 is formed by winding a separator 224 between the positive electrode plate 223 and the negative electrode plate 225.

The positive electrode plate 223 includes a positive electrode current collector made of a thin metal plate having excellent conductivity, for example, aluminum (Al) foil, and a positive electrode active material layer coated on both surfaces thereof. As the positive electrode active material is used a lithium oxide, such as _{LiCoO 2, LiMn 2 O 4,} LiNiO 2, LiMnO 2. At both ends of the positive electrode plate 223, a positive electrode current collector region in which a positive electrode active material layer is not formed, that is, a positive electrode non-coating portion is formed. One end of the positive electrode non-coating portion is generally formed of aluminum (Al), and the positive electrode tab 226 protruding a predetermined length to the upper portion of the electrode assembly 220 is bonded.

The negative electrode plate 225 includes a negative electrode current collector made of a conductive metal plate, for example, copper (Cu) or nickel (Ni) foil, and a negative electrode active material layer coated on both surfaces thereof. Both ends of the negative electrode plate 225 have a negative electrode current collector region, that is, a negative electrode non-coating portion, in which a negative electrode active material layer is not formed. One end of the negative electrode non-coating portion is generally formed of nickel (Ni), and the negative electrode tab 227 protruding a predetermined length to the lower portion of the electrode assembly 220 is bonded. In addition, a lower portion of the electrode assembly 220 may further include an insulating plate for preventing contact with the can 210.

The separator 224 may be interposed between the positive electrode plate 223 and the negative electrode plate 225 and extend to surround the outer circumferential surface of the electrode assembly 220. The separator 224 is formed of a porous membrane polymer material to prevent short circuit between the positive electrode plate 223 and the negative electrode plate 225 and to allow lithium ions to pass therethrough.

The can 210 is formed in an approximately box shape including a pair of long side walls, a pair of short side walls, and a bottom plate having an approximately rectangular shape, and an upper portion thereof is opened to form an upper opening. In addition, when the can 210 is formed in a substantially box shape, the cross section in the horizontal direction may be formed in various shapes such as a rectangular shape or an elliptical shape. The electrode assembly 220 is inserted into the upper opening. In addition, an electrolyte solution is impregnated between the electrode assemblies 220 to enable the movement of lithium ions. The material of the can 210 is mainly light aluminum (Al). The upper portion of the can 210 is sealed by the cap assembly 230, the leakage of the electrolyte is prevented. The long side walls and the short side walls of the can 210 are formed to have a thickness of about 0.2 to 0.4 mm, and the thickness of the bottom plate is approximately 0.2 to 0.7 mm. However, the thickness of the long side wall and the short side wall is not limited here. The can 210 is preferably formed by a deep drawing method, and the long side wall, the short side wall and the bottom plate are integrally formed. However, the method of forming the can 210 is not limited thereto.

The cap assembly 230 includes a cap plate 240, an insulating plate 250, a terminal plate 260, and an electrode terminal 235. The cap assembly 230 is coupled to a separate insulating case 270 is coupled to the upper opening of the can 210 to seal the can 210.

The cap plate 240 is welded to the upper opening of the can 210 to seal the can 210. The cap plate 240 is formed to include a terminal through-hole 1 (not shown) and the electrolyte inlet 242. In addition, the cap plate 240 may be formed including a safety vent (not shown). However, the safety vane may not be formed in the cap plate 240, of course. In addition, the electrolyte injection hole 242 is sealed by a sealing means 280, such as a ball.

The terminal through hole 1 is formed at an approximately center of the cap plate 240, and the electrode terminal 235 insulated by the gasket tube 246 is inserted therein.

The electrolyte injection hole 242 is formed on one side of the cap plate 240. The upper end of the electrolyte injection hole 242 is formed to face the upper direction of the lithium secondary battery 200, the lower end of the electrolyte injection hole 242 is inside the can 210 of the lithium secondary battery 200, that is, the electrode assembly ( It is formed to face 220. In addition, the electrolyte injection hole 242 is preferably formed by a press method, and the method of forming the electrolyte injection hole 242 is not limited thereto. The sealing means 280 is formed of a ductile metal material, preferably formed of an aluminum material. However, the material of the sealing means 280 is not limited thereto. In addition, the sealing means 280 may be formed in a ball shape, it is crimped, welded to the electrolyte inlet 242.

The safety vane is formed on the other side of the cap plate 240, and is formed in a thin thickness compared to other parts. The safety vent 243 may have an elliptical planar shape, but the safety vent 243 is not limited to the planar shape of the safety vent 243. In addition, the safety vent 243 may be formed by a compression method, and the safety vent 243 is not limited thereto. The safety vent 243 is damaged when the pressure inside the battery rises above a predetermined pressure to prevent ignition and explosion of the battery.

The insulating plate 250 is formed of an insulating material such as a gasket, and is coupled to the lower surface of the cap plate 240. The insulating plate 250 has a terminal through-hole 2 through which the electrode terminal 235 is inserted at a position corresponding to the terminal through-hole 1 of the cap plate 240. A mounting groove corresponding to the size of the terminal plate 260 is formed on the bottom surface of the insulating plate 250 so that the terminal plate 260 is seated.

The terminal plate 260 is generally formed of Ni alloy, and is mounted on the bottom surface of the insulating plate 250. The terminal plate 260 is provided with a terminal through-hole 3 into which the electrode terminal 235 is inserted at a position corresponding to the terminal through-hole 1 of the cap plate 240, and the electrode terminal 235 is formed by the gasket tube 246. Insulated by the () through the terminal through hole 1 of the cap plate 240, the terminal plate 260 is electrically connected to the electrode terminal 235 while being electrically insulated from the cap plate 240.

The negative electrode tab 227 coupled to the negative electrode plate 225 is welded to one side of the terminal plate 260, and the positive electrode tab 226 coupled to the positive electrode plate 223 is welded to the other side of the cap plate 240. . Resistance welding, laser welding, or the like is used as a welding method for bonding the negative electrode tab 227 and the positive electrode tab 226, and resistance welding is generally used.

The electrode terminal 235 is connected to the negative electrode tab 227 of the negative electrode plate 225 or the positive electrode tab 226 of the positive electrode plate 223 to act as a negative electrode terminal or a positive electrode terminal.

2 to 3B, the insulating plate 212 is inserted into a portion where the lower portion of the electrode assembly 220 and the lower plate of the can 210 contact each other. The insulating plate 212 is formed to include an upper surface 212a in contact with a lower portion of the electrode assembly 220 and a lower surface 212b in contact with a lower plate of the can 210. An electrolyte may be injected between the upper surface 212a and the electrode assembly 220 and between the lower surface 212b and the can 210. The insulating plate 212 is formed in a substantially rectangular shape in a planar shape, preferably in a rectangular shape so as to correspond to the shape of the bottom plate of the can 210. On the other hand, the insulating plate 212 may be formed in a shape corresponding to that when the lower side plate is formed in a stadium shape because the short side wall of the can 210 is formed in a smooth curved shape. However, the planar shape of the insulating plate 212 is not limited thereto. In addition, the insulating plate 212 is formed to a thickness such that the lower portion of the electrode assembly 220 and the can 210 can be insulated from each other. In addition, the insulating plate 212 is formed of an insulator having excellent insulating properties, and is preferably formed of a polyolefin-based such as polyethylene (PE) and polypropylene (PP). However, the material of the insulating plate 212 is not limited thereto. The insulating plate 212 is inserted to prevent electrical shorts that may occur between the electrode assembly 220 and the can 210.

On the other hand, the insulating plate 212 is formed with a groove 214 on the surface. The groove 214 may be formed on both the upper surface 212a and the lower surface 212b, and may be formed only on the upper surface 212a as shown in FIG. 3A. The groove 214 is formed in a matrix shape so as to cross the upper surface 212a. However, the shape of the groove 214 is not limited thereto. The groove 214 is formed to a depth enough to allow the electrolyte to be injected into a tight space between the lower portion of the electrode assembly 220 and the insulating plate 212. However, when the depth of the groove 214 is formed to be too deep, there is a problem that the insulating plate 212 may be damaged. In addition, the groove 214 may be formed by a press method, and the method of forming the groove 214 is not limited thereto. At least one groove 214 is formed in the horizontal direction of the upper surface 212a, and at least one groove is formed in the vertical direction of the upper surface 212b. The horizontal groove and the vertical groove meet each other to form an intersection 215, and the intersection 215 has a structure in which all four sides are open. Therefore, when the electrolyte flows into the groove 214, the electrolyte permeates in the horizontal direction and the vertical direction and meets each other at the intersection portion 215, thereby forming a flow path between the lower portion of the electrode assembly 220 and the insulating plate 212. Done. The groove 214 forms a flow path between the lower portion of the electrode assembly 220 and the insulating plate 212 so that the electrolyte solution can be more smoothly moistened into the electrode assembly 220. In addition, the lower surface or the side surface of the can may be heated so that the electrolyte solution may be more easily moistened into the electrode assembly. This will be described later.

Next, a lithium secondary battery according to another embodiment of the present invention will be described.

4A is a perspective view of an insulating plate according to another embodiment of the present invention, and FIG. 4B is a plan view of FIG. 4A. Since the embodiment of FIG. 4A is similar to the embodiment of FIG. 3A except that the groove 314 of the radial shape is formed in the insulating plate 312, the description will be mainly focused on differences.

According to another exemplary embodiment of the present invention, a lithium secondary battery includes an electrode assembly, a can, a cap assembly, and an insulating plate 312. Since the electrode assembly, the can, and the cap assembly have been sufficiently described in the embodiment of FIG. 3A, detailed description thereof will be omitted.

4A and 4B, the insulating plate 312 is formed in a substantially rectangular planar shape. In addition, the insulating plate 312 is formed to include an upper surface 312a in contact with the lower portion of the electrode assembly, and a lower surface 312b in contact with the lower plate of the can. Grooves 314 are formed on the surface of the insulating plate 312, and the grooves 314 may be formed on both the upper surface 312a and the lower surface 312b, or may be formed only on the upper surface 312a. It's like a hurry.

The groove 314 is formed in a radial shape. More specifically, two grooves 314 are formed in a diagonal direction, and at least one groove 314 is formed in a horizontal direction and a vertical direction of the upper surface 312a. The diagonal grooves and the horizontal and vertical grooves are formed to meet each other to form an intersection 315. The intersection portion 315 is formed in an open structure in four directions to facilitate the flow of the electrolyte. The groove 314 is formed to a depth enough to inject the electrolyte into the tight space between the lower portion of the electrode assembly and the insulating plate 312, it is preferably formed by a press method. The groove 314 has a longer flow path formed in both diagonal directions, and the diagonal direction and the horizontal / vertical direction are formed to meet each other, so that the electrolyte flowing into the lower portion of the can can be more easily moistened into the electrode assembly. Make sure In addition, the lower surface or the side surface of the can may be heated so that the electrolyte solution may be more easily moistened into the electrode assembly. This will be described later.

Next, a method of manufacturing a lithium secondary battery according to an embodiment of the present invention will be described. Hereinafter, the manufacturing method of the rectangular lithium secondary battery has been described as an example, but the present invention can be applied to the manufacturing method of the cylindrical lithium secondary battery. In the following, reference numerals will be given with reference to the embodiment of FIG. 2.

5A is a perspective view illustrating an example of a method of manufacturing a lithium secondary battery according to an embodiment of the present invention, and FIG. 5B is a schematic cross-sectional view of FIG. 5A. 6 is a perspective view showing another example of a method of manufacturing a lithium secondary battery according to an embodiment of the present invention. 5B shows that the spacing between the electrode assembly 220 and the side surface of the can 210 and the spacing between the electrode assembly 220 and the bottom surface of the can 210 are exaggerated for convenience.

Method for manufacturing a lithium secondary battery 200 according to an embodiment of the present invention is the electrode assembly 220 forming step of forming the electrode assembly 220, the insulating plate 212 to insert the insulating plate 212 in the can 210. ) Inserting step, inserting the electrode assembly 220 to insert the electrode assembly 220 into the top opening of the can 210, sealing the can 210 to seal the top opening with a cap assembly 230, electrolyte inlet And a heating step of heating the can 210. In addition, the manufacturing method of the lithium secondary battery 200 according to the embodiment of the present invention further includes a groove 214 forming step of forming a groove 214 to form a flow path of an electrolyte solution on the surface of the insulating plate 212. Can be done. Meanwhile, the forming of the electrode assembly 220 and the sealing of the can 210 are similar to those of a general lithium secondary battery manufacturing method, and thus a detailed description thereof will be omitted.

The groove 214 forming step is a process of forming the groove 214 on the surface of the insulating plate 212. The groove 214 may be formed in a matrix shape, a radial shape, or the like. The groove 214 forming step is preferably performed before the insulating plate 212 insertion step. The groove 214 forming step forms a flow path of the electrolyte solution in the insulating plate 212, so that the electrolyte solution can be more smoothly moistened into the electrode assembly 220 during the heating step.

Inserting the insulating plate 212 is a process of inserting the insulating plate 212 into the can 210. Inserting the insulating plate 212 is performed to prevent an electrical short between the electrode assembly 220 and the can 210.

Inserting the electrode assembly 220 is a process of inserting the electrode assembly 220 wound in a jelly-roll shape into the upper opening of the can 210. In the case of a square lithium secondary battery, the electrode assembly 220 is formed into an approximately elliptical shape by applying a predetermined pressure and then inserted into the can 210. On the other hand, in the case of a cylindrical lithium secondary battery, the electrode assembly 220 is inserted into the can 210 as it is a cylindrical shape wound.

The electrolyte injection step is a process of injecting the electrolyte through the electrolyte inlet 242. The electrolyte injection hole 242 is sealed by sealing means 280 such as aluminum balls when the injection of the electrolyte is completed.

5A to 6, the heating step is a process of heating the lower surface 216 or the side surfaces 217 and 218 of the can 210. 5A and 6 indicate the heating direction of the can 210. In the heating step, the can 210 is heated to form a temperature T _l of the electrolyte 290 and a temperature Tw of the can 210 differently, so that the heated electrolyte 290 is the can 210 and the electrode. This is a process for allowing convection inside the assembly 220. In the heating step, the lower surface 216 of the can 210 may be heated as shown in FIG. 5A, and the side surface 218 of the can 210 may be heated as shown in FIG. 6. Further, in the heating step, the short side wall 218 may be heated as shown in FIG. 6, and although not shown, the long side wall 217 may be heated. The lower surface 216 of the can 210 is heated so that Tw> T _l Is then shown in FIG. Likewise, the density of the electrolyte 290 around the lower surface of the can 216 is lowered, and the electrolyte 290 around the lower surface 216 moves upward due to buoyancy. At this time, the value that determines the buoyancy is measured by the Rayleigh number and is calculated as in Equation 1.

Equation 1 R = gβ (Tw-T _l H ³ / αυ

(g is gravitational acceleration, β is thermal expansion coefficient, H is can height, α is thermal diffusion coefficient, υ is kinematic viscosity)

At this time, the heating step is preferably heated to a temperature at least 10 ℃ higher than the temperature of the electrolyte (290). Thus, Tw-T _l ≥ 10. In addition, the Rayleigh number R is preferably heated to be 10 ⁴ to 10 ⁵ . In the heating step, since the electrolyte 290 is not stopped during the waiting time after the injection of the electrolyte and the vertical movement is continued inside the electrode assembly 220, the strength of the flow between the electrode plate and the separator is increased. This intensifies the dispersion in which the fluid spreads between the porous layers in the porous layer, resulting in an increase in the rate of wetting of the electrolyte. In addition, since the groove 214 is formed in the insulating plate 212 through the groove 214 forming step, the electrolyte 290 can more easily penetrate into the lower portion of the electrode assembly 220.

As described above, the present invention is not limited to the specific preferred embodiments described above, and any person having ordinary skill in the art to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Various modifications are possible, of course, and such changes are within the scope of the claims.

According to the lithium secondary battery and the method for manufacturing the same according to the present invention, the electrolyte is injected to the can by heating the can and convex the electrolyte so that the electrolyte can be more smoothly impregnated into the electrode assembly.

In addition, according to the lithium secondary battery according to the present invention and a method of manufacturing the same, by forming a groove to be the flow path of the electrolyte on the surface of the insulating plate so that the electrolyte accumulated in the bottom of the can can be impregnated well into the electrode assembly.

Claims (8)

A lithium secondary battery comprising an electrode assembly, a can housing the electrode assembly, and a cap assembly sealing an upper end of the can, An insulating plate is inserted between the lower part of the electrode assembly and the can, Lithium secondary battery, characterized in that the groove is formed on the surface of the insulating plate. The method of claim 1, The insulating plate is a lithium secondary battery, characterized in that the groove is formed on the upper surface in contact with the electrode assembly. The method of claim 1, The groove is a lithium secondary battery, characterized in that formed in a matrix or radial shape. An insulation plate insertion step of inserting an insulation plate into the can; An electrode assembly insertion step of inserting an electrode assembly into the can; An electrolyte injection step of injecting an electrolyte solution into the can; And Method of manufacturing a lithium secondary battery, characterized in that it comprises a heating step of heating the can. The method of claim 4, wherein Inserting the insulating plate is a manufacturing method of a lithium secondary battery, characterized in that after the groove forming step of forming a groove so that the flow path of the electrolyte is formed on the surface of the insulating plate. The method of claim 4, wherein The heating step is a method of manufacturing a lithium secondary battery, characterized in that for heating the bottom or side of the can. The method of claim 4, wherein The heating step is a method of manufacturing a lithium secondary battery, characterized in that heating to a temperature at least 10 ℃ higher than the temperature of the electrolyte. The method of claim 4, wherein The heating step is a method of manufacturing a lithium secondary battery, characterized in that the heating so that the Rayleigh number R of the electrolyte (10 ⁴ to 10 ⁵⁾ . R = gβ (Tw-T _l H ³ / αυ (g is gravitational acceleration, β is thermal expansion coefficient, H is can height, α is thermal diffusion coefficient, υ is kinematic viscosity)

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