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KR-20260066445-A - FIXING JIG FOR TENSILE STRENGTH TESTING OF ELECTRODE TAB AND TENSILE STRENGTH TESTING HAVING THE FIXING JIG

KR20260066445AKR 20260066445 AKR20260066445 AKR 20260066445AKR-20260066445-A

Abstract

The present invention relates to a fixing jig for measuring the tensile strength of an electrode tab and a method for measuring tensile strength using the same. Specifically, the invention comprises: a body portion for horizontally fixing a base material to which an electrode tab is attached and which has a circular outer shape; and a plurality of leg portions for separating the body portion by a certain distance upward; wherein a through hole is formed in the center of the body portion to accommodate the base material, the through hole having a structure in which the horizontal cross-section is circular and the inner diameter decreases toward the top, and the through hole has a narrower top and wider bottom structure.

Inventors

  • 박성근
  • 김성률
  • 임성상

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260512
Application Date
20241104

Claims (11)

  1. A body portion for horizontally fixing a base material having a circular shape and to which an electrode tab is attached; and A plurality of leg portions for separating the above body portion by a certain distance upward; comprising, A fixing jig for measuring the tensile strength of an electrode tab, characterized by having a through hole formed in the center of the body portion having a circular horizontal cross-section and a structure in which the inner diameter decreases toward the top and the top is narrower and the bottom is wider, in order to accommodate the base material.
  2. In paragraph 1, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that a cut portion is formed on the side of the body portion that communicates with the through hole so that the electrode tab can pass through.
  3. In paragraph 2, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that the maximum inner diameter of the through hole is larger than the outer diameter of the base material, and the minimum inner diameter of the through hole is smaller than the outer diameter of the base material.
  4. In paragraph 3, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that the above-mentioned base material is a cylindrical can with an anode tab welded thereto or a top cap with a cathode tab welded thereto.
  5. In paragraph 3, A fixing jig for measuring the tensile strength of an electrode tab, characterized by further including a cap portion inserted into a through hole below the base material while the base material is housed in the through hole.
  6. In paragraph 5, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that the cap portion has a shape corresponding to the through hole.
  7. In paragraph 5, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that the above-mentioned cap portion includes a contact portion that contacts the base material and a gripping portion provided on one side of the contact portion.
  8. In Paragraph 7, A fixing jig for measuring the tensile strength of an electrode tab, characterized in that the above-mentioned contact portion is made of an elastic material.
  9. A method for measuring the tensile strength of an electrode tab using a fixed jig for measuring the tensile strength of an electrode tab described in any one of claims 1 to 8, wherein A first step of preparing a base material having a circular shape to which the electrode tab is attached; A second step of horizontally positioning the base material in a through hole with a narrow upper and wide lower structure in the center of the body part, and protruding the electrode tab upward from the body part; A third step of connecting the protruding electrode tab to the gripper of a tensile strength tester; and A method for measuring the tensile strength of an electrode tab, characterized by including a fourth step of applying tensile force to the electrode tab.
  10. In Paragraph 9, A method for measuring the tensile strength of an electrode tab, characterized by further including a step between the second and third steps of inserting a cap portion into the through hole and bringing it into close contact with the lower surface of the base material so that the base material can be fixed while maintaining a horizontal state in the through hole.
  11. In Paragraph 10, A method for measuring the tensile strength of an electrode tab, characterized in that the above-mentioned cap portion is fixed by a forced press-fit method with the above-mentioned through hole.

Description

Fixing Jig for Tensile Strength Testing of Electrode Tab and Method for Testing Tensile Strength Using the Same The present invention relates to a fixing jig for measuring the tensile strength of an electrode tab and a method for measuring tensile strength using the same. Specifically, the invention relates to a fixing jig for measuring the tensile strength of an electrode tab that can firmly grip a top cap or battery case to which the electrode tab is connected while maintaining it in a horizontal state, and a method for measuring tensile strength using the same. Secondary batteries serve as an alternative energy source to fossil fuels that cause air pollutants, and are being applied to electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and energy storage devices (ESS). Currently, widely used types of battery cells include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. Additionally, depending on the shape of the battery case, they are classified into cylindrical and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch-type case made of aluminum laminate sheets. Meanwhile, in a cylindrical battery cell, a jelly-roll type electrode assembly wound with a separator sheet interposed between a positive electrode sheet and a negative electrode sheet is housed in a cylindrical battery case for use. At this time, the negative tab and the positive tab are fixed to the battery case and the top cap, respectively, by welding, and function as the negative terminal and the positive terminal. However, if the negative tab or positive tab is not properly welded and becomes over-welded or under-welded, the battery cell may not function properly and may lead to fire or explosion, so tensile strength is measured to determine whether the negative tab and positive tab are properly welded. That is, the battery case with the negative tab welded or the top cap with the positive tab welded is fixed, and the tensile strength is measured by pulling the electrode tabs with a constant force. However, because the exteriors of the battery case and top cap are curved, it is difficult to secure them properly, resulting in sample-specific variations caused by shaking during tensile testing. Additionally, while the electrode tab must be pulled perpendicular to the battery case or top cap during the tensile test, accurate results cannot be expected if the battery case or top cap is tilted. FIG. 1 is a perspective view of a fixed gripper used for measuring tensile strength according to the prior art, and discloses a fixed gripper for a tensile strength measuring instrument. In the above prior art, a gripper (10) capable of securely gripping and fixing a specimen, i.e., an electrode tab (21), is disclosed. However, regarding the fixing of the battery case or top cap connected to the electrode tab by welding, it has not been disclosed. FIG. 1 is a perspective view of a fixed gripper used for measuring tensile strength according to the prior art. Figure 2 is a cross-sectional view of a cylindrical battery cell. FIG. 3 is a perspective view of a fixing jig according to a first embodiment of the present invention. FIG. 4 is a perspective view of the body and leg portions constituting the fixed jig illustrated in FIG. 3, viewed from below. FIG. 5 is a cross-sectional view of a base material with a body part, a leg part, and an electrode tab attached, constituting a fixing jig according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view of a fixed base material with an electrode tab attached to a fixed jig according to the first embodiment of the present invention. FIG. 7 is a perspective view of a cap portion constituting a fixing jig according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view of a fixed base material with an electrode tab attached to a fixed jig according to a second embodiment of the present invention. Embodiments that enable a person skilled in the art to easily implement the present invention are described in detail below with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description is omitted. In addition, the same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected, but also cases where they are indirectly connected with other elements in b