Metal shell square battery safety valve exhaust hole sealing boss structure

Abstract

The utility model discloses a kind of metal shell square battery safety valve exhaust hole sealing boss structure.It relates to new energy battery parts technical field.Its structure includes sealing boss, battery metal shell, safety valve exhaust hole being set on battery shell.Sealing boss includes rivet and rivet pad, and rivet and rivet pad are nested installation in exhaust hole.Downward pressing is carried out to the rivet using press riveting process, and the rivet and the rivet pad form sealing boss, so that it is tightly covered the exhaust hole, and rivet and battery metal shell are insulated and isolated.The utility model sets sealing boss in safety valve exhaust hole, and exhaust passage and battery metal shell are insulated and isolated, and sealing boss of press riveting forming enhances sealing effect, effectively avoids the case that the phenomenon of alkaline climbing caused by the liquid phase penetration of existing nickel-metal hydride battery exhaust hole is electrified, improves battery service life.

Description

Technical Field

[0001] This utility model belongs to the field of new energy battery component technology, specifically a sealing boss structure for the exhaust hole of a metal-cased square battery safety valve. Background Technology

[0002] The metal-cased square battery is a nickel-metal hydride (NiMH) battery. NiMH batteries consist of a Ni(OH)₂ positive electrode, a hydrogen storage alloy negative electrode, and a potassium hydroxide solution as the electrolyte. They are rechargeable and have a wide range of applications. During use, NiMH batteries require timely release of internal pressure. Simultaneously, some of the electrolyte vapor generated by heating is released and condenses at the vent and its vicinity on the outer casing. Currently, the vent in existing NiMH batteries is formed directly by drilling holes in the casing, making it an integral part of the casing. The battery casing is typically the negative electrode. Since the metal ions in the electrolyte inside the battery are all positive ions, they are adsorbed onto the negative electrode of the casing. A large number of positive ions accumulate at the edge of the vent. Due to the presence of internal moisture, these positive ions flow outward along the vent protrusions through the fine grooves of the metal processing defects, forming alkali creep. Alkali creep leads to accelerated self-discharge, decreased insulation, electrolyte consumption, shortened lifespan, and damage to the battery's appearance. The existing method uses a riveting process to install the sealing boss for the vent hole. The specific steps involve fitting the boss onto the safety valve vent hole on the housing from bottom to top, followed by tightening it using a riveting machine. However, the riveting process generates temperatures as high as 600°C, which melts the rivet pads, thus compromising the crucial sealing performance. Summary of the Invention

[0003] To improve the sealing performance of the safety valve vent and prevent or avoid alkali creep in batteries while meeting the requirement of timely release of internal battery pressure, this invention provides a sealing boss structure for the safety valve vent of a square metal-cased battery. The structure includes a sealing boss, a battery metal casing, and a safety valve vent on the battery metal casing. The sealing boss includes a rivet and a rivet pad, which are nested within the vent. A press-fitting process is used to press the rivet downwards, forming a sealing boss with the rivet pad, tightly covering the vent and insulating the rivet from the battery metal casing. This invention, by setting a sealing boss in the safety valve vent, insulates the vent passage from the casing. The press-fitted sealing boss enhances the sealing effect, effectively preventing liquid phase penetration into the vent of existing nickel-metal hydride batteries, which can lead to alkali creep and improve battery life.

[0004] Furthermore, the rivet is a hollow metal tube with an upward-curved flange. The connection between the upward-curved flange and the hollow tube protrudes upward to form a boss.

[0005] Furthermore, the rivet pad is a hollow tube containing an insulating material with an upper groove, and the material of the rivet pad is nylon or foam.

[0006] Furthermore, the rivet and the rivet pad are nested and installed inside the vent hole.

[0007] Furthermore, the upper flange of the rivet deforms under pressure and forms a lower flange, so that it tightly covers the vent hole.

[0008] Furthermore, the bottom of the hollow tube in the rivet pad deforms during the riveting process and forms a downward flange structure, extending the sealing length between the rivet pad and the inner wall of the vent hole.

[0009] Furthermore, the vent is a circular through-hole on the metal casing of the battery. The width of the hole ranges from 0.1cm to 0.5cm.

[0010] The above technical solution has the following beneficial effects: This invention insulates the vent passage from the battery's metal casing by installing a sealing boss in the safety valve's vent hole. The press-formed sealing boss enhances the sealing effect, effectively preventing liquid phase penetration from the vent hole of existing nickel-metal hydride batteries, which can lead to alkali creep and extend battery life. The press-forming process used is simple, reliable, low-cost, and highly efficient. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the appearance of this utility model.

[0013] Figure 2 This is a cross-sectional view of the present invention.

[0014] Figure 3 This is a schematic diagram of the present invention before riveting.

[0015] Figure 4 This is a schematic diagram of the present invention after riveting.

[0016] Explanation of reference numerals in the attached diagram: 1. Battery metal casing; 2. Rivet; 3-1. Vent hole; 3-2. Detailed Implementation

[0017] See Figure 1-4As shown, the technical solution adopted in this specific embodiment is as follows: the sealing boss includes a rivet 2 and a rivet pad 3-2. The rivet 2 is a hollow tube with an upward-turned edge, and the rivet pad 3-2 is a hollow tube with an upward-grooved groove. The rivet 2 is pressed downward using a press-fitting process, and the rivet 2 and the rivet pad 3-2 form a sealing boss, which tightly covers the vent hole 3-1.

[0018] More specifically, the rivet 2 is a hollow metal tube with an upward-curved edge, and the connection between the upward-curved edge and the hollow tube protrudes upward to form a boss. The rivet pad 3-2 is an insulating hollow tube with an upward-curved groove, forming an I-shaped structure. By embedding the rivet 2 into the rivet pad 3-2, the two form a tightly fitting connection structure, effectively improving the overall sealing performance.

[0019] More specifically, the vent 3-1 is a circular through hole on the battery metal casing 1. The rivet 2 and the rivet pad 3-2 are nested and installed within the vent 3-1. The diameter and length of the rivet 2 are strictly matched with the diameter and thickness of the rivet pad 3-2 and the vent 3-1 to avoid poor fit due to dimensional deviations.

[0020] More specifically, the rivet 2 is pressed downwards using a press-fit process, forming a sealing boss with the rivet 2 and the rivet pad 3-2. The upper edge of the rivet 2 deforms under pressure and forms a lower edge, tightly covering the vent hole 3-1. After press-fitting, the bottom of the hollow tube of the rivet pad 3-2 deforms and forms a lower edge structure, effectively extending the sealing length between the rivet pad 3-2 and the inner wall of the vent hole 3-1. The rivet pad 3-2 and the inner wall of the vent hole 3-1 form a tight fit, making it difficult for electrolyte to leak through the gap between them to the outer surface of the battery metal casing 1, effectively preventing alkali creep.

[0021] More specifically, the rivet 2 replaces the vent 3-1 to connect the inside and outside of the battery metal casing 1 with air, thus meeting the requirement of timely release of internal battery pressure. The rivet 2 is insulated from the battery metal casing 1 by the rivet pad 3-2. The rivet 2 is not charged, so the electrolyte condensed on it will not grow to the outer surface of the battery metal casing 1.

[0022] More specifically, the connection between the sealing boss and the exhaust port 3-1 is achieved by press riveting, which is simple, reliable, low-cost, and efficient.

[0023] The process employed in this utility model is as follows: a riveting machine presses the rivet 2 downwards, and the rivet 2 and the rivet pad 3-2 form a sealing boss. The upper flange of the rivet 2 deforms under pressure and forms a lower flange, so that it tightly covers the vent hole 3-1. After the rivet pad 3-2 is riveted, the bottom of the hollow tube deforms and forms a lower flange structure, effectively extending the sealing length between the rivet pad 3-2 and the inner wall of the vent hole 3-1. The two form a tight fit. The rivet and the battery metal shell are insulated by the rivet pad, and the electrolyte cannot be discharged to the outer surface of the battery metal shell through the gap between the two, which can avoid the occurrence of alkali creep.

[0024] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A sealing boss structure for a safety valve vent hole of a square metal-cased battery, comprising a sealing boss, a metal battery casing, and a safety valve vent hole formed on the battery casing; characterized in that: The sealing boss includes a rivet and a rivet pad. The rivet is a hollow tube with an upward-turned edge, and the rivet pad is a hollow tube with an upward-grooved groove. The rivet is pressed downward using a press-riveting process, and the rivet and the rivet pad form a sealing boss that tightly covers the vent hole.

2. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The rivet is a hollow metal tube with an upward-curved edge, and the connection between the upward-curved edge and the hollow tube protrudes upward to form a boss.

3. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The rivet pad includes an insulating hollow tube with an upper groove, forming an I-shaped structure, and the rivet pad is made of nylon or foam.

4. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The rivet and the rivet pad are nested and installed inside the vent hole.

5. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The upper flange of the rivet deforms under pressure and forms a lower flange, which tightly covers the vent hole.

6. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The bottom of the hollow tube in the rivet pad deforms during the riveting process and forms a downward flange structure, which extends the sealing length between the rivet pad and the inner wall of the vent hole.

7. The sealing boss structure for the vent hole of a metal-cased square battery safety valve according to claim 1, characterized in that: The vent is a circular through hole on the metal casing of the battery, with a width ranging from 0.1cm to 0.5cm.

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