Small button-type high-capacity lithium battery with explosion-proof function
By adopting a segmented step structure and exhaust hole design in button-type lithium batteries, combined with a high-performance PVDF insulating film, the problem of explosion caused by expansion of conventional lithium batteries is solved, and safety and capacity are improved.
Patent Information
- Application Number
- CN201711008850.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2017-10-25
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2037-10-25
AI Technical Summary
Conventional button-type lithium batteries are prone to explosion due to internal expansion during charging, which poses safety hazards.
It adopts a segmented step structure and exhaust hole design, combined with a high-performance PVDF insulating film, to ensure that internal pressure can be released during expansion and prevent explosion.
It effectively prevents explosion caused by expansion of lithium batteries, improves safety, and increases the capacity of the battery by thinning the thickness of the insulating film.
Smart Images
Figure CN109713170B_ABST
Abstract
Description
Technical Field
[0001] The invention discloses a lithium battery, in particular to a button-type small-sized high-capacity lithium battery with explosion-proof function. Background Art
[0002] A button cell is also called a button cell. It is a battery with a small button-like appearance. Generally speaking, it has a larger diameter and a thinner thickness (compared to cylindrical batteries such as the No. 5 AA batteries on the market). There are two common types of button cells: rechargeable and non-rechargeable. Non-rechargeable ones include 3V lithium manganese button cells and 1.5V alkaline zinc manganese button cells; rechargeable ones include 3.6V rechargeable lithium ion button cells and 3V rechargeable lithium ion button cells.
[0003] Conventional lithium batteries mainly include an inner shell, an outer shell and a battery core. The inner shell and the outer shell are buckled together, and the battery core is arranged inside the inner shell. As we all know, lithium batteries generate heat during the charging process, and the interior of lithium batteries is a closed space. A large amount of heat is generated in a closed space, which will inevitably cause the internal space of the battery to expand. In severe cases, it may even explode. Conventional battery inner shells and outer shells are sealed and buckled together. There is a certain bonding force between the inner shell and the outer shell. Conventional slight expansion can be tolerated, but severe expansion will directly cause an explosion, and may even cause personal injury to the user. Summary of the invention
[0004] In view of the above-mentioned shortcomings of the button-type lithium battery in the prior art, which is unreasonable in structural design and prone to explosion, the present invention provides a button-type small-sized high-capacity lithium battery with explosion-proof function, which adopts a segmented step structure to release the pressure inside the battery when expansion occurs, and will not explode.
[0005] The technical solution adopted by the present invention to solve its technical problems is: a button-type small high-capacity lithium battery with explosion-proof function, the lithium battery comprising an inner shell, an outer shell, a battery core and an insulating film, the inner shell and the outer shell are both barrel-shaped, the outer shell cover is installed on the outside of the inner shell, the battery core is arranged inside the inner shell, the insulating film is arranged between the inner shell and the outer shell, the top of the inner shell is provided with an inward concave shoulder, the top of the outer shell is provided with a pressing edge, the pressing edge is pressed at the position above the insulating film, the inner shell is provided with a secondary step, the diameter of the inner shell at the upper position of the secondary step is smaller than the diameter of the inner shell at the lower position of the secondary step, the outer shell is provided with a waist corresponding to the position of the secondary step, the waist is recessed inwardly and clamped at the position of the secondary step, and one or more exhaust holes are opened on the inner shell at the position above the secondary step.
[0006] The technical solution adopted by the present invention to solve the technical problem further includes:
[0007] The secondary step is arranged at the middle and lower part of the battery body.
[0008] The insulating film is made of PVDF material.
[0009] The thickness of the insulating film is 0.08-0.1 mm.
[0010] The insulating film is divided into an outer insulating film and an inner insulating film. The outer insulating film is arranged on the outer side of the inner shell, and the inner insulating film is arranged on the inner side of the inner shell. The outer insulating film and the inner insulating film are arranged integrally.
[0011] The outer insulating film is arranged at the same height as the inner shell, and the inner insulating film has a height greater than 0.5 mm.
[0012] The inner shell and the outer shell are both in a round barrel shape.
[0013] The beneficial effects of the present invention are as follows: the present invention adopts a segmented step structure and is equipped with air holes on the inner shell, so that the pressure inside the battery can be released when expansion occurs, and explosion will not occur.
[0014] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention.
[0016] In the figure, 1-inner shell, 2-outer shell, 3-insulating film, 4-battery core, 5-shoulder, 6-pressing edge, 7-secondary step, 8-waist, 9-exhaust hole. DETAILED DESCRIPTION
[0017] This embodiment is a preferred implementation mode of the present invention. Other embodiments whose principles and basic structures are the same or similar to those of this embodiment are within the protection scope of the present invention.
[0018] Please refer to the attached Figure 1 The present invention mainly includes an inner shell 1, an outer shell 2, a battery core 4 and an insulating film 3. The inner shell 1 and the outer shell 2 are both barrel-shaped. In this embodiment, the inner shell 1 and the outer shell 2 are both circular barrel-shaped, that is, their longitudinal sections are "U"-shaped and their cross sections are circular. The outer shell 2 is covered on the outside of the inner shell 1 to form a closed cavity, which is the outer shell body of the present invention. The battery core is arranged inside the inner shell 1. In this embodiment, the battery core adopts a conventional lithium battery cell, and the insulating film 3 is arranged between the inner shell 1 and the outer shell 2.
[0019] In this embodiment, a concave shoulder 5 is provided on the top of the inner shell 1, and a pressing edge 6 is provided on the top of the outer shell 2. The pressing edge 6 is pressed at the position above the insulating film 3, and part of it is buckled inside the insulating film 3 to ensure insulation and sealing between the inner shell 1 and the outer shell 2. A secondary step 7 is provided at the middle and lower position of the inner shell 1. The diameter of the inner shell 1 at the upper position of the secondary step 7 is smaller than the diameter of the inner shell 1 at the lower position of the secondary step 7, thereby forming a secondary step 7. A waist 8 is provided on the outer shell 2 at the position corresponding to the secondary step 7. The waist 8 is concave inward and clamped at the position of the secondary step 7, thereby fixing the inner shell 1 and the outer shell 2. In this embodiment, the depth of the waist 8 is 0.5~1.0mm. In this embodiment, two-level fixation and sealing at the top and middle waist positions can ensure that the battery will not leak. In this embodiment, more than one exhaust hole 9 is opened on the inner shell 1 at the position above the secondary step 7 to release the internal pressure of the battery to ensure that it will not explode. In this embodiment, three exhaust holes are provided, and the three exhaust holes are evenly distributed around the circumference. In the present invention, the specific setting position of the secondary step 7 is relatively flexible, and is generally set at the middle and lower part of the battery body. In this embodiment, the upper height of the secondary step 7 is set to 4.0~4.2mm, and the lower height is set to 0.8~1.0mm.
[0020] In this embodiment, the insulating film 3 is made of PVDF (PVDF polyvinylidene fluoride, which has a translucent or white powder or granule appearance, with close arrangement between molecular chains and strong hydrogen bonds, an oxygen index of 46%, non-flammable, a crystallinity of 65%~78%, a density of 1.77~1.80g / cm3, a melting point of 172°C, a heat deformation temperature of 112~145°C, and a long-term use temperature of -40~150°C. PVDF mainly refers to vinylidene fluoride homopolymer or a copolymer of vinylidene fluoride and other small amounts of fluorine-containing vinyl monomers. It has the characteristics of both fluororesins and general-purpose resins. In addition to having good chemical corrosion resistance, high temperature resistance, oxidation resistance, weather resistance, and radiation resistance, it also has piezoelectricity, The insulating film 3 has special properties such as dielectric properties and thermoelectric properties. In specific implementation, other high-performance modified plastic materials resistant to electrolyte corrosion can also be selected. The thickness of the insulating film 3 is 0.08-0.1 mm. The insulating film 3 is divided into an outer insulating film and an inner insulating film. The outer insulating film is arranged on the outer side of the inner shell 1, and the inner insulating film is arranged on the inner side of the inner shell 1. The outer insulating film and the inner insulating film are arranged in one piece, that is, the outer insulating film extends downward to the bottom of the inner shell 1, turns to the inside of the inner shell 1, and then extends upward to form the inner insulating film. The outer insulating film is arranged at a height substantially the same as that of the inner shell 1, and the inner insulating film is arranged at a height only to meet the insulation between the bottom of the inner shell 1 and the outer shell 2. In this embodiment, the height of the inner insulating film is greater than 0.5 mm.
[0021] In this embodiment, the outer insulating film is arranged all the way to the shoulder 5 on the inner shell 1, that is, an outer insulating film is also arranged between the shoulder 5 and the pressing edge 6, so that the sealing is better and the insulation between the inner shell 1 and the outer shell 2 is ensured.
[0022] When the present invention is in use, once internal expansion occurs, the edge pressing 6 is first detached from the insulating film 3, and the inner shell 1 and the outer shell 2 slide relative to each other. When they slide to a certain position, the edge pressing 6 is engaged with the secondary step 7. At the same time, the inner shell 1 is partially exposed above the secondary step 7, and the internal pressure of the battery is released from the air holes on the inner shell 1, so that the battery will not explode.
[0023] The present invention adopts a segmented step structure and is provided with air holes on the inner shell, so that the pressure inside the battery can be released when expansion occurs, and explosion will not occur. The present invention adopts an insulating film structure to achieve insulation and sealing between the inner shell and the outer shell, and the thickness of the insulating film can be reduced to 0.1mm, so that the total thickness of the inner shell with the insulating film is reduced from the original 1.4mm to 0.35mm, and the inner shell wall thickness space in the conventional battery is converted into an effective battery capacity space, which can increase the capacity of its internal effective space.
Claims
1. A small button-type high-capacity lithium battery with explosion-proof function, characterized by: The lithium battery comprises an inner shell, an outer shell, a battery core and an insulating film. The inner shell and the outer shell are both barrel-shaped. The outer shell cover is mounted on the outer side of the inner shell. The battery core is arranged inside the inner shell. The insulating film is arranged between the inner shell and the outer shell. An inner concave shoulder is arranged on the top of the inner shell. A pressing edge is arranged on the top of the outer shell. The pressing edge is pressed at the position above the insulating film. A secondary step is arranged on the inner shell. The diameter of the inner shell at the upper position of the secondary step is smaller than the diameter of the inner shell at the lower position of the secondary step. A waist is arranged on the outer shell at the position corresponding to the secondary step. The waist is recessed inwardly and is clamped at the position of the secondary step. One or more exhaust holes are opened on the inner shell at the position above the secondary step. The secondary step is arranged at the middle and lower part of the battery body. The insulating film is made of PVDF. The insulating film is divided into an outer insulating film and an inner insulating film. The outer insulating film is arranged on the outer side of the inner shell, and the inner insulating film is arranged on the inner side of the inner shell. The outer insulating film and the inner insulating film are arranged integrally. The thickness of the insulating film is 0.08~0.1mm; The outer insulating film is arranged at the same height as the inner shell, and the inner insulating film has a height greater than 0.5 mm; The inner shell and the outer shell are both in a round barrel shape; The outer insulating film extends downward to the bottom of the inner shell 1, turns to the inside of the inner shell 1, and then extends upward to form an inner insulating film; The inner insulating film is set at a height that satisfies the insulation between the bottom of the inner shell and the outer shell; The outer insulating film is arranged all the way to the shoulder position on the inner shell, and an outer insulating film is also arranged between the shoulder and the pressing edge, wherein: When internal expansion occurs, the pressing edge is detached from the insulating film, the inner shell and the outer shell slide relatively, and the pressing edge is clamped at the secondary step. At the same time, the inner shell above the secondary step is partially exposed.