Secondary battery

Abstract

In order to solve the problems that when a battery is overcharged in the prior art, the internal pressure of the battery is too large, short circuit occurs, explosion or fire is caused, and a battery overcharge test cannot be passed, the utility model provides a secondary battery which comprises a battery cell, a first tab and an anti-explosion valve packaging piece, the battery cell is positioned in the packaging piece, and an anti-explosion valve is arranged on the packaging piece; the first tab is respectively connected with the battery cell and the anti-explosion valve, and the first tab is electrically connected with the packaging piece through the anti-explosion valve. According to the secondary battery provided by the utility model, when the internal air pressure reaches a certain threshold value, the anti-explosion valve is opened to release pressure so as to prevent explosion caused by overlarge internal air pressure, and meanwhile, when the anti-explosion valve is opened, the anti-explosion valve stretches the first tab and enables the first tab to be broken so as to cut off the electric connection between the first tab and the packaging piece; battery fire failure caused by continuous heat production due to continuous charging of an external circuit is avoided, and the capacity of the battery passing through an overcharge test is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel shell button batteries, and in particular relates to a secondary battery. Background Art

[0002] Steel case button batteries are a common small portable power source widely used in various electronic devices, such as calculators, watches, remote controls and various electronic instruments. They are usually composed of a stainless steel casing, a positive electrode cover, a negative electrode, as well as electrolytes and active materials. During the design and manufacturing process, it is crucial to ensure the safety of the battery, including the ability to prevent short circuits and overcharge.

[0003] The outer shell of the steel shell button battery is also part of the conductivity. If the insulating layer on the outside of the battery is damaged, or the internal structure is deformed due to mechanical pressure during the assembly process, it may cause direct contact between the positive and negative electrodes, causing a short circuit. The short circuit will cause the internal temperature of the battery to rise rapidly, and may even cause thermal runaway, causing the internal temperature of the battery to rise and produce a large amount of gas. If the gas is not extracted or discharged in time, the increase in internal pressure of the battery may cause battery explosion and other problems. In addition, the battery cannot pass the overcharge test if there are defects or short circuits. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a secondary battery for the problem that when the battery is overcharged in the prior art, the internal pressure of the battery is too large to cause a short circuit, causing explosion or fire, and the battery overcharge test cannot be passed.

[0005] The technical solution adopted by the utility model to solve the above technical problems is as follows:

[0006] A secondary battery is provided, comprising a battery cell, a first pole ear and a package, wherein the battery cell is located in the package, an explosion-proof valve is provided on the package, the first pole ear is respectively connected to the battery cell and the explosion-proof valve, and the first pole ear is electrically connected to the package through the explosion-proof valve, and when the explosion-proof valve is opened, the explosion-proof valve stretches the first pole ear and breaks the pole ear to disconnect the electrical connection between the first pole ear and the package.

[0007] Optionally, the packaging component includes a cover plate and a battery housing, and the battery housing is a semi-enclosed structure with an opening on one side, and the battery housing is enclosed by the cover plate.

[0008] Optionally, the explosion-proof valve is placed on the cover plate, and one end of the first pole ear is led out from a side of the battery cell facing the cover plate and connected to the explosion-proof valve.

[0009] Optionally, the explosion-proof valve is placed on the battery housing, and one end of the first pole ear is led out from a side of the battery cell facing away from the cover plate and connected to the explosion-proof valve on the battery housing.

[0010] Optionally, a second pole lug is further included, and the first pole lug and the second pole lug are respectively led out from the end surface of the battery cell and extend to a position away from the end surface of the battery cell.

[0011] Optionally, a pole is provided on the cover plate, an insulating layer is provided between the pole and the cover plate, and the second pole tab is electrically connected to the pole.

[0012] Optionally, the cover plate is made of aluminum and its alloys, magnesium and its alloys, iron and its alloys, nickel and its alloys, or copper and its alloys.

[0013] Optionally, the battery cell is a wound battery cell or a laminated battery cell.

[0014] Optionally, the first electrode tab and the explosion-proof valve are connected by welding.

[0015] The secondary battery provided by the utility model comprises a battery cell, a first pole ear and a package, wherein the battery cell is located in the package, an explosion-proof valve is arranged on the package, the first pole ear is respectively connected to the battery cell and the explosion-proof valve, and the first pole ear is electrically connected to the package through the explosion-proof valve. By utilizing the setting of the first pole ear being connected to the explosion-proof valve, when a large amount of accumulated gas is generated inside the battery, the explosion-proof valve is opened to exhaust and release pressure. Since the first pole ear is connected to the explosion-proof valve, after the explosion-proof valve is opened, the electrical connection path between the first pole ear and the battery cell is disconnected, thereby blocking the continued heat generation inside the battery, reducing the internal temperature of the battery, improving or avoiding the fire problem caused by the excessively high internal temperature of the battery, and thereby improving or enhancing the ability of the battery to pass the overcharge test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a secondary battery provided by an embodiment of the utility model.

[0017] The reference numerals in the drawings of the specification are as follows:

[0018] 1. Battery cell; 2. Explosion-proof valve; 3. Second pole ear; 4. First pole ear; 5. Cover plate; 6. Pole; 7. Insulation layer; 8. Battery case. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0020] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] An embodiment of the utility model provides a secondary battery, comprising a battery cell 1, a first pole ear 4 and a package, wherein the battery cell 1 is located in the package, an explosion-proof valve 2 is provided on the package, the first pole ear 4 is respectively connected to the battery cell 1 and the explosion-proof valve 2, and the first pole ear 4 is electrically connected to the package through the explosion-proof valve 2, and when the explosion-proof valve 2 is opened, the explosion-proof valve 2 stretches the first pole ear 4 and breaks the pole ear to disconnect the electrical connection between the first pole ear 4 and the package.

[0023] It should be noted that due to the small size and high sealing of steel shell button batteries, there are still challenges in overcharge testing. In addition to the need to accurately control the current and voltage during the test, it is also necessary to monitor the temperature and pressure changes of the battery. During the charging process, the chemical reaction inside the battery causes excessive gas to be produced, increasing the internal pressure. Excessive internal gas pressure in the battery may cause a short circuit, making it impossible to pass the overcharge test.

[0024] The secondary battery provided by the utility model comprises a battery cell 1, a first pole ear 4 and a package, wherein the battery cell 1 is located in the package, an explosion-proof valve 2 is arranged on the package, the first pole ear 4 is respectively connected to the battery cell 1 and the explosion-proof valve 2, and the first pole ear 4 is electrically connected to the package through the explosion-proof valve 2. By utilizing the setting of the first pole ear 4 being connected to the explosion-proof valve 2, when a large amount of accumulated gas is generated inside the battery, the explosion-proof valve 2 is opened to exhaust and release pressure. Since the first pole ear 4 is connected to the explosion-proof valve 2, after the explosion-proof valve 2 is opened, the electrical connection path between the first pole ear 4 and the battery cell 1 is disconnected, thereby blocking the continued heat generation inside the battery, reducing the internal temperature of the battery, improving or avoiding the problems of battery short circuit and fire and explosion caused by excessively high internal temperature of the battery, and thereby improving or enhancing the ability of the battery to pass the overcharge test.

[0025] The connection position between the first pole tab 4 and the battery cell 1 is coated with insulating glue, which is beneficial to further prevent the edge of the first pole tab 4 from contacting other structural parts and causing a short circuit.

[0026] In one embodiment, the packaging component includes a cover plate 5 and a battery housing 8 . The battery housing 8 is a semi-enclosed structure with a single-side opening, and the battery housing 8 is enclosed by the cover plate 5 .

[0027] Specifically, the battery cell 1 is loaded into the battery housing 8, and electrolyte is injected into the inner cavity of the battery housing 8 through the injection hole. After the injection or formation is completed, the injection port is sealed, and finally the cover plate 5 is used for packaging to obtain an internally closed and fully assembled secondary battery.

[0028] Specifically, the battery housing 8 may be a square housing, a cylindrical housing, a prismatic housing, or a housing in other shapes.

[0029] In one embodiment, the explosion-proof valve 2 is placed on the cover plate 5 , and one end of the first pole tab 4 is led out from a side of the battery cell 1 facing the cover plate 5 and connected to the explosion-proof valve 2 .

[0030] When a large amount of accumulated gas is generated inside the battery and the internal pressure of the battery exceeds the threshold of the explosion-proof valve 2, the explosion-proof valve 2 will open and the gas will be quickly discharged through the explosion-proof valve 2 at the moment of opening. The present application sets the explosion-proof valve 2 on the cover plate 5, and uses the moment when the explosion-proof valve 2 is opened to break the connection with the first pole ear 4, thereby cutting off the electrical connection between the battery cell 1 and the cover plate 5, terminating the chemical reaction of the battery cell 1, avoiding or improving battery short circuit to achieve safety, and thereby improving or enhancing the battery's ability to pass the overcharge test.

[0031] Reference Figure 1In one embodiment, the explosion-proof valve 2 is placed on the battery housing 8 , and one end of the first pole ear 4 is led out from a side of the battery cell 1 away from the cover plate 5 and connected to the explosion-proof valve 2 on the battery housing 8 .

[0032] Specifically, the explosion-proof valve 2 can also be arranged on the battery housing 8, and one end of the first pole ear 4 is connected to the explosion-proof valve 2. The working principle and effect of this setting are the same as those of the explosion-proof valve 2 being arranged on the cover plate 5. The explosion-proof valve 2 can be opened to break the connection with the first pole ear 4, cut off the electrical connection between the first pole ear 4 and the cover plate 5 or the first pole ear 4 and the battery housing 8, terminate the chemical reaction of the secondary battery, avoid battery short circuit, and promote the battery to pass the overcharge detection; collectively, the setting position of the explosion-proof valve 2 on the battery housing 8 can be the bottom of the battery housing 8. In specific operation, the explosion-proof valve 2 is set at the bottom of the battery housing 8 away from the cover plate 5, and the first pole ear 4 is led out from the end of the battery cell 1 away from the cover surface and connected to the explosion-proof valve 2; specifically, the secondary battery provided in the present application does not limit the specific setting position of the explosion-proof valve 2.

[0033] In one embodiment, a second pole lug 3 is further included, and the first pole lug 4 and the second pole lug 3 are respectively led out from the end surface of the battery cell 1 and extend to a position away from the end surface of the battery cell 1 .

[0034] It should be noted that the tabs are drawn out from the positive and negative current collectors of the battery as conductors and connected to the battery housing 8 or to external module structures, that is, the current must flow through the tabs to be connected to the outside of the battery.

[0035] Specifically, in the present application, the first pole tab 4 and the second pole tab 3 are respectively led out from the end face of the battery cell 1 for the purpose of leading out current. In addition, after being led out from the end face of the battery cell 1, the first pole tab 4 and the second pole tab 3 continue to extend to a position away from the end face of the battery cell 1 so as to contact with other components inside the secondary battery to conduct current and form a stable electrical connection.

[0036] In one embodiment, a pole 6 is disposed on the cover plate 5 , an insulating layer 7 is disposed between the pole 6 and the cover plate 5 , and the second pole tab 3 is electrically connected to the pole 6 .

[0037] Specifically, the pole 6 mainly conducts current, and connects the pole 6 with the positive electrode ear to ensure the function of conducting the charging and discharging current of the packaged secondary battery cell 1. The insulating layer 7 provided between the pole 6 and the cover plate 5 can well separate the pole 6 and the cover plate 5, avoiding the short circuit problem caused by direct contact between the two.

[0038] The insulating layer 7 may be made of polyethylene, polypropylene, EPDM rubber, polyimide or other materials that have good insulating effects.

[0039] In one embodiment, the secondary battery further includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet is connected to the first electrode tab 4 or the second electrode tab 3 , and the negative electrode sheet is connected to the first electrode tab 4 or the second electrode tab 3 .

[0040] Specifically, the positive electrode sheet is connected to the first electrode tab 4 or the second electrode tab 3, and the negative electrode sheet is connected to the first electrode tab 4 or the second electrode tab 3, so that the first electrode tab 4 and the second electrode tab 3 can conduct current from the positive electrode sheet or the negative electrode sheet to other electronic components of the battery, thereby reducing the connection impedance without reducing the energy density of the battery.

[0041] In one embodiment, the cover plate 5 is made of aluminum and its alloys, magnesium and its alloys, iron and its alloys, nickel and its alloys, or copper and its alloys.

[0042] In one embodiment, the battery cell 1 is a wound battery cell 1 or a laminated battery cell 1 .

[0043] In one embodiment, the first electrode tab is connected to the explosion-proof valve 2 by welding.

[0044] Specifically, the welding includes ultrasonic welding or laser welding.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A secondary battery, characterized in that: It includes a battery cell, a first pole ear and a package, the battery cell is located in the package, an explosion-proof valve is provided on the package, the first pole ear is respectively connected to the battery cell and the explosion-proof valve, and the first pole ear is electrically connected to the package through the explosion-proof valve. When the explosion-proof valve is opened, the explosion-proof valve stretches the first pole ear and breaks the pole ear to disconnect the electrical connection between the first pole ear and the package.

2. A secondary battery according to claim 1, characterized in that: The packaging component includes a cover plate and a battery housing. The battery housing is a semi-enclosed structure with a single-side opening, and the battery housing is enclosed by the cover plate.

3. A secondary battery according to claim 2, characterized in that: The explosion-proof valve is placed on the cover plate, and one end of the first pole ear is led out from a side of the battery cell facing the cover plate and connected to the explosion-proof valve.

4. A secondary battery according to claim 2, characterized in that: The explosion-proof valve is placed on the battery housing, and one end of the first pole ear is led out from a side of the battery core away from the cover plate and connected to the explosion-proof valve on the battery housing.

5. A secondary battery according to claim 2, characterized in that: It also includes a second pole lug, wherein the first pole lug and the second pole lug are respectively led out from the end surface of the battery cell and extend to a position away from the end surface of the battery cell.

6. A secondary battery according to claim 5, characterized in that: The cover plate is provided with a pole, an insulating layer is provided between the pole and the cover plate, and the second pole tab is electrically connected to the pole.

7. A secondary battery according to claim 3, characterized in that: The cover plate is made of aluminum and its alloys, magnesium and its alloys, iron and its alloys, nickel and its alloys, or copper and its alloys.

8. A secondary battery according to claim 1, characterized in that: The first pole lug is an L-shaped pole lug, one end of the L-shaped pole lug is connected to the explosion-proof valve, and the other end of the L-shaped pole lug is connected to the battery core, and the connection position is coated with insulating glue.

9. A secondary battery according to claim 1, characterized in that: The battery core is a wound battery core or a laminated battery core.

10. The secondary battery according to claim 1, characterized in that: The first electrode tab is connected to the explosion-proof valve by welding.

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