CN201087908Y - Cylindrical lithium battery structure - Google Patents

Abstract

The utility model relates to a cylindricality lithium cell technical field refers in particular to a can effectively ensure the cylindricality lithium cell structure of battery security and stability, and this cylindricality lithium cell includes the jar body, installs in jar internal upper end open-ended protection block and is located jar internal battery core, and wherein the jar body includes: the battery pack comprises a bottomless main body and a base plate welded at a port on the bottom surface of the main body, wherein the base plate is provided with an exhaust hole for exhausting gas generated after battery formation. After the above structure is adopted in the utility model, the lithium cell is in the formation and is handled the back, can come out the internal produced gas outgoing of jar through the exhaust hole, treat after the gas outgoing again through the hole stopper with this exhaust hole shutoff on can. Therefore, the safety and the stability of the battery can be ensured, and the manufacturing method is simple and is convenient for batch production.

Description

Cylindrical lithium battery structure

technical field

The utility model relates to the technical field of cylindrical lithium batteries, in particular to a cylindrical lithium battery structure that can effectively ensure the safety and stability of the battery. The cylindrical lithium battery with this structure can conveniently discharge the battery generated inside the battery after it is formed. gas.

Background technique

With the development of modern society, mobile devices such as camcorders, notebook computers, mobile DVDs and digital cameras have been more and more widely used, thus forming a large demand for high-energy batteries. Cylindrical lithium-ion batteries are due to their high energy density. Has been widely used. Because there are lithium/carbon compounds with high water activity in lithium-ion batteries, they need to be well sealed with the outside world. In order to solve the problem of battery sealing in the industry, the battery sealing ring is generally sealed with glue. However, when the lithium-ion battery is used improperly, gas will be generated due to the decomposition of the electrolyte, which will cause the battery to explode if the internal pressure is too high. Therefore, the lithium-ion battery needs to have power-off protection and protective devices when the internal pressure is too high. The safety protection device commonly used at present is to adopt a kind of protective cap. For example, the applicant applied for a utility model patent for a lithium-ion battery protective cap in 2006 (the patent application number is: 200620001193.3). As shown in FIG. 1 , the utility model includes: an explosion-proof valve 51 , a power failure protection device 52 , a positive temperature coefficient (PTC) ring piece 53 , a top cover 54 and a sealing body 55 . The explosion-proof valve 51 has an annular notch. The top cover 54, the ring piece 53, the explosion-proof valve 51 and the power-off protection device 52 are installed in the sealing body 55 to obtain the combined protective cap 5. The electric protection device 52 is welded together by laser, and the electric core 56 of the welded cap 5 is mechanically riveted and sealed to form an assembled battery. During use, if the external short circuit of the cell 56 or the charging and discharging current exceeds the operating current of the positive temperature coefficient ring sheet 53, the positive temperature coefficient ring sheet 53 reduces the current by increasing the temperature and increasing the resistance to protect the cell; When the internal gas pressure of the battery cell 56 increases to the set protection pressure due to failure, the explosion-proof valve 51 will turn upward from the notch, that is, the entire raised part will turn upward, and the power-off protection device 52 and the welding part will fall off. , resulting in an open circuit between the tab and the explosion-proof valve 51, so that the battery cell 56 cannot be charged and discharged in the open circuit failure state, thereby preventing the battery cell 56 from continuing to be used when it fails. If the internal air pressure of the battery cell continues to rise after the circuit break, when the set value is reached, the explosion-proof valve 51 bursts open to release the pressure, so as to avoid explosion accidents in the battery.

Although the safety of the cylindrical lithium battery adopting the above technical solution has been greatly improved, there are still some problems to be improved. When making such a cylindrical lithium-ion battery, firstly, the battery core is wound and put into a shell with one end open, and then the tabs drawn from the bottom end of the battery core are welded to the bottom of the battery shell, and then The electrolyte is injected into the battery casing, and then the battery tabs are welded to the protective cap, and then the battery cell with the protective cap welded is put into a casing with one end open, and then the protective cap is fixed on the upper opening of the casing. Then the packaged battery is formed. During the chemical conversion process, the battery cell will generate a certain amount of gas, which will affect the safety and stability of the battery if it cannot be discharged from the casing. But it is very difficult to discharge the gas in the shell, because the shell is sealed at this time, unless the shell is destroyed or the internal pressure of the cell reaches the set value, the explosion-proof valve is broken through to release the pressure, otherwise the gas is difficult to discharge.

Utility model content

The technical problem to be solved by the utility model is to provide a cylindrical lithium battery structure with high safety and stability for the shortcomings of current products. The cylindrical lithium battery with this structure can conveniently discharge the gas generated inside the battery after formation, effectively ensuring the safety and stability of the battery.

In order to solve the above technical problems, the utility model adopts the following technical scheme: the cylindrical lithium battery includes a tank body, a protective cap installed on the upper opening of the tank body, and a battery core located in the tank body, wherein the tank body includes: a bottomless main body And the chassis welded on the bottom surface of the main body, the chassis is made of stainless steel, and it is slightly thicker than the bottomless main body, and the chassis and the bottomless main body can be fixed by laser welding during assembly. The chassis is provided with a vent hole for exhausting the gas generated after the battery is formed. Before the vent hole is used to discharge the gas generated by the battery formation, a plastic film is pasted on the inside of the vent hole for sealing.

In addition, the tank body is also provided with a hole plug used in conjunction with the above-mentioned vent hole, and the hole plug can use a steel ball.

After the utility model adopts the above-mentioned structure, the lithium battery can pierce the plastic film attached to the inside of the vent hole after the chemical conversion treatment, and the gas in the battery can be extracted through the above-mentioned vent hole, and then the steel ball used as the hole plug can be pressed into the exhaust port. In the air hole to seal the battery. In this way, the safety and stability of the battery can be ensured. The manufacturing method is simple and convenient for mass production. In addition, the tank body of the utility model is formed by welding the bottomless main body and the chassis, and the stainless steel material is used to facilitate the opening of vent holes. At the same time, the stainless steel material does not need to be electroplated and can be directly welded. Likewise, the utility model retains the design of the protective cap in the original product to effectively avoid the potential safety hazard caused by excessive internal pressure of the battery, and can discharge the gas in time.

Description of drawings:

Figure 1 is a structural schematic diagram of an existing cylindrical lithium-ion battery product;

Fig. 2 is a structural representation of the utility model;

FIG. 3 is a partially enlarged view of FIG. 2 .

Specific examples:

2 and 3, the utility model includes: a tank body 1, a protective cap 2 installed on the upper opening of the tank body 1, and a battery core 3 located in the tank body 1.

The tank body 1 includes: a cylindrical bottomless main body 11 and a bottom plate 12 welded to the port on the bottom surface of the main body 11 . The chassis 12 is made of stainless steel, and it is slightly thicker than the bottomless main body 11. The chassis 12 and the main body 11 are fixed together by laser welding. The chassis 12 is provided with an exhaust hole 4 . The vent hole 4 is a non-through hole opened on the chassis 12 during manufacture, that is, the vent hole 4 needs to be pierced by foreign objects to form a through hole. Usually, the vent hole is sealed with a plastic film attached to the inside of the vent hole before it is used to discharge the gas generated by the formation of the battery. The main body 11 and the chassis 12 are made of stainless steel, which is convenient for processing the vent hole 4 and installing the hole plug 41 in the vent hole 4 . In addition, the use of stainless steel does not require electroplating.

The protective cap 2 adopted by the utility model is the same as the conventional battery cap at present, and it retains the internal power-off protection device. In this way, the utility model retains the safety protection function of the original battery, and further increases the stability and safety of the battery through the newly added improvement.

During installation, firstly, weld the negative electrode lug of the cell 3 to the chassis 12, then put the cell into the tank body 1, install the chassis 12 on the bottom port of the main body 11, and weld the two together. Next, roll groove the tank body 1, weld the positive pole lug of the battery cell 3 and the power-off protection device in the protective cap 2 together, and install the cap 2 welded with the battery cell 3 on the upper port of the tank body 1, and mechanically After riveting and sealing, the protective cap 2 is combined with the main body 11 of the tank body 1 . Finally inject the electrolyte. After the electrolyte is injected, the entire battery is packaged with a plastic film, and then the battery is sequentially chemically treated. At this moment, since the exhaust hole 4 is not penetrated, the tank body 1 is in a sealed state. After the formation process, the gas in the battery needs to be discharged. At this time, a foreign object is used to pierce the vent hole 4 to allow the internal space of the tank body 1 to communicate with the outside, to discharge the gas in the battery during the formation process, and then press a hole plug 41 into the The vent hole 4 is removed and welded at the vent hole 4, at which point an assembled battery is formed.

A steel ball can be selected for the hole plug 41, and the steel ball is firmly pressed into the vent hole 4, and then the steel ball is fixed in the vent hole 4 by welding to block the vent hole 4. In this way, the air vent 4 will not adversely affect the subsequent use of the battery.

During use, if the internal gas pressure of the battery cell 3 increases to the set protection pressure due to failure, for example, the air pressure inside the battery cell rises rapidly. The utility model can guarantee the safety of the battery through the protective cap 2, that is, when the air pressure reaches the set value, the explosion-proof valve in the protective cap 2 explodes to release the pressure, so as to avoid explosion accidents of the battery.

Of course, the above descriptions are only examples of the utility model, and are not intended to limit the implementation scope of the utility model. All equivalent changes or modifications made according to the structure, features and principles described in the patent scope of the utility model shall Should be included in the scope of the patent application.

Claims (4)

1. cylindricality lithium battery structure, comprise: tank body (1), the protection block (2) that is installed on tank body (1) upper end open and the battery (3) that is positioned at tank body (1), it is characterized in that: described tank body (1) comprising: main body of the no end (11) and the chassis (12) that is welded on main body (11) bottom surface port, and chassis (12) are provided with and are used to discharge the steam vent (4) that battery changes into the back gas that produces.

2. cylindricality lithium battery structure according to claim 1 is characterized in that: locate to be provided with a stopple with its shutoff (41) in described steam vent (4).

3. cylindricality lithium battery structure according to claim 2 is characterized in that: described stopple (41) is a steel ball, and this steel ball is welded in the steam vent (4).

4. according to any described cylindricality lithium battery structure in the claim 1～3, it is characterized in that: adopt the laser welding mode to fix between the chassis (12) that the employing stainless steel material is made and the main body (11) of tank body (1).

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