CN112201839A

CN112201839A - Lithium battery structure

Info

Publication number: CN112201839A
Application number: CN202011065540.XA
Authority: CN
Inventors: 刘礼刚
Original assignee: Guangzhou Kentli Electronics Technology Co ltd
Current assignee: Guangzhou Kentli Electronics Technology Co ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2021-01-08

Abstract

A lithium battery structure, the core is rolled up in the steel casing, the cap assembly seals with peripheral steel casing through the metal ring, there are perforating holes on the cap assembly, vacuumize and inject electrolyte through the perforating hole after sealing with the steel casing periphery through the metal ring, can fully utilize the inner space of the steel casing, improve the capacity of the lithium battery, reduce the battery cost; still install explosion-proof valve in the through-hole, can be fixed in the through-hole steadily under the normal conditions and seal the cavity, and in case when inside takes place unusually, the shell body is inside will be filled a large amount of gas and lead to atmospheric pressure to increase, and explosion-proof valve can open the through-hole again and make the inside and outside intercommunication of box hat, and excessive gas in the shell can be followed the through-hole and discharged in order to carry out the pressure release to make the inside atmospheric pressure of casing decline, and then prevented the lithium cell effectively and exploded.

Description

Lithium battery structure

Technical Field

The present invention relates to a battery structure, and more particularly, to a lithium battery structure.

Background

With the development of modernization and the improvement of living requirements, batteries are required to be used as energy sources for many electric appliances and appliances used by people. Batteries used in daily life mainly comprise dry batteries and lithium batteries. Among them, the dry battery is a voltaic battery, which is easy to manufacture and low in cost, but relatively poor in performance, low in electricity, and a disposable consumable, and has a large environmental pollution. The lithium battery is a battery which uses lithium metal or lithium alloy as a negative electrode material and uses a non-aqueous electrolyte solution, and the widely used battery is a soft package lithium battery, namely a battery which is formed by sleeving a layer of polymer shell on a liquid lithium ion battery, such as a common mobile phone battery. The soft package lithium battery has the advantages of good safety, light weight, large capacity and the like, but the type is less, the limitation of shape design is larger, and the soft package lithium battery cannot be applied to appliances using the traditional cylindrical dry battery.

Dry batteries are generally cylindrical batteries, are widely used in various electric devices, are convenient to purchase, carry and replace, and have poor performance. In order to improve such a situation, a step-down conversion type lithium ion battery has been developed to replace a dry battery, which has excellent performance by using a lithium ion cell while maintaining the external shape structure of a cylindrical battery and providing a cap assembly having a voltage conversion function inside the battery, such as a cylindrical battery in the publication No. 201174405Y and the name "one kind of dual voltage output cylindrical battery". Such a battery structure includes: the lithium ion battery comprises an external steel shell, a soft package lithium ion battery cell sealed by an aluminum plastic film and arranged in the steel shell, and a cap assembly which is arranged at the top of the battery cell and connected with the positive electrode and the negative electrode of the soft package lithium ion battery roll core and is provided with a voltage reduction circuit. The soft package cell sealed by the aluminum-plastic film is arranged in the steel shell, and is influenced by the soft package sealing structure, the soft package of the cell has an edge sealing, and when the cell is arranged in the steel shell, the edge sealing needs to occupy space; and because the material problem, in order to avoid the soft package to break and reveal, the soft package still can not vigorously press, and this all leads to having the clearance between soft-packaged electrical core and the box hat, and its space utilization is limited, produces the influence to battery capacity. In addition, the thickness of the sealed aluminum-plastic film itself occupies a certain space of the inner casing, which further affects the capacity of the battery.

Disclosure of Invention

The invention aims to provide a lithium battery structure which can fully utilize the space of an inner shell so as to further improve the capacity of the lithium battery.

The lithium battery structure comprises a steel shell, a winding core of the lithium battery arranged in the steel shell, and a cap assembly covering the port part of the steel shell; the cover cap assembly comprises a circuit board with a voltage conversion function, a metal ring hermetically connected with the top of the steel shell is arranged at the bottom or the periphery of the circuit board, and a positive electrode assembly fixedly mounted above the circuit board; the positive pole of the winding core is connected with the positive pole lead-in end of the circuit board circuit, and the negative pole of the winding core is electrically connected with the steel shell; the steel shell is in contact with the metal ring to be electrically conducted, the metal ring is communicated with a negative electrode lead-in end of the circuit board, and the positive electrode assembly is communicated with a positive electrode output end of the circuit board; the cap assembly is also provided with a through hole communicated with the inner cavity of the steel shell, an explosion-proof valve is arranged in the through hole, the explosion-proof valve seals the through hole when the pressure in the steel shell is normal, and the through hole is opened when the pressure in the steel shell is high.

According to the lithium battery structure, the winding core of the lithium battery is directly placed in the steel shell, the cap assembly of the battery is sealed with the peripheral steel shell through the metal ring, the through hole is formed in the cap assembly, the lithium battery can be vacuumized and injected with electrolyte through the through hole after the cap assembly of the battery is hermetically connected with the periphery of the steel shell through the metal ring, an aluminum-plastic film soft package is not required to be arranged in the steel shell to seal the winding core and the electrolyte, the internal space of the steel shell can be fully utilized, the capacity of the lithium battery is improved, and meanwhile, the cost of the battery is reduced. Simultaneously, still install explosion-proof valve in the through-hole, under normal use's condition, explosion-proof valve can be fixed in the through-hole steadily and seal the cavity, and in case lithium cell is inside to take place unusually, roll up the core and produce high fever and when causing the electrolyte gasification, the inside of shell body will be filled a large amount of gas and lead to atmospheric pressure to increase, explosion-proof valve can open the through-hole again and make the inside and outside intercommunication of box hat, the excessive gas in the shell can be followed the through-hole and discharged in order to carry out the pressure release, thereby make the inside atmospheric pressure decline of casing, and then prevented effectively that the.

Drawings

Fig. 1 is a schematic view of the internal structure of a lithium battery structure.

Fig. 2 is a schematic structural diagram of the external shape of the lithium battery structure.

Fig. 3 is a partial structural schematic view of a lithium battery structure.

Fig. 4 is a schematic structural view of the cap assembly.

Fig. 5 is a schematic diagram of an exploded structure of the cap assembly.

Fig. 6 is a schematic view of the processing of the circuit board.

Detailed Description

Referring to fig. 1-3, a lithium battery structure comprises a steel shell 1, a winding core 2 of the lithium battery mounted in the steel shell, and a cap assembly 3 covering the top of the steel shell; the cap component comprises a circuit board 31 with a voltage conversion function, a metal ring 32 which is hermetically connected with the top of the steel shell is arranged at the bottom or the periphery of the circuit board, and a positive component 33 which is fixedly arranged above the circuit board; the positive pole of the winding core 2 is connected with the positive pole lead-in end of the circuit board circuit, and the negative pole of the winding core 2 is electrically connected with the steel shell 1; the steel shell 1 is electrically connected with the metal ring 32 in a contact way, the metal ring 32 is communicated with the negative lead-in end of the circuit board 31, and the positive component 33 is communicated with the positive output end of the circuit board; the cap assembly 3 is also provided with a through hole 34 communicated with the inner cavity of the steel shell, an explosion-proof valve 4 is arranged in the through hole 34, the explosion-proof valve 4 seals the through hole 34 when the pressure in the steel shell is normal, and opens the through hole when the pressure in the steel shell is high. This lithium battery structure, roll up in the core directly arranges the box hat in, the block subassembly lid will roll up the core and seal up in the box hat top, through the perforating hole at block subassembly middle part, can carry out the evacuation to sealed box hat inner space to and pour into electrolyte into, form electric core. The battery has no soft package, has no gap between the soft package and the steel shell, and can fully utilize the inner cavity of the steel shell, thereby improving the capacity of the battery. And an explosion-proof valve is also arranged at the through hole of the cap assembly, so that the explosion-proof valve can be discharged when the pressure in the steel shell is too high, and the safety of the battery can be ensured.

In the lithium battery structure, as shown in fig. 2, the steel shell 1 can be cylindrical, and the positive electrode assembly 33 fixedly mounted above the circuit board 31 in the cap assembly 3 can be a cylindrical positive electrode with the same shape as the positive electrode of a dry battery, so that the shape of the whole lithium battery is consistent with that of a conventional cylindrical dry battery. The working voltage platform of the lithium battery core is 3.7V, the circuit board is provided with a voltage reduction circuit, and the high voltage of the lithium battery core is converted into 1.5V through the voltage reduction circuit, so that the lithium battery core adapts to the application occasions of the cylindrical dry battery, and the dry battery is replaced.

The explosion-proof valve 4, as shown in fig. 3 and 4, includes a tubular explosion-proof metal tube 41 embedded in the through hole 34 of the cap assembly, and the outer side of the metal tube is hermetically connected to the through hole, an explosion-proof bead 42 is installed in the tube hole of the explosion-proof metal tube 41, and the explosion-proof bead 42 and the tube hole are in interference fit to seal the tube hole inside and outside. When the abnormal air pressure in the battery is increased to a certain degree, the explosion-proof beads can be sprayed out of the explosion-proof metal tube, so that the interior of the battery is discharged, and the explosion is avoided.

In order to prevent the circuit components on the lower side of the circuit board from contacting the electrolyte, the circuit board 31 of the cap assembly 3 may be filled with plastic between the inner side of the metal ring 32 and the explosion-proof valve 4 to form a plastic block 5 to wrap the circuit components, as shown in fig. 3.

Circuit components may be disposed on both upper and lower sides of the circuit board 31, as shown in fig. 4, and plastic may be filled in the circuit components on both upper and lower sides of the circuit board to form a plastic block for sealing and wrapping, so as to better protect the circuit components. The plastic passing hole 35 can be formed in the circuit board, and when the circuit board is subjected to injection molding, plastic can flow from one side to the other side through the plastic passing hole, so that the upper side and the lower side of the circuit board can be subjected to injection molding encapsulation at one side simultaneously, the process is simplified, the processing cost is reduced, and the production efficiency is improved.

The outer diameter of the metal ring 32 can be slightly smaller than that of the circuit board 31 and is fixed on the lower side of the circuit board through a surface mounting process. According to the structure, when the circuit boards are subjected to synchronous surface mounting processing on the same PCB, after the circuit boards are subjected to injection molding and encapsulation from top to bottom, the circuit boards can be conveniently and directly punched from the upper sides of the PCB, and the processing is more convenient. As shown in fig. 5.

The positive electrode component can be in a cap shape, and the edge of the bottom of the positive electrode component is fixed on the circuit board and connected with the positive electrode output end of the circuit board; the top of the base is opposite to the through hole of the circuit board, and the side wall of the base is provided with a vent hole.

The positive electrode assembly 33, as shown in fig. 3, 4 and 6, may also include a positive electrode cap 331 as the positive electrode of the battery and a light-transmitting cover 332 at the bottom of the positive electrode cap, the light-transmitting cover 332 is in the shape of a circular cap, the bottom edge of the light-transmitting cover is fixed on the circuit board and connected with the positive electrode output end of the circuit board, the middle of the light-transmitting cover is provided with an arched platform 333, and the middle of the platform is provided with a through hole 334 opposite to the through hole 34 of the circuit board; the positive electrode cap 331 is fixed to the platform of the light-transmitting cover 332 to block the through hole, and a vent hole 335 is provided in the side wall thereof. The circuit board may have indicator lights for indicating the operating status of the battery mounted on the portion of the circuit board within the light transmissive cover 332, with a light transmissive window 336 in the raised portion of the connecting platform and bottom edge for transmitting the indicator lights therethrough. Through the structure, the battery can visually indicate the working state of the battery, so that a user can visually know the state of the battery.

Claims

1. A lithium battery structure, includes steel casing (1), its characterized in that: a winding core (2) of the lithium battery arranged in the steel shell, and a cover cap assembly (3) covering the top of the steel shell; the cap assembly comprises a circuit board (31) with a voltage conversion management function, a metal ring (32) which is hermetically connected with the port part of the steel shell is arranged on the bottom surface or the periphery of the circuit board, and a positive electrode assembly (33) fixedly mounted on the top surface of the circuit board; the positive pole of the winding core (2) is connected with the positive pole lead-in end of the circuit board circuit through an explosion-proof metal tube (41), and the negative pole of the winding core (2) is electrically connected with the steel shell (1); the steel shell (1) is in contact with the metal ring (32) to be electrically conducted, the metal ring (32) is communicated with the negative lead-in end of the circuit board (31), and the positive component (33) is communicated with the positive output end of the circuit board; the cap assembly (3) is further provided with a through hole (34) communicated with the inner cavity of the steel shell, an explosion-proof valve (4) is arranged in the through hole (34), the explosion-proof valve (4) seals the through hole (34) when the pressure in the steel shell is normal, and opens the through hole when the pressure in the steel shell is high.

2. The lithium battery structure of claim 1, wherein: the shape of the steel shell (1) can be cylindrical, and the positive electrode component (33) fixedly mounted above the circuit board (31) in the cap component (3) is a cylindrical positive electrode with the same shape as the positive electrode of the dry battery, so that the shape of the whole lithium battery is consistent with that of the conventional cylindrical dry battery.

3. The lithium battery structure of claim 1 or 2, characterized in that: the explosion-proof valve (4) comprises a tubular explosion-proof metal tube (41), wherein the explosion-proof metal tube is embedded into a through hole (34) of the cap assembly, the outer side of the explosion-proof metal tube is hermetically connected with the through hole, an explosion-proof bead (42) is arranged in a tube hole of the explosion-proof metal tube (41), and the explosion-proof bead (42) and the tube hole are in interference fit to seal the inside and the outside of the tube hole.

4. The lithium battery structure of claim 1 or 2, characterized in that: and the circuit board (31) is filled with plastic between the inner side of the metal ring (32) and the explosion-proof valve (4) to form a plastic block (5) to wrap the circuit element, so that an airtight blocking structure is formed.

5. The lithium battery cell structure of claim 4, wherein: the top surface side of the circuit board (31) is also filled with plastic to form a plastic block (5) for sealing and wrapping the circuit element.

6. The lithium battery structure of claim 5, wherein: plastic flow through holes (35) are arranged on the circuit board.

7. The lithium battery structure of claim 1, wherein: the outer diameter of the metal ring (32) is slightly smaller than that of the circuit board (31) and is fixed on the bottom side face of the circuit board through a surface mounting process.

8. The lithium battery structure of claim 1 or 2, characterized in that: the positive electrode component (33) is in a cap shape, and the edge of the bottom of the positive electrode component is fixed on the circuit board and connected with the positive electrode output end of the circuit board; the top of the base is opposite to the through hole of the circuit board, and the side wall of the base is provided with a vent hole.

9. The lithium battery structure of claim 1 or 2, characterized in that: the positive electrode assembly (33) comprises a positive electrode cap (331) serving as a battery positive electrode and a light-transmitting cover (332) at the bottom of the positive electrode cap, the light-transmitting cover (332) is in a circular cap shape, the edge of the bottom of the light-transmitting cover is fixed on the circuit board and connected with the positive electrode output end of the circuit board, an arched platform (333) is arranged in the middle of the light-transmitting cover, and a through hole (334) opposite to the through hole (34) of the circuit board is arranged in the center of the platform; the positive electrode cap (331) is fixedly connected on the platform of the light-transmitting cover (332) to shield the through hole, and a vent hole (335) is arranged on the side wall of the positive electrode cap; the circuit board can be provided with an indicator light for indicating the working state of the battery at the part of the light-transmitting cover (332), and the light-transmitting cover is provided with a light-transmitting window (336) for transmitting the indicator light at the arched part connecting the platform and the bottom edge.