Battery cell structure and lithium battery

Abstract

The utility model provides a battery cell structure which comprises a roll core, a packaging shell and a tab assembly, the packaging shell is provided with a containing cavity, the roll core is fixedly installed in the containing cavity, the tab assembly comprises a connecting tab and a fusing tab, the packaging shell is further provided with a fixing part, the fixing part is provided with an installation channel, one end of the connecting tab is located outside the packaging shell, and the other end of the connecting tab is located outside the fusing tab. The other end of the connecting tab penetrates through the mounting channel, the connecting tab is welded to the fixing part, the fusing tab is arranged in the containing cavity, the two ends of the fusing tab are connected with the electrode diaphragm of the roll core and the connecting tab respectively, and the fusing tab is used for fusing at high temperature. When a short circuit occurs, the temperature of the fusing tab rises to generate fusing to form an open circuit, so that the cell structure is prevented from being overheated; the fusing tab is arranged in the accommodating cavity, and the two ends of the fusing tab are fixedly connected to the connecting tab and the roll core respectively, so that the connection part of the fusing tab and the connecting tab is prevented from shaking, the connection part of the fusing tab and the connecting tab is prevented from being broken, and the durability of the battery cell structure is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of batteries, and particularly to a core structure and a lithium battery. Background Art

[0002] The positive electrode of a lithium battery mainly uses aluminum tabs, and the negative electrode uses copper-nickel plated or nickel tabs. To prevent safety risks caused by battery short circuits, lithium batteries are often used in combination with thermistors. When the internal temperature rises, the resistance value of the thermistor becomes larger, and the core is equivalent to an open circuit and has no output to the outside; when the temperature drops, the resistance value recovers and the core resumes normal output. However, the thermistor will increase the internal resistance of the battery, affecting the battery performance, and the cost of the thermistor is relatively high. Alternatively, a lithium battery can also be provided with a fusing portion on the tab. When the battery is short-circuited, the temperature rises, causing the fusing portion to heat up and fuse, thereby avoiding the safety hazard caused by overheating of the battery short circuit.

[0003] However, the fusing portion of the existing tab is provided outside the battery, and the tab and the fusing portion are prone to shaking under external forces. Since the connection strength between the fusing portion and the metal strip of the tab is not high, when the tab outside the battery shakes, the connection between the tab and the fusing portion is prone to breakage.

[0004] For example, the comparative document CN202320037962.9 discloses a lithium-ion battery with internal fusing and explosion prevention, including a conductive tab and a core. The conductive tab is provided on the core, and the conductive tab includes a metal strip and a hot-melt alloy material sheet, and the hot-melt alloy material sheet is provided between the metal strips; when under high temperature, the connection part between the hot-melt alloy material sheet and the metal strip separates to achieve disconnection between the conductive tab and the core. This solution ensures the safety performance of the lithium-ion battery by the disconnection of the hot-melt alloy material sheet between the metal strips at high temperature. However, the hot-melt alloy material sheet of this solution is outside the lithium-ion battery, and when the connection between the hot-melt alloy material sheet and the metal strip shakes, it is prone to breakage. Summary of the Utility Model

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a core structure and a lithium battery that can be short-circuited and fused and whose tab connections are not easily broken.

[0006] The purpose of the present disclosure is achieved by the following technical solutions:

[0007] A core structure includes a wound core, a packaging shell, and a tab assembly. The packaging shell is provided with a receiving cavity, and the wound core is fixedly installed in the receiving cavity.

[0008] The tab assembly includes a connecting tab and a fusing tab. The encapsulation shell is further provided with a fixing portion which is provided with an installation channel. One end of the connecting tab is located outside the encapsulation shell, and the other end of the connecting tab passes through the installation channel. The connecting tab is welded to the fixing portion. The fusing tab is arranged in the accommodation cavity, and two ends of the fusing tab are respectively connected to the electrode film of the winding core and the connecting tab. The fusing tab is used for being thermally fused when the positive and negative electrodes of the winding core are short-circuited.

[0009] In one embodiment, one end of the connecting tab is welded to the fusing tab, and a welding portion is formed at the overlapping position of the connecting tab and the fusing tab. A connecting solder joint is formed at the welding portion.

[0010] In one embodiment, the number of the connecting solder joints is multiple, and every two connecting solder joints are arranged at intervals on the welding portion.

[0011] In one embodiment, a limiting through groove is formed between the fixing portion and the winding core, and the welding portion is located in the limiting through groove.

[0012] In one embodiment, the number of the fusing tabs, the connecting tabs and the installation channels is two. Each connecting tab passes through the corresponding installation channel, each connecting tab is connected to the corresponding fixing portion, and two ends of each fusing tab are respectively connected to the corresponding connecting tab and the winding core.

[0013] In one embodiment, the two fusing tabs and the two connecting tabs are arranged in parallel.

[0014] In one embodiment, the tab assembly is further provided with tab glue. The tab glue is wound around the connecting tab. One end of the tab glue is arranged in the installation channel, and the other end of the tab glue is arranged outside the encapsulation shell.

[0015] In one embodiment, the winding core includes an electrode film for winding. The electrode film of the winding core includes an electrode conductive portion and a coating portion which are connected in sequence. The fusing tab is connected to the electrode conductive portion.

[0016] In one embodiment, both the fusing tab and the connecting tab are in a sheet structure.

[0017] A lithium battery includes the battery cell structure in any one of the above embodiments.

[0018] Compared with the prior art, the present disclosure has at least the following advantages:

[0019] In the above-described battery cell structure and lithium battery, when a short circuit occurs, the temperature of the fuse tab rises and fuses, thereby causing an open circuit to form between the connecting tab and the wound core, preventing overheating inside the battery cell structure and posing a safety hazard; the connecting tab is welded to the fixing portion, and the wound core is installed and fixed in the encapsulation case. By arranging the fuse tab in the receiving cavity, both ends of the fuse tab are respectively connected to the connecting tab and the wound core, so that the fuse tab is fixed, preventing the connection between the fuse tab and the connecting tab from shaking, thereby avoiding breakage at the connection between the fuse tab and the connecting tab, and improving the durability of the battery cell structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of a battery cell structure according to an embodiment;

[0022] Figure 2 It is Figure 1 A schematic structural diagram of the electrode film of the wound core before winding as shown;

[0023] Figure 3 It is a schematic structural diagram of the tab assembly. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant accompanying drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiment.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. The terms used in the description of the present disclosure herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0027] To better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure will be further described in detail below with reference to specific embodiments:

[0028] As Figures 1 to 3 shown, the core structure 10 of an embodiment of the present disclosure includes a wound core 100, a packaging shell 200, and an ear assembly 300. The packaging shell 200 is provided with a receiving cavity 201, and the wound core 100 is fixedly installed in the receiving cavity 201.

[0029] Further, the ear assembly 300 includes a connecting ear 310 and a fusing ear 320. The packaging shell 200 is further provided with a fixing portion 210. The fixing portion 210 is provided with an installation channel 2101. One end of the connecting ear 310 is located outside the packaging shell 200, and the other end of the connecting ear 310 passes through the installation channel 2101. The connecting ear 310 is welded to the fixing portion 210. The fusing ear 320 is disposed in the receiving cavity 201. Both ends of the fusing ear 320 are respectively connected to the electrode film 110 of the wound core 100 and the connecting ear 310. The electrode film 110 can be a positive electrode film or a negative electrode film. The fusing ear 320 is used to be thermally melted when the positive and negative poles of the wound core are short-circuited. The connecting ear 310 can be made of metals such as aluminum, copper, or nickel. The fusing ear 320 can be made of low-melting-point alloys such as aluminum-antimony, lead-antimony, or copper-tin. The melting point of the fusing ear 320 is 150°C - 300°C.

[0030] In this embodiment, the wound core 100 and the fusing ear 320 are encapsulated in the receiving cavity 201. One end of the connecting ear 310 is connected to the fusing ear 320, and the connecting ear 310 is also welded to the fixing portion 210, so that the connecting ear 310 is fixed on the fixing portion 210 and the connecting ear 310 does not shake. The fusing ear 320 is disposed in the receiving cavity 201, so that the fusing ear 320 does not shake frequently. When a short circuit occurs in the core structure 10, the temperature of the fusing ear 320 rises, and the low-melting-point alloy of the fusing ear 320 melts, causing the connection between the fusing ear 320 and the connecting ear 310 to be disconnected, thereby achieving the effect of breaking the circuit.

[0031] The above-mentioned battery cell structure, the above-mentioned battery cell structure 10 and the lithium battery, when a short circuit occurs, the temperature of the fuse tab 320 rises and fuses, so that an open circuit is formed between the connection tab 310 and the wound core 100, preventing overheating inside the battery cell structure and posing a safety hazard; the connection tab 310 is welded to the fixing part 210, and the wound core 100 is installed and fixed in the encapsulation shell 200, making the connection between the connection tab 310 and the fuse tab 320 more stable. By arranging the fuse tab 320 in the receiving cavity 201, the shaking at the connection between the fuse tab 320 and the connection tab 310 is prevented, thereby avoiding the breakage at the connection between the fuse tab 320 and the connection tab 310.

[0032] As Figure 3 shown, in one embodiment, one end of the connection tab 310 is welded to the fuse tab 320, and a welding part 321 is formed at the overlapping position of the connection tab 310 and the fuse tab 320, and connection solder joints 3211 are formed on the welding part 321. In this embodiment, the connection tab 310 and the fuse tab 320 are connected by row welding to form the connection solder joints 3211, and the connection area between the connection tab 310 and the fuse tab 320 is small. When a short circuit occurs in the battery cell structure 10, the fuse tab 320 fuses at the welding part 321.

[0033] As Figure 3 shown, in one embodiment, the number of the connection solder joints 3211 is multiple, and every two connection solder joints 3211 are arranged at intervals on the welding part 321. In this embodiment, the connection tab 310 and the fuse tab 320 are welded by multiple connection solder joints 3211, so that the connection strength between the connection tab 310 and the fuse tab 320 is strong, preventing the problem of breakage between the connection tab 310 and the fuse tab 320 during normal operation.

[0034] As Figure 1 shown, in one embodiment, a limiting through groove 2102 is formed between the fixing part 210 and the wound core 100, and the welding part 321 is located in the limiting through groove 2102. In this embodiment, the limiting through groove 2102 limits the movement of the welding part 321, reduces the shaking of the welding part 321, and thereby prevents the breakage between the connection tab 310 and the fuse tab 320.

[0035] As Figure 1As shown, in one embodiment, the number of fusing tabs 320, connecting tabs 310, and mounting channels 2101 is two. Each connecting tab 310 passes through a corresponding mounting channel 2101, and each connecting tab 310 is connected to a corresponding fixing portion 210. Both ends of each fusing tab 320 are respectively connected to a corresponding connecting tab 310 and the core 100. In this embodiment, the two fusing tabs 320 are respectively connected to the positive and negative connection points of the core 100. When a short circuit occurs in the cell structure, both fusing tabs 320 can be timely fused to generate a short circuit, thereby preventing the battery from short-circuiting and overheating to cause safety problems.

[0036] As Figure 1 shown, in one embodiment, the two fusing tabs 320 and the two connecting tabs 310 are arranged in parallel. In this embodiment, the two fusing tabs 320 are arranged in parallel, and the fixing portion 210 is provided with two parallel mounting channels 2101, so that the two fusing tabs 320 can be simultaneously led out from the middle of the core 100, and the distance from the connecting tab 310 connected to the fusing tab 320 to the outside is the shortest, thereby making the production of the cell structure 10 simpler and with lower cost.

[0037] As Figure 1 shown, in one embodiment, the tab assembly 300 is further provided with a tab glue 330. The tab glue 330 is wound around the connecting tab 310, the tab glue 330 is arranged in the mounting channel 2101, and the other end of the tab glue 330 is arranged outside the encapsulation shell 200. In this embodiment, one end of the tab glue 330 is arranged on the mounting channel 2101, so that the tab glue 330 seals the mounting channel 2101 to prevent the electrolyte from leaking out. The encapsulation shell 200 is made of a metal material, and the tab glue 330 is wound around the connecting tab 310 to avoid the direct contact between the connecting tab 310 and the encapsulation shell 200, thereby preventing a short circuit between the connecting tab 310 and the encapsulation shell 200.

[0038] As Figure 1 and Figure 3 shown, in one embodiment, the core 100 includes an electrode film 110 for winding. The electrode film 110 includes an electrode conductive portion 111 and a coating portion 112 connected in sequence, and the fusing tab 320 is connected to the electrode conductive portion 111. In this embodiment, the electrode film 110 forms the coating portion 112 by coating an active material, and the area of the electrode film 11 that is not coated with the active material forms the electrode conductive portion 111. The welding effect between the electrode conductive portion 111 and the fusing tab 320 is better. When the electrode film 110 is wound, the electrode conductive portion 111 and the fusing tab 320 are located in the middle of the core 100, so that the connection strength between the fusing tab 320 and the core 100 is improved.

[0039] As Figure 1As shown, in one of the embodiments, both the fuse tab 320 and the connection tab 310 are sheet-like structures. In this embodiment, the sheet-like fuse tab 320 and connection tab 310 are easy to process and form, and the contact surfaces of the two ends of the sheet-like fuse tab 320 with the core 100 and the connection tab 310 are flat, thus facilitating the welding of the fuse tab 320 to the core 100 and the connection tab 310 respectively.

[0040] This application also provides a lithium battery, including the cell structure 10 described in any of the above embodiments. In this embodiment, when the lithium battery is short-circuited, the internal temperature rises, and the fuse tab 320 can generate a fuse break in time, thereby preventing the safety problems caused by overheating of the lithium battery.

[0041] Compared with the prior art, the present disclosure has at least the following advantages:

[0042] For the above-described cell structure 10 and lithium battery, when a short circuit occurs, the temperature of the fuse tab 320 rises and generates a fuse break, so that an open circuit is formed between the connection tab 310 and the core 100, preventing potential safety hazards caused by overheating inside the cell structure; the connection tab 310 is welded to the fixing part 210, and the core 100 is installed and fixed in the encapsulation case 200, making the connection between the connection tab 310 and the fuse tab 320 more stable. By arranging the fuse tab 320 in the receiving cavity 201, it is possible to prevent the connection between the fuse tab 320 and the connection tab 310 from shaking, thereby avoiding breakage at the connection between the fuse tab 320 and the connection tab 310.

[0043] The above-described embodiments merely represent several implementation manners of the present disclosure. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the disclosed patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications and improvements can still be made, and these all fall within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A battery core structure, comprising a winding core, a packaging shell and a tab assembly, wherein the packaging shell is provided with a receiving cavity, and the winding core is installed and fixed in the receiving cavity, characterized in that: The tab assembly includes a connecting tab and a fuse tab. The packaging shell is also provided with a fixing portion, and the fixing portion is provided with an installation channel. One end of the connecting tab is located outside the packaging shell, and the other end of the connecting tab is passed through the installation channel. The connecting tab is welded to the fixing portion, and the fuse tab is arranged in the accommodating cavity. The two ends of the fuse tab are respectively connected to the electrode diaphragm of the winding core and the connecting tab. The fuse tab is used to be heated and melted when the positive and negative electrodes of the winding core are short-circuited.

2. The battery cell structure according to claim 1, characterized in that: One end of the connecting tab is welded to the fuse tab, and a welding portion is formed at a position where the connecting tab and the fuse tab overlap, and a connecting welding point is formed in the welding portion.

3. The battery cell structure according to claim 2, characterized in that: The number of the connection welding points is multiple, and every two of the connection welding points are arranged at intervals in the welding portion.

4. The battery cell structure according to claim 2, characterized in that: A limiting groove is formed between the fixing portion and the winding core, and the welding portion is located in the limiting groove.

5. The battery cell structure according to claim 3, characterized in that: The number of the fuse tabs, the connecting tabs and the mounting channels is two, each connecting tab is inserted into the corresponding mounting channel, each connecting tab is connected to the corresponding fixing portion, and both ends of each fuse tab are respectively connected to the corresponding connecting tab and the winding core.

6. The battery cell structure according to claim 5, characterized in that: The two fuse tabs and the two connecting tabs are arranged in parallel.

7. The battery cell structure according to claim 1, characterized in that: The tab assembly is further provided with tab glue, which is wound around the connecting tab, one end of the tab glue is arranged in the installation channel, and the other end of the tab glue is arranged outside the packaging shell.

8. The battery cell structure according to claim 1, characterized in that: The electrode film of the winding core includes an electrode conductive portion and a coating portion connected in sequence, and the fuse tab is connected to the electrode conductive portion.

9. The battery core structure according to claim 1, characterized in that: The fuse tab and the connecting tab are both sheet-like structures.

10. A lithium battery, characterized in that: The invention comprises a battery core structure as claimed in any one of claims 1 to 9.

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