A lithium battery with a built-in PTC protection structure

Abstract

The present invention relates to the technical field of lithium power batteries, and in particular to a lithium battery with a PTC built-in protection structure. Its technical solution includes: a battery shell, an electrode sheet core installed inside the battery shell, and an electrode sheet terminal installed at the end of the battery shell. A PTC built-in mechanism for limiting power protection of the battery to improve safety performance is designed inside the battery shell and between the electrode sheet terminal and the electrode sheet core. The PTC built-in mechanism includes a conductive sheet located at the top of the electrode sheet core. A support member is provided inside the battery shell and located on the upper part of the conductive sheet, and a pressure member is provided on the upper part of the support member. The present invention can provide thermal protection for the battery by installing a PTC thermistor patch in the battery, preventing the battery from thermal runaway and causing a fire accident. The PTC thermistor patch is detachably installed in the battery through the PTC built-in mechanism, which is convenient for later disassembly and replacement or recycling and secondary use, and is more flexible to use.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium power batteries, and in particular to a lithium battery with a PTC built-in protection structure. Background Art

[0002] Lithium-powered batteries are high-energy batteries that use metallic lithium for the negative electrode and MnO2, SOCL2, (CFx)n, etc. for the positive electrode. They have a wide range of applications, but are also prone to fire accidents caused by thermal runaway of lithium-ion batteries.

[0003] To address this issue, some battery manufacturers have implemented thermal protection by adding PTC thermistors, which increase their resistance to limit current when the battery temperature rises. However, the existing method of installing PTC thermistors involves soldering the resistor patches to the battery electrodes. This effectively prevents the resistor patches from shifting, but also makes them difficult to remove, replace, or recycle. To address this issue, we propose a lithium battery with a built-in PTC protection structure. The PTC thermistor is removable, providing greater flexibility. Summary of the Invention

[0004] The purpose of the present invention is to address the problems existing in the background technology and to provide a lithium battery with a PTC built-in protection structure.

[0005] The technical solution of the present invention is as follows: A lithium battery with a PTC built-in protection structure comprises a battery shell, an electrode sheet core installed inside the battery shell, and an electrode sheet terminal installed at the end of the battery shell; a PTC built-in mechanism for limiting power protection of the battery to improve safety performance is designed inside the battery shell and between the electrode sheet terminal and the electrode sheet core; the PTC built-in mechanism comprises a conductive sheet located at the top end of the electrode sheet core; a support is provided inside the battery shell and on the upper part of the conductive sheet; a pressing piece is provided on the upper part of the support; a PTC thermistor patch is provided at the center of the pressing piece; the bottom end of the PTC thermistor patch contacts the upper surface of the conductive sheet, and the top end of the PTC thermistor patch contacts the lower surface of the electrode sheet terminal.

[0006] Preferably, a protrusion is provided on the central upper surface of the conductive sheet, and a groove matching the protrusion is provided on the central lower surface of the pressure piece. An insulating ring sleeve is fixedly sleeved on the outer wall of the protrusion, and an annular limiting groove is provided on the outer wall of the insulating ring sleeve. The inner wall of the groove is fixedly connected with a limiting wedge block that can be inserted into the annular limiting groove.

[0007] Preferably, the outer wall of the insulating ring sleeve is provided with a release groove which allows the limiting wedge block to escape from the annular limiting groove. The release grooves are the same in number as the limiting wedge blocks, have corresponding positions and are connected to the annular limiting groove.

[0008] Preferably, a cylindrical groove is provided on the upper surface of the support member, a spring is provided inside the cylindrical groove, the bottom end of the spring is fixedly connected to the inner wall of the cylindrical groove, and the top end of the spring is fixedly connected to an insulating cylinder.

[0009] Preferably, a connecting assembly is fixedly connected to both the upper and lower ends of the battery housing, and adjacent single batteries are connected to each other via the connecting assembly.

[0010] Preferably, the connecting assembly includes a connecting frame that can be clipped onto the end of the battery housing, two of the outer edge surfaces of the connecting frame are provided with T-shaped mortises, and the other two outer edge surfaces of the connecting frame are fixedly connected with T-shaped tenons that can be clipped into the T-shaped mortises.

[0011] Preferably, a limiting ball is fixedly connected to the inner edge surface of the connecting frame and can abut against the outer surface of the battery housing to limit the connecting assembly on the battery housing.

[0012] Preferably, rectangular positioning bars are symmetrically fixedly connected to the outer surface of the battery housing, and the inner edge surface of the connecting frame is provided with rectangular positioning grooves into which the rectangular positioning bars can be vertically inserted.

[0013] Preferably, an inner edge hole is opened in the middle of the connecting frame, and the diameter of the inner edge hole is smaller than the diameter of the outer edge of the end of the battery shell to avoid slipping and falling on the battery shell.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] (1): This application can provide thermal protection for the battery by installing a PTC thermistor patch inside the battery, preventing the battery from thermal runaway and causing fire accidents. The PTC thermistor patch is detachably installed inside the battery through the PTC built-in mechanism, which is convenient for later disassembly and replacement or recycling for secondary use, making it more flexible to use and improving the utilization rate of materials;

[0016] (2): This application not only improves the external protection of the battery through the design of the connection component, but also can quickly realize the series and parallel installation of each battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of a high-safety lithium power battery with a built-in PTC structure;

[0018] Figure 2 for Figure 1 sectional view of

[0019] Figure 3 for Figure 2 Schematic diagram of the separate connection of the conductive sheet, support member and pressure member;

[0020] Figure 4 A schematic diagram of the connection between the battery housing and the connection assembly;

[0021] Figure 5 is another schematic diagram of the connection between the battery housing and the connecting assembly;

[0022] Figure 6 is a structural diagram of the connection components;

[0023] Figure 7 Schematic diagram of the assembly between two batteries;

[0024] Figure 8 Schematic diagram of the assembly between four batteries.

[0025] Reference numerals: 1, battery housing;

[0026] 2. Electrode terminal;

[0027] 3. Inner core of electrode sheet;

[0028] 4. PTC built-in mechanism; 41. Conductive sheet; 411. Protrusion; 42. Support member; 421. Cylindrical groove; 43. Pressing member; 431. Groove; 44. PTC thermistor patch; 45. Limiting wedge; 46. Insulating ring; 461. Annular limiting groove; 462. Release groove; 47. Spring; 48. Insulating cylinder;

[0029] 5. Connecting assembly; 51. Connecting frame; 52. T-shaped tenon; 53. T-shaped mortise; 54. Rectangular positioning strip; 55. Rectangular positioning groove; 56. Limiting ball; 57. Inner edge hole. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figure 1-3As shown, the present invention proposes a lithium battery with a PTC built-in protection structure, comprising a battery housing 1, an electrode sheet core 3 installed inside the battery housing 1, and an electrode sheet terminal 2 installed at the end of the battery housing 1. A PTC built-in mechanism 4 is designed inside the battery housing 1 and located between the electrode sheet terminal 2 and the top of the electrode sheet core 3 to provide power limiting protection for the battery to improve safety performance. The PTC thermistor patch 44 is made of thermistor material and can act as a temperature sensor. When the temperature inside the battery rises to a certain level, the material will change from a good conductive state to an insulating state, and the internal resistance will increase rapidly, thereby limiting the current and reducing the voltage between the positive and negative electrodes to a safe voltage, thereby realizing the automatic protection function of the battery. Since the PTC thermistor patch 44 belongs to the existing technology, it will not be described in detail here.

[0033] like Figure 2-3 As shown, the PTC built-in mechanism 4 includes a conductive sheet 41 located at the top of the electrode sheet inner core 3, and a support member 42 is fixedly connected to the interior of the battery shell 1 and located on the upper part of the conductive sheet 41. A pressing member 43 is provided on the upper part of the support member 42, and both the support member 42 and the pressing member 43 are made of insulating material.

[0034] like Figure 3 As shown, a protrusion 411 is provided on the central upper surface of the conductive sheet 41, and a groove 431 matching the protrusion 411 is provided on the central lower surface of the pressing piece 43, and a PTC thermistor patch 44 is movably sleeved in the groove 431. The bottom end of the PTC thermistor patch 44 contacts the upper surface of the conductive sheet 41, and the top end of the PTC thermistor patch 44 contacts the lower surface of the electrode sheet terminal 2, thereby forming a current path among the electrode sheet inner core 3, the conductive sheet 41, the PTC thermistor patch 44, and the electrode sheet terminal 2.

[0035] like Figure 2-3 As shown, an insulating ring 46 is fixedly mounted on the outer wall of the protrusion 411. An annular retaining groove 461 is defined on the outer wall of the insulating ring 46. A pair of retaining wedges 45 that fit into the annular retaining grooves 461 are symmetrically fixedly connected to the inner wall of the groove 431. Both the retaining wedges 45 and the insulating ring 46 are made of insulating material. A pair of release grooves 462 are symmetrically defined on the outer wall of the insulating ring 46 to allow the retaining wedges 45 to escape from the annular retaining grooves 461. The release grooves 462 are in communication with the annular retaining grooves 461.

[0036] like Figure 3 As shown, a pair of cylindrical grooves 421 are opened on the upper surface of the support member 42, and a spring 47 is provided inside each cylindrical groove 421. The bottom end of the spring 47 is fixedly connected to the inner wall of the cylindrical groove 421, and the top end of the spring 47 is fixedly connected to the insulating tube 48.

[0037] The working principle of this embodiment is that the PTC thermistor patch 44 is connected to the conductive sheet 41 without direct welding, so it can be removed for secondary use during the battery recycling process. Figure 2-3 As shown, the pressure piece 43 is rotated horizontally. When the limiting wedge block 45 is rotated to the position of the release groove 462, the spring 47 drives the pressure piece 43 to move slightly upward through the upward elastic thrust, and the limiting wedge block 45 is released from the annular limiting groove 461 to the release groove 462. Then the pressure piece 43 can be removed upward, and finally the PTC thermistor patch 44 can be removed from the pressure piece 43.

[0038] Example 2

[0039] The present invention proposes a lithium battery with a PTC built-in protection structure, comprising a battery housing 1, an electrode sheet core 3 mounted within the battery housing 1, and an electrode sheet terminal 2 mounted at the end of the battery housing 1. A PTC built-in mechanism 4 is designed within the battery housing 1, located between the electrode sheet terminal 2 and the top of the electrode sheet core 3, to provide current limiting protection for the battery and improve safety performance. The PTC thermistor patch 44 is made of a thermistor material and functions as a temperature sensor. When the temperature within the battery rises to a certain level, the material changes from a good conductive state to an insulating state, rapidly increasing its internal resistance, thereby limiting current and reducing the voltage between the positive and negative electrodes to a safe voltage, thus achieving automatic battery protection. Since the PTC thermistor patch 44 is prior art, it will not be described in detail here. The PTC built-in mechanism 4 includes a conductive sheet 41 located at the top of the electrode sheet core 3. A support member 42 is fixedly connected to the interior of the battery housing 1 and located above the conductive sheet 41. A pressure member 43 is provided above the support member 42. Both the support member 42 and the pressure member 43 are made of insulating material. A protrusion 411 is provided on the central upper surface of the conductive sheet 41, and a groove 431 is provided on the central lower surface of the pressure piece 43, which matches the protrusion 411. A PTC thermistor patch 44 is movably mounted within the groove 431. The bottom end of the PTC thermistor patch 44 contacts the upper surface of the conductive sheet 41, and the top end of the PTC thermistor patch 44 contacts the lower surface of the electrode sheet terminal 2. Thus, a current path is formed between the electrode sheet core 3, the conductive sheet 41, the PTC thermistor patch 44, and the electrode sheet terminal 2. An insulating ring 46 is fixedly mounted on the outer wall of the protrusion 411. The outer wall of the insulating ring 46 has an annular limiting groove 461. A pair of limiting wedges 45 that can be snapped into the annular limiting groove 461 are symmetrically fixedly connected to the inner wall of the groove 431. The limiting wedges 45 and the insulating ring 46 are both made of insulating material. The outer wall of the insulating ring 46 is symmetrically formed with a pair of release slots 462 that allow the limiting wedge 45 to escape from the annular limiting slot 461. The release slots 462 are connected to the annular limiting slot 461. The upper surface of the support member 42 is formed with a pair of cylindrical slots 421. Each cylindrical slot 421 is provided with a spring 47. The bottom end of the spring 47 is fixedly connected to the inner wall of the cylindrical slot 421, and the top end of the spring 47 is fixedly connected to the insulating cylinder 48.

[0040] Compared with the first embodiment, this embodiment further includes:

[0041] like Figure 4-8 As shown, a connecting assembly 5 is fixedly connected to both the upper and lower ends of the battery housing 1, and adjacent single batteries are connected to each other through the connecting assembly 5 to achieve series and parallel connection between the batteries.

[0042] like Figure 4-6As shown, the connecting assembly 5 includes a connecting frame 51 that can be snapped onto the end of the battery housing 1. Two of the outer edges of the connecting frame 51 are provided with T-shaped mortises 53, and the other two outer edges of the connecting frame 51 are fixedly connected to T-shaped tenons 52 that snap into the T-shaped mortises 53. The four corners of the inner edge of the connecting frame 51 are fixedly connected to retaining balls 56 that can press against the outer surface of the battery housing 1 to retain the connecting assembly 5 on the battery housing 1. The retaining balls 56 can be made of a rubber material with a certain degree of elasticity and friction. A pair of rectangular positioning bars 54 are symmetrically fixedly connected to the outer surfaces of both ends of the battery housing 1. The inner edge of the connecting frame 51 is provided with rectangular positioning grooves 55 that allow the rectangular positioning bars 54 to snap vertically into place. An inner edge hole 57 is provided in the middle of the connecting frame 51. The diameter of the inner edge hole 57 is smaller than the outer edge diameter of the end of the battery housing 1 to prevent it from slipping and falling on the battery housing 1.

[0043] The working principle of this embodiment is: by adding a connecting component 5 to the end of the battery shell 1, not only can the protection effect of the battery be improved, but also when multiple batteries are connected in series and parallel, the batteries can be quickly connected through the connecting component 5. Compared with the traditional method of connecting the battery electrodes only with metal sheets, it is more stable, safe, and easy to disassemble.

[0044] The above specific embodiments are only several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A lithium battery with a PTC built-in protection structure, comprising a battery housing (1), an electrode sheet core (3) installed inside the battery housing (1), and an electrode sheet terminal (2) installed at the end of the battery housing (1), characterized in that: A PTC built-in mechanism (4) for limiting the power supply of the battery to improve safety performance is designed inside the battery housing (1) and between the electrode sheet terminal (2) and the electrode sheet inner core (3). The PTC built-in mechanism (4) includes a conductive sheet (41) located at the top of the electrode sheet inner core (3). A support member (42) is provided inside the battery housing (1) and on the top of the conductive sheet (41). A pressing member (43) is provided on the top of the support member (42). A PTC thermistor patch (44) is provided at the center of the pressing member (43). The bottom end of the PTC thermistor patch (44) contacts the upper surface of the conductive sheet (41), and the top end of the PTC thermistor patch (44) contacts the lower surface of the electrode sheet terminal (2). The central upper surface of the conductive sheet (41) is provided with a protrusion (411), the central lower surface of the pressing piece (43) is provided with a groove (431) matching the protrusion (411), the outer wall of the protrusion (411) is fixedly sleeved with an insulating ring (46), the outer wall of the insulating ring (46) is provided with an annular limiting groove (461), and the inner wall of the groove (431) is fixedly connected with a limiting wedge (45) capable of being inserted into the annular limiting groove (461); The outer wall of the insulating ring sleeve (46) is provided with a release groove (462) that allows the limiting wedge block (45) to escape from the annular limiting groove (461), and the release grooves (462) are the same in number and position as the limiting wedge block (45) and are connected to the annular limiting groove (461); the upper surface of the support member (42) is provided with a cylindrical groove (421), and a spring (47) is provided inside the cylindrical groove (421), the bottom end of the spring (47) is fixedly connected to the inner wall of the cylindrical groove (421), and the top end of the spring (47) is fixedly connected to the insulating tube (48).

2. A lithium battery with a built-in PTC protection structure according to claim 1, characterized in that: A connecting assembly (5) is fixedly connected to both the upper and lower ends of the battery housing (1), and adjacent single batteries are connected to each other via the connecting assembly (5).

3. The lithium battery with a built-in PTC protection structure according to claim 2, characterized in that: The connecting assembly (5) comprises a connecting frame (51) that can be clamped onto the end of the battery housing (1), two outer edge surfaces of the connecting frame (51) are provided with T-shaped mortises (53), and the other two outer edge surfaces of the connecting frame (51) are fixedly connected with T-shaped tenons (52) that can be clamped into the T-shaped mortises (53).

4. The lithium battery with a built-in PTC protection structure according to claim 3, characterized in that: The inner edge surface of the connection frame (51) is fixedly connected with a limiting ball (56) capable of abutting against the outer surface of the battery housing (1) to limit the connection assembly (5) on the battery housing (1).

5. The lithium battery with a built-in PTC protection structure according to claim 3, characterized in that: A rectangular positioning strip (54) is symmetrically fixedly connected to the outer surface of the battery housing (1), and a rectangular positioning groove (55) is provided on the inner edge surface of the connection frame (51) to allow the rectangular positioning strip (54) to be vertically inserted.

6. The lithium battery with a built-in PTC protection structure according to claim 3, characterized in that: An inner edge hole (57) is provided in the middle of the connection frame (51), and the diameter of the inner edge hole (57) is smaller than the outer edge diameter of the end of the battery housing (1) to prevent the battery from slipping and falling on the battery housing (1).

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