Buck circuit assembly for lithium battery, and 1.5 v lithium battery

Abstract

A buck circuit assembly for a lithium battery, and a 1.5 V lithium battery. The buck circuit assembly comprises a PCB (1), an outer conductive cap (2) and an inner conductive cap (3); the front surface of the PCB (1) is provided with a positive electrode copper ring (11) and a negative electrode copper ring (12); the positive electrode copper ring (11) is electrically connected to the outer conductive cap (2); the outer conductive cap (2) is used as a low-voltage output positive electrode; the negative electrode copper ring (12) is used as a common negative electrode; the back surface of the PCB (1) is provided with a high-voltage input copper ring (13); the high-voltage input copper ring (13) is electrically connected to the inner conductive cap (3); and the inner conductive cap (3) is used as a high-voltage input positive electrode. The PCB (1) achieves the functions of high-voltage input and low-voltage output by means of the three copper rings; the high-voltage input copper ring (13) serves as a high-voltage input positive electrode, the positive electrode copper ring (11) serves as an output positive electrode of a lithium battery, the negative electrode copper ring (12) serves as an output negative electrode of the lithium battery, achieving charging and discharging functions by means of the same port; and there is no need to provide any conductive cable, achieving higher stability of electrical performance, simplifying the internal connection structure of the lithium battery, and making the lithium battery safer.

Description

A lithium battery step-down circuit assembly and a 1.5V lithium battery Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a lithium battery step-down circuit assembly and a 1.5V lithium battery. Background Art

[0002] No. 5 and No. 7 batteries are very common batteries, widely used in various devices such as remote controls, electric toys, electric toothbrushes, shavers, wireless microphones, doorbells, etc. They are generally disposable dry batteries, but there are also rechargeable nickel-metal hydride batteries. Nickel-metal hydride batteries have memory effects, a limited number of recharges, and a short lifespan, so their practical applications are relatively limited.

[0003] Lithium batteries have the advantages of no memory effect, high energy density, and long service life. However, the voltage of a single lithium battery is generally between 3.0 and 4.2V. Even if they are made into AA and AA batteries, they cannot be directly used in various existing devices. To address this, researchers have designed step-down lithium batteries, reducing the output voltage to 1.5V. This improves the battery's versatility and can replace existing disposable batteries and nickel-metal hydride batteries, showing broad application prospects.

[0004] For example, the Chinese patent application with publication number CN203787480U, entitled "A Cylindrical Battery Device with Variable Voltage," discloses a low-voltage lithium battery that converts the high voltage of the lithium battery to a low voltage of 1.5V via a voltage-drop circuit board. The Chinese patent application with publication number CN204966611U, entitled "A 1.5V Constant Voltage Lithium-ion Battery," discloses a step-down circuit that can constantly output a low voltage of 1.5V, enabling the same-port charge and discharge function. However, none of the above-mentioned prior art discloses a detailed internal structure, and the disclosed content is not reasonable. Due to the small size of AA and AA batteries, how to design the step-down circuit assembly, properly place it inside the lithium battery, and how to achieve electrical connection with the lithium battery cell are very critical links and require further improvement.

[0005] Summary of the Invention

[0006] In order to solve the technical problem that the internal structure of existing lithium batteries is not reasonable, the present invention provides a lithium battery step-down circuit component and a 1.5V lithium battery.

[0007] On the one hand, the present application provides a step-down circuit assembly for a lithium battery, including a PCB board, on which a step-down circuit, a charging and discharging circuit, and a protection circuit are integrated. The step-down circuit assembly also includes an outer conductive cap and an inner conductive cap. The front of the PCB board is provided with a positive copper ring and a negative copper ring, the positive copper ring is electrically connected to the outer conductive cap, the outer conductive cap is used as a low-voltage output positive pole, and the negative copper ring is used as a common negative pole. The back of the PCB board is provided with a high-voltage input copper ring, the high-voltage input copper ring is electrically connected to the inner conductive cap, and the inner conductive cap is used as a high-voltage input positive pole.

[0008] By adopting the above technical solution, the PCB board of the present application can adopt existing necessary circuits, such as a step-down circuit, a voltage stabilizing circuit, a charging circuit, an over-discharge protection circuit, etc. The circuit principle does not need to be improved too much, but the structure has been greatly improved. That is, a positive copper ring, a negative copper ring and a high-voltage input copper ring are arranged on the PCB board. The positive copper ring serves as the low-voltage output positive pole, the high-voltage input copper ring serves as the high-voltage input positive pole, and the negative copper ring serves as the common negative pole. The functions of high-voltage input and low-voltage output are realized through these three copper rings; the high-voltage input copper ring is then electrically connected to the inner conductive cap as the high-voltage input positive pole, the positive copper ring is then electrically connected to the outer conductive cap, the outer conductive cap serves as the output positive pole of the lithium battery, and the negative copper ring is then electrically connected to the metal shell of the lithium battery as the output negative pole of the lithium battery, realizing the same-port charging and discharging function, without the need to arrange any conductive cables, the electrical performance is more stable, and the internal connection structure of the lithium battery is simplified, which is safer.

[0009] Preferably, the outer conductive cap and the inner conductive cap are both soldered on the PCB board through patch welding.

[0010] Preferably, the electronic components on the PCB are centrally arranged inside the outer conductive cap and the inner conductive cap.

[0011] Preferably, the electronic components located in the outer conductive cap are capacitors, inductors and resistors, and the electronic components located in the inner conductive cap are three-in-one chips.

[0012] Preferably, a flange edge is provided at the lower end of the outer conductive cap.

[0013] Preferably, the step-down circuit assembly further includes an elastic ring, which is electrically connected to the negative electrode copper ring.

[0014] Preferably, the elastic ring includes a base ring and warping pieces evenly distributed around the base ring, and the back of the base ring is welded to the negative electrode copper ring through patch welding.

[0015] On the other hand, the present application provides a 1.5V lithium battery, comprising a metal casing, a PVC outer skin, a wound battery cell assembly and the step-down circuit assembly of the lithium battery described above, wherein the wound battery cell assembly and the step-down circuit assembly are both arranged in the metal casing, the positive pole tab of the wound battery cell assembly is welded to the inner conductive cap, and the negative pole tab is welded to the bottom of the metal casing, the elastic ring is elastically abutted against the metal casing, and the PVC outer skin is used to wrap the metal casing.

[0016] In summary, this application includes at least one of the following beneficial technical effects:

[0017] 1. This application is equipped with an outer conductive cap and an inner conductive cap, and a positive copper ring, a negative copper ring, and a high-voltage input copper ring are set on the PCB board. No conductive cables are used, and the electrical performance is more stable;

[0018] 2. The internal structure of the lithium battery of the present application is simplified, and the internal connection structure is more reliable and safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a front perspective view of a step-down circuit assembly according to an embodiment of the present application;

[0020] FIG2 is a rear perspective view of the step-down circuit assembly according to an embodiment of the present application;

[0021] FIG3 is a schematic diagram of a half-section structure of a step-down circuit assembly according to an embodiment of the present application;

[0022] FIG4 is a perspective view of the back side of the PCB board according to an embodiment of the present application;

[0023] FIG5 is a perspective view of a 1.5V lithium battery according to an embodiment of the present application;

[0024] FIG6 is a schematic diagram of a half-section structure of a 1.5V lithium battery according to an embodiment of the present application;

[0025] Figure 7 is an enlarged view of point A in Figure 6;

[0026] Figure 8 is an enlarged view of point B in Figure 6;

[0027] FIG9 is a three-dimensional diagram of the wound battery cell assembly according to an embodiment of the present application.

[0028] Explanation of the accompanying reference numerals: 1. PCB board; 11. Positive copper ring; 12. Negative copper ring; 13. High-voltage input copper ring; 14. Electronic component; 2. Outer conductive cap; 21. Flange edge; 3. Inner conductive cap; 4. Elastic ring; 41. Base ring; 42. Warp tab; 100. Step-down circuit assembly; 200. Metal shell; 300. PVC outer shell; 400. Wound battery cell assembly; 401. Positive electrode tab; 402. Negative electrode tab; 500. Plastic middle frame. DETAILED DESCRIPTION

[0029] The present application is further described in detail below with reference to Figures 1-9.

[0030] 1 to 4 , an embodiment of the present application discloses a step-down circuit assembly 100 for a lithium battery, comprising a PCB board 1, on which a step-down circuit, a charge-discharge circuit, and a protection circuit are integrated. The step-down circuit assembly 100 also includes an outer conductive cap 2 and an inner conductive cap 3. The front of the PCB board 1 is provided with a positive copper ring 11 and a negative copper ring 12, the positive copper ring 11 is electrically connected to the outer conductive cap 2, the outer conductive cap 2 is used as a low-voltage output positive electrode, and the negative copper ring 12 is used as a common negative electrode. The back of the PCB board 1 is provided with a high-voltage input copper ring 13, the high-voltage input copper ring 13 is electrically connected to the inner conductive cap 3, and the inner conductive cap 3 is used as a high-voltage input positive electrode.

[0031] Referring to Figure 3, the outer conductive cap 2 and the inner conductive cap 3 are both soldered to the PCB board 1 through patch welding. The electronic components 14 on the PCB board 1 are centrally arranged inside the outer conductive cap 2 and the inner conductive cap 3. The electronic components 14 are reasonably arranged, making full use of the internal space of the outer conductive cap 2 and the inner conductive cap 3. The electronic components 14 located in the outer conductive cap 2 are capacitors, inductors and resistors, and the electronic components 14 located in the inner conductive cap 3 are three-in-one chips. The three-in-one chip is an existing technology with the advantages of high integration and small size, making the design of the PCB board 1 easier. The outer conductive cap 2 and the inner conductive cap 3 not only have good connection strength, reliable fixation, low resistance at the connection, and good conductivity, but also have a certain sealing performance to prevent water and dust from entering, thereby protecting the internal electronic components 14. The electronic components 14 will not come into contact with the outside world and will not be damaged by collision. Because the outer conductive cap 2 is exposed and susceptible to external impact, it requires enhanced fixing strength. To this end, a flange 21 is provided at the lower end of the outer conductive cap 2. The flange 21 has a certain width, several times the wall thickness of the outer conductive cap 2, which provides a large welding area with the positive copper ring 11, ensuring a secure fixation and impact resistance. Since the inner conductive cap 3 is not exposed and is not subject to external impact, the strength requirement is slightly lower, so a flange is not required.

[0032] 1 and 3 , the step-down circuit assembly 100 further includes an elastic ring 4, which is electrically connected to the negative electrode copper ring 12. The elastic ring 4 includes a base ring 41 and lift tabs 42 evenly distributed around the base ring 41. The back of the base ring 41 is soldered to the negative electrode copper ring 12 via patch welding.

[0033] The PCB board 1 of the present application can adopt existing necessary circuits, such as a step-down circuit, a voltage stabilization circuit, a charging circuit, and an over-discharge protection circuit. The circuit principle does not require much improvement, but the structure has been greatly improved. A positive copper ring 11, a negative copper ring 12, and a high-voltage input copper ring 13 are provided on the PCB board 1. The positive copper ring 11 serves as the low-voltage output positive electrode, the high-voltage input copper ring 13 serves as the high-voltage input positive electrode, and the negative copper ring 12 serves as the common negative electrode. These three copper rings realize the functions of high-voltage input and low-voltage output. The high-voltage input copper ring 13 is further electrically connected to the inner conductive cap 3 to serve as the high-voltage input positive electrode. The positive copper ring 11 is further electrically connected to the outer conductive cap 2, which serves as the output positive electrode of the lithium battery. The negative copper ring 12 is further electrically connected to the metal shell 200 of the lithium battery to serve as the output negative electrode of the lithium battery. This realizes the same-port charging and discharging function without the need for any conductive cables. The electrical performance is more stable and the internal connection structure of the lithium battery is simplified, making it safer.

[0034] 5 to 9 , an embodiment of the present application discloses a 1.5V lithium battery, comprising a metal shell 200 , a PVC outer skin 300 , a wound cell assembly 400 , a plastic middle frame 500 and the step-down circuit assembly 100 of the lithium battery described above. The wound cell assembly 400 , the plastic middle frame 500 and the step-down circuit assembly 100 are all arranged in the metal shell 200 , and the plastic middle frame 500 is used to support the step-down circuit assembly 100 . The positive pole tab 401 of the wound cell assembly 400 is welded to the inner conductive cap 3 , and the negative pole tab 402 is welded to the bottom of the metal shell 200 . The elastic ring 4 is elastically in contact with the metal shell 200 , and the PVC outer skin 300 is used to wrap the metal shell 200 .

[0035] The positive electrode tab 401 of the wound battery cell assembly 400 is connected to the PCB board 1 through the inner conductive cap 3 and the high-voltage input copper ring 13, and the negative electrode tab 402 of the wound battery cell assembly 400 is connected to the PCB board 1 through the metal shell 200, the elastic ring 4, and the negative copper ring 12. After the circuit on the PCB board 1 is stepped down, the positive electrode of the lithium battery is output from the positive copper ring 11 and the outer conductive cap 2, and the negative electrode of the lithium battery is output from the negative copper ring 12, the elastic ring 4, and the metal shell 200.

[0036] The lifter 42 of the elastic ring 4 is elastically pressed against the metal shell 200. The elastic pressing can prevent the metal shell 200 from being loosely pressed against the negative copper ring 12 on the PCB board 1 or from being damaged.

[0037] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A step-down circuit assembly for a lithium battery, comprising a PCB board (1), wherein a step-down circuit, a charge-discharge circuit, and a protection circuit are integrated on the PCB board (1), characterized in that: The invention also includes an outer conductive cap (2) and an inner conductive cap (3); a positive copper ring (11) and a negative copper ring (12) are provided on the front of the PCB board (1); the positive copper ring (11) is electrically connected to the outer conductive cap (2); the outer conductive cap (2) serves as a low-voltage output positive electrode; the negative copper ring (12) serves as a common negative electrode; a high-voltage input copper ring (13) is provided on the back of the PCB board (1); the high-voltage input copper ring (13) is electrically connected to the inner conductive cap (3); and the inner conductive cap (3) serves as a high-voltage input positive electrode.

2. The step-down circuit assembly for a lithium battery according to claim 1, wherein: The outer conductive cap (2) and the inner conductive cap (3) are both soldered on the PCB board (1) via patch welding.

3. The step-down circuit assembly of a lithium battery according to claim 1, characterized in that: The electronic components (14) on the PCB board (1) are centrally arranged inside the outer conductive cap (2) and the inner conductive cap (3).

4. The step-down circuit assembly for a lithium battery according to claim 3, wherein: The electronic components (14) located in the outer conductive cap (2) are capacitors, inductors and resistors, and the electronic components (14) located in the inner conductive cap (3) are three-in-one chips.

5. The step-down circuit assembly of a lithium battery according to claim 2, characterized in that: The lower end of the outer conductive cap (2) is provided with a flange edge (21).

6. The step-down circuit assembly of a lithium battery according to any one of claims 1 to 5, characterized in that: The step-down circuit assembly (100) further comprises an elastic ring (4), wherein the elastic ring (4) is electrically connected to the negative electrode copper ring (12).

7. The step-down circuit assembly of a lithium battery according to claim 6, characterized in that: The elastic ring (4) comprises a base ring (41) and flaps (42) uniformly arranged around the base ring (41); the back of the base ring (41) is welded to the negative electrode copper ring (12) via patch welding.

8. A 1.5V lithium battery, characterized in that: The invention comprises a metal shell (200), a PVC outer skin (300), a wound battery cell assembly (400) and a step-down circuit assembly (100) of a lithium battery according to claim 6, wherein the wound battery cell assembly (400) and the step-down circuit assembly (100) are both arranged in the metal shell (200), the positive pole tab (401) of the wound battery cell assembly (400) is welded to the inner conductive cap (3), and the negative pole tab (402) is welded to the bottom of the metal shell (200), the elastic ring (4) is elastically abutted against the metal shell (200), and the PVC outer skin (300) is used to wrap the metal shell (200).

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