Low internal resistance lithium to dry battery and its preparation process

Abstract

The application discloses a low-internal-resistance lithium dry battery and a preparation process thereof, and relates to the technical field of battery preparation. The contact mode of a voltage conversion unit and a lithium battery positive electrode is optimized, multi-point contact is adopted, and conductive liquid is filled to reduce the contact resistance. Meanwhile, a temperature compensation mechanism is realized by using a thermal expansion piece to ensure the stability of the electrical contact at different temperatures. In addition, the battery is designed with a heat dissipation system combining a heat dissipation piece and a phase change heat absorption material, which can automatically adjust the heat dissipation efficiency according to the temperature change. The preparation process of the battery comprises the preparation of a lithium battery unit and a voltage conversion unit, the installation of a thermal expansion piece, the assembly of the voltage conversion unit and the lithium battery unit, and the packaging of a battery shell. The battery not only has the characteristics of low internal resistance and high efficiency, but also has excellent heat management performance and safety, and is suitable for the power supply demand of small-power electronic products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery preparation, and more particularly, to a low-internal-resistance lithium dry cell and a preparation process thereof. BACKGROUND

[0002] With the increasing miniaturization and diversification of modern electronic products, the requirements for power supplies are also becoming higher and higher. Although traditional dry batteries are widely used, they have shortcomings in providing stable low-voltage output, reducing internal resistance, and adapting to high-temperature environments. In particular, for small-power electronic products such as smart watches, Bluetooth earphones, etc., they need to work stably for a long time, and have high requirements for the internal resistance and voltage stability of the battery. High internal resistance will cause the battery to generate a lot of heat during use, resulting in large energy loss and shortening the service life of the battery. At the same time, as the temperature of the battery rises, the contact resistance between the electrodes will also increase, further affecting the performance and safety of the battery.

[0003] Traditional dry batteries usually use a simple voltage dividing circuit for voltage conversion. This circuit not only has low conversion efficiency, but also cannot provide stable output when the voltage fluctuates. In addition, traditional dry batteries often ignore thermal management in their structural design, resulting in a sharp decline in battery performance in high-temperature environments, and even causing safety problems. In particular, in a vibration and impact environment, the electrical connections inside the battery are prone to looseness, increasing the contact resistance and seriously affecting the stability and reliability of the battery.

[0004] In recent years, lithium batteries have been widely used in portable electronic devices due to their high energy density, long cycle life, and stable electrochemical performance. However, direct application of lithium batteries in small-power electronic products faces the problem of excessively high voltage, requiring additional voltage conversion circuits. In addition, lithium batteries also have performance degradation and safety problems in high-temperature environments. Therefore, it is particularly important to develop a lithium dry cell that can adapt to the needs of small-power electronic products, with low internal resistance, high-efficiency voltage conversion, and good thermal management performance. SUMMARY

[0005] The present application relates to the technical field of battery preparation, and more particularly, to a low-internal-resistance lithium dry cell and a preparation process thereof.

[0006] To achieve the above-mentioned purpose, the technical solution provided by an embodiment of the present application is as follows:

[0007] The application discloses a low-internal-resistance lithium-to-dry battery, which comprises a battery shell, a lithium battery unit, a voltage conversion unit and a thermal expansion element, the battery shell comprises a shell, a positive electrode end cover and a negative electrode end cover, the lithium battery unit comprises a lithium battery body, a lithium battery positive electrode and a lithium battery negative electrode, the negative electrode end cover is matched with the lithium battery negative electrode, the voltage conversion unit is electrically connected with the lithium battery positive electrode and is used for converting the output voltage of the lithium battery unit into a low voltage suitable for small-power electronic products, and the thermal expansion element is fixedly installed in the shell and is used for keeping good electrical contact between the voltage conversion unit and the lithium battery positive electrode.

[0008] As a further improvement of the application, the voltage conversion unit comprises a step-down circuit board, a negative electrode terminal and a positive electrode terminal, the negative electrode terminal is directly electrically connected with the input end of the step-down circuit board, the other surface of the negative electrode terminal is electrically connected with the lithium battery positive electrode, the positive electrode terminal is electrically connected with the output end of the step-down circuit board through a flexible lead wire, and the positive electrode end cover is matched with the positive electrode terminal.

[0009] As a further improvement of the application, the negative electrode terminal is provided with a plurality of integrally-formed and uniformly-distributed contact protrusions at the lower end, the lithium battery positive electrode is provided with a plurality of contact grooves matched with the contact protrusions at the upper end, and the contact grooves are filled with conductive liquid, the contact area between the negative electrode terminal and the lithium battery positive electrode is increased in a multi-point contact mode, so that the contact resistance is reduced, the conductive liquid can significantly reduce the contact resistance of the connection, the conductive liquid can ensure that the electrical connection between the negative electrode terminal and the lithium battery positive electrode is smoother, energy loss is reduced, the overall efficiency of the battery system is improved, meanwhile, the conductive liquid can fill the small gaps and uneven surfaces of the connection, form a uniform conductive layer, not only can enhance the mechanical stability of the connection, but also can prevent electric sparks or arcs caused by poor contact, so as to improve the safety and reliability of the battery system, compared with crimping, the negative electrode terminal and the lithium battery positive electrode can be protected to a certain extent, and material damage caused by excessive contact pressure can be avoided.

[0010] As a further improvement of the application, the contact protrusions and the contact grooves are all in the structure of a circular truncated cone with the upper part being large and the lower part being small, and the upper surface of the lithium battery positive electrode is a small arc surface with an angle of 5-10 degrees, the structure of the circular truncated cone can further increase the contact area, and when the contact protrusions and the contact grooves are just combined, there is a certain space for the conductive liquid inside to seep out from the gap, so as to be filled on the contact surface of the negative electrode terminal and the lithium battery positive electrode to improve the conductivity, the arc surface design of the lithium battery positive electrode can ensure that the connection is tightly fitted, reduce the contact gap, avoid the influence of air or other impurities on the conductivity, and facilitate the distribution of the conductive liquid on the surface after being squeezed out from the contact grooves.

[0011] As a further improvement of the application, the thermal expansion piece comprises a guide ring fixedly installed at the inner end of the shell, a moving ring is arranged between the guide ring and the voltage reduction circuit board, a plurality of uniformly distributed thermal expansion pads are fixedly installed between the guide ring and the moving ring, a plurality of uniformly distributed elastic washers are fixedly installed at the end of the moving ring close to the voltage reduction circuit board, the guide ring can not only guide the installation of the voltage conversion unit, but also provide positioning function, when the thermal expansion pads are heated and expanded, the elastic washers can be pressed by the moving ring to apply contact pressure between the negative terminal and the positive pole of the lithium battery, when the negative terminal and the positive pole of the lithium battery are in close contact, the contact area is increased and the contact resistance is reduced, thereby improving the efficiency and stability of the electrical connection, and after the battery is cooled, the shape is restored, the contact pressure between the negative terminal and the positive pole of the lithium battery can be reduced and kept stable, which can not only improve the stress fatigue of the material, but also avoid the problem of increased contact resistance caused by loose connection under the installation and vibration environment.

[0012] As a further improvement of the application, a plurality of annularly arrayed heat dissipation holes are formed in the positive terminal cover, heat dissipation pieces are inlaidly installed in the heat dissipation holes, and the heat dissipation pieces are fixedly connected with the moving ring, the heat dissipation pieces are used to conduct heat inside the battery shell to the outside in normal state, when there is too much heat and the thermal expansion piece is triggered to expand, the moving ring moves to drive the heat dissipation pieces to move inward and open the heat dissipation holes, at this time, the heat inside the battery shell can be quickly dissipated to the outside for interaction, thereby achieving the effect of rapid cooling.

[0013] As a further improvement of the application, the heat dissipation piece comprises a heat dissipation block movably inlaid in the heat dissipation hole, a heat dissipation column is fixedly connected between the heat dissipation block and the moving ring, and a plurality of guide holes matched with the heat dissipation column are formed in the guide ring.

[0014] As a further improvement of the application, the heat dissipation block is a hollow structure and filled with phase change heat absorption material, the phase change heat absorption material uses the characteristic of absorbing a large amount of heat in the phase change process of the phase change material to dissipate heat, which can avoid the problem of performance degradation of the battery caused by excessive temperature fluctuation in the battery shell, and can be reused with a long service life, when it enters the inside of the battery shell together with the heat dissipation block, it can improve the absorption effect of the heat in the internal environment, and slowly dissipate to the external environment after the heat dissipation block is reset.

[0015] As a further improvement of the application, the positive terminal cover and the shell are integrally formed, a positive terminal mounting hole matched with the positive terminal is formed at the center of the positive terminal cover, a negative terminal mounting hole matched with the negative pole of the lithium battery is formed at the center of the negative terminal cover, a sealing ring is installed at the positive terminal mounting hole and the negative terminal mounting hole, and the negative terminal cover is connected with the shell by encapsulation.

[0016] A preparation process of a low-internal-resistance lithium-to-dry battery, comprising the following steps:

[0017] S1, a lithium battery unit and a voltage conversion unit are prepared;

[0018] S2, the thermal expansion piece is fixedly installed in the area close to the positive terminal cover in the shell by welding or bonding;

[0019] S3, then the voltage conversion unit is pushed into the negative terminal cover from the bottom of the shell, and then the lithium battery unit is installed in the battery shell and abuts against the voltage conversion unit;

[0020] S4, the lithium battery negative pole is packaged through the negative terminal cover, so that the battery shell becomes a sealed packaging body.

[0021] Compared with the prior art, the advantages of the present application are:

[0022] (1) The present scheme fills the conductive liquid between the negative terminal and the lithium battery positive pole by adopting the multi-point contact mode, significantly increases the contact area, reduces the contact resistance, not only reduces the energy loss in the battery, improves the energy conversion efficiency of the battery, but also prolongs the service life of the battery.

[0023] (2) The thermal expansion piece of the present scheme can automatically adjust the contact pressure according to the temperature change of the battery, ensure that stable electrical contact can be maintained at different temperatures, this temperature compensation mechanism effectively avoids the problem of increasing contact resistance caused by temperature change, improves the stability and reliability of the battery system, especially in high temperature environment, the thermal expansion piece can significantly increase the contact pressure between the electrodes, reduce the contact resistance, and prevent the performance of the battery from declining.

[0024] (3) The heat dissipation piece of the present scheme adopts a phase change heat absorption material, which can absorb a large amount of heat when the battery temperature rises, stabilize the internal temperature of the battery, at the same time, the heat dissipation piece is linked with the thermal expansion piece, when the battery temperature is too high, the heat dissipation hole is automatically opened, the heat dissipation is accelerated, and rapid cooling is realized, this self-heating design effectively prevents the safety problem caused by overheating of the battery, and improves the service life of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0026] Figure 2 It is a schematic diagram of the side view structure of the present application;

[0027] Figure 3 It is a schematic diagram of the bottom view structure of the present application;

[0028] Figure 4Fig. 1 is a schematic diagram of the cross-sectional structure of the present application;

[0029] Figure 5 Fig. 4 is a schematic diagram of the heat sink structure of the present application;

[0030] Figure 6 Fig. 5 is a schematic diagram of the cross-sectional structure of the positive and negative terminal parts of the lithium battery of the present application.

[0031] Explanation of the reference numerals in the figures:

[0032] 1, battery housing; 101, outer shell; 102, positive terminal cover; 103, negative terminal cover; 2, lithium battery cell; 201, lithium battery body; 202, lithium battery positive electrode; 2021, contact groove; 203, lithium battery negative electrode; 3, voltage conversion unit; 301, step-down circuit board; 302, negative terminal; 3021, contact protrusion; 303, positive terminal; 4, heat sink; 401, heat dissipation block; 402, heat dissipation column; 403, phase change heat absorption material; 5, thermal expansion piece; 501, guide ring; 502, moving ring; 503, thermal expansion pad; 504, elastic gasket. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] Embodiment:

[0035] Please refer to Figures 1-6 A low-internal-resistance lithium dry battery includes a battery housing 1, a lithium battery cell 2, a voltage conversion unit 3, and a thermal expansion piece 5. The battery housing 1 includes an outer shell 101, a positive terminal cover 102, and a negative terminal cover 103. The lithium battery cell 2 includes a lithium battery body 201, a lithium battery positive electrode 202, and a lithium battery negative electrode 203. The negative terminal cover 103 matches the lithium battery negative electrode 203. The voltage conversion unit 3 is electrically connected to the lithium battery positive electrode 202, and is used to convert the output voltage of the lithium battery cell 2 into a low voltage suitable for use in small-power electronic products. The thermal expansion piece 5 is fixedly installed in the outer shell 101, and is used to keep good electrical contact between the voltage conversion unit 3 and the lithium battery positive electrode 202.

[0036] The voltage conversion unit 3 comprises a step-down circuit board 301, a negative terminal 302 and a positive terminal 303, the step-down circuit board 301 is integrated with a high-efficiency step-down chip and peripheral circuits, and can stably convert the high voltage of the lithium battery unit 2 into a low voltage suitable for small-power electronic products, the negative terminal 302 is directly electrically connected with the input end of the step-down circuit board 301, the other side of the negative terminal 302 is electrically connected with the lithium battery positive electrode 202, the positive terminal 303 is electrically connected with the output end of the step-down circuit board 301 through a flexible wire, and the positive terminal cover 102 is matched with the positive terminal 303.

[0037] A plurality of integral and uniformly distributed contact protrusions 3021 are arranged at the lower end of the negative terminal 302, a plurality of contact grooves 2021 matched with the contact protrusions 3021 are arranged at the upper end of the lithium battery positive electrode 202, and the contact grooves 2021 are filled with conductive liquid. Through the multi-point contact mode, the contact area between the negative terminal 302 and the lithium battery positive electrode 202 is increased, so as to reduce the contact resistance. The conductive liquid can significantly reduce the contact resistance of the connection, and through the filling of the conductive liquid, the electrical connection between the negative terminal 302 and the lithium battery positive electrode 202 can be ensured to be smoother, the energy loss is reduced, the overall efficiency of the battery system is improved, and at the same time, the conductive liquid can fill the small gaps and uneven surfaces of the connection to form a uniform conductive layer, which can not only enhance the mechanical stability of the connection, but also prevent the electric spark or electric arc caused by poor contact, so as to improve the safety and reliability of the battery system. Compared with crimping, the negative terminal 302 and the lithium battery positive electrode 202 can be protected to a certain extent, and material damage caused by excessive contact pressure can be avoided.

[0038] The contact protrusions 3021 and the contact grooves 2021 are both circular truncated cone structures with large upper part and small lower part, the upper surface of the lithium battery positive electrode 202 is a small arc surface with an angle of 5-10 degrees. The circular truncated cone structure can further increase the contact area, and at the same time, when the contact protrusions 3021 and the contact grooves 2021 are just combined, there is a certain space for the conductive liquid inside to seep out from the gap, so as to fill the contact surface of the negative terminal 302 and the lithium battery positive electrode 202 to improve the conductivity. The arc surface design of the lithium battery positive electrode 202 can not only ensure the close fit of the connection, reduce the contact gap and avoid the influence of air or other impurities on the conductivity, but also facilitate the distribution of the conductive liquid on the surface after being squeezed out from the contact grooves 2021.

[0039] The thermal expansion piece 5 includes a guide ring 501 fixedly installed at the inner end of the shell 101, a moving ring 502 is arranged between the guide ring 501 and the voltage reduction circuit board 301, a plurality of uniformly distributed thermal expansion pads 503 are fixedly installed between the guide ring 501 and the moving ring 502, a plurality of uniformly distributed elastic washers 504 are fixedly installed at the end of the moving ring 502 close to the voltage reduction circuit board 301, the guide ring 501 can not only guide the installation of the voltage conversion unit 3, but also provide a positioning function, when the thermal expansion pads 503 are heated and expanded, the elastic washers 504 can be extruded through the moving ring 502 to apply contact pressure between the negative terminal 302 and the positive electrode 202 of the lithium battery, when the negative terminal 302 and the positive electrode 202 of the lithium battery are in close contact, the contact area increases and the contact resistance decreases, thereby improving the efficiency and stability of the electrical connection, and after the battery cools down, the negative terminal 302 and the positive electrode 202 of the lithium battery can restore their shapes, the contact pressure between the negative terminal 302 and the positive electrode 202 of the lithium battery can be reduced and kept stable, which can not only improve the stress fatigue of the material, but also avoid the problem of increased contact resistance caused by loose connection under the installation and vibration environment.

[0040] The thermal expansion pads 503 are made of materials with high thermal expansion coefficients, such as certain high-molecular polymers or metal alloys, for example, shape memory alloys, to ensure that they can quickly expand and generate sufficient thrust when the battery temperature rises; the elastic washers 504 are made of high-elasticity materials, such as silicone or spring steel sheets, which can deform and store energy when subjected to pressure, and can restore their original shape when the pressure is released.

[0041] The thermal expansion piece 5 can serve as a temperature compensation mechanism to automatically adjust the contact pressure according to the temperature change of the battery, which is very important in the thermal management of the battery system, and can ensure stable electrical contact at different temperatures. Through the expansion and contraction of the thermal expansion piece 5, the contact between the voltage conversion unit 3 and the positive electrode 202 of the lithium battery can be made more tight, thereby reducing the contact resistance and improving the reliability of the electrical connection. Although the spring contactor in the prior art can provide certain fault tolerance, its reliability may be affected in a long-term vibration, impact or temperature change environment, and the spring contactor may increase the thermal resistance, affecting the thermal management of the battery system.

[0042] A plurality of annularly arrayed heat dissipation holes are formed in the positive electrode end cover 102, and a heat dissipation piece 4 is embedded and installed in the heat dissipation holes, and the heat dissipation piece 4 is fixedly connected with the moving ring 502. The heat dissipation piece 4 is used to conduct heat from the inside of the battery shell 1 to the outside in the normal state, when the heat is too much and forces the thermal expansion piece 5 to trigger the thermal expansion action, the moving ring 502 moves to move the heat dissipation piece 4 as a whole inward and open the heat dissipation holes, at this time the heat in the battery shell 1 can be quickly dissipated to the outside for interaction, thereby achieving the effect of rapid cooling.

[0043] The heat dissipation piece 4 includes a heat dissipation block 401 movably embedded in the heat dissipation hole, and a heat dissipation column 402 fixedly connected between the heat dissipation block 401 and the moving ring 502. The guide ring 501 is provided with a plurality of guide holes matched with the heat dissipation column 402.

[0044] The heat dissipation block 401 is a hollow structure and filled with a phase change heat absorption material 403. The heat dissipation block 401 and the heat dissipation column 402 are made of a high-thermal-conductivity metal material, such as aluminum alloy or copper alloy. The hollow structure helps to reduce weight and improve heat dissipation efficiency. The phase change heat absorption material 403 uses the characteristic of absorbing a large amount of heat during the phase change of the phase change material to dissipate heat, which can avoid the performance degradation of the battery caused by excessive temperature fluctuation in the battery shell 1, and can be reused with a long service life. When the heat dissipation block 401 and the phase change heat absorption material 403 enter the inside of the battery shell 1, the absorption effect of the heat in the internal environment can be improved, and the heat can be slowly dissipated to the external environment after the heat dissipation block 401 is reset.

[0045] The positive end cover 102 is integrally formed between the shell 101, and the positive end cover 102 is provided with a positive mounting hole matched with the positive electrode 303 at the center. The negative end cover 103 is provided with a negative mounting hole matched with the lithium battery negative electrode 203 at the center. Sealing rings are installed at the positive mounting hole and the negative mounting hole, which are made of high-elastic rubber material and have good sealing performance and corrosion resistance, so as to ensure that the electrolyte in the battery will not leak. The negative end cover 103 is connected with the shell 101 by packaging, such as laser welding.

[0046] A preparation process of a low-internal-resistance lithium dry battery includes the following steps:

[0047] S1, a lithium battery unit 2 and a voltage conversion unit 3 are prepared. The lithium battery unit 2 includes the preparation of positive and negative electrodes and electrolyte. The voltage conversion unit 3 includes the preparation of a step-down circuit and a chip.

[0048] The lithium battery body 201 is made of high-performance lithium material, which has high energy density, long cycle life and stable electrochemical performance.

[0049] The lithium battery positive electrode 202 and the negative electrode 203: the positive electrode material is selected from lithium transition metal oxide with high specific capacity, and the negative electrode material is selected from graphite or silicon-based material to improve the overall performance of the battery.

[0050] The electrolyte: a high-conductivity and low-viscosity organic solvent system is used to ensure the rapid transmission of lithium ions and the efficient operation of the battery.

[0051] S2, the thermal expansion piece 5 is fixedly installed in the shell 101 near the positive end cover 102 by welding or bonding.

[0052] S3, then push the voltage conversion unit 3 from the bottom of the shell 101 into the fixed installation to the negative terminal cover 103, wherein the positive terminal 303 can be fixed in the positive installation hole by bonding or clamping, and then install the lithium battery unit 2 into the battery shell 1 and abut with the voltage conversion unit 3;

[0053] S4, encapsulate the lithium battery negative 203 through the negative terminal cover 103, so that the battery shell 1 becomes a closed package.

[0054] Working principle:

[0055] Voltage conversion and low resistance design:

[0056] The lithium battery unit 2 as an energy source, its positive 202 through the negative terminal 302 and voltage conversion unit 3 in the step-down circuit board 301, the contact convex 3021 at the lower end of the negative terminal 302 and the contact groove 2021 at the upper end of the lithium battery positive 202 through the filling of conductive liquid to form a multi-point contact, significantly increase the contact area, reduce the contact resistance, not only improve the efficiency of electrical connection, reduce the energy loss, also enhance the mechanical stability and safety of the connection.

[0057] The circular truncated cone structure of the contact convex 3021 and the contact groove 2021 and the arc surface design of the lithium battery positive 202 further promote the uniform distribution of the conductive liquid, ensure the tightness and reliability of the electrical connection.

[0058] Thermal expansion temperature compensation mechanism:

[0059] The thermal expansion 5 is composed of guide ring 501, moving ring 502, thermal expansion pad 503 and elastic washer 504, when the battery temperature rises, especially when the positive 202 and negative terminal 302 contact unstable leads to excessive resistance, more prone to generate a large amount of heat, thermal expansion pad 503 is heated and expanded, moving ring 502 is pushed to the direction of step-down circuit board 301, and then the elastic washer 504 is pressed against the negative terminal 302, increasing the contact area with the lithium battery positive 202, further reducing the contact resistance, when the battery cools down, the thermal expansion pad 503 returns to its original state, the contact pressure also decreases and remains stable, avoiding material stress fatigue and connection loose problem.

[0060] Thermal management and heat dissipation design:

[0061] The heat dissipation hole on the positive end cover 102 is inlaid with a heat dissipation piece 4, which is composed of a heat dissipation block 401 and a heat dissipation column 402, and the heat dissipation block 401 is filled with a phase change heat absorption material 403 inside. In the normal state, the heat dissipation piece 4 conducts the heat inside the battery shell 1 to the outside. When the battery temperature rises to a certain extent, the thermal expansion piece 5 triggers the action, and the moving ring 502 drives the heat dissipation piece 4 to move inward as a whole, opens the heat dissipation hole, accelerates the heat dissipation, realizes the rapid cooling, and the phase change heat absorption material 403 absorbs a large amount of heat in the phase change process, which helps to stabilize the internal temperature of the battery and avoid performance degradation.

[0062] Battery packaging and safety:

[0063] The battery shell 1 is composed of a shell 101, a positive end cover 102 and a negative end cover 103, the positive end cover 102 is integrally formed with the shell 101, which enhances the stability of the structure. The sealing ring is installed in the mounting hole on the positive end cover 102 and the negative end cover 103, which ensures the sealing of the battery interior and prevents electrolyte leakage. The negative end cover 103 is connected with the shell 101 by packaging, which completes the overall packaging of the battery and improves the safety and reliability of the battery.

[0064] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than by the foregoing description, and it is intended that all changes which come within the meaning and range of equivalency of the claims are resolvable position the present application. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0065] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other implementation manners which can be understood by those skilled in the art.

Claims

1. A low internal resistance lithium to dry cell battery characterized by: The application relates to a lithium battery unit, which comprises a battery shell (1), a lithium battery unit (2) and a voltage conversion unit (3). The battery shell (1) comprises a shell (101), a positive electrode end cover (102) and a negative electrode end cover (103). The lithium battery unit (2) comprises a lithium battery body (201), a lithium battery positive electrode (202) and a lithium battery negative electrode (203), wherein the negative electrode end cover (103) is matched with the lithium battery negative electrode (203). The voltage conversion unit (3) is electrically connected with the lithium battery positive electrode (202) and is used for converting the output voltage of the lithium battery unit (2) into low voltage suitable for small-power electronic products, wherein the voltage conversion unit (3) comprises a voltage reduction circuit board (301), a negative electrode terminal (302) and a positive electrode terminal (303), the negative electrode terminal (302) is directly electrically connected with the input end of the voltage reduction circuit board (301), the other side of the negative electrode terminal (302) is electrically connected with the lithium battery positive electrode (202), the positive electrode terminal (303) is electrically connected with the output end of the voltage reduction circuit board (301) through a flexible lead wire, and the positive electrode end cover (102) is matched with the positive electrode terminal (303). A thermal expansion piece (5) is fixedly installed in the shell (101) and is used for tightly abutting the voltage conversion unit (3) and the lithium battery positive electrode (202) to keep good electrical contact, wherein the thermal expansion piece (5) comprises a guide ring (501) fixedly installed at the inner end of the shell (101), a moving ring (502) arranged between the guide ring (501) and the voltage reduction circuit board (301), a plurality of uniformly distributed thermal expansion pads (503) fixedly installed between the guide ring (501) and the moving ring (502), a plurality of uniformly distributed elastic washers (504) fixedly installed at the end of the moving ring (502) close to the voltage reduction circuit board (301), a plurality of annularly arrayed heat dissipation holes formed in the positive electrode end cover (102), a heat dissipation piece (4) inlaid and installed in the heat dissipation holes, and the heat dissipation piece (4) is fixedly connected with the moving ring (502), wherein the heat dissipation piece (4) comprises a heat dissipation block (401) movably inlaid in the heat dissipation hole, a heat dissipation column (402) fixedly connected between the heat dissipation block (401) and the moving ring (502), and a plurality of guide holes matched with the heat dissipation column (402) formed in the guide ring (501).

2. The low internal resistance lithium-to-mercury battery according to claim 1, characterized in that: The lower end of the negative electrode terminal (302) is provided with a plurality of integrally formed and uniformly distributed contact protrusions (3021), and the upper end of the lithium battery positive electrode (202) is provided with a plurality of contact grooves (2021) matched with the contact protrusions (3021), and the contact grooves (2021) are filled with conductive liquid.

3. A low internal resistance lithium-to-mercury cell according to claim 2, characterized in that: The contact protrusions (3021) and the contact grooves (2021) are all circular truncated cone structures with the upper part being large and the lower part being small, the upper surface of the lithium battery positive electrode (202) is a tiny arc surface, and the corresponding angle is 5-10 degrees.

4. The low internal resistance lithium-to-mercury battery of claim 1, wherein: The heat dissipation block (401) is a hollow structure and is filled with phase change heat absorption material (403).

5. The low internal resistance lithium-to-mercury battery of claim 1, wherein: The positive end cover (102) is integrally formed with the shell (101), a positive mounting hole matched with the positive electrode terminal (303) is arranged at the center of the positive end cover (102), a negative mounting hole matched with the lithium battery negative electrode (203) is arranged at the center of the negative end cover (103), sealing rings are arranged at the positive mounting hole and the negative mounting hole, and the negative end cover (103) is connected with the shell (101) by encapsulation.

6. The process for preparing a low internal resistance lithium primary cell according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1, preparing a lithium battery unit (2) and a voltage conversion unit (3) in advance; S2, fixing and installing a thermal expansion element (5) in the area close to the positive end cover (102) in the shell (101) by welding or bonding; S3, then pushing the voltage conversion unit (3) into the negative end cover (103) from the bottom of the shell (101), and then installing the lithium battery unit (2) into the battery shell (1) and abutting against the voltage conversion unit (3); S4, encapsulating the lithium battery negative electrode (203) through the negative end cover (103), so that the battery shell (1) becomes a closed encapsulation body.

Images