Lithium battery with overload protection and preparation process thereof

Abstract

The invention relates to the technical field of lithium battery boxes, and discloses a lithium battery with overload protection and a preparation process thereof.The lithium battery comprises a battery box and a lithium battery cell, and a protective sleeve used for protecting the lithium battery cell is arranged in the battery box; the protective sleeve filled with the heat absorption phase change material is used for performing mechanical overload protection and thermal overload protection on the lithium battery cell. The invention further comprises preparation steps of the lithium battery. And a plurality of circulating pipes in different directions are distributed in the filling cavity. The protective sleeve is arranged in the battery box to accommodate the phase change material, so that mechanical overload protection and thermal overload protection of the lithium battery cell can be considered at the same time, and meanwhile, the phase change material in the protective sleeve can be circulated to obtain a better thermal overload protection effect; circulating pipes in different modes are arranged in the protective sleeve, so that a more uniform circulating effect is achieved; and a heat dissipation temperature control threshold value is set, so that the circulating pump is controlled to circulate the phase-change material in the circulating pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery boxes, and in particular to a lithium battery with overload protection and a preparation process thereof. Background Art

[0002] Lithium battery overload often occurs during special driving of electric vehicles and specific operation of consumer electronic devices. At this time, the current exceeds the design value, harmful reactions and changes occur inside, and the high current causes a sharp rise in temperature, which poses a risk of thermal runaway, causing safety accidents and accelerating damage to electrode materials and active substances, shortening cycle life, and reducing performance and endurance.

[0003] The prior art discloses a lithium battery with a self-protection function and a preparation process, with application number CN202010838009.5. The invention effectively realizes the connection between the overall mechanism and the external power equipment through the action of the electrode, thereby achieving the working purpose, and then through the protection circuit connected to the electrode, it can effectively prevent the overall mechanism from being overloaded, thereby effectively extending the service life of the overall mechanism, and then through the cooperation of the sleeve, buffer sleeve, slot and pin hole, effectively realizing the protection of the lithium battery body, greatly reducing the impact of vibration on the lithium battery body, thereby reducing the situation of poor contact, and then effectively ensuring the stability of the overall mechanism. However, the scheme still has the following technical problems:

[0004] Existing lithium battery cells are generally arranged inside the battery box. Overload phenomenon of lithium battery generally includes mechanical overload protection and thermal overload protection. Mechanical overload refers to mechanical damage of lithium battery caused by external impact or vibration, while thermal overload protection refers to battery overheating caused by abnormal input and output or other abnormalities of the battery. In order to take into account the overload protection problems of lithium battery cells from both aspects, we propose a lithium battery with overload protection and its preparation process. Summary of the invention

[0005] The purpose of the present invention is to provide a technical solution, in which a protective cover is provided to accommodate a phase change material, which can take into account both the mechanical overload protection and thermal overload protection problems of the lithium battery cell. At the same time, the phase change material inside the protective cover can be circulated to obtain a better thermal overload protection effect, so as to solve the problems in the prior art raised in the above background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A lithium battery with overload protection, comprising:

[0008] A battery box and a lithium battery cell, wherein a protective cover is provided inside the battery box, and the lithium battery cell is installed in a battery slot inside the protective cover, and the protective cover is provided as a cavity structure, and the cavity is provided as a filling cavity filled with an endothermic phase change material, and the protective cover filled with the endothermic phase change material is used to provide mechanical overload protection and thermal overload protection for the lithium battery cell;

[0009] A plurality of circulation tubes in different directions are distributed inside the filling cavity. When the endothermic phase change material absorbs the heat of the lithium battery cell and changes into a liquid state during thermal overload protection, the circulation tube circulates the endothermic phase change material inside the protective cover. Heat-conducting parts are arranged inside and outside the protective cover, and the heat-conducting parts inside and outside the protective cover are connected by a connecting part. The heat-conducting part outside the protective cover is attached to the lithium battery cell, and the heat-conducting part inside the protective cover is connected to a heat-conducting sleeve. The heat-conducting sleeve is sleeved on the circulation tube so that the heat of the lithium battery cell is firstly transferred to the circulation tube. A circulation pump for driving the circulation inside the circulation tube is arranged on the battery box.

[0010] Preferably, a first protrusion and a second protrusion are provided on the inner side of the protective cover, the first protrusion and the second protrusion are located on both sides of the battery slot, the first protrusion contacts the top and bottom ends of the lithium battery cell, and the second protrusion contacts both sides of the lithium battery cell.

[0011] Preferably, the circulation pipe includes a first circulation pipe, a second circulation pipe and a third circulation pipe. The three groups of circulation pipes are vertically staggered and each group is provided with multiple groups. The three groups of circulation pipes are commonly connected to two groups of connecting pipes used for liquid phase change materials respectively. The circulation pump circulates the three groups of circulation pipes simultaneously through the connecting pipes.

[0012] Preferably, the first circulation pipe and the second circulation pipe are provided with a first pair of joints, a plurality of groups of third circulation pipes are connected in parallel via a second pair of joints, and the first pair of joints and the second pair of joints are connected to the connecting pipe.

[0013] Preferably, it also includes an external circulation chamber, the connecting tube seal passes through the protective cover, the protective covers of multiple battery boxes are connected to the external circulation chamber through the connecting tube, and a circulation pump is provided on the external circulation chamber to simultaneously realize the circulation of liquid phase change inside the protective covers of multiple battery boxes through the external circulation chamber.

[0014] Preferably, the circulation pump is configured as a peristaltic pump, which includes a rotating member and an external pipeline, wherein both ends of the external pipeline are respectively connected to connecting pipes, and the rotating member continuously rotates to squeeze the external pipeline to realize the circulation of the circulating phase change material.

[0015] Preferably, the first circulation pipe, the second circulation pipe and the third circulation pipe are provided with circulation holes which are evenly distributed, and the phase change material enters the circulation pipe through the circulation holes to realize the circulation flow.

[0016] Preferably, the top of the first circulation tube and the third circulation tube are surrounded at the first raised portion to dissipate heat at the battery ear position of the lithium battery cell, and the second circulation tube is surrounded at the second raised portion to dissipate heat at the outer edge of the lithium battery cell.

[0017] Preferably, the heat conducting member and the heat conducting sleeve are arranged in multiple groups, the heat conducting sleeve is provided with multiple groups of temperature sensing probes, the multiple groups of temperature sensing probes are connected to the temperature sensor, the temperature sensor is connected to the PLC controller, the PLC controller is used to control the operation of the circulation pump, and the multiple groups of temperature sensing probes are arranged at multiple positions inside the protective cover; the temperature sensor simultaneously detects the multiple groups of temperature sensing probes, that is, the temperature sensor detects the temperature of multiple positions inside the protective cover, the PLC controller sets the temperature threshold range T degrees Celsius, when the temperatures of the multiple groups of temperature sensing probes are all higher than T degrees Celsius, the circulation pump is started to start the circulation of the phase change material, and when the temperatures of the multiple groups of temperature sensing probes are all lower than T degrees Celsius, the circulation pump is turned off to start the circulation of the phase change material.

[0018] The present invention also provides a process for preparing a lithium battery with overload protection, comprising the following steps:

[0019] Step 1: Install heat-conducting parts and heat-conducting sleeves on multiple groups of circulation pipes;

[0020] Step 2: Install the heat conducting member and multiple sets of circulation pipes in the protective cover, and connect the multiple sets of circulation pipes to the circulation pump;

[0021] Step 3: Put the protective cover into the battery box, and put the lithium battery cell into the protective cover;

[0022] Step 4: Close the battery box and place the battery box outside the battery box.

[0023] Technical effects and advantages of the present invention: Compared with the prior art, the lithium battery with overload protection and the preparation process thereof proposed by the present invention have the following advantages:

[0024] The present invention provides a protective cover inside the battery box to accommodate the phase change material, thereby taking into account the mechanical overload protection and thermal overload protection problems of the lithium battery cell at the same time. At the same time, the phase change material inside the protective cover can be circulated to obtain a better thermal overload protection effect; different types of circulation tubes are arranged inside the protective cover to obtain a more uniform circulation effect while focusing on the heat dissipation requirements of the lithium battery cell ear position; a heat dissipation temperature control threshold is set to control the circulation pump to circulate the phase change material inside the circulation tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the lithium battery of the present invention;

[0026] Figure 2It is a schematic structural diagram of a circulating pump of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the lithium battery cell and protective cover of the present invention;

[0028] Figure 4 This is a schematic diagram of the disassembly of the lithium battery cell and protective cover of the present invention;

[0029] Figure 5 For the present invention Figure 4 A schematic diagram of the enlarged structure at A in the middle;

[0030] Figure 6 It is a schematic diagram of the circulation mode of three groups of circulation pipes of the present invention;

[0031] Figure 7 This is a schematic diagram of the structure of the third circulation pipe of the present invention;

[0032] Figure 8 It is a front cross-sectional structural schematic diagram of a lithium battery cell and a protective sleeve of the present invention;

[0033] Fig. 9 For the present invention Figure 8 Schematic diagram of the enlarged structure at point B in the middle.

[0034] In the figure:

[0035] 11. Battery box; 12. Box cover; 13. Lithium battery cell; 14. Protective cover; 15. Battery slot;

[0036] 21. Circulation pump; 22. External pipeline; 23. Connecting pipe; 24. External circulation chamber; 25. Filling chamber; 26. First circulation pipe; 27. Second circulation pipe; 28. Third circulation pipe; 29. ​​First protrusion; 210. Second protrusion; 211. First pair of joints; 212. Circulation holes; 213. Second pair of joints; 214. Heat conducting member; 215. Heat conducting sleeve; 216. Connecting member; 217. Temperature sensing probe. DETAILED DESCRIPTION

[0037] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Various examples may omit, replace, or add various processes or components as needed. In addition, the features described in some examples may also be combined in other examples.

[0038] Embodiment 1: The invention provides Figures 1 to 3 As shown, a lithium battery with overload protection includes:

[0039] A battery box 11 and a lithium battery cell 13, wherein a protective cover 14 is disposed inside the battery box 11, and the lithium battery cell 13 is installed in a battery slot 15 inside the protective cover 14, and the protective cover 14 is configured as a cavity structure, and the cavity is configured as a filling cavity 25 filled with an endothermic phase change material, and the protective cover 14 filled with the endothermic phase change material is used to provide mechanical overload protection and thermal overload protection for the lithium battery cell 13;

[0040] A plurality of circulation pipes in different directions are distributed inside the filling cavity 25. When the endothermic phase change material absorbs the heat of the lithium battery cell 13 and changes into a liquid state during thermal overload protection, the circulation pipe circulates the endothermic phase change material inside the protective sleeve 14. The inside and outside of the protective sleeve 14 are both provided with heat-conducting parts 214, and the heat-conducting parts 214 inside and outside the protective sleeve 14 are connected by a connecting part 216. The heat-conducting parts 214 outside the protective sleeve 14 are attached to the lithium battery cell 13, and the heat-conducting parts 214 inside the protective sleeve 14 are connected with a heat-conducting sleeve 215, and the heat-conducting sleeve 215 is sleeved on the circulation pipe so that the heat of the lithium battery cell 13 is first conducted to the circulation pipe. The battery box 11 is provided with a circulation pump 21 for driving the circulation inside the circulation pipe.

[0041] Specifically, Figure 1 and Figure 3 As shown, a box cover 12 is provided on the top of the battery box 11. The closed structure formed by the box cover 12 and the battery box 11 encloses the lithium battery cell 13 and the protective cover 14 inside the box. The closed structure allows the protective cover 14 to cover the outside of the lithium battery cell 13, thereby obtaining a larger heat dissipation contact area while also buffering external mechanical impacts.

[0042] Regarding the setting of the phase change material, the phase change material is specifically selected from paraffin substances or other composite phase change materials with a melting point between 40-50°C. When the battery is overloaded and generates heat, and the temperature in the box rises to the melting point of the phase change material, the phase change material begins to change from solid to liquid, absorbing a large amount of heat in the process, thereby reducing the temperature peak in the battery box 11, playing a role in buffering and suppressing the temperature rise; the phase change material is encapsulated in a flat container of the battery box 11 made of aluminum alloy, and the battery box 11, the lithium battery cell 13 and the protective cover 14 are tightly fitted to ensure good shock absorption and heat conduction effects.

[0043] The following effects are achieved by setting up a circulation structure for the phase change material: uniform temperature distribution, the circulation structure enables the liquid phase change material to circulate inside the shell, and brings the phase change material from a higher temperature area to a lower temperature area; enhanced heat dissipation capacity, through circulation, the phase change material is more fully in contact with the inner wall of the protective cover 14 and the pipe wall of the circulation pipe, and the heat exchange efficiency is significantly improved; extended service life of the phase change material, when there is no circulation structure, the phase change material may gradually lose its performance after the phase change occurs due to being in a high temperature area for a long time; improved adaptability to mechanical overload, after the endothermic phase change material absorbs heat and becomes liquid, especially when the protective cover 14 is set to a soft structure at the same time, it can more effectively buffer external mechanical shocks.

[0044] like Figure 4 As shown, in order to make the contact area between the protective cover 14 and the lithium battery cell 13 larger, the inner side of the protective cover 14 is provided with a first protrusion 29 and a second protrusion 210, the first protrusion 29 and the second protrusion 210 are located on both sides of the battery slot 15, the first protrusion 29 contacts the top and bottom of the lithium battery cell 13, and the second protrusion 210 contacts both sides of the lithium battery cell 13. Specifically, the position of the lithium battery cell 13 that is not in contact with the first protrusion 29 and the second protrusion 210 can accommodate air, which is used for the design of other air circulation modes for the lithium battery.

[0045] like Figures 4 to 7 As shown, regarding the multiple circulation pipes distributed in different directions inside the filling cavity 25, in order to allow the phase change material inside the protective sleeve 14 to fully circulate after melting, the circulation pipes include a first circulation pipe 26, a second circulation pipe 27 and a third circulation pipe 28. The three groups of circulation pipes are vertically staggered and each group is provided with multiple groups. The three groups of circulation pipes are commonly connected to two groups of connecting pipes 23 for liquid phase change materials respectively. The circulation pump 21 circulates the three groups of circulation pipes simultaneously through the connecting pipes 23.

[0046] like Figures 5 to 7 As shown, regarding the connection method between the three groups of circulation pipes and the connecting pipe 23, as shown in Figure 5 As shown, the first circulation pipe 26 and the second circulation pipe 27 are provided with a first pair of joints 211 , and the plurality of third circulation pipes 28 are connected in parallel via a second pair of joints 213 . The first pair of joints 211 and the second pair of joints 213 are connected to the connecting pipe 23 .

[0047] like Figure 3 As shown, it also includes an external circulation chamber 24, the connecting tube 23 seals and penetrates the protective cover 14, and the protective covers 14 of multiple battery boxes 11 are connected to the external circulation chamber 24 through the connecting tube 23. A circulation pump 21 is provided on the external circulation chamber 24 to simultaneously realize the circulation of liquid phase change inside the protective covers 14 of multiple battery boxes 11 through the external circulation chamber 24.

[0048] like Figure 1 and Figure 2 As shown, the circulation pump 21 is configured as a peristaltic pump, which includes a rotating member and an external pipe 22. The two ends of the external pipe 22 are respectively connected to the connecting pipe 23. The rotating member continuously rotates and squeezes the external pipe 22 to realize the circulation of the circulating phase change material. The advantage of using a peristaltic pump as a circulation power source for the circulation pump 21 is that the flow rate can be accurately controlled and it has good adaptability to the medium in the pipe (including solid-liquid mixed phase change materials).

[0049] like Figure 6 and Figure 7 As shown, in order to make the internal circulation of the three groups of circulation pipes more diverse and uniform, the first circulation pipe 26, the second circulation pipe 27 and the third circulation pipe 28 are provided with evenly distributed circulation holes 212, and the phase change material enters the circulation pipe through the circulation holes 212 to realize circulation flow.

[0050] like Figure 4 As shown, in actual use, when the lithium battery cell 13 has a thermal overload problem, more heat is concentrated at the battery ear position of the lithium battery cell 13. In order to dissipate the heat of the lithium battery cell 13 in a targeted manner, the top of the first circulation tube 26 and the third circulation tube 28 are surrounded at the first protrusion 29 for dissipating the heat at the battery ear position of the lithium battery cell 13, and the second circulation tube 27 is surrounded at the second protrusion 210 for dissipating the heat at the outer edge of the lithium battery cell 13.

[0051] Regarding the control of phase change material cycles, such as Figure 8 and Fig. 9 As shown, the connector 216 seals and penetrates the protective sleeve 14, the heat-conducting member 214 and the heat-conducting sleeve 215 are arranged in multiple groups, the heat-conducting sleeve 215 is provided with multiple groups of temperature sensing probes 217, the multiple groups of temperature sensing probes 217 are connected to the temperature sensor, the temperature sensor is connected to the PLC controller, the PLC controller is used to control the operation of the circulation pump 21, the multiple groups of temperature sensing probes 217 are arranged at multiple positions inside the protective sleeve 14, the temperature sensor can detect the multiple groups of temperature sensing probes 217 at the same time, that is, the temperature sensor can detect the temperature of multiple positions inside the protective sleeve 14, the PLC controller sets the temperature threshold range T degrees Celsius, when the temperature of the multiple groups of temperature sensing probes 217 are all higher than T degrees Celsius, the circulation pump 21 is started to start the circulation of the phase change material, and when the temperature of the multiple groups of temperature sensing probes 217 are all lower than T degrees Celsius, the circulation pump 21 is closed to start the circulation of the phase change material.

[0052] Embodiment 2: The present invention also provides a process for preparing a lithium battery with overload protection, comprising the following steps:

[0053] Step 1: install the heat conductive member 214 and the heat conductive sleeve 215 on multiple groups of circulation pipes; Step 2: install the heat conductive member 214 and multiple groups of circulation pipes inside the protective cover 14, and connect the multiple groups of circulation pipes with the circulation pump 21; Step 3: install the protective cover 14 into the battery box 11, and install the lithium battery cell 13 into the protective cover 14; Step 4: close the battery box 11 and make the battery box 11 outside the battery box 11.

[0054] In summary, the present invention has the following comprehensive effects: when thermally overloaded, the heat of the lithium battery cell 13 is transferred to the circulation pipe through the internal and external heat conducting parts 214 and the heat conducting sleeve 215 of the protective sleeve 14, so that the phase change material reaches the melting point and liquefies and absorbs heat. Multiple groups of temperature sensing probes monitor the temperature. When the temperature exceeds the threshold value T set by the PLC controller, the circulation pump 21 (peristaltic pump) starts, the rotating part squeezes the external pipe 22, and the liquid phase change material circulates in the three groups of circulation pipes through the circulation holes 212 to dissipate heat evenly. When mechanically overloaded, the protective sleeve 14 and the phase change material in the closed structure of the battery box 11 and the box cover 12 buffer the external force. The first and second protrusions increase the contact area and reserve air buffer space. The protective sleeves 14 of multiple battery boxes 11 can also cooperate through the external circulation chamber 24 to cope with the changes in the phase change material caused by the impact. In terms of thermal overload protection, the circulation structure enhances heat dissipation, accurately controls temperature, and prolongs the life of the phase change material. It can quickly cool down, intelligently control the circulation, and reduce maintenance. In terms of mechanical overload protection, it can effectively buffer the impact, and the raised parts and air space can enhance the buffering effect and protect the battery cells. Overall, the multiple battery boxes 11 provide coordinated protection, improve the system stability, and the circulation pipes are reasonably arranged to dissipate heat from the battery ears and outer edges, making the heat dissipation uniform and efficient, improving the overall performance and reliability of the lithium battery, reducing the safety hazards and performance degradation caused by overload, and extending the service life. It is suitable for a variety of application scenarios that require high stability of lithium batteries.

[0055] The above describes an embodiment of the present invention, but this embodiment is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Under the guidance of this embodiment, ordinary technicians in this field can also make many forms, all of which are protected by this embodiment.

Claims

1. A lithium battery with overload protection, characterized in that: include: A battery box (11) and a lithium battery cell (13), wherein a protective cover (14) is arranged inside the battery box (11), and the lithium battery cell (13) is installed in a battery slot (15) inside the protective cover (14), and the protective cover (14) is arranged as a cavity structure, and the cavity is arranged as a filling cavity (25) filled with an endothermic phase change material, and the protective cover (14) filled with the endothermic phase change material is used to provide mechanical overload protection and thermal overload protection for the lithium battery cell (13); A plurality of circulation pipes in different directions are distributed inside the filling cavity (25); when the endothermic phase change material absorbs the heat of the lithium battery cell (13) and changes into a liquid state during thermal overload protection, the circulation pipe circulates the endothermic phase change material inside the protective sleeve (14); a heat conducting member (214) is arranged inside and outside the protective sleeve (14); the heat conducting members (214) inside and outside the protective sleeve (14) are connected via a connecting member (216); the heat conducting member (214) outside the protective sleeve (14) is attached to the lithium battery cell (13); the heat conducting member (214) inside the protective sleeve (14) is connected to a heat conducting sleeve (215); the heat conducting sleeve (215) is sleeved on the circulation pipe so that the heat of the lithium battery cell (13) is firstly transferred to the circulation pipe; and a circulation pump (21) for driving the circulation inside the circulation pipe is arranged on the battery box (11).

2. A lithium battery with overload protection according to claim 1, characterized in that: A first protrusion (29) and a second protrusion (210) are provided on the inner side of the protective cover (14); the first protrusion (29) and the second protrusion (210) are located on both sides of the battery slot (15); the first protrusion (29) contacts the top and bottom ends of the lithium battery cell (13); and the second protrusion (210) contacts both sides of the lithium battery cell (13).

3. A lithium battery with overload protection according to claim 2, characterized in that: The circulation pipes include a first circulation pipe (26), a second circulation pipe (27) and a third circulation pipe (28). The three groups of circulation pipes are arranged in a vertical staggered manner and multiple groups are provided. The three groups of circulation pipes are commonly connected to two groups of connecting pipes (23) respectively used for liquid phase change materials. The circulation pump (21) circulates the three groups of circulation pipes simultaneously through the connecting pipes (23).

4. A lithium battery with overload protection according to claim 3, characterized in that: The first circulation pipe (26) and the second circulation pipe (27) are provided with a first pair of joints (211), and a plurality of groups of third circulation pipes (28) are connected in parallel via a second pair of joints (213), and the first pair of joints (211) and the second pair of joints (213) are connected to the connecting pipe (23).

5. A lithium battery with overload protection according to claim 4, characterized in that: The invention also comprises an external circulation chamber (24), wherein the connecting pipe (23) seals and penetrates the protective sleeve (14), and the protective sleeves (14) of multiple battery boxes (11) are connected to the external circulation chamber (24) through the connecting pipe (23). A circulation pump (21) is provided on the external circulation chamber (24) so ​​as to realize the circulation of liquid phase change inside the protective sleeves (14) of multiple battery boxes (11) at the same time through the external circulation chamber (24).

6. A lithium battery with overload protection according to claim 4, characterized in that: The circulation pump (21) is configured as a peristaltic pump, which comprises a rotating member and an external pipe (22), wherein both ends of the external pipe (22) are respectively connected to connecting pipes (23), and the rotating member continuously rotates to squeeze the external pipe (22) to realize the circulation of the circulating phase change material.

7. A lithium battery with overload protection according to claim 3, characterized in that: The first circulation pipe (26), the second circulation pipe (27) and the third circulation pipe (28) are provided with circulation holes (212) which are evenly distributed, and the phase change material enters the circulation pipe through the circulation holes (212) to realize circulation flow.

8. A lithium battery with overload protection according to claim 3, characterized in that: The top of the first circulation tube (26) and the third circulation tube (28) are surrounded at the position of the first protrusion (29) for dissipating heat at the battery tab position of the lithium battery cell (13), and the second circulation tube (27) is surrounded at the position of the second protrusion (210) for dissipating heat at the outer edge of the lithium battery cell (13).

9. A lithium battery with overload protection according to claim 3, characterized in that: The heat conducting member (214) and the heat conducting sleeve (215) are arranged in a plurality of groups. The heat conducting sleeve (215) is provided with a plurality of groups of temperature sensing probes (217). The plurality of groups of temperature sensing probes (217) are connected to a temperature sensor. The temperature sensor is connected to a PLC controller. The PLC controller is used to control the operation of a circulation pump (21). The plurality of groups of temperature sensing probes (217) are arranged at a plurality of positions inside the protective sleeve (14). The temperature sensor simultaneously detects the plurality of groups of temperature sensing probes (217), that is, the temperature sensor detects the temperature of a plurality of positions inside the protective sleeve (14). The PLC controller sets a temperature threshold range of T degrees Celsius. When the temperatures of the plurality of groups of temperature sensing probes (217) are all higher than T degrees Celsius, the circulation pump (21) is started to start the circulation of the phase change material. When the temperatures of the plurality of groups of temperature sensing probes (217) are all lower than T degrees Celsius, the circulation pump (21) is closed to start the circulation of the phase change material.

10. A process for preparing a lithium battery with overload protection according to any one of claims 1 to 9, characterized in that: The steps include: Step 1, installing heat conducting members (214) and heat conducting sleeves (215) on multiple groups of circulation pipes; Step 2: insert the heat conducting member (214) and multiple groups of circulation pipes into the protective sleeve (14), and connect the multiple groups of circulation pipes to the circulation pump (21); Step 3: Install the protective cover (14) into the battery box (11), and install the lithium battery cell (13) into the protective cover (14); Step 4: close the battery box (11) and place the battery box (11) outside the battery box (11).

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