Closed structure lithium battery unit with cooling closed compartment

Abstract

The invention relates to the technical field of lithium battery units, in particular to a closed structure lithium battery unit with a cooling closed compartment, and solves the problems that the overall sealing performance of the lithium battery unit needs to be relatively high for installation, so that heat generated in the charging and discharging process of the lithium battery unit cannot be dissipated in time, the interior of the lithium battery unit is easy to overheat, and the service life of the lithium battery unit is influenced. And the safe operation of the lithium battery unit is influenced. A closed structure lithium battery unit with a cooling closed compartment comprises a cooling liquid storage box, a battery pack upper shell and a battery pack lower shell, the battery pack upper shell and the battery pack lower shell are vertically symmetrical and connected through bolts, sealing clamping grooves are formed in the bottom face of the battery pack upper shell and the upper surface of the battery pack lower shell, and the cooling liquid storage box is arranged in the sealing clamping grooves. And a sealing ring is clamped on the inner side of the sealing clamping groove. On the premise that the sealing performance of the lithium battery unit is not damaged, dissipation of heat in the lithium battery unit is accelerated, and the situation that the running safety of the lithium battery is affected due to the fact that the interior of the lithium battery unit is overheated is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery cells, and specifically to a sealed structure lithium battery cell with a cooling sealed compartment. Background Art

[0002] A lithium battery cell is a type of battery with lithium metal or lithium alloy as the positive / negative electrode material and a non-aqueous electrolyte solution. Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain metallic lithium and are rechargeable. Lithium metal batteries have better safety, specific capacity, self-discharge rate, and performance-price ratio than lithium-ion batteries. Lithium metal batteries generally use manganese dioxide as the positive electrode material, metallic lithium or its alloy as the negative electrode material, and a non-aqueous electrolyte solution.

[0003] However, for the existing lithium battery cells, due to the need for high overall sealing for installation, the heat generated during the charging and discharging process of the lithium battery cells cannot be dissipated in time, resulting in easy overheating inside the lithium battery cells and affecting the safe operation of the lithium battery cells. Therefore, it does not meet the existing requirements, and for this reason, we propose a sealed structure lithium battery cell with a cooling sealed compartment. Summary of the Invention

[0004] The purpose of the present invention is to provide a sealed structure lithium battery cell with a cooling sealed compartment to solve the problems mentioned in the above background art, that is, for the lithium battery cells, due to the need for high overall sealing for installation, the heat generated during the charging and discharging process of the lithium battery cells cannot be dissipated in time, resulting in easy overheating inside the lithium battery cells and affecting the safe operation of the lithium battery cells.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A sealed structure lithium battery cell with a cooling sealed compartment, including a coolant storage tank, an upper battery pack housing, and a lower battery pack housing. The upper battery pack housing and the lower battery pack housing are symmetrically arranged up and down and are connected by bolts. Sealing grooves are provided on the bottom surface of the upper battery pack housing and the upper surface of the lower battery pack housing. Sealing rings are clamped inside the sealing grooves. A plurality of lithium battery sealed compartments are distributed in a rectangular array between the upper battery pack housing and the lower battery pack housing. A lithium battery cooling compartment is provided between the lithium battery sealed compartments and the upper battery pack housing and the lower battery pack housing. Water pipe clamping grooves are provided on the upper surface of the upper battery pack housing and the bottom surface of the lower battery pack housing. The end of the coolant storage tank facing the upper housing and the lower housing of the battery pack is fixedly penetrated with a coolant outlet pipe and a coolant recovery pipe. A first circulating cooling pump is fixedly installed at the end of the coolant outlet pipe. The output end of the first circulating cooling pump is fixedly connected with a coolant inlet pipe. The coolant inlet pipe is clamped inside the water pipe clamping groove at the bottom of the lower housing of the battery pack. And the end of the coolant inlet pipe away from the first circulating cooling pump passes through the lower housing of the battery pack and is fixedly connected to the bottom of the lithium battery cooling compartment. The end of the coolant recovery pipe is fixedly installed with a second circulating cooling pump. The input end of the second circulating cooling pump is fixedly connected with a coolant return pipe. The coolant return pipe is clamped inside the water pipe clamping groove at the top of the upper housing of the battery pack. And the end of the coolant return pipe away from the second circulating cooling pump passes through the upper housing of the battery pack and is fixedly connected to the top of the lithium battery cooling compartment.

[0006] Preferably, the lithium battery cooling compartment includes a cooling protective liquid bag. The inside of the cooling protective liquid bag is hollow and is communicated with the coolant return pipe and the coolant inlet pipe. A plurality of top buffer water bags are distributed in a rectangular array at the top of the cooling protective liquid bag. A plurality of bottom buffer water bags are distributed in a rectangular array at the bottom of the cooling protective liquid bag. Connecting water pipes are fixedly installed on the same side of the adjacent top buffer water bag and bottom buffer water bag from top to bottom. The ends of the connecting water pipes are communicated with the top buffer water bag and the bottom buffer water bag.

[0007] Preferably, two first docking branch pipes with coincident axes are fixedly installed on the outer side of the end of the coolant return pipe connected to the cooling protective liquid bag. A plurality of first docking branch pipes are fixedly installed on both sides of the first docking branch pipe. One end of the first docking branch pipe is fixedly connected to the top buffer water bag and is communicated with the inside of the top buffer water bag.

[0008] Preferably, two second docking branch pipes with coincident axes are fixedly installed on the outer side of the end of the coolant inlet pipe connected to the cooling protective liquid bag. A plurality of second docking branch pipes are fixedly installed on both sides of the second docking branch pipe. One end of the second docking branch pipe is fixedly connected to the bottom buffer water bag and is communicated with the inside of the bottom buffer water bag.

[0009] Preferably, the lithium battery enclosed compartment includes a battery wrapping housing. A lithium battery partition is detachably installed inside the battery wrapping housing. The lithium battery partition divides the inside of the battery wrapping housing into a plurality of lithium battery installation compartments. A single lithium battery is installed inside the lithium battery installation compartment.

[0010] Preferably, a plurality of plugging holes are provided on both the upper surface and the lower surface of the lithium battery partition and are distributed in a rectangular array. Heat dissipation grooves are provided between the plugging holes distributed on the upper and lower surfaces of the lithium battery partition. The heat dissipation grooves are communicated with the lithium battery installation compartments.

[0011] Preferably, heat dissipation plates are inlaid on the bottom surface of the top buffer water sac and the upper surface of the bottom buffer water sac. A plurality of heat dissipation hollow tubes are fixedly arranged in a rectangular array on the surface of the heat dissipation plate, and the heat dissipation hollow tubes extend through the insertion holes to the inside of the heat dissipation grooves.

[0012] Preferably, a closed partition board is arranged inside the heat dissipation groove. The closed partition board is fixed inside the lithium battery partition board to partition adjacent lithium battery installation compartments.

[0013] Preferably, a plurality of insertion positioning grooves distributed in a rectangular array are arranged on the upper surface and the bottom surface of the closed partition board. The number of the insertion positioning grooves is the same as that of the insertion holes and they correspond to each other one by one.

[0014] Preferably, the bottom end of the heat dissipation hollow tube extends to the inside of the insertion positioning groove. A closed cross insertion block is fixed inside the insertion positioning groove. The closed cross insertion block is inserted inside the heat dissipation hollow tube and the outer edge thereof fits with the inner wall of the heat dissipation hollow tube.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention comprehensively wraps the lithium battery unit by using the cooling protection liquid sac, the top buffer water sac and the bottom buffer water sac, absorbs the heat generated by the single lithium battery through the heat dissipation hollow tubes and the heat dissipation plates, and then dissipates the heat transferred to the inside of the battery wrapping shell by the single lithium battery and the heat absorbed by the heat dissipation plates and the heat dissipation hollow tubes through the flow of the cooling liquid in the cooling protection liquid sac, the top buffer water sac and the bottom buffer water sac. Without damaging the sealing performance of the sealed structure of the lithium battery unit, the heat dissipation inside the sealed structure of the lithium battery unit is accelerated, and the operation safety of the lithium battery is prevented from being affected by overheating inside the sealed structure of the lithium battery unit. 2. Due to the existence of the heat dissipation grooves in the present invention, the heat generated by the single lithium battery inside the lithium battery installation compartment can flow towards the ends of the heat dissipation hollow tubes, and the heat dissipation grooves inside the lithium battery partition board are partitioned by the closed partition board, so that the heat between adjacent lithium battery installation compartments will not be transmitted to each other, preventing heat interference caused by the mutual transmission of heat between adjacent single lithium batteries. And the ends of the heat dissipation hollow tubes are separated by the closed cross insertion blocks, so that the heat inside adjacent - the heat mixes after entering the heat dissipation hollow tubes for a certain distance, thus preventing the heat from flowing directly into another lithium battery installation compartment through the gap between the heat dissipation hollow tube and the closed partition board after the heat is too high at the end of the heat dissipation hollow tube. 3. The present invention uses the lithium battery partition board to divide the inside of the battery wrapping shell into a plurality of lithium battery installation compartments, making the single lithium batteries that make up the lithium battery unit independent of each other, so that the heat generated during the operation of the single lithium batteries inside adjacent lithium battery installation compartments will not be transmitted to each other, preventing heat interference caused by the mutual transmission of heat between adjacent single lithium batteries and affecting the operation of the single lithium batteries. Brief Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the whole of the present invention; Figure 2 is a structural sectional view of the upper housing and the lower housing of the battery pack of the present invention; Figure 3 is a schematic structural diagram of the lithium battery cooling compartment of the present invention; Figure 4 is an assembly schematic diagram of the lithium battery cooling compartment and the lithium battery closed compartment of the present invention; Figure 5 is Figure 4 an enlarged structural view of part A in; Figure 6 is a connection schematic diagram of the top buffer water bag and the bottom buffer water bag of the present invention; Figure 7 is a bottom view of the bottom buffer water bag of the present invention; Figure 8 is a schematic structural diagram of the lithium battery closed compartment of the present invention; Figure 9 is a transverse structural sectional view of the lithium battery partition of the present invention; Figure 10 is Figure 9 an enlarged structural view of part B in; Figure 11 is a schematic structural diagram of the closed cross plug-in block of the present invention.

[0017] In the figure: 1, coolant storage tank; 2, upper housing of the battery pack; 3, lower housing of the battery pack; 4, lithium battery cooling compartment; 401, cooling protection liquid bag; 402, top buffer water bag; 403, bottom buffer water bag; 404, connecting water pipe; 405, first docking branch pipe; 406, first docking branch pipe; 407, second docking branch pipe; 408, second docking branch pipe; 409, heat dissipation plate; 410, heat dissipation hollow pipe; 5, lithium battery closed compartment; 501, battery wrapping housing; 502, lithium battery partition; 503, lithium battery installation compartment; 504, single lithium battery; 505, plug-in hole; 506, closed partition; 507, heat dissipation groove; 508, plug-in positioning groove; 509, closed cross plug-in block; 6, coolant outlet pipe; 7, coolant recovery pipe; 8, coolant inlet pipe; 9, coolant return pipe; 10, water pipe clamping groove; 11, sealing card slot; 12, first circulating cooling pump; 13, second circulating cooling pump; 14, sealing ring. Detailed Description of the Invention

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0019] As shown Figures 1 to 3 in the figure, a sealed-structured lithium battery cell with a cooling closed compartment includes a coolant storage tank 1, an upper battery pack housing 2, and a lower battery pack housing 3. The upper battery pack housing 2 and the lower battery pack housing 3 are symmetrically arranged up and down and are connected by bolts. Sealing grooves 11 are provided on the bottom surface of the upper battery pack housing 2 and the upper surface of the lower battery pack housing 3. Sealing rings 14 are clamped inside the sealing grooves 11. A plurality of lithium battery closed compartments 5 are distributed in a rectangular array between the upper battery pack housing 2 and the lower battery pack housing 3. A lithium battery cooling compartment 4 is provided between the lithium battery closed compartments 5 and the upper battery pack housing 2 and the lower battery pack housing 3. Water pipe clamping grooves 10 are provided on the upper surface of the upper battery pack housing 2 and the bottom surface of the lower battery pack housing 3.

[0020] The end of the coolant storage tank 1 facing the upper battery pack housing 2 and the lower battery pack housing 3 is fixedly penetrated with a coolant outlet pipe 6 and a coolant recovery pipe 7. A first circulation cooling pump 12 is fixed to the end of the coolant outlet pipe 6. The output end of the first circulation cooling pump 12 is fixed with a coolant inlet pipe 8. The coolant inlet pipe 8 is clamped inside the water pipe clamping groove 10 at the bottom of the lower battery pack housing 3, and the end of the coolant inlet pipe 8 far from the first circulation cooling pump 12 passes through the lower battery pack housing 3 and is fixed to the bottom of the lithium battery cooling compartment 4. A second circulation cooling pump 13 is fixed to the end of the coolant recovery pipe 7. The input end of the second circulation cooling pump 13 is fixed with a coolant return pipe 9. The coolant return pipe 9 is clamped inside the water pipe clamping groove 10 at the top of the upper battery pack housing 2, and the end of the coolant return pipe 9 far from the second circulation cooling pump 13 passes through the upper battery pack housing 2 and is fixed to the top of the lithium battery cooling compartment 4.

[0021] The lithium battery cooling compartment 4 is used to wrap the lithium battery closed compartment 5 in which the single lithium battery 504 is installed. When the lithium battery cell is operating, the coolant stored inside the coolant storage tank 1 is extracted and sent into the lithium battery cooling compartment 4 through the coolant outlet pipe 6, the first circulation cooling pump 12, and the coolant inlet pipe 8. Then the coolant returns to the coolant storage tank 1 through the coolant return pipe 9, the second circulation cooling pump 13, and the coolant recovery pipe 7, realizing the circulating flow of the coolant, and dissipating the internal heat of the lithium battery cell during the flow of the coolant, avoiding overheating inside the lithium battery cell and affecting the operation and operation safety.

[0022] As shown Figures 4 to 7As shown, the lithium battery cooling compartment 4 includes a cooling protection liquid sac 401. The interior of the cooling protection liquid sac 401 is hollow and is connected to a coolant return pipe 9 and a coolant inlet pipe 8. A plurality of top buffer water sacs 402 are distributed in a rectangular array at the top of the cooling protection liquid sac 401, and a plurality of bottom buffer water sacs 403 are distributed in a rectangular array at the bottom of the cooling protection liquid sac 401. Connecting water pipes 404 are fixed on the same side of the adjacent top buffer water sac 402 and bottom buffer water sac 403. The ends of the connecting water pipes 404 are connected to the top buffer water sac 402 and the bottom buffer water sac 403. The coolant is transported into the interior of the cooling protection liquid sac 401 through the coolant inlet pipe 8 and the coolant in the interior of the cooling protection liquid sac 401 is refluxed through the coolant return pipe 9 to realize the circulating flow of the coolant.

[0023] On the outer side of the end of the coolant return pipe 9 connected to the cooling protection liquid sac 401, two first docking branch pipes 406 with coincident axes are fixed. A plurality of first docking branch pipes 405 are fixed on both sides of the first docking branch pipe 406. One end of the first docking branch pipe 405 is fixed to the top buffer water sac 402 and is connected to the interior of the top buffer water sac 402. On the outer side of the end of the coolant inlet pipe 8 connected to the cooling protection liquid sac 401, two second docking branch pipes 408 with coincident axes are fixed. A plurality of second docking branch pipes 407 are fixed on both sides of the second docking branch pipe 408. One end of the second docking branch pipe 407 is fixed to the bottom buffer water sac 403 and is connected to the interior of the bottom buffer water sac 403. The coolant in the coolant inlet pipe 8 is transported into the interior of the bottom buffer water sac 403 through the second docking branch pipe 408 and the second docking branch pipe 407. Then the coolant enters the top buffer water sac 402 from the connecting water pipe 404. Subsequently, the coolant enters the coolant return pipe 9 through the first docking branch pipe 405 and the first docking branch pipe 406. The coolant flows in the interior of the top buffer water sac 402 and the bottom buffer water sac 403 and dissipates heat from the top and bottom of the single lithium battery 504, improving the heat dissipation efficiency of the lithium battery.

[0024] As Figures 8 to 11 shown, the lithium battery enclosed compartment 5 includes a battery wrapping housing 501. A lithium battery partition 502 is detachably installed inside the battery wrapping housing 501. The lithium battery partition 502 divides the interior of the battery wrapping housing 501 into a plurality of lithium battery installation compartments 503. A single lithium battery 504 is installed on the inner side of the lithium battery installation compartment 503. The adjacent single lithium batteries 504 are enclosed and partitioned by the lithium battery partition 502 to prevent the heat between the adjacent single lithium batteries 504 from being transferred to each other and causing interference.

[0025] The upper surface and the lower surface of the lithium battery separator 502 are both provided with a plurality of insertion holes 505 distributed in a rectangular array. A heat dissipation groove 507 is provided between the insertion holes 505 distributed on the upper and lower surfaces of the lithium battery separator 502. The heat dissipation groove 507 communicates with the lithium battery installation compartment 503. The bottom surface of the top buffer water bag 402 and the upper surface of the bottom buffer water bag 403 are both inlaid with heat dissipation plates 409. A plurality of heat dissipation hollow tubes 410 are fixedly arranged in a rectangular array on the surface of the heat dissipation plate 409. The heat dissipation hollow tubes 410 pass through the insertion holes 505 and extend to the inside of the heat dissipation groove 507. The heat generated during the operation of the single lithium battery 504 enters the inside of the heat dissipation groove 507. After the heat enters the insertion positioning groove 508, it enters the heat dissipation hollow tube 410 from the hollow end of the heat dissipation hollow tube 410 and is transferred to the heat dissipation plate 409. The heat absorbed by the heat dissipation plate 409 is absorbed by the cooling liquid flowing in the top buffer water bag 402 and the bottom buffer water bag 403.

[0026] A closed partition 506 is arranged inside the heat dissipation groove 507. The closed partition 506 is fixed inside the lithium battery separator 502 to partition the adjacent lithium battery installation compartments 503. A plurality of insertion positioning grooves 508 are arranged on the upper surface and the bottom surface of the closed partition 506 in a rectangular array. The number of the insertion positioning grooves 508 is the same as that of the insertion holes 505 and they correspond one by one. The bottom end of the heat dissipation hollow tube 410 extends to the inside of the insertion positioning groove 508. A closed cross insertion block 509 is fixed inside the insertion positioning groove 508. The closed cross insertion block 509 is inserted inside the heat dissipation hollow tube 410 and the outer edge thereof fits with the inner wall of the heat dissipation hollow tube 410. By inserting the closed cross insertion block 509 inside the end of the heat dissipation hollow tube 410, the inside of the heat dissipation hollow tube 410 is divided into four regions. Cooperating with the closed partition 506 to completely partition the adjacent lithium battery installation compartments 503, so that the heat generated by the single lithium battery 504 inside the lithium battery installation compartment 503 will not enter the adjacent lithium battery installation compartment 503, but independently enter the inside of the heat dissipation hollow tube 410.

[0027] Working principle: When the lithium battery unit in a closed structure is charged and discharged, the single lithium battery 504 inside the lithium battery unit generates heat. The heat generated by the single lithium battery 504 flows in the lithium battery installation compartment 503. The heat enters the inside of the heat dissipation groove 507 from the lithium battery installation compartment 503. After the heat enters the inside of the heat dissipation groove 507, it enters the inside of the heat dissipation hollow tube 410 from the gap at the contact part between the end of the heat dissipation hollow tube 410 and the first butt joint branch pipe 406. Since the inside of the heat dissipation hollow tube 410 is divided into four regions by the closed cross insertion block 509, the heat inside the adjacent lithium battery installation compartments 503 independently enters the heat dissipation hollow tube 410 and then mixes, and there is no heat exchange between the adjacent lithium battery installation compartments 503; After heat enters the heat dissipation hollow tube 410, it is transferred to the heat dissipation plate 409 and absorbed by the heat dissipation plate 409. At this time, the power supplies of the first circulation cooling pump 12 and the second circulation cooling pump 13 are turned on and started. The first circulation cooling pump 12 extracts the coolant stored inside the coolant storage tank 1 through the coolant outlet pipe 6. The extracted coolant enters the inside of the cooling protection liquid sac 401 through the coolant inlet pipe 8. The coolant fills the inside of the cooling protection liquid sac 401. During the filling process, the coolant absorbs the heat transferred from the monomer lithium battery 504 to the cooling protection liquid sac 401 through the battery wrapping housing 501. After the inside of the cooling protection liquid sac 401 is filled with the coolant, the coolant return pipe 9 extracts the coolant in the cooling protection liquid sac 401 and sends it back to the coolant storage tank 1 through the second circulation cooling pump 13 and the coolant recovery pipe 7, realizing the circulating flow of the coolant, thereby dissipating the heat inside the sealed structure lithium battery unit; While the coolant inlet pipe 8 conveys cooling, part of the coolant enters the inside of the bottom buffer water sac 403 through the second docking branch pipe 408 and the second docking branch pipe 407. The coolant flows inside the bottom buffer water sac 403 and absorbs and takes away the heat of the heat dissipation plate 409 in contact with the bottom buffer water sac 403. The coolant enters the inside of the top buffer water sac 402 from the bottom buffer water sac 403 through the connecting water pipe 404. When the coolant flows inside the top buffer water sac 402, it absorbs and takes away the heat of the heat dissipation plate 409 in contact with the top buffer water sac 402. Thereby, the heat accumulated inside the lithium battery installation compartment 503 is dissipated through the heat dissipation plate 409 and the heat dissipation hollow tube 410. The coolant that absorbs heat enters the coolant return pipe 9 through the first docking branch pipe 405 and the first docking branch pipe 406 and returns to the coolant storage tank 1. On the premise of not destroying the sealing of the sealed structure lithium battery unit, the heat dissipation inside the sealed structure lithium battery unit is accelerated, and the overheating inside the sealed structure lithium battery unit is avoided, which affects the operation safety of the lithium battery.

[0028] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A sealed lithium battery cell with a cooling sealed compartment, comprising a coolant storage tank (1), an upper battery pack housing (2) and a lower battery pack housing (3), characterized in that: The upper housing (2) and the lower housing (3) of the battery pack are symmetric up and down and are connected by bolts. Sealing grooves (11) are provided on the bottom surface of the upper housing (2) of the battery pack and the upper surface of the lower housing (3) of the battery pack. A sealing ring (14) is clamped inside the sealing groove (11). A plurality of lithium battery closed compartments (5) are distributed in a rectangular array between the upper housing (2) and the lower housing (3) of the battery pack. A lithium battery cooling compartment (4) is provided between the lithium battery closed compartment (5) and the upper housing (2) and the lower housing (3) of the battery pack. Water pipe clamping grooves (10) are provided on the upper surface of the upper housing (2) and the bottom surface of the lower housing (3) of the battery pack; Coolant storage tank (1) is fixedly penetrated at the ends facing the upper housing (2) and the lower housing (3) of the battery pack with a coolant outlet pipe (6) and a coolant recovery pipe (7). A first circulating cooling pump (12) is fixed at the end of the coolant outlet pipe (6). The output end of the first circulating cooling pump (12) is fixed with a coolant inlet pipe (8). The coolant inlet pipe (8) is clamped inside the water pipe clamping groove (10) at the bottom of the lower housing (3) of the battery pack. And the end of the coolant inlet pipe (8) far from the first circulating cooling pump (12) passes through the lower housing (3) of the battery pack and is fixed to the bottom of the lithium battery cooling compartment (4). A second circulating cooling pump (13) is fixed at the end of the coolant recovery pipe (7). The input end of the second circulating cooling pump (13) is fixed with a coolant return pipe (9). The coolant return pipe (9) is clamped inside the water pipe clamping groove (10) at the top of the upper housing (2) of the battery pack. And the end of the coolant return pipe (9) far from the second circulating cooling pump (13) passes through the upper housing (2) of the battery pack and is fixed to the top of the lithium battery cooling compartment (4).

2. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 1, characterized in that: The lithium battery cooling compartment (4) includes a cooling protection liquid bag (401). The inside of the cooling protection liquid bag (401) is hollow and is communicated with the coolant return pipe (9) and the coolant inlet pipe (8). A plurality of top buffer water bags (402) are distributed in a rectangular array at the top of the cooling protection liquid bag (401). A plurality of bottom buffer water bags (403) are distributed in a rectangular array at the bottom of the cooling protection liquid bag (401). Connecting water pipes (404) are fixed on the same side of the adjacent top buffer water bag (402) and bottom buffer water bag (403) up and down. The ends of the connecting water pipes (404) are communicated with the top buffer water bag (402) and the bottom buffer water bag (403).

3. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 2, characterized in that: Two first docking branch pipes (406) with coincident axes are fixed on the outer side of the end of the coolant return pipe (9) connected to the cooling protection liquid bag (401). A plurality of first docking branch pipes (405) are fixed on both sides of the first docking branch pipe (406). One end of the first docking branch pipe (405) is fixed to the top buffer water bag (402) and is communicated with the inside of the top buffer water bag (402).

4. A sealed structure lithium battery unit with a cooling sealed compartment according to claim 3, characterized in that: On the outer side of the end of the coolant inlet pipe (8) connected to the cooling protection liquid bag (401), two second docking branch pipes (408) with coincident axes are fixed. On both sides of the second docking branch pipe (408), a plurality of second docking branch pipes (407) are fixed. One end of the second docking branch pipe (407) is fixed to the bottom buffer water bag (403) and is in internal communication with the bottom buffer water bag (403).

5. A sealed structure lithium battery unit with a cooling sealed compartment according to claim 4, characterized in that: The lithium battery closed compartment (5) includes a battery wrapping housing (501). Inside the battery wrapping housing (501), a lithium battery partition (502) is detachably installed. The lithium battery partition (502) divides the interior of the battery wrapping housing (501) into a plurality of lithium battery installation compartments (503). Inside the lithium battery installation compartment (503), a single lithium battery (504) is installed.

6. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 5, characterized in that: On the upper surface and the lower surface of the lithium battery partition (502), a plurality of plug holes (505) distributed in a rectangular array are provided. Between the plug holes (505) distributed on the upper and lower surfaces of the lithium battery partition (502), there are heat dissipation grooves (507). The heat dissipation grooves (507) are in communication with the lithium battery installation compartments (503).

7. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 6, characterized in that: On the bottom surface of the top buffer water bag (402) and the upper surface of the bottom buffer water bag (403), heat dissipation plates (409) are inlaid. On the surface of the heat dissipation plates (409), a plurality of heat dissipation hollow tubes (410) are fixedly arranged in a rectangular array. The heat dissipation hollow tubes (410) pass through the plug holes (505) and extend to the inside of the heat dissipation grooves (507).

8. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 7, characterized in that: Inside the heat dissipation grooves (507), a closed partition (506) is provided. The closed partition (506) is fixed inside the lithium battery partition (502) to partition adjacent lithium battery installation compartments (503).

9. A sealed structure lithium battery cell with a cooling sealed compartment according to claim 8, characterized in that: On the upper surface and the bottom surface of the closed partition (506), a plurality of plugging positioning grooves (508) distributed in a rectangular array are provided. The number of the plugging positioning grooves (508) is the same as that of the plug holes (505) and they correspond to each other one by one.

10. A sealed structure lithium battery unit with a cooling sealed compartment according to claim 9, characterized in that: The bottom end of the heat dissipation hollow tube (410) extends to the inside of the plugging positioning groove (508). Inside the plugging positioning groove (508), a closed cross plugging block (509) is fixed. The closed cross plugging block (509) is plugged inside the heat dissipation hollow tube (410) and its outer edge fits with the inner wall of the heat dissipation hollow tube (410).

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