A method for the cascaded utilization of a new type of square battery

Abstract

The present application discloses a method for the cascade utilization of a new type of square battery. The new type of square battery includes a housing, a first pole column, a second pole column, and an electric core. The first pole column and the second pole column are electrically connected to the electric core respectively. The new type of square battery further includes a first side housing and a middle housing. The first side housing includes an outer side wall of the side housing and a first annular sliding wall. The middle housing includes an outer side wall of the middle housing and an inner slide rail on the side wall of the middle housing. Wherein, one end of the first annular sliding wall is connected to the outer side wall of the side housing, and the inner slide rail on the side wall of the middle housing is located inside the outer side wall of the middle housing. During the assembly process of the middle housing and the first side housing, the first annular sliding wall can be inserted into the inner slide rail on the side wall of the middle housing and slide within the inner slide rail on the side wall of the middle housing. The new type of square battery in the present application is convenient for improving the cycle performance and electrical performance of the battery under the condition of cascade utilization.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to batteries for cascade utilization. Background Art

[0002] With the advancement of the new energy industry, the application of lithium batteries is becoming more and more widespread, especially the popularity of new energy vehicles, but it also generates a large number of waste new energy vehicle batteries. Although these batteries can no longer meet the needs of new energy vehicles, they can still be used in cascades to meet the needs of other fields such as energy storage.

[0003] In the current lithium battery system, the size of the battery cell continues to expand as the cycle progresses, and with the formation of internal SEI and other materials, the electrolyte inside the battery that can be used for battery cell circulation is continuously consumed. Among them, the reduction in the amount of electrolyte required for battery cell circulation is an important factor affecting battery performance.

[0004] Application Contents

[0005] In order to solve the problems existing in the prior art, the present application discloses a novel cascade utilization method of a square battery, wherein the novel square battery comprises a first side shell, a middle shell, and a battery cell, wherein the battery cell is located in a space enclosed by the first side shell and the middle shell; air holes and liquid holes are respectively arranged on opposite sides of the middle shell, wherein the liquid holes are used for injecting and discharging electrolyte, and the air holes are used for discharging gas in the novel square battery during the process of injecting or discharging electrolyte; a part of the structure of the first side shell can slide relatively in the middle shell, thereby adjusting the size of the space enclosed by the first side shell and the middle shell;

[0006] The cascade utilization method includes a post-cycle electrolyte renewal process, and the post-cycle electrolyte renewal process includes the following steps:

[0007] Step R1, electrolyte cleaning: opening the pores and connecting the pores to an inert atmosphere, and opening the liquid holes to discharge the circulated electrolyte in the novel square battery;

[0008] Step R2, partially withdrawing the side shell: withdrawing the first side shell partially from the middle shell, so that the space enclosed by the first side shell and the middle shell is expanded;

[0009] Step R3, assembling the annular shell: arranging the annular shell on the outer surface of the portion of the first side shell that is pulled out from the middle shell, and connecting the annular shell to the first side shell and the middle shell;

[0010] Step R4, re-injecting: injecting new electrolyte into the space enclosed by the first side shell and the middle shell through the liquid hole;

[0011] Step R5, Sealing: Close the air hole and the liquid hole, and seal the connection part between the annular housing and the first side housing, and seal the connection part between the annular housing and the middle housing.

[0012] In the step R1, after discharging the recycled electrolyte, the following process is further included:

[0013] Inject new electrolyte into the new square battery through the liquid hole and close the liquid hole. After maintaining a preset time, open the liquid hole and discharge the electrolyte in the new square battery through the liquid hole. During the process of maintaining the preset time, the new square battery can be shaken uniformly, or the ultrasonic process can be added synchronously. The purpose is to discharge the impurities between the electrodes of the new square battery and the electrodes of the battery core through the new electrolyte. The impurities include SEI fragments, electrode materials that are separated from contact on the surface of the electrodes, etc.

[0014] The new square battery further includes a first pole column and a second pole column. The first pole column and the second pole column are arranged on the surface of the middle housing, and the first pole column and the second pole column are respectively electrically connected to the battery core; the first side housing includes a side housing outer wall and a first annular sliding wall, and the middle housing includes a middle housing outer wall and an inner slide rail on the side wall of the middle housing;

[0015] Among them, one end of the first annular sliding wall is connected to the side housing outer wall, and the inner slide rail on the side wall of the middle housing is located inside the middle housing outer wall. During the assembly process of the middle housing and the first side housing, the first annular sliding wall can be inserted into the inner slide rail on the side wall of the middle housing and slide inside the inner slide rail on the side wall of the middle housing. Along the insertion direction, the cross-section of the first annular sliding wall is a closed structure, and the cross-section of the middle housing is also a closed structure. The projection of the cross-section of the first annular sliding wall falls within the projection of the cross-section of the middle housing outer wall; thus, by the sliding of the first annular sliding wall inside the inner slide rail on the side wall of the middle housing, it is convenient to increase the internal space size of the new square battery, which not only provides space for the expansion of the battery core but also facilitates the replenishment of sufficient electrolyte, thereby improving the service life of the new square battery and further improving the performance and utilization value of the cascade battery;

[0016] Along the insertion direction, the length of the first annular sliding wall is not less than 5 cm;

[0017] After the middle housing and the first side housing are assembled, a sealing ring is provided between the inner slide rail on the side wall of the middle housing and the first annular sliding wall. Multiple sealing rings can be provided to improve the sealing performance of the new square battery. At the same time, the length of the first annular sliding wall is not less than 5 cm to facilitate the setting of multiple sealing rings. The cross-sectional diameter of the sealing ring used is 10-20 mm. When the diameter of the sealing ring is less than 10 mm, about 5 mm of the sealing ring is fixed inside the wall of the inner slide rail on the side wall of the middle housing. When sliding inside the inner slide rail on the side wall of the middle housing, the stability is poor. When the cross-sectional diameter of the sealing ring is greater than 10 mm, such as 10-20 mm, about 5-10 mm of the sealing ring is fixed inside the wall of the inner slide rail on the side wall of the middle housing, so the stability is good. When the cross-sectional diameter of the sealing ring is greater than 20 mm, more than 10 mm of the sealing ring will leak outside the wall of the inner slide rail on the side wall of the middle housing, which means that there is a distance of more than 10 mm between the first annular sliding wall and the inner slide rail on the side wall of the middle housing except for the position of the sealing ring. Under this distance, according to the experiments on the viscosity and wettability of the electrolyte, it is easy for the electrolyte to leak between the first annular sliding wall and the inner slide rail on the side wall of the middle housing under the external negative pressure environment. When the length of the first annular sliding wall is not less than 5 cm, at least 3 sealing rings can be set to further improve the sealing performance and stability.

[0018] The secondary utilization method further includes the assembly process of the new square battery. The assembly process of the new square battery is before the process of updating the electrolyte after the cycle. The assembly process of the new square battery includes the following steps:

[0019] Step S1, placing the battery cell in the middle housing: Keep the first side housing and the middle housing out of contact, place the battery cell in the middle housing, and connect the battery cell to the first pole and the second pole.

[0020] Step S2, closing and sealing the side housing: Completely insert the first annular sliding wall of the first side housing into the middle housing, and tightly connect the first side housing and the middle housing.

[0021] Step S3, injecting liquid: Open the air hole, and inject new electrolyte into the new square battery through the liquid hole.

[0022] Step S4, sealing: Close the air hole and the liquid hole, and seal the connection part between the middle housing and the first side housing. The sealing in both step R5 and step S4 can be carried out by coating with sealant.

[0023] The novel square battery further includes fastening screws and middle housing threaded holes, the middle housing threaded holes are located inside the outer side wall of the middle housing. After the middle housing and the first side housing are assembled, the fastening screws penetrate through the outer side wall of the side housing and the fastening screws are inserted into the middle housing threaded holes.

[0024] The novel square battery further includes a plurality of the fastening screws and a plurality of the middle housing threaded holes. The plurality of fastening screws are respectively located around the outer side wall of the side housing, and the plurality of middle housing threaded holes are respectively located outside the slide rails inside the side walls of the middle housing. This structural design can prevent the electrolyte from being contaminated by the screws, and at the same time improve the sealing performance of the novel square battery formed after the first side housing and the middle housing are assembled.

[0025] The air hole and the liquid hole are respectively located on two sides of the novel square battery, and the air hole, the first pole column and the second pole column are located on the same side;

[0026] The insertion direction is the width direction of the novel square battery, the insertion direction is perpendicular to the pole pieces of the battery cell, and the battery cell is formed by winding or stacking positive and negative pole pieces.

[0027] After the first annular sliding wall is partially pulled out from the slide rail inside the side wall of the middle housing, the annular housing can be located on the outer surface of the pulled-out part of the first annular sliding wall. The hardness of the material of the annular housing is not less than the hardness of the material of the middle housing, so as to prevent the annular housing from deforming first in case of abnormal situations such as external collisions, thereby causing damage to the entire novel square battery.

[0028] The annular housing includes an annular main housing and a packaging wall, and the packaging wall is detachably connected to the annular main housing.

[0029] The annular housing further includes an annular housing threaded hole. After the annular housing is located on the outer surface of the pulled-out part of the first annular sliding wall, the annular housing threaded hole corresponds to the middle housing threaded hole, and the fastening screw can pass through the annular housing threaded hole.

[0030] The method disclosed in this application has the following advantages:

[0031] The cascade utilization method of this application, combined with the structure of the novel square battery of this application, can, when the novel square battery is used for a period of time and then before being cascaded into other application scenarios, increase the internal space size of the novel square battery, and at the same time inject more electrolyte through the liquid hole, thereby increasing the service life and electrical performance of the original novel square battery. Description of the Drawings

[0032] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments.

[0033] Figure 1 It is a schematic diagram of the overall structure and section position of a conventional square battery of the present application.

[0034] Figure 2 It is a schematic diagram of the section structure of a conventional square battery of the present application.

[0035] Figure 3 It is a schematic diagram of the overall structure and section position of the novel square battery of the first embodiment of the present application.

[0036] Figure 4 It is a schematic diagram of the overall structure of the novel square battery of the first embodiment of the present application.

[0037] Figure 5 It is a schematic diagram of the section structure at the AA position of the novel square battery of the first embodiment of the present application.

[0038] Figure 6 It is a three-dimensional structure schematic diagram after pulling out the first annular sliding wall part of the novel square battery of the first embodiment of the present application.

[0039] Figure 7 It is a schematic diagram of the projection relationship between the first annular sliding wall and the outer side wall of the middle shell of the novel square battery of the present application.

[0040] Figure 8 It is a left view of the section structure at the BB position after pulling out the first annular sliding wall part of the novel square battery of the first embodiment of the present application.

[0041] Figure 9 It is a left view of the section structure at the BB position after pulling out the first annular sliding wall part of the novel square battery of the first embodiment of the present application and adding an annular shell.

[0042] Figure 10 It is a three-dimensional diagram of the annular shell structure of the novel square battery of the present application.

[0043] Figure 11 It is a schematic diagram of the electrolyte update process after cycling the cascade utilization method of the present application.

[0044] Figure 12 It is a schematic diagram of the corresponding structure of the electrolyte update process after cycling of the present application, where Figure 12 The three diagrams inside respectively correspond to the structure diagrams after the R1, R2, and R3 processes.

[0045] Figure 13 It is a schematic diagram of the assembly process of the cascade utilization method of the present application.

[0046] Figure 14 is a schematic diagram of the assembly process of this application, where Figure 13 the two figures inside respectively correspond to the schematic diagrams of the structures after the S1 and S2 processes. Embodiment

[0047] Next, the technical solutions of the embodiments of the present invention will be described clearly and completely;

[0048] Next, the present invention will be further described in conjunction with specific embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention. Next, the technical solutions of the embodiments of this application will be described clearly and completely; the orientation expressions involved in this application, such as up and down, etc., are all positioned according to the layout mode of the views of this application.

[0049] Figure 1 is the structure of the existing conventional square battery 1, Figure 2 is the AA cross-sectional view of the structure of the existing conventional square battery 1. It can be seen that the outer shell 11 of the conventional square battery 1 is an integral structure. When the battery cell 14 expands square, the size of the outer shell 11 cannot be adjusted, and at the same time, the electrolyte cannot be supplemented or updated;

[0050] To solve the problems existing in the prior art,

[0051] As Figures 3 - 11 shown, to solve the problems existing in the prior art, this application discloses a method for the cascade utilization of a new type of square battery 2. The new type of square battery 2 includes a first side shell 21, a middle shell 22, and a battery cell 14. The battery cell 14 is located in the space surrounded by the first side shell 21 and the middle shell 22; air holes 31 and liquid holes 32 are respectively arranged on the opposite sides of the middle shell 22. The liquid hole 32 is used for injecting and flowing out the electrolyte, and the air hole 31 is used for discharging the gas in the new type of square battery 2 during the process of injecting or flowing out the electrolyte; a part of the structure of the first side shell 21 can slide relative to the middle shell 22, so as to adjust the size of the space surrounded by the first side shell 21 and the middle shell 22;

[0052] The first side shell 21 is located on one side of the middle shell 22. There may also be a second side shell 23 on the other side of the middle shell 22. The structure of the second side shell 23 is the same as that of the first side shell 21, and the connection relationship between the second side shell 23 and the middle shell 22 is the same as that between the first side shell 21 and the middle shell 22;

[0053] When only the first side housing 21 of the middle housing 22 is for the first embodiment, and when there is a first side housing 21 on one side of the middle housing 22 and a second side housing 23 on the other side at the same time, it is the second embodiment;

[0054] The stepwise utilization method includes a post-cycle electrolyte update process, and the post-cycle electrolyte update process includes the following steps:

[0055] Step R1, electrolyte cleaning: Open the air hole 31 and connect the air hole 31 to an inert atmosphere. Open the liquid hole 32 to discharge the post-cycle electrolyte in the new square battery 2.

[0056] Step R2, partially extract the side housing: Partially extract the first side housing 21 from the middle housing 22 to expand the space enclosed by the first side housing 21 and the middle housing 22.

[0057] Step R3, assemble the ring-shaped housing 4: Arrange the ring-shaped housing 4 on the outer surface of the part of the first side housing 21 extracted from the middle housing 22, and connect the ring-shaped housing 4 to the first side housing 21 and the middle housing 22.

[0058] Step R4, refill the liquid: Inject new electrolyte into the space enclosed by the first side housing 21 and the middle housing 22 through the liquid hole 32.

[0059] Step R5, sealing: Close the air hole 31 and the liquid hole 32, and seal the connection part between the ring-shaped housing 4 and the first side housing 21, and seal the connection part between the ring-shaped housing 4 and the middle housing 22.

[0060] In the step R1, after discharging the post-cycle electrolyte, the following process is further included:

[0061] Inject new electrolyte into the new square battery 2 through the liquid hole 32, close the liquid hole 32 and keep it for a preset time, then open the liquid hole 32 to discharge the electrolyte in the new square battery 2 through the liquid hole 32. During the process of keeping the preset time, the new square battery 2 can be shaken uniformly, or the ultrasonic process can be added synchronously. The purpose is to discharge the impurities between the inside of the new square battery 2 and the electrodes of the battery cell 14 through the new electrolyte. The impurities include SEI fragments, electrode materials that are separated from contact on the surface of the electrodes, etc.;

[0062] At Figure 1 In the AA section position, the battery cell 14 is not cut, only part of the structure of the outer housing 11 is cut. The AA section position corresponds to the interface position between the middle housing 22 and the first side housing 21 in Figure 3 at the same time;

[0063] The novel square battery 2 further includes a first pole column 12 and a second pole column 13. The first pole column 12 and the second pole column 13 are arranged on the surface of the middle housing 22, and the first pole column 12 and the second pole column 13 are electrically connected to the battery cell 14 respectively; the first side housing 21 includes a side housing outer side wall 211 and a first annular sliding wall 212, and the middle housing 22 includes a middle housing outer side wall 221 and an inner slide rail 2211 on the side wall of the middle housing;

[0064] Wherein, one end of the first annular sliding wall 212 is connected to the side housing outer side wall 211, and the inner slide rail 2211 on the side wall of the middle housing is located inside the middle housing outer side wall 221. During the assembly process of the middle housing 22 and the first side housing 21, the first annular sliding wall 212 can be inserted into the inner slide rail 2211 on the side wall of the middle housing and slide inside the inner slide rail 2211 on the side wall of the middle housing. Along the insertion direction, the cross-section of the first annular sliding wall 212 is a closed structure, and the cross-section of the middle housing 22 is also a closed structure. The projection 213 of the cross-section of the first annular sliding wall falls within the projection 222 of the cross-section of the middle housing outer side wall; thus, through the sliding of the first annular sliding wall 212 inside the inner slide rail 2211 on the side wall of the middle housing, it is convenient to increase the internal space size of the novel square battery 2, which not only provides space for the expansion of the battery cell 14, but also facilitates the replenishment of sufficient electrolyte, thereby improving the service life of the novel square battery 2 and further improving the performance and utilization value of the cascade battery;

[0065] Along the insertion direction, the length of the first annular sliding wall 212 is not less than 5 cm;

[0066] After the middle housing 22 and the first side housing 21 are assembled, a sealing ring 2212 is provided between the inner slide rail 2211 on the side wall of the middle housing and the first annular sliding wall 212. Multiple sealing rings 2212 can be provided to improve the sealing performance of the new square battery 2. At the same time, the length of the first annular sliding wall 212 is not less than 5 cm to facilitate the arrangement of multiple sealing rings 2212. The cross-sectional diameter of the used sealing ring 2212 is 10-20 mm. When the diameter of the sealing ring 2212 is less than 10 mm, about 5 mm of the sealing ring 2212 is fixed inside the wall of the inner slide rail 2211 on the side wall of the middle housing. When sliding inside the inner slide rail 2211 on the side wall of the middle housing, the stability is poor. When the cross-sectional diameter of the sealing ring 2212 is greater than 10 mm, such as 10-20 mm, about 5-10 mm of the sealing ring 2212 is fixed inside the wall of the inner slide rail 2211 on the side wall of the middle housing, so the stability is good. When the cross-sectional diameter of the sealing ring 2212 is greater than 20 mm, more than 10 mm of the sealing ring 2212 will leak outside the wall of the inner slide rail 2211 on the side wall of the middle housing, which means that there is a distance of more than 10 mm between the first annular sliding wall 212 and the inner slide rail 2211 on the side wall of the middle housing except at the position of the sealing ring 2212. Under this distance, according to the experiments on the viscosity and wettability of the electrolyte, it is easy to cause the leakage of the electrolyte between the first annular sliding wall 212 and the inner slide rail 2211 on the side wall of the middle housing under the external negative pressure environment. When the length of the first annular sliding wall 212 is not less than 5 cm, at least 3 sealing rings 2212 can be arranged to further improve the sealing performance and stability.

[0067] The secondary utilization method further includes the assembly process of the new square battery 2, which is before the process of updating the electrolyte after circulation. The assembly process of the new square battery 2 includes the following steps:

[0068] Step S1, placing the battery cell 14 into the middle housing 22: Keep the first side housing 21 and the middle housing 22 out of contact, place the battery cell 14 into the middle housing 22, and connect the battery cell 14 to the first pole 12 and the second pole 13.

[0069] Step S2, closing and sealing the side housing: Completely insert the first annular sliding wall 212 of the first side housing 21 into the middle housing 22, and tightly connect the first side housing 21 and the middle housing 22.

[0070] Step S3, injecting liquid: Open the air hole 31, and inject new electrolyte into the new square battery 2 through the liquid hole 32.

[0071] Step S4, Sealing: Close the air hole 31 and the liquid hole 32, and seal the connection part between the middle shell 22 and the first side shell 21. For the sealing in both Step R5 and Step S4, the way of applying sealant can be adopted for sealing;

[0072] The novel square battery 2 further includes fastening screws 51 and middle shell threaded holes 52. The middle shell threaded holes 52 are located inside the outer side wall 221 of the middle shell. After the middle shell 22 and the first side shell 21 are assembled, the fastening screws 51 penetrate through the outer side wall 211 of the side shell and the fastening screws 51 are inserted into the middle shell threaded holes 52.

[0073] The novel square battery 2 further includes a plurality of the fastening screws 51 and a plurality of the middle shell threaded holes 52. The plurality of fastening screws 51 are respectively located around the outer side wall 211 of the side shell, and the plurality of middle shell threaded holes 52 are respectively located outside the inner slide rail 2211 of the side wall of the middle shell. This structural design can prevent the electrolyte from being contaminated by the screws, and at the same time improve the sealing performance of the novel square battery 2 formed after the first side shell 21 and the middle shell 22 are assembled.

[0074] The air hole 31 and the liquid hole 32 are respectively located on both sides of the novel square battery 2, and the air hole 31, the first pole column 12 and the second pole column 13 are located on the same side;

[0075] The insertion direction is the width direction of the novel square battery 2, the insertion direction is perpendicular to the pole pieces of the battery core 14, and the battery core 14 is formed by winding or stacking positive and negative pole pieces.

[0076] After the first annular sliding wall 212 is partially pulled out from the inner slide rail 2211 of the middle shell side wall, the annular shell 4 can be located on the outer surface of the pulled-out part of the first annular sliding wall 212. The hardness of the material of the annular shell 4 is not less than the hardness of the material of the middle shell 22, which is to prevent the annular shell 4 from deforming first in case of abnormal situations such as external collision, thus causing damage to the entire novel square battery 2.

[0077] The annular shell 4 includes an annular main shell 41 and a packaging wall 42. The packaging wall 42 is detachably connected to the annular main shell 41.

[0078] The annular shell 4 further includes an annular shell threaded hole 43. After the annular shell 4 is located on the outer surface of the pulled-out part of the first annular sliding wall 212, the annular shell threaded hole 43 corresponds to the middle shell threaded hole 52, and the fastening screw 51 can pass through the annular shell threaded hole 43.

[0079] The method disclosed in this application has the following advantages:

[0080] The cascade utilization method of the present application, in combination with the structure of the new square battery 2 of the present application, can, when the new square battery 2 has been used for a period of time and before being cascaded and utilized in other application scenarios, increase the internal space size of the new square battery 2 and inject more electrolyte through the liquid holes 32, thereby increasing the service life and electrical performance of the original new square battery 2.

[0081] The above should be understood that these embodiments are only used to illustrate the present invention more clearly and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modification of the present invention by those skilled in the art all fall within the scope defined by the appended claims of the present application.

Claims

1. A method for the cascaded utilization of a new type of square battery, characterized in that, The novel square battery includes a first side housing, a middle housing, and an electric core, and the electric core is located in the space surrounded by the first side housing and the middle housing; air holes and liquid holes are respectively arranged on two opposite sides of the middle housing, the liquid holes are used for injecting and discharging electrolyte, and the air holes are used for discharging gas in the novel square battery during the injection or discharge of the electrolyte; a part of the structure of the first side housing can slide relatively in the middle housing, so as to adjust the size of the space surrounded by the first side housing and the middle housing. The secondary utilization method includes a process of updating the electrolyte after cycling, and the process of updating the electrolyte after cycling includes the following steps: Step R1, electrolyte cleaning: Open the air hole and connect the air hole to an inert atmosphere, open the liquid hole, and discharge the cycled electrolyte in the novel square battery. Step R2, partially extract the side housing: Partially extract the first side housing from the middle housing to expand the space surrounded by the first side housing and the middle housing. Step R3, assemble the ring-shaped housing: Arrange the ring-shaped housing on the outer surface of the part of the first side housing extracted from the middle housing, and connect the ring-shaped housing to the first side housing and the middle housing. Step R4, refill the liquid: Inject new electrolyte into the space surrounded by the first side housing and the middle housing through the liquid hole. Step R5, sealing: Close the air hole and the liquid hole, and seal the connection part between the ring-shaped housing and the first side housing, and seal the connection part between the ring-shaped housing and the middle housing.

2. The novel method for recycling square batteries according to claim 1, characterized in that: In step R1, after discharging the cycled electrolyte, the following process is further included: Inject new electrolyte into the novel square battery through the liquid hole and close the liquid hole. After maintaining for a preset time, open the liquid hole and discharge the electrolyte in the novel square battery through the liquid hole.

3. A method for the cascaded utilization of a novel square battery according to claim 2, characterized in that, The novel square battery further includes a first pole column and a second pole column, the first pole column and the second pole column are arranged on the surface of the middle housing, and the first pole column and the second pole column are respectively electrically connected to the electric core; the first side housing includes a side housing outer wall and a first ring-shaped sliding wall, and the middle housing includes a middle housing outer wall and an inner slide rail on the side wall of the middle housing. Wherein, one end of the first ring-shaped sliding wall is connected to the side housing outer wall, the inner slide rail on the side wall of the middle housing is located inside the middle housing outer wall, and during the assembly process of the middle housing and the first side housing, the first ring-shaped sliding wall can be inserted into the inner slide rail on the side wall of the middle housing and slide in the inner slide rail on the side wall of the middle housing. Along the insertion direction, the cross-section of the first ring-shaped sliding wall is a closed structure, the cross-section of the middle housing is also a closed structure, and the projection of the cross-section of the first ring-shaped sliding wall falls within the projection of the cross-section of the middle housing outer wall. Along the insertion direction, the length of the first ring-shaped sliding wall is not less than 5 cm. After the middle housing and the first side housing are assembled, a sealing ring is arranged between the inner slide rail on the side wall of the middle housing and the first ring-shaped sliding wall.

4. A method for the cascade utilization of a novel square battery according to claim 3, characterized in that, The above-mentioned secondary utilization method further includes the assembly process of a new type of square battery, which is before the electrolyte update process after the cycle. The assembly process of the new type of square battery includes the following steps: Step S1, placing the battery cell in the middle shell: Keep the first side shell disengaged from the middle shell, place the battery cell in the middle shell, and connect the battery cell to the first pole and the second pole; Step S2, closing and sealing the side shell: Completely insert the first annular sliding wall of the first side shell into the middle shell, and tightly connect the first side shell and the middle shell; Step S3, injecting liquid: Open the air hole, and inject new electrolyte into the new type of square battery through the liquid hole; Step S4, sealing: Close the air hole and the liquid hole, and seal the connection part between the middle shell and the first side shell.

5. A method for the cascaded utilization of a novel square battery according to claim 4, characterized in that, The new type of square battery further includes fastening screws and threaded holes in the middle shell. The threaded holes in the middle shell are located inside the outer side wall of the middle shell. After the middle shell and the first side shell are assembled, the fastening screws penetrate through the outer side wall of the side shell and the fastening screws are inserted into the threaded holes in the middle shell.

6. The method for cascade utilization of a novel square battery according to claim 5, characterized in that, The new type of square battery further includes a plurality of the fastening screws and a plurality of the threaded holes in the middle shell. The plurality of fastening screws are respectively located around the outer side wall of the side shell, and the plurality of threaded holes in the middle shell are respectively located outside the slide rails on the side wall of the middle shell.

7. The method for cascaded utilization of a novel square battery according to claim 6, characterized in that, The air hole and the liquid hole are respectively located on both sides of the new type of square battery, and the air hole, the first pole and the second pole are located on the same side; The insertion direction is the width direction of the new type of square battery, and the insertion direction is perpendicular to the electrode plate of the battery cell.

8. A method for the cascade utilization of a new type of square battery according to claim 7, characterized in that, When the first annular sliding wall is partially pulled out from the slide rail on the side wall of the middle shell, the annular shell can be located on the outer surface of the pulled-out part of the first annular sliding wall, and the hardness of the material of the annular shell is not less than the hardness of the material of the middle shell.

9. The method for cascade utilization of a novel square battery according to claim 8, characterized in that, The annular shell includes an annular main shell and a packaging wall, and the packaging wall is detachably connected to the annular main shell.

10. A method for the cascaded utilization of a novel square battery according to claim 9, characterized in that, The annular shell further includes threaded holes in the annular shell. After the annular shell is located on the outer surface of the pulled-out part of the first annular sliding wall, the threaded holes in the annular shell correspond to the threaded holes in the middle shell, and the fastening screws can pass through the threaded holes in the annular shell.

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