Liquid injection device and liquid injection method for lithium ion battery

Abstract

The application relates to the technical field of lithium ion battery production, and provides a liquid injection device and a liquid injection method for a lithium ion battery, the liquid injection device for the lithium ion battery comprising a sleeve cup assembly, a liquid injection needle and a lifting driving mechanism; the sleeve cup assembly is in a cylindrical shape, one end of the sleeve cup assembly is used for being sealingly connected with a liquid injection port of the lithium ion battery; one end of the liquid injection needle is used for sequentially penetrating through the other end of the sleeve cup assembly and the liquid injection port and extending into the bottom of the lithium ion battery; the other end of the liquid injection needle is used for being communicated with a liquid injection pump; the lifting driving mechanism is connected with the liquid injection needle, and the lifting driving mechanism is used for driving the liquid injection needle to move along the height direction of the lithium ion battery; the electrolyte is injected into the inside of the lithium ion battery through the liquid injection needle, air in the lithium ion battery can be effectively discharged, and the electrolyte can be fully absorbed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion battery production, and in particular to a liquid injection device and a liquid injection method for lithium ion batteries. BACKGROUND

[0002] Lithium ion batteries have the characteristics of high energy density, good cycle performance and no memory effect, and also have the advantages of safety, reliability and fast charging and discharging, and have been widely used in many fields.

[0003] Liquid injection is an important process in the production of lithium ion batteries. The existing liquid injection method is to set a sleeve cup on the liquid injection port of the lithium ion battery, pour the electrolyte into the lithium ion battery through the sleeve cup, and then put the lithium ion battery into a bell jar to promote the absorption of the electrolyte by vacuum and pressure. Since the sleeve cup contains a certain height of electrolyte, the electrolyte in the sleeve cup forms a liquid seal. This open type of liquid injection mode is easy to seal the air in the lithium ion battery, and the electrolyte is difficult to soak into the position with air in the lithium ion battery, resulting in poor electrolyte soaking and incomplete absorption of the electrolyte, which leads to poor quality of the lithium ion battery. SUMMARY

[0004] The present application provides a liquid injection device and a liquid injection method for lithium ion batteries to solve or improve the problem that the electrolyte is difficult to be fully absorbed during the liquid injection process of the existing lithium ion batteries.

[0005] The present application provides a liquid injection device for lithium ion batteries, comprising: a sleeve cup assembly, a liquid injection needle and a lifting driving mechanism; the sleeve cup assembly is in a cylindrical shape, one end of the sleeve cup assembly is used for sealing connection with the liquid injection port of the lithium ion battery; one end of the liquid injection needle is used for sequentially passing through the other end of the sleeve cup assembly and the liquid injection port to extend into the bottom of the lithium ion battery; the other end of the liquid injection needle is used for communication with a liquid injection pump; the lifting driving mechanism is connected with the liquid injection needle, and the lifting driving mechanism is used for driving the liquid injection needle to move along the height direction of the lithium ion battery.

[0006] According to the liquid injection device for lithium ion batteries provided by the present application, the sleeve cup assembly comprises: a cup body and a sealing piece; one end of the sealing piece is detachably connected with the cup body, and the other end of the sealing piece is connected with the liquid injection port.

[0007] According to the liquid injection device for lithium ion batteries provided by the present application, the liquid injection device for lithium ion batteries further comprises: a positioning sleeve; the positioning sleeve and the cup body are both in a cylindrical shape, the positioning sleeve is sleeved outside the cup body, a first groove is recessed in the outer side wall of one end of the cup body, and the sealing piece is connected with the first groove and the inner side wall of the positioning sleeve respectively.

[0008] The application provides a liquid injection device for a lithium ion battery, wherein the positioning sleeve is rotationally connected with the cup body; the positioning sleeve is provided with a clamping part, and a second groove is formed in one side of the clamping part which faces the cup body; the outer side wall of the cup body is provided with a protruding part which extends along the circumferential direction of the cup body, and a third groove is formed in the protruding part which extends along the axial direction of the cup body; the positioning sleeve has a first matching state and a second matching state with the cup body; in the first matching state, the clamping part is used for extending into the third groove, and the positioning sleeve can move along the extending direction of the third groove; in the second matching state, the protruding part extends into the second groove, and the positioning sleeve can rotate along the extending direction of the protruding part.

[0009] The application provides a liquid injection device for a lithium ion battery, wherein the clamping part and the third groove are both provided with two, and the two clamping parts and the two third grooves are one-to-one correspondingly arranged; wherein the two clamping parts are oppositely arranged.

[0010] The application provides a liquid injection device for a lithium ion battery, wherein the liquid injection device further comprises a translation driving mechanism; the translation driving mechanism is connected with the lifting driving mechanism, and is used for driving the lifting driving mechanism and the liquid injection needle to move along the direction which is perpendicular to the axial line of the lithium ion battery.

[0011] The application provides a liquid injection device for a lithium ion battery, wherein the liquid injection device further comprises a tray; the tray is used for supporting the lithium ion battery.

[0012] The application further provides a liquid injection method of the liquid injection device for a lithium ion battery.

[0013] One end of the sleeve-cup assembly is sealingly connected with the liquid injection port of the lithium ion battery;

[0014] The liquid injection needle is driven to sequentially pass through the sleeve-cup assembly and the liquid injection port and extend into the bottom of the lithium ion battery;

[0015] The liquid injection pump is opened, and the liquid injection needle is driven to ascend along the height direction of the lithium ion battery.

[0016] According to the liquid injection method, after the liquid injection pump is opened and the liquid injection needle is driven to move along the height direction of the lithium ion battery, the following steps are further included:

[0017] Driving the liquid injection needle to move out of the cup assembly, moving the cup assembly and the lithium ion battery into the bell jar, performing vacuumizing operation in the bell jar, and performing pressurizing operation in the bell jar after the vacuumizing operation.

[0018] According to the liquid injection method provided by the application, the end of the cup assembly is connected with the liquid injection port of the lithium ion battery, and the method comprises the following steps:

[0019] The sealing member is connected with one end of the cup body, and the positioning clamp sleeve is sleeved outside the cup body.

[0020] The liquid injection device and the liquid injection method for the lithium ion battery provided by the application are characterized in that the liquid injection needle is liftable, the end of the cup assembly is connected with the liquid injection port of the lithium ion battery during the liquid injection operation of the lithium ion battery, the cup assembly and the lithium ion battery form a container for receiving electrolyte together, the liquid level of the electrolyte is actually higher than the liquid injection port after the liquid injection is completed, that is, a certain amount of electrolyte is stored in the cup assembly, and the electrolyte in the cup assembly is completely absorbed into the lithium ion battery through the subsequent vacuumizing and pressurizing operations in the bell jar; the height of the liquid injection needle is gradually lowered through the lifting driving mechanism, the liquid injection needle is inserted into the cup assembly from the other end of the cup assembly, and then is inserted into the bottom of the lithium ion battery through the liquid injection port, the liquid injection pump is started, the electrolyte is directly injected into the bottom of the lithium ion battery under the guidance of the liquid injection needle, the liquid level of the electrolyte in the lithium ion battery is gradually raised, and at the same time, the lifting driving mechanism drives the liquid injection needle to synchronously rise, so as to realize the layer-by-layer injection of the electrolyte, avoid the influence of the too deep immersion depth of the liquid injection needle on the absorption of the electrolyte, and improve the absorption efficiency of the electrolyte; the electrolyte is directly injected into the lithium ion battery, the air in the lithium ion battery is gradually squeezed out by the electrolyte during the rising of the liquid level of the electrolyte, and is discharged through the liquid injection port, the phenomenon that the electrolyte is liquid-sealed to cause the air to be difficult to discharge is avoided, the air content in the lithium ion battery is correspondingly reduced, the influence of the residual air on the absorption of the electrolyte is avoided, the absorption rate of the electrolyte is improved, the impregnation effect of the electrolyte is ensured, and the quality of the lithium ion battery is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0022] Figure 1 is a structural schematic view of the liquid injection device for the lithium ion battery provided by the application.

[0023] Figure 2 is one of the structural schematic diagrams of the cup provided by the application;

[0024] Figure 3 is one of the structural schematic diagrams of the cup provided by the application;

[0025] Figure 4 is one of the structural schematic diagrams of the positioning sleeve provided by the application;

[0026] Figure 5 is one of the structural schematic diagrams of the positioning sleeve provided by the application;

[0027] Figure 6 is one of the structural schematic diagrams of the injection needle provided by the application;

[0028] Figure 7 is one of the structural schematic diagrams of the injection needle provided by the application;

[0029] Reference signs:

[0030] 1: sleeve cup assembly; 11: cup; 111: first groove; 112: protrusion; 113: third groove; 12: sealing element; 2: injection needle; 21: first segment; 22: second segment; 3: lifting drive mechanism; 4: lithium ion battery; 5: positioning sleeve; 51: clamping portion; 511: second groove; 6: translation drive mechanism; 7: tray. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "connected", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0034] The following will be described in combination with Figures 1 to 7 The present application provides a kind of for lithium ion battery and injection method of injection device.

[0035] Wherein, when the injection operation is carried out, the lithium ion battery is vertically placed, and the injection port of the lithium ion battery is upwards.

[0036] As Figure 1 The injection device for lithium ion battery shown in the embodiment includes: sleeve cup assembly 1, injection needle 2 and lifting drive mechanism 3.

[0037] Sleeve cup assembly 1 is cylindrical, one end of sleeve cup assembly 1 is used to be sealedly connected with the injection port of lithium ion battery 4;One end of injection needle 2 is used to be sequentially inserted into the bottom of lithium ion battery 4 through the other end of sleeve cup assembly 1 and injection port;The other end of injection needle 2 is used to communicate with injection pump;Lifting drive mechanism 3 is connected with injection needle 2, and lifting drive mechanism 3 is used to drive injection needle 2 to move along the height direction of lithium ion battery 4.

[0038] Specifically, the liquid injection device for lithium ion battery shown in the embodiment is provided with a liftable liquid injection needle 2. When the lithium ion battery 4 is subjected to liquid injection operation, one end of the sleeve cup assembly 1 is sealingly connected with the liquid injection port of the lithium ion battery 4. The sleeve cup assembly 1 and the lithium ion battery 4 jointly form a container for receiving electrolyte. During the liquid injection process, the lithium ion battery 4 cannot completely absorb the electrolyte in a short time. The liquid level of the electrolyte after the liquid injection is actually higher than the liquid injection port, that is, a certain amount of electrolyte is stored in the sleeve cup assembly 1. Subsequently, the vacuum and pressure operation in the bell jar makes the electrolyte in the sleeve cup assembly 1 completely absorbed into the lithium ion battery. The lifting driving mechanism 3 gradually lowers the height of the liquid injection needle 2, so that the liquid injection needle 2 extends into the sleeve cup assembly 1 from the other end of the sleeve cup assembly 1, and then extends into the bottom of the lithium ion battery 4 through the liquid injection port. The liquid injection pump is started, and the electrolyte is directly injected into the bottom of the lithium ion battery 4 under the guidance of the liquid injection needle 2. The liquid level of the electrolyte in the lithium ion battery 4 gradually rises, and at the same time, the lifting driving mechanism 3 drives the liquid injection needle 2 to synchronously rise, so as to realize the layer-by-layer injection of the electrolyte, avoid the liquid injection needle 2 being too deep, and improve the absorption efficiency of the electrolyte. By directly injecting the electrolyte into the lithium ion battery 4, the electrolyte can gradually squeeze out the air in the lithium ion battery 4 and be discharged through the liquid injection port during the rising of the electrolyte, avoiding the phenomenon that the electrolyte forms a liquid seal to make it difficult to discharge the air. Accordingly, the air content in the lithium ion battery 4 is reduced, the residual air does not affect the absorption of the electrolyte, the absorption rate of the electrolyte is improved, the soaking effect of the electrolyte is ensured, and the quality of the lithium ion battery 4 is improved.

[0039] It should be noted that the required amount of electrolyte in a single lithium ion battery is certain, and therefore the amount of electrolyte pumped by the liquid injection pump each time is certain. As described above, after the liquid injection is completed, the lithium ion battery cannot completely absorb the electrolyte in a short time, and a certain amount of electrolyte is stored in the sleeve cup assembly. Subsequently, the vacuum and pressure operation can ensure that the electrolyte in the sleeve cup assembly is fully absorbed into the lithium ion battery. For example, the required amount of electrolyte in a single lithium ion battery is 10g, the amount of electrolyte pumped by the liquid injection pump each time is 10g, 8g of electrolyte is in the lithium ion battery after the liquid injection is completed, and 2g of electrolyte is stored in the sleeve cup assembly. The 2g of electrolyte can be ensured to be absorbed into the lithium ion battery under the conditions of vacuum and pressure. By setting the pumping amount of the liquid injection pump to be equal to the required amount of the lithium ion battery, the effective use of the electrolyte is ensured.

[0040] In some embodiments, as shown in Figure 1 The sleeve cup assembly 1 shown in the embodiment includes a cup body 11 and a sealing member 12. One end of the sealing member 12 is detachably connected with the cup body 11, and the other end of the sealing member 12 is connected with the liquid injection port.

[0041] Specifically, the cup body 11 is connected with the liquid injection port through the sealing member 12, so as to ensure the sealing of the cup body 11 and the liquid injection port, and prevent the electrolyte in the cup body 11 from leaking out of the cup body 11 when the liquid level of the electrolyte is higher than the liquid injection port, thereby ensuring the effective use of the electrolyte.

[0042] In some embodiments, the sealing member 12 can be a rubber ring.

[0043] In some embodiments, as shown in Figure 1 and Figure 2 , the liquid injection device for the lithium ion battery also includes a positioning sleeve 5, and the positioning sleeve 5 and the cup body 11 are both cylindrical, the positioning sleeve 5 is sleeved on the cup body 11, the axis of the positioning sleeve 5 coincides with the axis of the cup body 11, the outer side wall of one end of the cup body 11 is concave with a first groove 111, and the sealing member 12 is connected with the first groove 111 and the inner side wall of the positioning sleeve 5 respectively.

[0044] Specifically, by arranging the first groove 111 on the outer side wall of one end of the cup body 11, the sealing member 12 is placed in the first groove 111, and after the positioning sleeve 5 is sleeved on the cup body 11, the inner side wall of the positioning sleeve 5 and the side wall of the first groove 111 can jointly hold the sealing member 12, thereby ensuring the stability of the sealing member 12 and the sealing of the cup body 11 and the liquid injection port. In addition, the positioning sleeve 5 is used to be connected with a clamping mechanism, the clamping mechanism drives the positioning sleeve 5 and the sleeve cup assembly 1 to move along the height direction of the lithium ion battery 4, so that the sealing member 12 of the sleeve cup assembly 1 can be tightly pressed on the liquid injection port, thereby realizing the sealing connection of the cup body 11 and the liquid injection port.

[0045] In some embodiments, as shown in Figures 1 to 5 , the positioning sleeve 5 and the cup body 11 are rotationally connected in the embodiment; the positioning sleeve 5 is provided with a clamping portion 51, the clamping portion 51 is concave with a second groove 511 on the side facing the cup body 11; the outer side wall of the cup body 11 is provided with a protruding portion 112, the protruding portion 112 extends along the circumferential direction of the cup body 11, the protruding portion 112 is provided with a third groove 113, and the third groove 113 extends along the axial direction of the cup body 11; the positioning sleeve 5 and the cup body 11 have a first matching state and a second matching state; in the first matching state, the clamping portion 51 is used to extend into the third groove 113, and the positioning sleeve 5 can move along the extension direction of the third groove 113; in the second matching state, the protruding portion 112 extends into the second groove 511, and the positioning sleeve 5 can rotate along the extension direction of the protruding portion 112.

[0046] Specifically, by arranging the third groove 113 on the protrusion 112, i.e., the third groove 113 forms a gap on the protrusion 112, when it is needed to connect the positioning sleeve 5 with the cup body 11, the clamping part 51 is aligned with the gap, at this time, the clamping part 51 can slide in the third groove 113, i.e., the positioning sleeve 5 can move axially relative to the cup body 11, at this time, the positioning sleeve 5 and the cup body 11 are in the first matching state; under the condition that the positioning sleeve 5 moves axially relative to the cup body 11, the second groove 511 is flush with the protrusion 112, the positioning sleeve 5 is rotated to make the second groove 511 clamped on the protrusion 112, the protrusion 112 plays an axial limiting role, at this time, the positioning sleeve 5 and the cup body 11 are in the second matching state, the positioning sleeve 5 can only rotate relative to the cup body 11, but cannot move axially relative to the cup body 11; when it is needed to separate the positioning sleeve 5 from the cup body 11, the clamping part 51 is rotated to the gap, so that the positioning sleeve 5 is axially taken off from the cup body 11.

[0047] In some embodiments, as shown in Figure 3 and Figure 4 The clamping part 51 and the third groove 113 shown in the present embodiment are each provided with two, and the two clamping parts 51 and the two third grooves 113 are arranged one by one in correspondence; wherein the two clamping parts 51 are oppositely arranged.

[0048] Specifically, by symmetrically arranging the two clamping parts 51 and the two third grooves 113, i.e., the central angle of the two clamping parts 51 is 180 degrees, on the one hand, the two clamping parts 51 ensure the stability of the connection between the positioning sleeve 5 and the cup body 11, and on the other hand, only a small angle needs to be rotated to align the clamping part 51 with the third groove 113, thereby facilitating the disassembly between the positioning sleeve 5 and the cup body 11.

[0049] In some embodiments, as shown in Figure 1 The liquid injection device for the lithium ion battery shown in the present embodiment further comprises a translation driving mechanism 6; the translation driving mechanism 6 is connected with the lifting driving mechanism 3, and the translation driving mechanism 6 is used to drive the lifting driving mechanism 3 and the liquid injection needle 2 to move in the direction perpendicular to the axis of the lithium ion battery 4.

[0050] Specifically, when it is needed to perform the liquid injection operation on the lithium ion battery 4, the translation driving mechanism 6 is started to horizontally move the lifting driving mechanism 3 and the liquid injection needle 2, until the liquid injection needle 2 moves to the position directly above the liquid injection port; by arranging the translation driving mechanism 6, the relative position of the liquid injection needle 2 and the liquid injection port in the horizontal direction is adjusted, so as to avoid the phenomenon that the liquid injection needle 2 collides with the liquid injection port in the process of lifting.

[0051] Wherein, the lifting driving mechanism 3 and the translation driving mechanism 6 can each be a servo motor.

[0052] In some embodiments, as shown inFigure 1 As shown, the liquid injection device for lithium-ion batteries shown in this embodiment further includes: a tray 7; the tray 7 is used to support the lithium-ion batteries 4.

[0053] Specifically, by placing the lithium-ion battery 4 on the tray 7, the lithium-ion battery 4 can be stably supported. When the clamping mechanism presses the seal 12 of the cup assembly 1 onto the liquid filling port, the lithium-ion battery 4 ensures the sealing between the liquid filling port and the cup assembly 1 under the support of the tray 7.

[0054] In some embodiments, as Figure 6 As shown, the injection needle 2 shown in this embodiment includes a first segment 21 and a second segment 22. The first segment 21 is used to extend into the lithium-ion battery 4. The first segment 21 is connected to the second segment 22, and the second segment 22 is connected to the injection pump; wherein, the diameter of the first segment 21 is smaller than the diameter of the second segment 22.

[0055] Specifically, since the diameter of the first segment 21 is smaller than the diameter of the second segment 22 , the injection rate of the electrolyte can be appropriately slowed down so that the electrolyte can be fully absorbed in the lithium-ion battery.

[0056] In some embodiments, the liquid injection device for lithium-ion batteries shown in this embodiment further includes: a controller; the controller is communicatively connected to the lifting drive mechanism 3 and the liquid injection pump respectively.

[0057] Specifically, the controller is used to control the flow rate of the injection pump and the lifting rate of the lifting drive mechanism 3 so that the rising rate of the electrolyte level in the lithium-ion battery 4 matches the rising rate of the injection needle 2.

[0058] This embodiment also provides a liquid injection method for the liquid injection device for lithium-ion batteries as described above.

[0059] like Figure 7 As shown, the liquid injection method includes: step 710, step 720 and step 730.

[0060] Step 710: sealingly connect one end of the cup assembly to the liquid filling port of the lithium-ion battery.

[0061] By sealingly connecting one end of the cup assembly to the filling port of the lithium-ion battery, the cup assembly and the lithium-ion battery together form a container for receiving the electrolyte. When the liquid level of the electrolyte is higher than the filling port, the sealed connection between the cup assembly and the filling port can prevent leakage of the electrolyte.

[0062] Step 720: Drive the injection needle through the cup assembly and the injection port in sequence to extend into the bottom of the lithium-ion battery.

[0063] Firstly, the liquid injection needle is moved to the top of the liquid injection port by the translation driving mechanism, and then the liquid injection needle is driven to descend by the lifting driving mechanism, and the liquid injection needle penetrates the cup assembly and the liquid injection port in turn and extends into the bottom of the lithium ion battery, so that the electrolyte is directly injected into the bottom of the lithium ion battery through the liquid injection needle.

[0064] In step 730, the liquid injection pump is started and the liquid injection needle is driven to rise along the height direction of the lithium ion battery.

[0065] While the liquid injection pump is injecting electrolyte into the lithium ion battery through the liquid injection needle, the lifting driving mechanism drives the liquid injection needle to gradually rise, so that the liquid level of the electrolyte in the lithium ion battery rises synchronously with the liquid injection needle, thereby realizing layer-by-layer injection of the electrolyte, gradually expelling the air in the lithium ion battery, reducing the residual amount of air in the lithium ion battery, avoiding the influence of residual air on the absorption of electrolyte, and ensuring the absorption rate of electrolyte.

[0066] Before step 710, step 700 is further included.

[0067] In step 700, the sealing member is connected to one end of the cup body, and the positioning clamp sleeve is sleeved outside the cup body.

[0068] The sealing member is connected to the first groove on the cup body, then the clamping part on the positioning clamp sleeve is aligned with the third groove, and then the positioning clamp sleeve is switched from the first fitting state to the second fitting state, so that the sealing member is clamped by the first groove and the inner side wall of the positioning clamp sleeve, ensuring the stability of the sealing member.

[0069] After step 730, step 740 is further included.

[0070] In step 740, the liquid injection needle is driven to move out of the cup assembly, the cup assembly and the lithium ion battery are moved into the bell jar, the bell jar is subjected to vacuumizing operation, and the bell jar is subjected to pressurizing operation after the vacuumizing operation.

[0071] After the liquid injection operation is completed, the liquid level of the electrolyte is higher than the liquid injection port, and the electrolyte remaining in the cup assembly needs to be completely injected into the lithium ion battery. At this time, the liquid injection needle is first moved out of the cup assembly, and then the cup assembly and the lithium ion battery are moved into the bell jar for vacuumizing operation. During the vacuumizing operation, the residual air in the lithium ion battery is extracted, and the electrolyte in the cup assembly can enter the lithium ion battery; after the vacuumizing operation is completed, the bell jar is subjected to pressurizing operation, so that the electrolyte remaining in the cup assembly can be completely pressed into the lithium ion battery, thereby ensuring the injection amount of electrolyte in each lithium ion battery.

[0072] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A liquid injection device for lithium-ion batteries, characterized in that: include: A sleeve cup assembly, wherein the sleeve cup assembly is cylindrical, and one end of the sleeve cup assembly is used to be sealed and connected to the liquid injection port of the lithium-ion battery; An injection needle, one end of which is used to sequentially pass through the other end of the cup assembly and the injection port and extend into the bottom of the lithium-ion battery; the other end of the injection needle is used to communicate with the injection pump; a lifting drive mechanism, the lifting drive mechanism being connected to the injection needle and configured to drive the injection needle to move along a height direction of the lithium-ion battery; The cup assembly includes: a cup body and a sealing member; One end of the sealing member is detachably connected to the cup body, and the other end of the sealing member is connected to the liquid filling port; The liquid injection device for lithium-ion batteries further includes: a positioning jacket; The positioning sleeve and the cup body are both cylindrical, the positioning sleeve is sleeved on the cup body, the outer wall of one end of the cup body is concavely provided with a first groove, and the sealing member is respectively connected to the first groove and the inner wall of the positioning sleeve; The positioning sleeve is rotatably connected to the cup body; the positioning sleeve is provided with a clamping portion, and the clamping portion is provided with a second groove on a side facing the cup body; the outer wall of the cup body is provided with a protrusion, and the protrusion extends along the circumference of the cup body, and the protrusion is provided with a third groove, and the third groove extends along the axial direction of the cup body; The positioning sleeve and the cup body have a first mating state and a second mating state; in the first mating state, the clamping portion is used to extend into the third groove, and the positioning sleeve can move along the extension direction of the third groove; in the second mating state, the protrusion extends into the second groove, and the positioning sleeve can rotate along the extension direction of the protrusion; The liquid injection device for lithium-ion batteries further includes: a translation drive mechanism; The translation drive mechanism is connected to the lifting drive mechanism, and the translation drive mechanism is used to drive the lifting drive mechanism and the injection needle to move in a direction perpendicular to the axis of the lithium-ion battery.

2. The liquid injection device for lithium-ion batteries according to claim 1, characterized in that: There are two of each of the clamping parts and the third grooves, and the two clamping parts are arranged in a one-to-one correspondence with the two third grooves; wherein the two clamping parts are arranged opposite to each other.

3. The liquid injection device for lithium-ion batteries according to claim 1, characterized in that: The liquid injection device for lithium-ion batteries further includes: a tray; The tray is used to support the lithium-ion battery.

4. A method for injecting liquid into a liquid injection device for a lithium-ion battery according to any one of claims 1 to 3, characterized in that: include: Sealingly connect one end of the cup assembly to the liquid filling port of the lithium-ion battery; Driving the injection needle to sequentially pass through the sleeve cup assembly and the injection port and extend into the bottom of the lithium-ion battery; The injection pump is turned on and the injection needle is driven to rise along the height direction of the lithium-ion battery.

5. The liquid injection method according to claim 4, characterized in that: The method of starting the injection pump and driving the injection needle to move along the height direction of the lithium-ion battery includes: The injection needle is driven to move out of the cup assembly, the cup assembly and the lithium-ion battery are moved into a bell jar, a vacuum operation is performed on the bell jar, and a pressurization operation is performed on the bell jar after the vacuum operation.

6. The liquid injection method according to claim 5, characterized in that: The method of sealingly connecting one end of the cup assembly to the liquid injection port of the lithium-ion battery includes: The sealing member is connected to one end of the cup body, and the positioning jacket is sleeved outside the cup body.

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