Electrolyte filling method for battery

Abstract

Disclosed is an electrolyte filling method for a battery (2), the battery (2) comprising a switching valve (21) having an open state and a closed state. A processing apparatus comprises a vacuum evacuation system and an electrolyte filling system which are independent from each other. The electrolyte filling method comprises a vacuum evacuation step followed by an electrolyte filling step. The vacuum evacuation step comprises: connecting a vacuum evacuation pipe of the vacuum evacuation system to the switching valve (21) to bring the switching valve (21) into the open state; controlling a vacuum evacuation device of the vacuum evacuation system to perform vacuum evacuation on the battery (2); and separating the vacuum evacuation pipe from the switching valve (21) after it is confirmed that the vacuum evacuation is completed, so as to bring the switching valve (21) into the closed state. The electrolyte filling step comprises: connecting an electrolyte filling device (1) of the electrolyte filling system to the switching valve (21) to bring the switching valve (21) into the open state; controlling the electrolyte filling system to fill the battery (2) with an electrolyte; and separating an electrolyte filling pipe from the switching valve (21) after it is confirmed that the electrolyte filling is completed, so as to bring the switching valve (21) into the closed state.

Description

A battery injection method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on Chinese patent application number 202410012251.5, application date January 3, 2024, and invention name “A method for injecting liquid into a battery”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into the present disclosure as a reference. Technical Field

[0003] The present disclosure relates to the technical field of batteries, and in particular to a battery injection method. Background Art

[0004] This section is intended to provide a background or context for the embodiments of the present disclosure. No admission is made that the description herein is prior art by virtue of its inclusion in this section.

[0005] In the related art, before the battery's injection hole is sealed, the inside of the battery shell is connected to the external environment, so that the shell environment is not a vacuum environment before the battery is injected. It is necessary to maintain a relatively sealed state with the external environment after the battery vacuum operation is completed. The general solution is to use a common pipeline for vacuuming and injecting electrolyte. After the vacuum operation is completed, the function is switched by switching to the injection switch valve. Since residual electrolyte is difficult to avoid in the pipeline, combined with the vacuum diffusion effect, the pipeline and valve body of the vacuum device will eventually be blocked by electrolyte crystals.

[0006] Summary of the Invention

[0007] In view of this, the embodiments of the present disclosure hope to provide a battery injection method that can avoid the problem of pipelines and valve bodies of the vacuum pumping system being blocked by electrolyte crystals.

[0008] To achieve the above objectives, an embodiment of the present disclosure provides a battery liquid injection method, which is applied to a processing device for battery production, wherein the battery includes a switch valve having an open state and a closed state, and the processing device includes a vacuum pumping system and a liquid injection system that are independent of each other;

[0009] The liquid injection method includes a vacuuming step and a liquid injection step after the vacuuming step;

[0010] Wherein, the vacuuming step comprises:

[0011] Connecting the vacuum pumping pipe of the vacuum pumping system to the switch valve to open the switch valve;

[0012] Controlling the vacuum device of the vacuum system to vacuum the battery;

[0013] After confirming that the vacuuming is completed, the vacuuming pipe is separated from the switch valve to close the switch valve;

[0014] The liquid injection step comprises:

[0015] Connecting the liquid injection device of the liquid injection system to the switch valve to open the switch valve;

[0016] controlling the liquid injection system to inject liquid into the battery;

[0017] After confirming that the liquid injection is completed, the liquid injection device is separated from the switch valve to put the switch valve in a closed state.

[0018] The liquid injection method of the battery of the embodiment of the present disclosure is applied to the processing equipment for battery production, the battery includes a switch valve with an open state and a closed state, and the processing equipment includes a vacuum pumping system and a liquid injection system that are independent of each other. The vacuum pumping pipe of the vacuum pumping system is docked with the switch valve and vacuum is performed. After confirming that the vacuum pumping is completed, the vacuum pumping pipe is separated from the switch valve to keep the vacuum state in the battery. Then, the liquid injection device of the liquid injection system is docked with the switch valve and liquid is injected. After confirming that the liquid injection is completed, the liquid injection device is separated from the switch valve to complete the liquid injection of the battery. In this way, the vacuum pumping system and the liquid injection system are independent of each other and do not need to share a pipe. This can prevent the vacuum pumping system from sucking in residual electrolyte, thereby avoiding the problem of the vacuum pumping system's pipeline and valve body being blocked by electrolyte crystals.

[0019] In some embodiments, the processing equipment includes a first workstation and a second workstation, the vacuuming step is performed at the first workstation, and the liquid injection step is performed at the second workstation.

[0020] That is to say, the vacuuming step and the liquid injection step are set at different workstations, that is, the vacuuming step and the liquid injection step are separated, the vacuuming step is carried out at the first workstation, and the liquid injection step is carried out at the second workstation. In this way, the vacuuming time in the vacuuming step can be increased, which is used to increase the vacuum degree of the internal cavity of the battery and improve the liquid injection efficiency. At the same time, it does not affect the production rhythm.

[0021] In some embodiments, the liquid injection device includes a liquid injection cup and a valve opening device having an open state and a closed state, the valve opening device being configured to dock with the switch valve and open the switch valve so that the internal cavity of the liquid injection cup communicates with the internal cavity of the battery; docking the liquid injection device of the liquid injection system with the switch valve to open the switch valve includes:

[0022] The valve opening device is docked with the switch valve so that both the switch valve and the valve opening device are in an open state.

[0023] By providing a valve opening device with open and closed states, in the closed state, the flow channel of the valve opening device is disconnected from the internal cavity of the battery. Thus, even if electrolyte in the liquid filling cup enters the flow channel of the valve opening device, the electrolyte in the valve opening device will not flow out through the flow channel. During the battery filling process, the battery's on-off valve can exert a force on the valve opening device, causing the valve opening device to switch from a closed state to an open state under the action of the external force. At this point, the flow channel of the valve opening device is connected to the internal cavity of the battery, allowing the electrolyte in the liquid filling cup to enter the battery through the flow channel, thereby achieving liquid filling. After liquid filling is completed, the valve opening device and the on-off valve are separated, and the valve opening device switches from the open state to the closed state. In other words, the valve opening device is a normally closed valve opening device. Thus, electrolyte can be pre-injected into the liquid filling cup at any time before the battery and liquid filling cup are assembled, which can reduce serialization time (liquid preparation time) and improve production efficiency and production cycle time.

[0024] In some embodiments, the liquid injection method further includes a liquid preparation step, which is performed before the vacuuming step or simultaneously with the vacuuming step; wherein the liquid preparation step is used to inject electrolyte into the liquid injection cup.

[0025] Since the battery's on-off valve and the valve opening device of the liquid injection system are both normally closed, electrolyte can be injected into the liquid injection cup in advance at any time before the battery and the liquid injection cup are combined, reducing the serial time (liquid preparation time) and improving production efficiency.

[0026] In some embodiments, the switch valve and the valve opening device are both in the open state, which includes:

[0027] The switch valve is controlled to open before the valve opening device; or, the switch valve and the valve opening device are controlled to open simultaneously.

[0028] By setting the opening pressure of the valve opening device to be greater than or equal to the opening pressure of the switch valve, it is possible to avoid the situation where the switch valve of the battery is still in a closed state after the valve opening device is opened, thereby improving the problem of electrolyte leakage.

[0029] In some embodiments, the injection method further includes a grouping step, which is performed before the vacuuming step or after the vacuuming step; wherein the grouping step is used to group the individual batteries into a battery pack.

[0030] The liquid injection method also includes a grouping step, which is used to group individual batteries into battery packs. This is beneficial for the transfer of batteries and subsequent operations, thereby improving production efficiency.

[0031] The grouping step can be performed before or after the vacuuming step. That is, the vacuuming can be performed before the battery grouping, i.e., the individual batteries are vacuumed before forming the battery group, or the vacuuming can be performed after the battery grouping, i.e., the individual batteries are first formed into a battery group and then the battery group is vacuumed.

[0032] In some embodiments, the processing equipment further includes a detection device, and before the vacuuming step, the detection device is used to detect whether the switch valve is in a closed state.

[0033] By setting up a detection device and detecting whether the switch valve is in a closed state before the vacuuming step, for example, detecting whether the switch valve is missing or damaged, it can be avoided to a certain extent that the battery cannot be vacuumed due to the switch valve being missing or damaged, thereby improving the battery production efficiency and battery quality to a certain extent.

[0034] In some embodiments, the processing equipment further includes a detection device, and before the liquid injection step, the detection device is used to detect whether the switch valve is in a closed state.

[0035] By setting up a detection device and detecting whether the switch valve is in a closed state before the liquid injection step, for example, detecting whether the switch valve is missing or damaged, this can avoid, to a certain extent, the inability to inject liquid into the battery due to the detection of the switch valve being missing or damaged, thereby improving the battery production efficiency and battery quality to a certain extent.

[0036] In some embodiments, the detection device is a fiber optic sensor or a machine vision device.

[0037] In some embodiments, the method for confirming the completion of vacuuming includes: confirming the completion of vacuuming based on a target vacuum level inside the battery.

[0038] That is to say, by detecting the vacuum degree inside the battery, when the vacuum degree inside the battery reaches the target vacuum degree, it means that the vacuuming is completed and the vacuuming can be stopped.

[0039] In some embodiments, the method for confirming the completion of vacuuming includes: confirming the completion of vacuuming based on a target vacuuming time for the battery.

[0040] That is to say, by timing the vacuum pumping time of the battery, when the vacuum pumping time of the battery reaches the target vacuum pumping time, it means that the vacuum pumping is completed and the vacuum pumping can be stopped.

[0041] The liquid injection method of the battery of the embodiment of the present disclosure is applied to the processing equipment for battery production, the battery includes a switch valve with an open state and a closed state, and the processing equipment includes a vacuum pumping system and a liquid injection system that are independent of each other. The vacuum pumping pipe of the vacuum pumping system is docked with the switch valve and vacuum is performed. After confirming that the vacuum pumping is completed, the vacuum pumping pipe is separated from the switch valve to keep the vacuum state in the battery. Then, the liquid injection device of the liquid injection system is docked with the switch valve and liquid is injected. After confirming that the liquid injection is completed, the liquid injection device is separated from the switch valve to complete the liquid injection of the battery. In this way, the vacuum pumping system and the liquid injection system are independent of each other and do not need to share a pipe. This can prevent the vacuum pumping system from sucking in residual electrolyte, thereby avoiding the problem of the vacuum pumping system's pipeline and valve body being blocked by electrolyte crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic flow chart of a battery injection method according to an embodiment of the present disclosure;

[0043] FIG2 is a schematic diagram of a portion of the structure of a processing device according to an embodiment of the present disclosure;

[0044] FIG3 is a cross-sectional view of FIG2 .

[0045] DESCRIPTION OF REFERENCE NUMERALS 1. Liquid filling device; 11. Liquid filling cup; 12. Valve opening device; 13. Liquid filling cup tray; 2. Battery; 21. Switch valve; 3. Battery tray DETAILED DESCRIPTION

[0046] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of the present disclosure can be combined with each other, and the detailed description in the specific implementation methods should be understood as an explanation of the purpose of the present disclosure and should not be regarded as an improper limitation on the present disclosure.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this disclosure; the terms "including" and "having" and any variations thereof in this disclosure are intended to cover non-exclusive inclusions.

[0048] In the description of the embodiments of the present disclosure, technical terms such as "first," "second," and "third" are used solely to distinguish different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0049] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] In the description of the embodiments of the present disclosure, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0051] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential", "height direction", "first direction", and "second direction" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present disclosure.

[0052] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0053] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0054] With the development of clean energy, more and more devices are using electricity as a driving force. Consequently, power batteries, such as lithium-ion batteries, that can store large amounts of electricity and undergo multiple charge and discharge cycles are rapidly developing. These batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in aerospace and other fields.

[0055] The battery referred to in the embodiments of this disclosure refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this disclosure may include a battery module or a battery pack. Batteries generally include a housing for enclosing one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0056] In the present disclosure, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and the present disclosure is not limited thereto. Battery cells may be cylindrical, rectangular, or in other shapes, and the present disclosure is not limited thereto.

[0057] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon. To ensure high current flow without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0058] A battery cell also includes an insulating film and a casing. The insulating film is applied to the outside of the electrode assembly, and the casing encapsulates the electrode assembly coated with the insulating film to form a battery cell. The insulating film can be Mylar film, and the casing can be aluminum. After the electrode assembly is wound, the Mylar film and casing are encapsulated through the Mylar wrapping process and the casing insertion process. The Mylar film seals and protects the electrode assembly, effectively insulating the electrode assembly and casing from each other, preventing internal short circuits in the battery cell. The casing also provides protection.

[0059] The injection process is an important step in the battery manufacturing process. The injection accuracy is directly related to the cycle performance and consistency of lithium ions.

[0060] In the related art, before the battery's injection hole is sealed, the inside of the battery shell is connected to the external environment, so that the shell environment is not a vacuum environment before the battery is injected. It is necessary to maintain a relatively sealed state with the external environment after the battery vacuum operation is completed. The general solution is to use a common pipeline for vacuuming and injecting electrolyte. After the vacuum operation is completed, the function is switched by switching to the injection switch valve. Since residual electrolyte is difficult to avoid in the pipeline, combined with the vacuum diffusion effect, the pipeline and valve body of the vacuum device will eventually be blocked by electrolyte crystals.

[0061] To prevent electrolyte crystallization from clogging the lines and valves of a vacuum system, embodiments of the present disclosure provide a method for filling a battery 2, applicable to processing equipment used to manufacture the battery 2. Battery 2 includes an on / off valve 21 with open and closed states. The processing equipment includes independent vacuum and filling systems. Referring to Figure 1 , the filling method includes a vacuum step and a subsequent filling step.

[0062] The vacuuming step includes:

[0063] Step S100: connecting the vacuum pipe of the vacuum system to the switch valve to open the switch valve;

[0064] Step S200: Controlling the vacuum device of the vacuum system to vacuum the battery;

[0065] Step S300: After confirming that the vacuuming is completed, the vacuuming pipe is separated from the switch valve to close the switch valve;

[0066] The injection steps include:

[0067] Step S400: docking the liquid injection device of the liquid injection system with the switch valve to open the switch valve;

[0068] Step S500: controlling the liquid injection system to inject liquid into the battery;

[0069] Step S600: After confirming that the liquid injection is completed, the liquid injection pipeline is separated from the switch valve to close the switch valve.

[0070] The battery 2 includes a switch valve 21 having an open state and a closed state. That is, when the switch valve 21 is not subjected to external force, the internal cavity of the battery 2 remains relatively sealed from the external environment. In other words, the switch valve 21 is a normally closed valve.

[0071] The embodiment of the present disclosure further provides a processing device for producing a battery 2, which includes a vacuum pumping system and a liquid injection system that are independent of each other.

[0072] The vacuum pumping system and the liquid injection system are independent of each other, which means that the vacuum pumping system and the liquid injection system are completely separated and do not share the same pipeline.

[0073] The vacuum system includes a vacuum device and a vacuum pipe. The vacuum pipe is connected to the switch valve 21 so that the switch valve 21 is in an open state. At this time, the vacuum pipe is connected to the internal cavity of the battery 2, and the vacuum device is turned on to achieve vacuuming of the battery 2.

[0074] The vacuuming device is, for example, a vacuum pump.

[0075] Exemplarily, the vacuum system further includes a vacuum valve body for selectively connecting or disconnecting the vacuum pipeline.

[0076] Please refer to Figures 2 and 3. The liquid injection system includes a liquid injection device 1, which is connected to the switch valve 21 to open the switch valve 21. At this time, the liquid injection device 1 is connected to the internal cavity of the battery 2, and the liquid injection system is controlled to inject liquid into the battery 2 to achieve liquid injection into the battery 2.

[0077] In some embodiments, the liquid injection device 1 includes a liquid injection cup 11 and a valve opening device 12 with an open state and a closed state. The valve opening device 12 is used to connect with the switch valve 21 and open the switch valve 21 to connect the internal cavity of the liquid injection cup 11 with the internal cavity of the battery 2.

[0078] For example, referring to Figures 2 and 3, the processing equipment also includes a liquid filling cup tray 13, and the valve opening device 12 is arranged on the liquid filling cup tray 13. When the liquid filling cup 11 is set on the liquid filling cup tray 13, the cavity in the liquid filling cup 11 is connected to the flow channel of the valve opening device 12, so that the electrolyte in the liquid filling cup 11 enters the internal cavity of the battery 2 through the flow channel.

[0079] For example, referring to Figures 2 and 3, the processing equipment also includes a battery tray 3, and the battery 2 is arranged on the battery tray 3. The valve opening device 12 and the switch valve 21 can be docked by controlling the movement of the liquid filling cup tray 13 and / or the battery tray 3.

[0080] Please continue to refer to Figures 2 and 3. When the battery 2 is filled with liquid, the valve opening device 12 can serve as a liquid filling nozzle. The valve opening device 12 is connected to the liquid filling cup 11, and the electrolyte in the liquid filling cup 11 flows into the internal cavity of the battery 2 from the flow channel of the valve opening device 12. In the open state, the electrolyte in the liquid filling cup 11 is injected into the internal cavity of the battery 2 from the flow channel of the valve opening device 12.

[0081] In some embodiments, the liquid injection device 1 includes a liquid injection cup 11 and a valve opening device 12 having an open state and a closed state. The valve opening device 12 is used to connect with the on-off valve 21 and open the on-off valve 21, thereby connecting the internal cavity of the liquid injection cup 11 with the internal cavity of the battery 2. Connecting the liquid injection device 1 of the liquid injection system with the on-off valve 21 to open the on-off valve 21 includes: connecting the valve opening device 12 with the on-off valve 21 so that both the on-off valve 21 and the valve opening device 12 are in the open state.

[0082] By providing a valve opening device 12 that includes an open state and a closed state, in the closed state, the flow channel of the valve opening device 12 is not connected to the internal cavity of the battery 2. In this way, even if the electrolyte in the injection cup 11 enters the flow channel of the valve opening device 12, the electrolyte in the valve opening device 12 will not flow out through the flow channel. During the process of injecting liquid into the battery 2, the switch valve 21 of the battery 2 can exert a force on the valve opening device 12, and the valve opening device 12 can be switched from the closed state to the open state under the action of the external force. At this time, the flow channel of the valve opening device 12 is connected to the internal cavity of the battery 2, and the electrolyte in the injection cup 11 can enter the interior of the battery 2 through the flow channel to achieve injection. After the injection is completed, the valve device 12 and the switch valve 21 are separated, and the valve opening device 12 is switched from the open state to the closed state. That is to say, the valve opening device 12 is a normally closed valve opening device 12. In this way, electrolyte can be injected into the liquid filling cup 11 in advance at any time before the battery 2 is combined with the liquid filling cup 11, which can reduce the serial time (liquid preparation time) and improve production efficiency and production rhythm.

[0083] In some embodiments, the opening pressure of the valve opening device 12 is greater than or equal to the opening pressure of the switch valve 21 .

[0084] The opening pressure of the valve opening device 12 is greater than the opening pressure of the on-off valve 21. In other words, after the valve opening device 12 contacts the on-off valve 21, the on-off valve 21 opens first due to the interaction force between the valve opening device 12 and the on-off valve 21, and the valve opening device 12 opens later. This prevents the on-off valve 21 of the battery 2 from remaining closed after the valve opening device 12 opens during the electrolyte injection process, thereby improving the problem of electrolyte leakage.

[0085] The opening pressure of the valve opening device 12 is equal to the opening pressure of the on-off valve 21. In other words, after the valve opening device 12 contacts the on-off valve 21, the on-off valve 21 and the valve opening device 12 are opened simultaneously due to the interaction force between the valve opening device 12 and the on-off valve 21. This prevents the on-off valve 21 of the battery 2 from remaining closed after the valve opening device 12 opens during the electrolyte injection process, thereby improving the problem of electrolyte leakage.

[0086] By setting the opening pressure of the valve opening device 12 to be greater than or equal to the opening pressure of the switch valve 21, it is possible to avoid the situation where the switch valve 21 of the battery 2 is still in a closed state after the valve opening device 12 is opened, thereby improving the problem of electrolyte leakage.

[0087] The battery 2 includes a switch valve 21 with an open state and a closed state. That is, the switch valve 21 is a normally closed type. When the switch valve 21 is not subjected to external force, the internal cavity of the battery 2 remains relatively sealed from the external environment.

[0088] The liquid injection system includes a vacuum pumping system that is independent of the liquid injection system. This eliminates the need to share the vacuum pumping system's vacuum pumping and liquid injection system's liquid injection pipes. This prevents residual electrolyte in the pipes from spreading to other pipes and valves in the vacuum module during the vacuum pumping process, potentially causing blockage.

[0089] The liquid injection method of the battery 2 of the embodiment of the present disclosure is applied to the processing equipment for the production of the battery 2. The battery 2 includes a switch valve 21 with an open state and a closed state. The processing equipment includes a vacuum pumping system and a liquid injection system that are independent of each other. The vacuum pumping pipe of the vacuum pumping system is docked with the switch valve 21 and vacuum is performed. After confirming that the vacuum pumping is completed, the vacuum pumping pipe is separated from the switch valve 21 to maintain a vacuum state in the battery 2. Then, the liquid injection device 1 of the liquid injection system is docked with the switch valve 21 and liquid is injected. After confirming that the liquid injection is completed, the liquid injection device 1 is separated from the switch valve 21 to complete the liquid injection of the battery 2. In this way, the vacuum pumping system and the liquid injection system are independent of each other and do not need to share a pipe. This can prevent the vacuum pumping system from inhaling residual electrolyte, thereby avoiding the problem of the pipeline and valve body of the vacuum pumping system being blocked by electrolyte crystals.

[0090] In related technologies, the vacuuming and liquid injection steps are performed at the same workstation. To ensure production efficiency, this is achieved by reducing the vacuum level within the battery's internal cavity and shortening the vacuuming time before liquid injection. Since a higher vacuum level leads to higher liquid injection efficiency, lowering the target vacuum level will also reduce liquid injection efficiency.

[0091] In some embodiments, the processing equipment includes a first station and a second station. The vacuuming step is performed at the first station, and the liquid injection step is performed at the second station.

[0092] That is to say, the vacuuming step and the liquid injection step are set at different workstations, that is, the vacuuming step and the liquid injection step are separated, the vacuuming step is performed at the first workstation, and the liquid injection step is performed at the second workstation. In this way, the vacuuming time in the vacuuming step can be increased, which is used to increase the vacuum degree of the internal cavity of the battery 2 and improve the liquid injection efficiency. At the same time, it does not affect the production rhythm.

[0093] In some embodiments, the liquid injection method further includes a liquid preparation step, which is performed before the vacuuming step, or simultaneously with the vacuuming step; wherein the liquid preparation step is used to inject electrolyte into the liquid injection cup 11 .

[0094] Since the switch valve 21 of the battery 2 and the valve opening device 12 of the liquid injection system are both normally closed, electrolyte can be injected into the liquid injection cup 11 in advance at any time before the battery 2 is combined with the liquid injection cup 11, reducing the serial time (liquid preparation time) to improve production efficiency.

[0095] In some embodiments, the on-off valve 21 and the valve opening device 12 are both in the open state, which includes: controlling the on-off valve 21 to open before the valve opening device 12; or controlling the on-off valve 21 and the valve opening device 12 to open simultaneously.

[0096] During liquid injection, the lifting system brings the valve opening device 12 of the liquid injection cup 11 into contact with the switch valve 21 of the battery 2 (for example, controls the liquid injection cup tray 13 to move toward the battery 2, or controls the battery tray 3 to move toward the liquid injection cup 11). First, the valve opening device 12 of the liquid injection cup 11 contacts the switch valve 21 of the battery 2. The liquid injection channel formed after the contact remains sealed from the external environment. Due to the interaction force between the valve opening device 12 and the switch valve 21, the switch valve 21 is forced to open. At the same time, the valve opening device 12 is also opened by the interaction force. At this time, the valve opening device 12 and the switch valve 21 are both in the open state, and the liquid injection module is controlled to inject liquid into the battery 2. After confirming that the liquid injection is completed, the valve opening device 12 is separated from the switch valve 21 so that the valve opening device 12 and the switch valve 21 are both in the closed state.

[0097] In some embodiments, the switch valve 21 is controlled to open before the valve opening device 12, or the switch valve 21 and the valve opening device 12 are controlled to open at the same time, that is, the opening pressure of the valve opening device 12 is greater than or equal to the opening pressure of the switch valve 21.

[0098] The opening pressure of the valve opening device 12 is greater than the opening pressure of the on-off valve 21. In other words, after the valve opening device 12 contacts the battery 2, the on-off valve 21 opens first due to the interaction force between the valve opening device 12 and the on-off valve 21, and then the valve opening device 12 opens. This prevents the on-off valve 21 of the battery 2 from remaining closed after the valve opening device 12 opens during the electrolyte injection process, thereby improving the problem of electrolyte leakage.

[0099] The opening pressure of the valve opening device 12 is equal to the opening pressure of the on-off valve 21. In other words, after the valve opening device 12 contacts the battery 2, the on-off valve 21 and the valve opening device 12 are opened simultaneously due to the interaction force between the valve opening device 12 and the on-off valve 21. This prevents the on-off valve 21 of the battery 2 from remaining closed after the valve opening device 12 opens during the electrolyte injection process, thereby improving the problem of electrolyte leakage.

[0100] By setting the opening pressure of the valve opening device 12 to be greater than or equal to the opening pressure of the switch valve 21, it is possible to avoid the situation where the switch valve 21 of the battery 2 is still in a closed state after the valve opening device 12 is opened, thereby improving the problem of electrolyte leakage.

[0101] In some embodiments, referring to Figures 2 and 3 , the liquid injection method further includes a grouping step, which is performed before or after the vacuuming step. The grouping step is used to group the individual batteries 2 into a battery group 2 .

[0102] The liquid injection method further includes a grouping step, which is used to group the individual batteries 2 into a battery group 2. This is beneficial for the transfer of the batteries 2 and subsequent operations, thereby improving production efficiency.

[0103] Exemplarily, a plurality of batteries 2 are placed on a battery tray 3 to form a battery 2 tray.

[0104] It should be noted that the grouping step can be performed before or after the vacuuming step. That is, the vacuuming step can be performed before the batteries 2 are grouped, i.e., the individual batteries 2 are vacuumed before forming the battery group 2. Alternatively, the vacuuming step can be performed after the batteries 2 are grouped, i.e., the individual batteries 2 are first grouped into the battery group 2 and then the battery group 2 is vacuumed.

[0105] In some embodiments, the processing equipment further includes a detection device, which detects whether the switch valve 21 is in a closed state before the vacuuming step.

[0106] By providing a detection device and detecting whether the switch valve 21 is in a closed state before the vacuuming step, for example, detecting whether the switch valve 21 is missing or damaged, it is possible to avoid, to a certain extent, the inability to vacuum the battery 2 due to the detection of the switch valve 21 being missing or damaged, thereby improving the production efficiency and quality of the battery 2 to a certain extent.

[0107] In some embodiments, the processing equipment further includes a detection device, which detects whether the switch valve 21 is in a closed state before the liquid injection step.

[0108] By setting up a detection device and detecting whether the switch valve 21 is in a closed state before the liquid injection step, for example, detecting whether the switch valve 21 is missing or damaged, it can be avoided to a certain extent that the battery 2 cannot be injected due to the detection of the switch valve 21 being missing or damaged, thereby improving the production efficiency of the battery 2 and the quality of the battery 2 to a certain extent.

[0109] It should be noted that the specific type of the detection device is not limited here, as long as it can detect whether the switch valve 21 is missing or damaged.

[0110] Exemplarily, the detection device is a fiber optic sensor or a machine vision device.

[0111] Machine vision is a rapidly developing branch of artificial intelligence. Simply put, it uses machines to replace the human eye for measurement and judgment. A machine vision system uses a machine vision product (i.e., an image capture device, available in CMOS and CCD) to convert captured objects into image signals. This signal is then transmitted to a dedicated image processing system, which obtains the object's morphological information and converts it into a digital signal based on pixel distribution, brightness, color, and other information. The image system then performs various operations on these signals to extract the target's features and, based on the resulting analysis, controls the operation of on-site equipment.

[0112] In some embodiments, the method for confirming the completion of vacuuming includes: confirming the completion of vacuuming based on a target vacuum level inside the battery 2 .

[0113] That is to say, by detecting the vacuum degree inside the battery 2, when the vacuum degree inside the battery 2 reaches the target vacuum degree, it means that the vacuuming is completed and the vacuuming can be stopped.

[0114] In some embodiments, the method for confirming the completion of vacuuming includes: confirming the completion of vacuuming based on a target vacuuming time for the battery 2 .

[0115] That is to say, by timing the vacuuming time of the battery 2, when the vacuuming time of the battery 2 reaches the target vacuuming time, it means that the vacuuming is completed and the vacuuming can be stopped.

[0116] In some embodiments, the priming system includes a mounting base, a priming module, and a weighing module.

[0117] During the preparation of the liquid for the injection cup 11, the weighing module and the injection module are first assembled onto the mounting base. The injection cup 11 is switched from the pre-assembled state to the assembled state. The weight of the injection cup 11 is carried by the weighing module, which is used to weigh the injection cup 11. The weighing module obtains the initial weight A1 of each injection cup 11 (i.e., the weight of each injection cup 11 before injection). After weighing, the system records the initial weight A1 of each injection cup 11, opens the injection valve of the injection device 1, and injects electrolyte into the injection cup 11. The real-time weight A2 of the injection cup 11 is obtained through the weighing module. The system compares A2-A1 with the target weight A0 to confirm whether the liquid preparation requirements are met. If the liquid preparation requirements are met, the liquid preparation is completed. In other words, by setting up a weighing module to weigh the injection cup 11 and thereby determine the amount of electrolyte injected into the injection cup 11, there is no need for an injection pump to control the injection amount, and there is no need for de-bubbling, thereby improving the liquid preparation efficiency. Furthermore, after being filtered, the electrolyte in the electrolyte chamber can be directly injected into the injection cup 11, simplifying the structure, reducing costs, reducing space requirements, and improving the compactness of the injection system. This injection method's preparation steps are highly efficient, and the injection cup 11 remains relatively sealed from the outside world until the normally closed valve opening device 12 is unlocked, ensuring that the electrolyte does not leak during injection and weighing. Furthermore, the injection and weighing process can be completed while two battery packs are being assembled, improving production cycle time.

[0118] In addition, after the liquid filling cup 11 is filled, the real-time weight A2 of the liquid filling cup 11 can be obtained through the weighing module (A2 refers to the weight of the liquid filling cup 11 after the electrolyte is injected, that is, the weight of the liquid filling cup 11 itself and the weight of the electrolyte). After the electrolyte in the liquid filling cup 11 is injected into the battery 2, the liquid filling cup 11 at this time is weighed to obtain A3 (A3 refers to the weight of the liquid filling cup 11 itself and the weight of the residual electrolyte), that is, the weight of the electrolyte injected into the battery 2 is A2-A3. In other words, the liquid filling method of the embodiment of the present disclosure can eliminate the process of weighing the battery 2 separately before and after liquid filling, thereby improving production efficiency.

[0119] In a specific embodiment, the process of the battery 2 injection method is as follows:

[0120] Grouping step: grouping the single battery 2 into 2 battery groups;

[0121] First detection step: Before the vacuuming step, the switch valve 21 of the battery 2 is detected to see whether it is in a normal state (whether it is damaged or not) by means of detection means such as optical fiber sensors and machine vision.

[0122] Vacuuming step: At the first station, the vacuuming system evacuates the battery pack 2. When the target vacuum level is reached inside the battery pack 2, the vacuuming is stopped (this step can be completed at any time, either individually or as a whole, before the battery pack 2 is filled). The normally closed switch valve 21 provided at the filling hole of the battery 2 ensures that the vacuum state inside the battery pack 2 is maintained after the vacuuming is stopped.

[0123] Second detection step: Before injecting liquid, detect whether the normally closed switch valve 21 of the battery 2 is in normal condition (whether there is damage or not) by using detection means such as optical fiber sensor and machine vision.

[0124] Preparation Step: The injection pump injects electrolyte into the injection cup 11. This can be done at any time before combining the battery 2 and the injection cup 11 to improve efficiency. The injection cup 11 is designed with a normally closed valve opening mechanism 12. When the valve opening mechanism 12 is not subject to external forces, the bottom of the injection cup 11 remains relatively sealed from the external environment. Once it contacts and applies pressure to the on / off valve 21 of the battery 2, the electrolyte within the injection cup 11 flows out.

[0125] Liquid injection steps: The lifting mechanism applies and maintains pressure to the on-off valve 21 of the battery 2 through the liquid injection cup 11. The valve opening device 12 and the on-off valve 21 are both open, and the electrolyte is injected into the battery 2 under the action of vacuum and gravity. After the electrolyte injection is completed, the applied pressure is released, and the valve opening device 12 and the on-off valve 21 are both closed, releasing the seal between the battery 2 and the liquid injection cup 11, and the electrolyte injection is completed.

[0126] In the description of the present disclosure, the descriptions with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present disclosure. In the present disclosure, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present disclosure and features of different embodiments or examples, unless they are mutually inconsistent.

[0127] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure are intended to be within the scope of protection of the present disclosure.

Claims

1. A method for injecting liquid into a battery, which is applied to a processing device for battery production. The battery includes a switching valve having an open state and a closed state, and the processing device includes an independent vacuum pumping system and a liquid injection system; The liquid injection method includes a vacuum pumping step and a liquid injection step after the vacuum pumping step; Among them, The vacuum pumping step includes: Docking the vacuum pumping pipeline of the vacuum pumping system with the switching valve to make the switching valve in the open state; Controlling the vacuum pumping device of the vacuum pumping system to pump vacuum for the battery; After confirming that the vacuum pumping is completed, separating the vacuum pumping pipeline from the switching valve to make the switching valve in the closed state; The liquid injection step includes: Docking the liquid injection device of the liquid injection system with the switching valve to make the switching valve in the open state; Controlling the liquid injection system to inject liquid into the battery; After confirming that the liquid injection is completed, separating the liquid injection device from the switching valve to make the switching valve in the closed state.

2. The liquid injection method according to claim 1, wherein The processing device includes a first station and a second station. The vacuum pumping step is carried out at the first station, and the liquid injection step is carried out at the second station.

3. The liquid injection method according to claim 1 or 2, wherein The liquid injection device includes a liquid injection cup and a valve opening device having an open state and a closed state. The valve opening device is used to dock with the switching valve and open the switching valve to connect the internal cavity of the liquid injection cup with the internal cavity of the battery. The docking the liquid injection device of the liquid injection system with the switching valve to make the switching valve in the open state includes: Docking the valve opening device with the switching valve to make both the switching valve and the valve opening device in the open state.

4. The liquid injection method according to claim 3, wherein, The liquid injection method further includes a liquid preparation step, which is carried out before the vacuum pumping step or simultaneously with the vacuum pumping step. Wherein, the liquid preparation step is used to inject electrolyte into the liquid injection cup.

5. The liquid injection method according to claim 3 or 4, wherein, Both the switching valve and the valve opening device being in the open state includes: Controlling the switching valve to open earlier than the valve opening device; or, controlling the switching valve and the valve opening device to open simultaneously.

6. The liquid injection method according to any one of claims 1-5, wherein, The liquid injection method further includes a grouping step, which is carried out before the vacuum pumping step or after the vacuum pumping step. Wherein, the grouping step is used to form a battery pack from individual batteries.

7. The liquid injection method according to any one of claims 1-6, wherein, The processing device further includes a detection device. Before the vacuum pumping step, the detection device is used to detect whether the switching valve is in the closed state.

8. The liquid injection method according to any one of claims 1-7, wherein, The processing device further includes a detection device. Before the liquid injection step, the detection device is used to detect whether the switching valve is in the closed state.

9. The liquid injection method according to claim 7 or 8, wherein The detection device is a fiber optic sensor or a machine vision device.

10. The liquid injection method according to any one of claims 1-9, wherein, The method for confirming the completion of vacuum pumping includes: Confirming the completion of vacuum pumping based on the target vacuum degree inside the battery.

11. The liquid injection method according to any one of claims 1-10, wherein, The method for confirming the completion of vacuum pumping includes: Confirming the completion of vacuum pumping based on the target vacuum pumping time of the battery.

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