Battery electrolyte injection system and battery electrolyte injection method

Abstract

Disclosed in the embodiments of the present disclosure are a battery electrolyte injection system and a battery electrolyte injection method. The battery electrolyte injection system comprises a frame, an electrolyte preparation device, and an electrolyte injection device. The electrolyte injection device comprises a housing, an electrolyte injection assembly, and a positive / negative pressure switching interface. The housing has an accommodating cavity. The electrolyte injection assembly and the positive / negative pressure switching interface are both disposed on the housing and are not in communication with each other. The positive / negative pressure switching interface is used for evacuating the accommodating cavity in a sealed state and a battery cell located in the accommodating cavity, or to introduce air into the accommodating cavity in a vacuum state. The electrolyte injection assembly is used for injecting an electrolyte into the battery cell. The electrolyte preparation device comprises a moving mechanism and a liquid dispensing valve. The moving mechanism is used for driving the liquid dispensing valve to move, such that a liquid dispensing port is detachably coupled to a liquid inlet of an electrolyte preparation assembly.

Description

Battery liquid injection system and battery liquid injection method

[0001] Cross-reference to related applications

[0002] The present disclosure is based on a Chinese patent application No. 202411344573.6, filed on September 25, 2024, entitled "Battery liquid injection system and battery liquid injection method", and claims priority to the Chinese patent application, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

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

[0004] New energy batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also increasingly used in the field of energy storage and the like. During the production process of the battery, a liquid electrolyte needs to be injected into the battery to form an ion channel, so that there are enough lithium ions to migrate between the positive and negative electrodes during the charging and discharging process, thereby realizing reversible circulation.

[0005] In the related art, the liquid injection device includes a negative pressure module, a liquid preparation cup, and a liquid injection module. The liquid injection module has a liquid injection nozzle. The negative pressure module is in communication with the liquid injection nozzle. When the liquid injection nozzle is docked with the liquid injection port of the battery monomer, the battery monomer is vacuumed. After the battery monomer is vacuumed, the electrolyte is injected into the liquid preparation cup to prepare the liquid. Then, the liquid injection module injects the electrolyte in the liquid preparation cup into the battery monomer through the liquid injection nozzle to complete the liquid injection of the battery.

[0006] However, the negative pressure path between the negative pressure module and the battery monomer and the liquid injection path between the liquid injection module and the battery monomer share a common part. On the one hand, the vacuuming step needs to be completed before the liquid preparation can be started. Vacuuming and liquid preparation cannot be performed simultaneously, which affects the liquid injection efficiency. On the other hand, the residual electrolyte during liquid injection is easily sucked into the negative pressure path during the next vacuuming, which easily forms electrolyte crystals and causes the negative pressure path and the liquid injection path to be blocked, thereby reducing the liquid injection efficiency. SUMMARY

[0007] To solve the above technical problems, the present disclosure provides a battery liquid injection system and a battery liquid injection method. The liquid injection assembly and the positive and negative pressure switching interface are not in communication with each other. When the containing cavity is vacuumed through the positive and negative pressure switching interface, the electrolyte in the liquid injection assembly will not enter the positive and negative pressure switching interface, and the probability of electrolyte crystallization is reduced, thereby increasing the liquid injection efficiency.

[0008] The present disclosure is achieved by the following technical solutions.

[0009] The first aspect of the present disclosure provides a battery liquid injection system, comprising:

[0010] a rack;

[0011] a liquid preparation device connected to the rack, the liquid preparation device comprising a liquid preparation assembly for storing liquid to be injected, the liquid preparation assembly having a liquid outlet;

[0012] a liquid injection device connected to the rack, the liquid injection device comprising a housing, a liquid injection assembly and a positive-negative pressure switching interface, the housing having a receiving cavity for accommodating a battery cell, the liquid injection assembly and the positive-negative pressure switching interface being arranged in the housing and not being in communication with each other, the positive-negative pressure switching interface being used for vacuumizing the receiving cavity in a sealed state or introducing gas into the receiving cavity in a vacuum state, the liquid outlet of the liquid preparation assembly being in communication with the liquid injection assembly, and the liquid injection assembly being used for injecting liquid into the battery cell accommodated in the receiving cavity.

[0013] In the technical scheme of the present disclosure, the liquid injection assembly and the positive-negative pressure switching interface are not in communication with each other, when the receiving cavity is vacuumized through the positive-negative pressure switching interface, the electrolyte in the liquid injection assembly will not enter the positive-negative pressure switching interface, thereby reducing the probability of electrolyte crystallization, reducing the probability of the positive-negative pressure switching interface being blocked, increasing the smoothness of vacuumizing, thereby increasing the liquid injection efficiency, and the positive-negative pressure switching interface can also introduce gas into the battery cell when the battery cell is being injected with liquid, so as to make the pressure inside and outside the battery cell the same, thereby reducing the probability of the battery cell swelling and increasing the stability of the battery cell liquid injection. Moreover, the positive-negative pressure switching interface and the liquid preparation assembly are not in communication with each other, that is, when the receiving cavity is being vacuumized, the liquid preparation assembly can also be independently operated, thereby facilitating the simultaneous implementation of the vacuumizing step and the liquid preparation step, fully improving the liquid injection efficiency of the battery cell and improving the battery production capacity. In addition, the liquid preparation device and the liquid injection device are integrated together through the rack, which can also reduce the equipment floor area, simplify the layout, and make the structure of the battery liquid injection system more simple and reasonable.

[0014] In some embodiments, the liquid injection assembly comprises a valve and a liquid injection nozzle, the valve being connected to the liquid outlet and the liquid injection nozzle, and the liquid injection nozzle being used for detachably connecting to the liquid injection port of the battery cell, and the valve being used for opening or closing the channel between the liquid injection nozzle and the liquid outlet.

[0015] In the technical scheme of the present disclosure, the valve and the liquid injection nozzle are arranged, when the battery cell is being vacuumized, the valve is closed and the liquid injection nozzle is separated from the battery cell, so as to reduce the probability of electrolyte leakage in the non-injection state, when the battery cell is being injected with liquid, the liquid injection nozzle is connected to the liquid injection port of the battery cell, so as to directly and accurately inject the electrolyte into the battery cell. When the liquid injection process is completed or no longer needs to be performed, the valve is closed, so as to accurately control the liquid injection, and the detachable design of the liquid injection nozzle and the liquid injection port of the battery cell can easily connect or separate the liquid injection nozzle and the battery cell, so as to facilitate the next liquid injection operation or cleaning and maintenance.

[0016] In some embodiments, the liquid injection device comprises a first lifting mechanism, which is configured to drive the battery cell to move towards the liquid injection assembly or away from the liquid injection assembly, so as to connect or disconnect the liquid injection port of the battery cell with the liquid injection nozzle of the liquid injection assembly.

[0017] In the technical scheme of the embodiments of the present disclosure, the first lifting mechanism is configured to drive the liquid injection port of the battery cell to connect or disconnect with the liquid injection nozzle of the liquid injection assembly, so as to accurately control the position of the battery cell, increase the connection accuracy of the liquid injection nozzle and the liquid injection port, and adjust the position of the battery cell without changing the position of the liquid injection nozzle, which facilitates the removal of the battery cell after liquid injection and increases the reliability of liquid injection.

[0018] In some embodiments, the shell comprises a shell cover and a base which are separately arranged, the shell cover and the base are detachably connected along a first direction to jointly define a receiving cavity, and the liquid injection assembly and the positive and negative pressure switching interface are arranged on the top side of the shell cover.

[0019] The liquid injection device comprises a second lifting mechanism connected with the base, which is configured to drive the base to move along the first direction to connect or disconnect with the shell cover.

[0020] In the technical scheme of the embodiments of the present disclosure, the second lifting mechanism is accurately controlled to facilitate the reliable connection and disconnection of the shell cover and the base, thereby facilitating the vacuumizing, liquid injection and removal of the battery cell after liquid injection, and the separately arranged shell cover and base can facilitate the maintenance and cleaning of the receiving cavity.

[0021] In some embodiments, the shell comprises a locking mechanism arranged on the base or the top cover, which is configured to lock the shell cover and the base when the base moves to connect with the shell cover, so as to seal the receiving cavity.

[0022] In the technical scheme of the embodiments of the present disclosure, the locking mechanism can make the structure of the shell more stable, further increase the sealing state of the receiving cavity during the vacuumizing and liquid injection processes, reduce the probability of external air and impurities entering the receiving cavity, and increase the reliability of the vacuumizing and liquid injection processes. Meanwhile, the locking of the shell cover and the base by the locking mechanism during the vacuumizing and liquid injection processes can reduce the probability of damage to the seal caused by impact.

[0023] In some embodiments, the first lifting mechanism comprises a driving rod and a top plate, the top plate is arranged in the receiving cavity and is configured to support the battery cell, one end of the driving rod is located in the receiving cavity and connected with the top plate, and the other end of the driving rod is located on the bottom side outside the base, the top plate is configured to drive the battery cell to move along the first direction under the driving action of the driving rod, so as to connect or disconnect the liquid injection port of the battery cell with the liquid injection nozzle of the liquid injection assembly.

[0024] In the technical scheme of the embodiments of the present disclosure, the cooperation of the driving rod and the top plate plays a supporting role on the battery monomer, and under the driving of the driving rod, the stability and safety of the battery monomer during movement can be further increased. Moreover, the position of the battery monomer can be positioned by the top plate, so that the liquid injection port of the battery monomer can be accurately connected with the liquid injection nozzle. Meanwhile, the cooperation of the top plate and the driving rod can also adapt to battery monomers of different sizes and shapes, and adapt to the liquid injection requirements of various batteries.

[0025] In some embodiments, the housing has a rectangular shape in a cross section perpendicular to a first direction, wherein the first direction is parallel to a top-bottom direction of the battery liquid injection system.

[0026] In the technical scheme of the embodiments of the present disclosure, the cross-sectional shape design of the housing can make the housing have enough space to accommodate the battery monomer, facilitate the close arrangement of the battery monomer in the housing, and at the same time, the rectangular shape can also make the housing have stability, facilitating maintenance.

[0027] In some embodiments, the liquid preparation assembly includes a liquid preparation cup and a positive pressure liquid injection interface, the liquid preparation cup has a liquid inlet, a liquid storage space and a liquid outlet, the liquid inlet is used to introduce the liquid to be injected into the liquid storage space, the positive pressure liquid injection interface is not in communication with the liquid inlet and is in communication with the liquid storage space, and the positive pressure liquid injection interface is used to introduce gas to transport the liquid to be injected in the liquid storage space to the battery monomer through the liquid outlet and the liquid injection assembly.

[0028] In the technical scheme of the embodiments of the present disclosure, the liquid to be injected enters the liquid storage space from the liquid inlet to complete the liquid preparation, the positive and negative pressure switching interface can simultaneously vacuumize the accommodation cavity and the battery monomer located in the accommodation cavity, after vacuumization, the positive pressure liquid injection interface injects gas into the liquid storage space, the liquid to be injected flows to the liquid injection assembly through the liquid outlet under the action of the gas and then flows to the battery monomer, so as to complete the liquid injection of the battery monomer, the positive pressure liquid injection mode can control the delivery rate of the liquid to be injected, and at the same time, the positive and negative pressure switching interface also introduces gas into the accommodation cavity, so that the pressure inside and outside the battery monomer is equal, and the liquid injection stability of the battery monomer is increased.

[0029] In some embodiments, the liquid preparation assembly includes a plugging member, and the plugging member can open or block the liquid inlet.

[0030] In the technical scheme of the embodiments of the present disclosure, when the liquid preparation is performed, the plugging member opens the liquid inlet, so that the liquid to be injected can enter the liquid storage space from the liquid inlet, and when the liquid preparation is completed, the plugging member closes the liquid inlet, so as to reduce the probability of impurities entering the liquid storage space, and facilitate the introduction of gas from the positive pressure liquid injection interface into the liquid storage space, so that the liquid to be injected flows from the liquid storage space to the liquid injection assembly, and the battery monomer is injected.

[0031] In some embodiments, the liquid preparation assembly further comprises a negative pressure liquid pumping interface, which is in communication with the liquid storage space but not in communication with the liquid inlet, and is used for vacuumizing the liquid storage space.

[0032] In the technical scheme of the embodiments of the present disclosure, through the cooperation of the positive pressure liquid pumping interface and the negative pressure liquid pumping interface, when the positive pressure liquid pumping comfort is reduced, the flow of the liquid to be injected is adjusted through negative pressure suction, so that the positive pressure liquid pumping is more smooth, thereby increasing the liquid injection efficiency of the battery monomer.

[0033] In some embodiments, the positive pressure liquid pumping interface is in communication with the liquid storage space through a first channel, and the negative pressure liquid pumping interface is in communication with the liquid storage space through a second channel, and at least part of the first channel and the second channel overlap.

[0034] In the technical scheme of the embodiments of the present disclosure, at least part of the first channel and the second channel overlap, which can reduce the need for additional pipelines, so that the structure of the entire liquid preparation assembly is more compact, occupies less space, and the liquid injection is realized through the alternating work of the positive pressure liquid pumping interface and the negative pressure liquid pumping interface.

[0035] In some embodiments, the liquid preparation device comprises a moving mechanism and a liquid distribution valve, the liquid distribution valve has a liquid distribution port, and the liquid distribution valve is arranged on the top side of the liquid preparation assembly. The moving mechanism is used to drive the liquid distribution valve to move so that the liquid distribution port is detachably connected with the liquid inlet of the liquid preparation assembly.

[0036] In the technical scheme of the embodiments of the present disclosure, through the flow control of the liquid distribution valve, the amount of the liquid to be injected distributed to each battery monomer can be accurately adjusted, the battery consistency is increased, and the combination of the moving mechanism and the liquid distribution valve can realize the automation of the liquid to be injected distribution, thereby improving the liquid preparation efficiency and the liquid preparation precision.

[0037] In some embodiments, the liquid preparation assembly comprises a plurality of liquid preparation cups arranged at intervals along a second direction, and the number of the liquid preparation assemblies is a plurality. The plurality of liquid preparation assemblies are fixed on a rack and arranged side by side along a third direction.

[0038] The moving mechanism comprises a first moving module, a second moving module and a third moving module. The liquid distribution valve is connected to the first moving module, and the first moving module is used to drive the liquid distribution valve to move along a first direction.

[0039] The second moving module extends along the second direction, and the first moving module is arranged on the second moving module. The second moving module is used to drive the first moving module to move along the second direction.

[0040] The third moving module is connected to the rack and extends along the third direction. The second moving module is arranged on the third moving module, and the third moving module is used to drive the second moving module to move along the third direction.

[0041] The first direction, the second direction and the third direction are perpendicular to each other.

[0042] In the technical scheme of the embodiment of the present disclosure, through movement in three-dimensional space, the moving mechanism can quickly and accurately switch between multiple standby liquid cups and adapt to the standby liquid demand of standby liquid cups at different positions, thereby improving the liquid injection efficiency. The battery liquid injection system can perform standby liquid injection on multiple standby liquid assemblies, thereby facilitating simultaneous liquid injection of battery monomers arranged in a two-dimensional array structure and increasing the liquid injection efficiency.

[0043] The second aspect of the embodiment of the present disclosure provides a battery liquid injection method, which comprises:

[0044] The standby liquid injection step is to inject the to-be-injected liquid into the liquid storage space of the standby liquid assembly.

[0045] The vacuum extraction step is to seal the accommodation cavity, and in the state that the liquid injection port of the battery monomer is separated from the liquid injection assembly, the positive-negative pressure switching interface is controlled to extract vacuum from the accommodation cavity, wherein the battery monomer is accommodated in the accommodation cavity.

[0046] The liquid injection step is to control the movement of the battery monomer to make the liquid injection port of the battery monomer be connected with the liquid injection assembly, and the to-be-injected liquid in the standby liquid assembly is injected into the battery monomer through the liquid injection assembly, and in the process of liquid injection, the positive-negative pressure switching interface is controlled to introduce gas into the accommodation cavity.

[0047] The positive-negative pressure switching interface and the liquid injection assembly are not in communication with each other.

[0048] In the technical scheme of the embodiment of the present disclosure, the standby liquid injection step and the vacuum extraction step do not interfere with each other, the liquid injection path and the vacuum extraction path are separated, the probability of electrolyte crystallization is low, and in the process of liquid injection, the positive-negative pressure switching interface can assist in balancing the pressure inside and outside the battery monomer, thereby improving the liquid injection efficiency and reliability of the battery monomer.

[0049] In some embodiments, the to-be-injected liquid in the standby liquid assembly is injected into the battery monomer through the liquid injection assembly, which comprises:

[0050] The positive pressure liquid injection is to control the positive pressure liquid injection interface of the standby liquid assembly to introduce gas into the liquid storage space of the standby liquid assembly, so as to inject the required amount of to-be-injected liquid into the battery monomer.

[0051] In the technical scheme of the embodiment of the present disclosure, the positive pressure liquid injection mode can further improve the liquid injection efficiency and shorten the time required for the battery monomer to be filled with liquid.

[0052] In some embodiments, the to-be-injected liquid in the standby liquid assembly is injected into the battery monomer through the liquid injection assembly, which comprises alternately executed positive pressure liquid injection and negative pressure suction, wherein,

[0053] The positive pressure liquid injection is to close the negative pressure liquid injection interface of the standby liquid assembly, and control the positive pressure liquid injection interface of the standby liquid assembly to introduce gas into the liquid storage space of the standby liquid assembly.

[0054] Negative pressure suction: close the positive pressure liquid injection interface of the liquid preparation assembly, and control the negative pressure liquid injection interface of the liquid preparation assembly to vacuum the liquid storage space of the liquid preparation assembly.

[0055] In the technical scheme of the embodiments of the present disclosure, the flow of the electrolyte can be adjusted in time by the combination of the positive pressure injection and the negative pressure suction, so that the positive pressure injection is smoother, and the injection efficiency of the battery monomer is increased. BRIEF DESCRIPTION OF DRAWINGS

[0056] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are intended to depict only preferred embodiments of the disclosure and therefore should not be considered to narrow its scope. Furthermore, like reference numerals denote like parts throughout the drawings. In the drawings:

[0057] FIG. 1 is a structural schematic diagram of a battery injection system according to an embodiment of the present disclosure;

[0058] FIG. 2 is a structural schematic diagram of a liquid preparation device according to an embodiment of the present disclosure;

[0059] FIG. 3 is a partial structural schematic diagram of the liquid preparation assembly shown in FIG. 2;

[0060] FIG. 4 is a structural schematic diagram of the liquid preparation assembly shown in FIG. 3 from another perspective;

[0061] FIG. 5 is a structural schematic diagram of the liquid injection device shown in FIG. 2, in which the shell cover and the base are in a separated state;

[0062] FIG. 6 is a schematic diagram of a battery injection method according to an embodiment of the present disclosure;

[0063] FIG. 7 is a flow schematic diagram of a battery injection method according to an application embodiment of the present disclosure.

[0064] The reference signs are explained as follows: 1-battery liquid injection system; 10-rack; 11-liquid preparation device; 111-liquid preparation assembly; 111a-liquid inlet; 111b-liquid outlet; 111c-liquid storage space; 111d-positive pressure liquid injection interface; 111e-negative pressure liquid injection interface; 111f-first channel; 111g-second channel; 1111-liquid preparation cup; 1112-plugging member; 112-liquid distribution valve; 113-moving mechanism; 1131-first moving module; 1132-second moving module; 1133-third moving module; 12-liquid injection device; 121-housing; 121a-accommodation cavity; 1211-base; 1212-housing cover; 1213-locking mechanism; 122-liquid injection assembly; 1221-valve; 1222-liquid injection nozzle; 123-positive and negative pressure switching interface; 124-first lifting mechanism; 1241-driving rod; 1242-lifting plate; 125-second lifting mechanism; 20-battery cell. DETAILED DESCRIPTION

[0065] The embodiments of the technical solutions of the present disclosure will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present disclosure, and therefore only serve as examples, and cannot limit the protection scope of the present disclosure.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill 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 the present disclosure; the terms "include" and "have" and any variations thereof in the present disclosure are intended to cover non-exclusive inclusion.

[0067] In the description of the embodiments of the present disclosure, the technical terms "first", "second", "third" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0068] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0069] In the description of the embodiments of the present disclosure, the term "and / or" is merely an association relationship of associated objects, and can represent three relationships, for example, A and / or B, which can represent three cases of A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0070] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by the technical terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", and the like are based on the orientations or positional relationships shown in the drawings, and are merely 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 particular orientation, be constructed, operated or used in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0071] In the description of the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing", and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0072] In the description of the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the technical term "contact" should be understood in a broad sense, which can be direct contact or contact through an intermediate medium layer, and can be contact between two objects in contact without interaction force, or contact between two objects in contact with interaction force.

[0073] Next, the present disclosure will be described in detail.

[0074] At present, new energy batteries are more and more widely used in life and industry. New energy batteries are not only applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also increasing.

[0075] In the production process of the battery, the injection of liquid electrolyte (hereinafter referred to as injection) is a very critical step, therefore, the injection amount of liquid electrolyte (hereinafter referred to as electrolyte) and the injection condition inside the battery monomer need to meet certain conditions. Therefore, in order to facilitate the smooth injection of electrolyte, the air inside the battery monomer needs to be extracted (hereinafter referred to as vacuum extraction) before injection, so that the inside of the battery monomer is in a vacuum condition, so as to facilitate the smooth flow of electrolyte, and in order to facilitate the control of the injection amount of electrolyte, a suitable amount needs to be prepared before injection.

[0076] Based on this, the inventor of the present disclosure noticed that in the existing injection equipment, the injection equipment includes a negative pressure module, a liquid preparation cup and an injection module, the injection module has an injection nozzle, the negative pressure module is communicated with the injection nozzle, when the injection nozzle is connected with the injection port of the battery monomer, the battery monomer is vacuumed, after the battery monomer is vacuumed, the electrolyte in the liquid preparation cup is injected to prepare liquid, then the electrolyte in the liquid preparation cup is injected into the battery monomer through the injection nozzle by the injection module, so as to complete the injection of the battery.

[0077] However, the negative pressure passage between the negative pressure module and the battery monomer and the injection passage between the injection module and the battery monomer have a common part, on the one hand, the vacuum extraction step needs to be completed first before starting the liquid preparation, the vacuum extraction and the liquid preparation cannot be carried out at the same time, which affects the injection efficiency; on the other hand, the residual electrolyte during injection is easy to be sucked into the negative pressure passage during the next vacuum extraction, which is easy to form electrolyte crystallization, and causes the blockage of the negative pressure passage and the injection passage, and reduces the injection efficiency.

[0078] Based on the above considerations, in order to reduce the probability of electrolyte crystallization and improve the efficiency of liquid injection, the first aspect of the present disclosure provides a battery liquid injection system. The battery liquid injection system comprises a rack, a liquid preparation device and a liquid injection device. The liquid preparation device is connected to the rack. The liquid preparation device comprises a liquid preparation assembly for storing the liquid to be injected. The liquid preparation assembly has a liquid outlet. The liquid injection device is connected to the rack. The liquid injection device comprises a shell, a liquid injection assembly and a positive and negative pressure switching interface. The shell has a receiving cavity for accommodating a battery monomer. The liquid injection assembly and the positive and negative pressure switching interface are both arranged in the shell and are not in communication with each other. The positive and negative pressure switching interface is used to vacuumize the receiving cavity in a sealed state and the battery monomer located in the receiving cavity, or to introduce gas into the receiving cavity in a vacuum state. The liquid outlet of the liquid preparation assembly is in communication with the liquid injection assembly. The liquid injection assembly is used to inject liquid into the battery monomer accommodated in the receiving cavity. In this way, the liquid injection assembly and the positive and negative pressure switching interface are not in communication with each other. When the receiving cavity is vacuumized through the positive and negative pressure switching interface, the electrolyte in the liquid injection assembly will not enter the positive and negative pressure switching interface, thereby reducing the probability of electrolyte crystallization, reducing the probability of positive and negative pressure switching interface blockage, increasing the smoothness of vacuumization, thereby increasing the efficiency of liquid injection. The positive and negative pressure switching interface can also introduce gas into the battery monomer when injecting liquid into the battery monomer, so that the pressure inside and outside the battery monomer is the same, thereby reducing the probability of battery monomer swelling and increasing the stability of battery monomer liquid injection. Moreover, the positive and negative pressure switching interface and the liquid preparation assembly are not in communication with each other, that is, when the receiving cavity is vacuumized, the liquid preparation assembly can also operate independently, thereby facilitating the simultaneous implementation of the vacuumization step and the liquid preparation step, fully improving the efficiency of battery monomer liquid injection and improving the battery production capacity. In addition, the liquid preparation device and the liquid injection device are integrated together through the rack, which can also reduce the equipment floor area, simplify the layout, and make the structure of the battery liquid injection system more simple and reasonable.

[0079] It should be noted that the battery monomer can be a secondary battery, which refers to a battery monomer that can be activated by charging after discharging to continue to be used. The battery monomer can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The present disclosure is not limited thereto.

[0080] The battery liquid injection system 1 of some embodiments of the present disclosure will be further described in detail below in combination with FIGS. 1-5.

[0081] Referring to FIGS. 1-5, the battery liquid injection system 1 comprises a rack 10, a liquid preparation device 11 and a liquid injection device 12. The liquid preparation device 11 is connected to the rack 10, and comprises a liquid preparation assembly 111 for storing liquid to be injected. The liquid preparation assembly 111 has a liquid outlet 111b. The liquid injection device 12 is connected to the rack 10, and comprises a housing 121, a liquid injection assembly 122 and a positive-negative pressure switching interface 123. The housing 121 has a receiving cavity 121a for accommodating a battery monomer 20. The liquid injection assembly 122 and the positive-negative pressure switching interface 123 are arranged in the housing 121 and are not in communication with each other. The positive-negative pressure switching interface 123 is used to vacuumize the receiving cavity 121a in a sealed state and the battery monomer 20 located in the receiving cavity 121a, or to introduce gas into the receiving cavity 121a in a vacuum state. The liquid outlet 111b of the liquid preparation assembly 111 is in communication with the liquid injection assembly 122. The liquid injection assembly 122 is used to inject liquid to the battery monomer 20 accommodated in the receiving cavity 121a.

[0082] It can be understood that the rack 10 can serve as the main frame of the battery liquid injection system 1, and is used to carry the liquid preparation device 11 and the liquid injection device 12. The liquid preparation device 11 and the liquid injection device 12 are connected to the rack 10, i.e., the liquid preparation device 11 and the liquid injection device 12 are integrated together through the rack 10, so as to reduce the equipment floor area and simplify the layout. The liquid preparation device 11 and the liquid injection device 12 can be integrally connected through the liquid preparation assembly 111 and the liquid injection assembly 122, without the need for additional logistics.

[0083] Exemplarily, the liquid injection assembly 122 can be directly connected to the liquid outlet 111b of the liquid preparation assembly 111, or can be connected to the liquid outlet 111b of the liquid preparation assembly 111 through a hose.

[0084] Exemplarily, the liquid injection device 12 can be arranged at the bottom side of the liquid preparation device 11.

[0085] Exemplarily, the rack 10 can be a structure composed of beams, columns and the like, which can vertically bear and resist horizontal action, is not easy to be bent, and is not easy to be broken. Exemplarily, the beams and columns can be made of metal materials, so as to improve the structural strength and reliability.

[0086] The liquid preparation device 11 is used to prepare liquid. The liquid preparation assembly 111 is used to store liquid to be injected. The liquid to be injected can be liquid electrolyte, i.e., electrolyte. The electrolyte stored in the liquid preparation assembly 111 can leave the liquid preparation assembly 111 through the liquid outlet 111b.

[0087] The liquid injection device 12 is used to inject liquid to the battery monomer 20 and provide a required pressure environment.

[0088] The housing 121 is used to provide the receiving cavity 121a for the battery monomer 20, and provide a sealed space for vacuumizing the battery monomer 20.

[0089] The liquid injection assembly 122 is in communication with the liquid preparation assembly 111, i.e., capable of injecting the electrolyte in the liquid preparation assembly 111 into the battery monomer 20 to form an ion channel, so that there are enough lithium ions in the battery monomer 20 to migrate between the positive and negative electrodes during the charging and discharging process, realizing reversible circulation.

[0090] The positive and negative pressure switching interface 123 can control the pressure environment in the accommodation cavity 121a by vacuumizing or introducing gas, so as to change the internal pressure of the battery monomer 20, and assist the progress of the liquid injection process.

[0091] It should be noted that the liquid injection assembly 122 and the positive and negative pressure switching interface 123 are not in communication, i.e., the liquid injection assembly 122 and the positive and negative pressure switching interface 123 can be two independent parts and can be independently operated, the liquid injection assembly 122 is used for liquid injection, and the positive and negative pressure switching interface 123 is used for providing the required pressure environment for the battery monomer 20, the liquid injection assembly 122 and the positive and negative pressure switching interface 123 have no cross or shared part, the liquid injection assembly 122 and the positive and negative pressure switching interface 123 are connected with the shell 121, when the positive and negative pressure switching interface 123 works, the electrolyte in the liquid injection assembly 122 will not enter the positive and negative pressure switching interface 123. In this way, when the positive and negative pressure switching interface 123 is vacuumized, the electrolyte will not enter the positive and negative pressure switching interface 123, so as to reduce the probability of electrolyte crystallization, make the vacuumizing step smooth, and not easy to be blocked.

[0092] It can be understood that the liquid preparation assembly 111 and the positive and negative pressure switching interface 123 are not in communication, the electrolyte flows between the liquid injection assembly 122 and the liquid preparation assembly 111, flows to the battery monomer 20 through the liquid injection assembly 122, and the electrolyte will not enter the positive and negative pressure switching interface 123. In this way, when the positive and negative pressure switching interface 123 is vacuumized, the liquid preparation assembly 111 can also perform liquid preparation operation, i.e., the vacuumizing step and the liquid preparation step can be performed synchronously or have time overlap, of course, one of the vacuumizing step and the liquid preparation step can be performed first, and the other can be performed later, which is not limited herein.

[0093] Specifically, when the accommodating cavity 121a is in the sealed state, the positive and negative pressure switching interface 123 evacuates the accommodating cavity 121a and the battery monomer 20 located in the accommodating cavity 121a, and it can be understood that at this time, the liquid injection assembly 122 is not in communication with the liquid injection port of the battery monomer 20, the electrolyte does not flow into the battery monomer 20, the liquid injection port of the battery monomer 20 is in communication with the accommodating cavity 121a, and thus the positive and negative pressure switching interface 123 evacuates the accommodating cavity 121a to extract the air in the battery monomer 20, so that the battery monomer 20 is in a vacuum state, facilitating the injection of the electrolyte; after the accommodating cavity 121a is in the vacuum state, the battery monomer 20 can be injected, and it can be understood that at this time, the liquid injection assembly 122 is in communication with the liquid injection port of the battery monomer 20, the liquid to be injected stored in the liquid storage assembly 111 flows into the battery monomer 20 through the liquid outlet 111b and the liquid injection assembly 122, and the positive and negative pressure switching interface 123 introduces gas into the accommodating cavity 121a to make the pressure inside and outside the battery monomer 20 the same, thereby reducing the probability of the battery monomer 20 swelling and increasing the stability of the injection of the battery monomer 20.

[0094] The battery liquid injection system 1 provided by the embodiments of the present disclosure is characterized in that the liquid injection assembly 122 and the positive and negative pressure switching interface 123 are not in communication with each other, when the accommodating cavity 121a is evacuated by the positive and negative pressure switching interface 123, the electrolyte in the liquid injection assembly 122 will not enter the positive and negative pressure switching interface 123, thereby reducing the probability of electrolyte crystallization, reducing the probability of the positive and negative pressure switching interface 123 being blocked, increasing the smoothness of the evacuation, thereby increasing the efficiency of the injection, and the positive and negative pressure switching interface 123 can also introduce gas into the battery monomer 20 when the battery monomer 20 is injected, so that the pressure inside and outside the battery monomer 20 is the same, thereby reducing the probability of the battery monomer 20 swelling and increasing the stability of the injection of the battery monomer 20. In addition, the positive and negative pressure switching interface 123 and the liquid storage assembly 111 are not in communication with each other, that is, when the accommodating cavity 121a is evacuated, the liquid storage assembly 111 can also operate independently, thereby facilitating the simultaneous implementation of the evacuation step and the liquid storage step, fully improving the efficiency of the injection of the battery monomer 20 and improving the production capacity of the battery. In addition, the liquid storage device 11 and the liquid injection device 12 are integrated together by the rack 10, which can also reduce the floor area occupied by the equipment, simplify the layout, and make the structure of the battery liquid injection system 1 more simple and reasonable.

[0095] In some embodiments, referring to FIG. 2, the liquid storage device 11 includes a moving mechanism 113 and a liquid distribution valve 112, the liquid distribution valve 112 has a liquid distribution port, and the liquid distribution valve 112 is arranged on the top side of the liquid storage assembly 111. The moving mechanism 113 is used to drive the liquid distribution valve 112 to move so that the liquid distribution port is detachably connected to the liquid inlet 111a of the liquid storage assembly 111.

[0096] Specifically, the liquid distribution valve 112 is used to be connected with the liquid inlet 111a of the liquid preparation assembly 111 through the liquid distribution port, so as to realize the transmission of the liquid to be injected. The moving mechanism 113 is used to drive the liquid distribution valve 112 to move, so as to realize the connection and separation of the liquid distribution port and the liquid inlet 111a.

[0097] In this embodiment, the flow of the liquid distribution valve 112 can be controlled to accurately adjust the amount of the liquid to be injected into each battery monomer 20, thereby increasing the consistency of the battery. The combination of the moving mechanism 113 and the liquid distribution valve 112 can realize the automation of the distribution of the liquid to be injected, thereby improving the efficiency and accuracy of the liquid preparation.

[0098] The specific structure of the liquid injection assembly 122 is not limited.

[0099] In some embodiments, referring to FIG. 5, the liquid injection assembly 122 includes a valve 1221 and a liquid injection nozzle 1222. The valve 1221 is connected with the liquid outlet 111b and the liquid injection nozzle 1222. The liquid injection nozzle 1222 is used to be detachably connected with the liquid injection port of the battery monomer 20. The valve 1221 is used to open or close the channel between the liquid injection nozzle 1222 and the liquid outlet 111b.

[0100] It can be understood that when the positive-negative pressure switching interface 123 is used to vacuumize the accommodation cavity 121a in the sealed state, the liquid injection nozzle 1222 is separated from the liquid injection port of the battery monomer 20, so as to facilitate the positive-negative pressure switching interface 123 to extract the air in the battery monomer 20 through the liquid injection port of the battery monomer 20, so that the inside of the battery monomer 20 is in a vacuum state. When the battery monomer 20 is injected with the liquid, the liquid injection nozzle 1222 is connected with the liquid injection port of the battery monomer 20, so as to inject the electrolyte in the liquid preparation assembly 111 into the battery monomer 20 through the liquid injection nozzle 1222.

[0101] It can be understood that when the battery monomer 20 is injected with the liquid, the positive-negative pressure switching interface 123 is used to introduce air into the accommodation cavity 121a. The liquid injection nozzle 1222 is in a sealed connection state with the liquid injection port of the battery monomer 20. In this way, the air introduced by the positive-negative pressure switching interface 123 into the accommodation cavity 121a cannot enter the battery monomer 20, thereby increasing the reliability of the liquid injection.

[0102] The valve 1221 is used to connect the liquid outlet 111b and the liquid injection nozzle 1222, and open or close the channel between the liquid injection nozzle 1222 and the liquid outlet 111b, so as to realize the connection or disconnection between the liquid injection nozzle 1222 and the liquid outlet 111b.

[0103] Specifically, when the battery cell 20 needs to be vacuumized, the liquid injection nozzle 1222 is separated from the liquid injection port of the battery cell 20, and the valve 1221 closes the channel between the liquid injection nozzle 1222 and the liquid outlet 111b, so that the electrolyte cannot flow out through the liquid injection nozzle 1222, reducing the probability of electrolyte leakage. When the battery cell 20 needs to be injected, the liquid injection nozzle 1222 is connected to the liquid injection port of the battery cell 20, and the valve 1221 opens the channel between the liquid injection nozzle 1222 and the liquid outlet 111b, so that the electrolyte in the liquid preparation assembly 111 can be injected into the battery cell 20 through the liquid outlet 111b and the liquid injection nozzle 1222, thereby completing the injection of the battery cell 20.

[0104] It can be understood that the opening and closing of the valve 1221 can be switched by manual control or automatic control, which is not limited herein.

[0105] In this embodiment, the valve 1221 and the liquid injection nozzle 1222 are provided, and when the battery cell 20 is vacuumized, the valve 1221 is closed, and the liquid injection nozzle 1222 is separated from the battery cell 20, so as to reduce the probability of electrolyte leakage in the non-injection state. When the battery cell 20 is injected, the liquid injection nozzle 1222 is connected to the liquid injection port of the battery cell 20, so that the electrolyte can be directly and accurately injected into the inside of the battery cell 20. When the injection process is completed or no further injection is needed, the valve 1221 is closed to achieve accurate control of the injection. The liquid injection nozzle 1222 and the liquid injection port of the battery cell 20 can be easily connected or separated from the battery cell 20 for the next injection operation or cleaning and maintenance.

[0106] The way in which the liquid injection nozzle 1222 of the liquid injection assembly 122 is separated from or connected to the liquid injection port of the battery cell 20 is not limited.

[0107] For example, in some embodiments, referring to FIG. 5, the liquid injection device 12 comprises a first lifting mechanism 124 for driving the battery cell 20 to move towards the liquid injection assembly 122 or away from the liquid injection assembly 122, so as to connect or separate the liquid injection port of the battery cell 20 from the liquid injection nozzle 1222 of the liquid injection assembly 122.

[0108] Specifically, the first lifting mechanism 124 can provide driving force for the battery cell 20 to adjust the position of the battery cell 20. When injection is needed, the first lifting mechanism 124 pushes the battery cell 20 until the liquid injection port of the battery cell 20 is completely connected to the liquid injection nozzle 1222 of the liquid injection assembly 122. After the injection is completed, the first lifting mechanism 124 pushes the battery cell 20 to move reversely, so as to separate the liquid injection port of the battery cell 20 from the liquid injection nozzle 1222 of the liquid injection assembly 122, for the next injection operation or removal of the injected battery cell 20.

[0109] In this embodiment, the first lifting mechanism 124 drives the liquid injection port of the battery monomer 20 to be connected with or separated from the liquid injection nozzle 1222 of the liquid injection assembly 122, the position of the battery monomer 20 can be accurately controlled, the connection accuracy of the liquid injection nozzle 1222 and the liquid injection port is increased, and the position of the battery monomer 20 is adjusted, without changing the position of the liquid injection nozzle 1222, the removal of the battery monomer 20 after liquid injection is facilitated, and the liquid injection reliability is increased.

[0110] The first lifting mechanism 124 can be powered by hydraulic, pneumatic or electric power, which is not limited here.

[0111] The specific structure of the shell 121 is not limited.

[0112] In some embodiments, referring to FIG. 5, the shell 121 includes a shell cover 1212 and a base 1211 arranged separately, the shell cover 1212 and the base 1211 are detachably connected along a first direction to jointly define a receiving cavity 121a, and the liquid injection assembly 122 and the positive and negative pressure switching interface 123 are arranged on the top side of the shell cover 1212.

[0113] The liquid injection device 12 includes a second lifting mechanism 125 connected with the base 1211, used to drive the base 1211 to move along the first direction to be connected with or separated from the shell cover 1212.

[0114] It can be understood that the shell cover 1212 and the base 1211 arranged separately means that the shell cover 1212 and the base 1211 are manufactured separately. The shell cover 1212 is arranged on the top side of the base 1211, and the shell cover 1212 and the base 1211 are connected to form the completed shell 121, and the internal space is the receiving cavity 121a for accommodating the battery monomer 20.

[0115] Specifically, when vacuumizing is needed, the second lifting mechanism 125 drives the base 1211 to move along the first direction to be connected with the shell cover 1212, forming a closed receiving cavity 121a, so as to facilitate the vacuumizing of the receiving cavity 121a by the positive and negative pressure switching interface 123 and the subsequent liquid injection of the battery monomer 20. After the liquid injection is completed, the second lifting mechanism 125 drives the base 1211 to move reversely along the first direction to be separated from the shell cover 1212, so as to facilitate the removal of the battery monomer 20 after liquid injection and the placement of a new battery monomer 20 for the next round of liquid injection.

[0116] In this embodiment, the accurate control of the second lifting mechanism 125 facilitates the reliable abutment and separation of the shell cover 1212 and the base 1211, thereby facilitating the vacuumizing, liquid injection and taking out of the battery monomer 20, and the separately arranged shell cover 1212 and base 1211 can also facilitate the maintenance and cleaning of the accommodating cavity 121a.

[0117] The second lifting mechanism 125 can adopt hydraulic, pneumatic or electric mode as the power source, which is not limited herein.

[0118] It should be noted that the first direction can be any direction, and exemplarily, the first direction is parallel to the height direction of the battery liquid injection system 1.

[0119] In some embodiments, referring to FIG. 5, the shell 121 comprises a locking mechanism 1213 arranged on the base 1211 or the top cover, and the locking mechanism 1213 is used to lock the shell cover 1212 and the base 1211 when the base 1211 moves to abut with the shell cover 1212, so as to make the accommodating cavity 121a in a sealed state.

[0120] It can be understood that the locking mechanism 1213 is a mechanism for locking a target object.

[0121] The locking mode of the locking mechanism 1213 is not limited, and the locking mechanism 1213 can be locked by a buckle type locking, a threaded type locking, a magnetic type locking, a pneumatic or hydraulic locking.

[0122] In this embodiment, the arrangement of the locking mechanism 1213 can make the structure of the shell 121 more stable, further increase the sealing state of the accommodating cavity 121a in the vacuumizing process and the liquid injection process, reduce the probability of external air and impurities entering the accommodating cavity 121a, and increase the reliability of the vacuumizing process and the liquid injection process. At the same time, the locking of the locking mechanism 1213 to the shell cover 1212 and the base 1211 in the vacuumizing process and the liquid injection process can reduce the probability of damage to the sealing due to impact.

[0123] The specific structure of the first lifting mechanism 124 is not limited.

[0124] Exemplarily, in some embodiments, referring to FIG. 5, the first lifting mechanism 124 comprises a driving rod 1241 and a top plate 1242, the top plate 1242 is arranged in the accommodating cavity 121a and is used to support the battery monomer 20, one end of the driving rod 1241 is located in the accommodating cavity 121a and is connected with the top plate 1242, the other end of the driving rod 1241 is located at the bottom side outside the base 1211, the top plate 1242 is used to drive the battery monomer 20 to move along the first direction under the driving action of the driving rod 1241, so as to make the liquid injection port of the battery monomer 20 and the liquid injection nozzle 1222 of the liquid injection assembly 122 butt joint or separate.

[0125] Specifically, when the accommodating cavity 121a needs to be vacuumized, the second lifting mechanism 125 drives the base 1211 to move along the first direction to butt joint with the shell cover 1212, at this time, the second lifting mechanism 125 drives the battery monomer 20, the top plate 1242 and the driving rod 1241 located in the accommodating cavity 121a to move along the first direction together, but the liquid injection port of the battery monomer 20 does not butt joint with the liquid injection nozzle 1222 of the liquid injection assembly 122, and the driving rod 1241 does not produce driving action on the battery monomer 20. When the accommodating cavity 121a and the battery monomer 20 are in the vacuum state, the driving rod 1241 drives the top plate 1242 to drive the battery monomer 20 to continue to move along the first direction in the accommodating cavity 121a, so that the liquid injection port of the battery monomer 20 moves towards the liquid injection nozzle 1222 of the liquid injection assembly 122, until the liquid injection port of the battery monomer 20 butt joint with the liquid injection nozzle 1222 of the liquid injection assembly 122, so as to inject the battery monomer 20 through the liquid injection nozzle 1222. After the battery monomer 20 is fully injected, the driving rod 1241 drives the top plate 1242 to drive the battery monomer 20 to move along the first direction in the opposite direction to separate from the liquid injection nozzle 1222, the second lifting mechanism 125 drives the base 1211 to drive the driving rod 1241, the top plate 1242 and the battery monomer 20 to move along the first direction to separate from the shell cover 1212, so as to take out the battery monomer 20 after injection and put the next batch of battery monomers 20 to be injected.

[0126] The power source of the driving rod 1241 can be a motor, and the second lifting mechanism 125 can be a lifting cylinder, which is not limited here.

[0127] In this embodiment, the cooperation of the driving rod 1241 and the top plate 1242 plays a supporting role on the battery monomer 20, and under the driving of the driving rod 1241, the stability and safety of the battery monomer 20 during movement can be further increased. Moreover, the position of the battery monomer 20 can be positioned by the top plate 1242, so that the liquid injection port of the battery monomer 20 can be accurately connected with the liquid injection nozzle 1222. At the same time, the cooperation of the top plate 1242 and the driving rod 1241 can also adapt to battery monomers 20 of different sizes and shapes, and adapt to the liquid injection needs of various batteries.

[0128] It can be understood that a limiting structure can be arranged on the top plate 1242 to limit the battery monomer 20 and reduce the shaking and displacement of the battery monomer 20 during movement.

[0129] In some embodiments, the shell 121 has a rectangular shape in a cross section perpendicular to a first direction, wherein the first direction is parallel to the top-bottom direction of the battery liquid injection system 1.

[0130] In this embodiment, the cross-sectional shape design of the shell 121 can make the shell 121 have enough space to accommodate the battery monomer 20, facilitate the close arrangement of the battery monomers 20 in the shell 121, and at the same time, the rectangular shape can also make the shell 121 have stability, which is convenient for maintenance.

[0131] The specific structure of the liquid preparation assembly 111 is not limited.

[0132] In some embodiments, referring to FIG. 4, the liquid preparation assembly 111 includes a liquid preparation cup 1111 and a positive pressure liquid injection interface 111d. The liquid preparation cup 1111 has a liquid inlet 111a, a liquid storage space 111c, and a liquid outlet 111b. The liquid inlet 111a is used to introduce the liquid to be injected into the liquid storage space 111c. The positive pressure liquid injection interface 111d is not in communication with the liquid inlet 111a and is in communication with the liquid storage space 111c. The positive pressure liquid injection interface 111d is used to introduce gas to transport the liquid to be injected in the liquid storage space 111c to the battery monomer 20 through the liquid outlet 111b and the liquid injection assembly 122.

[0133] Specifically, the liquid inlet 111a is used to introduce the liquid to be injected into the liquid storage space 111c. The liquid storage space 111c is used to store the liquid to be injected. The liquid to be injected leaves the liquid preparation assembly 111 from the liquid outlet 111b and enters the liquid injection assembly 122.

[0134] The positive pressure liquid injection interface 111d is not in communication with the liquid inlet 111a, which means that the positive pressure liquid injection interface 111d does not interfere with the liquid inlet 111a. The positive pressure liquid injection interface 111d and the liquid inlet 111a are both in communication with the liquid storage space 111c. The channel between the positive pressure liquid injection interface 111d and the liquid storage space 111c and the channel between the liquid inlet 111a and the liquid storage space 111c do not have a cross section, which means that the positive pressure liquid injection interface 111d does not interfere with the liquid to be injected from the liquid inlet 111a into the liquid storage space 111c.

[0135] The positive pressure liquid injection interface 111d injects gas into the liquid storage space 111c, and the pressure in the liquid storage space 111c increases, forcing the liquid to be injected to flow out of the liquid storage space 111c through the liquid outlet 111b and be delivered to the battery cell 20 through the liquid injection assembly 122.

[0136] In this embodiment, the liquid to be injected enters the liquid storage space 111c from the liquid inlet 111a to complete the liquid preparation. The positive and negative pressure switching interface 123 can simultaneously vacuumize the accommodation cavity 121a and the battery cell 20 located in the accommodation cavity 121a. After vacuumization, the positive pressure liquid injection interface 111d injects gas into the liquid storage space 111c. The liquid to be injected flows to the liquid injection assembly 122 through the liquid outlet 111b under the action of the gas and then flows to the battery cell 20 to complete the liquid injection of the battery cell 20. The positive pressure liquid injection method can control the delivery rate of the liquid to be injected. At the same time, the positive and negative pressure switching interface 123 also injects gas into the accommodation cavity 121a, so that the pressure inside and outside the battery cell 20 is equal, which increases the stability of the liquid injection of the battery cell 20.

[0137] In some embodiments, referring to FIGS. 3 and 4, the liquid preparation assembly 111 includes a blocking member 1112, which can open or block the liquid inlet 111a.

[0138] Specifically, during the liquid preparation, the blocking member 1112 opens the liquid inlet 111a, so that the liquid to be injected can enter the liquid storage space 111c from the liquid inlet 111a. When the liquid preparation is completed, the blocking member 1112 closes the liquid inlet 111a to reduce the probability of impurities entering the liquid storage space 111c. At the same time, it is convenient to inject gas into the liquid storage space 111c from the positive pressure liquid injection interface 111d, so that the liquid to be injected flows from the liquid storage space 111c to the liquid injection assembly 122 to inject the battery cell 20.

[0139] The way to switch the blocking member 1112 between the position of opening the liquid inlet 111a and the position of closing the liquid inlet 111a is not limited. It can be manually operated or automatically controlled. For example, a gas cylinder can be used to drive the blocking member 1112 to move to open or close the liquid inlet 111a.

[0140] In some embodiments, referring to FIGS. 3 and 4, the liquid preparation assembly 111 further comprises a negative pressure liquid pumping interface 111e, which is not in communication with the liquid inlet 111a and is in communication with the liquid storage space 111c, and is used to draw a vacuum on the liquid storage space 111c.

[0141] Specifically, the negative pressure liquid pumping interface 111e is not in communication with the liquid inlet 111a, which means that the negative pressure liquid pumping interface 111e does not interfere with the liquid inlet 111a, and the negative pressure liquid pumping interface 111e and the liquid inlet 111a are respectively in communication with the liquid storage space 111c. The channel between the negative pressure liquid pumping interface 111e and the liquid storage space 111c and the channel between the liquid inlet 111a and the liquid storage space 111c do not have a crossing part, that is, the negative pressure liquid pumping interface 111e does not interfere with the entry of the liquid to be injected into the liquid storage space 111c from the liquid inlet 111a.

[0142] The negative pressure liquid pumping interface 111e is used to draw a vacuum on the liquid storage space 111c. When the flow of the liquid to be injected to the battery monomer 20 through the liquid injection assembly 122 under the action of the gas introduced through the positive pressure liquid pumping interface 111d is not smooth, the introduction of the gas can be stopped, a vacuum is drawn on the liquid storage space 111c through the negative pressure liquid pumping interface 111e to generate a suction force on the liquid to be injected, the flow of the liquid to be injected is adjusted, then the negative pressure liquid pumping interface 111e is closed, and the gas is introduced through the positive pressure liquid pumping interface 111d to continue the liquid injection.

[0143] In this embodiment, through the cooperation of the negative pressure liquid pumping interface 111e and the positive pressure liquid pumping interface 111d, when the positive pressure liquid pumping is not smooth, the flow of the liquid to be injected is adjusted through negative pressure suction, so that the positive pressure liquid pumping is more smooth, thereby increasing the liquid injection efficiency of the battery monomer 20.

[0144] It should be noted that the liquid injection of the battery can be performed only by introducing the gas through the positive pressure liquid pumping interface 111d, that is, in the positive pressure liquid pumping mode, the battery monomer 20 can be filled with liquid at one time, at which time the negative pressure liquid pumping interface 111e is not needed to assist in suction. When the positive pressure liquid pumping is not smooth, the positive pressure liquid pumping interface 111d and the negative pressure liquid pumping interface 111e can be alternately opened to perform the liquid injection, at which time the number of times of negative pressure suction can be one or multiple, which can be adapted according to the model of the battery monomer 20.

[0145] In some embodiments, referring to FIG. 4, the positive pressure liquid pumping interface 111d is in communication with the liquid storage space 111c through a first channel 111f, and the negative pressure liquid pumping interface 111e is in communication with the liquid storage space 111c through a second channel 111g, and at least part of the first channel 111f and the second channel 111g overlap.

[0146] It can be understood that the at least partial overlap of the first channel 111f and the second channel 111g means that the passage between the positive pressure liquid injection interface 111d and the liquid storage space 111c and the passage of the negative pressure liquid injection interface 111e and the liquid storage space 111c at least partially share the same physical path.

[0147] In this embodiment, the at least partial overlap of the first channel 111f and the second channel 111g can reduce the need for additional pipelines, so that the structure of the entire liquid preparation assembly 111 is more compact and occupies less space. The injection is realized by the alternating work of the positive pressure liquid injection interface 111d and the negative pressure liquid injection interface 111e.

[0148] It can be understood that the positive pressure liquid injection interface 111d and the negative pressure liquid injection interface 111e can be opened or closed by a switch valve respectively. When gas needs to be introduced, the positive pressure liquid injection interface 111d is opened and the negative pressure liquid injection interface 111e is closed. The positive pressure liquid injection interface 111d is in communication with the first channel 111f to introduce gas into the liquid storage space 111c. When the positive pressure liquid injection is not smooth, the positive pressure liquid injection interface 111d is closed and the negative pressure liquid injection interface 111e is opened. The negative pressure liquid injection interface 111e is in communication with the second channel 111g to vacuumize the liquid storage space 111c.

[0149] It can be understood that in some examples, after the negative pressure liquid injection interface 111e vacuumizes the liquid storage space 111c, the pressure in the liquid storage space 111c is not less than -90 kPa (kilopascal), for example, -90 kPa, -80 kPa, -75 kPa, -50 kPa, -30 kPa, -20 kPa, etc. That is, under the action of the negative pressure liquid injection interface 111e, the liquid storage space 111c is roughly in a low vacuum environment. In this pressure environment, the electrolyte is not easy to crystallize. That is, in the case of at least partial overlap of the first channel 111f and the second channel 111g, the probability of electrolyte crystallization can be reduced, and the positive pressure liquid injection rate can be improved.

[0150] It should be noted that after the positive and negative pressure switching interface 123 vacuumizes the accommodation cavity 121a and the battery monomer 20, the pressure in the accommodation cavity 121a and the battery monomer 20 is not more than -95 kPa, for example, -95 kPa, -100 kPa, -120 kPa, -150 kPa, -170 kPa, -180 kPa, etc. That is, under the action of the positive and negative pressure switching interface 123, the accommodation cavity 121a and the battery monomer 20 are roughly in a high vacuum environment. In this pressure environment, the oxygen and moisture in the battery monomer 20 can be effectively removed, and the electrolyte can fully contact the positive and negative electrodes of the battery during injection, thereby increasing the performance of the battery. The specific structure of the liquid preparation assembly 111 and the moving mechanism 113 is not limited.

[0151] In some embodiments, referring to FIG. 2, the liquid preparation assembly 111 includes a plurality of liquid preparation cups 1111 arranged in the second direction, and a plurality of liquid preparation assemblies 111 are arranged in the third direction.

[0152] The moving mechanism 113 includes a first moving module 1131, a second moving module 1132, and a third moving module 1133. The liquid distribution valve 112 is connected to the first moving module 1131, and the first moving module 1131 is configured to drive the liquid distribution valve 112 to move in the first direction.

[0153] The second moving module 1132 extends in the second direction, and the first moving module 1131 is arranged on the second moving module 1132. The second moving module 1132 is configured to drive the first moving module 1131 to move in the second direction.

[0154] The third moving module 1133 is connected to the rack 10 and extends in the third direction. The second moving module 1132 is arranged on the third moving module 1133, and the third moving module 1133 is configured to drive the second moving module 1132 to move in the third direction.

[0155] The first direction, the second direction, and the third direction are perpendicular to each other.

[0156] Specifically, the liquid preparation assembly 111 includes a plurality of liquid preparation cups 1111 arranged in the second direction. A plurality of liquid preparation assemblies 111 are arranged in the third direction to form a two-dimensional array structure. The first moving module is connected to the liquid distribution valve 112 and configured to drive the liquid distribution valve 112 to move in the first direction. The liquid distribution valve 112 is configured to connect and separate the liquid distribution port and the liquid inlet 111a of the liquid preparation cup 1111. The second moving module 1132 carries the first moving module 1131 and is configured to drive the first moving module 1131 to move in the second direction to complete the liquid injection of different liquid preparation cups 1111 of a liquid preparation assembly 111. The third moving module 1133 is connected to the rack 10 and carries the second moving module 1132. The third moving module 1133 is configured to drive the second moving module 1132, the first moving module 1131, and the liquid distribution valve 112 to move in the third direction to realize the movement of the liquid distribution valve 112 in different liquid preparation assemblies 111, thereby completing the liquid preparation of different liquid preparation assemblies 111.

[0157] In this embodiment, the moving mechanism 113 can quickly and accurately switch between a plurality of liquid preparation cups 1111 through three-dimensional movement and adapt to the liquid preparation requirements of liquid preparation cups 1111 at different positions, thereby improving the liquid injection efficiency. The battery liquid injection system 1 can perform liquid preparation on a plurality of liquid preparation assemblies 111, thereby facilitating simultaneous liquid injection of battery monomers 20 arranged in a two-dimensional array structure and increasing the liquid injection efficiency.

[0158] In one embodiment, referring to FIGS. 1-5, the battery liquid injection system 1 comprises a rack 10, a liquid preparation device 11 and a liquid injection device 12. The liquid preparation device 11 comprises a distribution valve 112, a moving mechanism 113 and a plurality of liquid preparation assemblies 111 arranged side by side along a third direction, each of the liquid preparation assemblies 111 comprising a plurality of liquid preparation cups 1111 arranged at intervals along a second direction, the liquid preparation cups 1111 having a liquid inlet 111a, a liquid storage space 111c and a liquid outlet 111b, the liquid preparation assembly 111 further being provided with a positive pressure liquid pumping interface 111d and a negative pressure liquid pumping interface 111e, the positive pressure liquid pumping interface 111d being in communication with the liquid storage space 111c and not in communication with the liquid inlet 111a, the negative pressure liquid pumping interface 111e being in communication with the liquid storage space 111c and not in communication with the liquid inlet 111a, the positive pressure liquid pumping interface 111d and the negative pressure liquid pumping interface 111e at least partially coinciding with the passage of the liquid storage space 111c. The moving mechanism 113 comprises a first moving module 1131, a second moving module 1132 and a third moving module 1133.

[0159] The liquid injection device 12 comprises a housing 121, a liquid injection assembly 122, a positive-negative pressure switching interface 123, a first lifting mechanism 124 and a second lifting mechanism 125. The housing 121 has a receiving cavity 121a for accommodating a battery monomer 20, the housing 121 comprising a housing cover 1212 and a base 1211 arranged separately, the second lifting mechanism 125 being connected to the base 1211, the positive-negative pressure switching interface 123 and the liquid injection assembly 122 being arranged on the housing cover 1212 and not in communication with each other, the liquid injection assembly 122 comprising a valve 1221 and a liquid injection nozzle 1222, the first lifting mechanism 124 comprising a driving rod 1241 and a top plate 1242, the top plate 1242 being arranged in the receiving cavity 121a and used for supporting the battery monomer 20, the driving rod 1241 extending into the receiving cavity 121a and being connected to the top plate 1242. The first direction is parallel to the top-bottom direction.

[0160] In the liquid preparation stage, the first moving module 1131, the second moving module 1132 and the third moving module 1133 cooperate to drive the distribution valve 112 to move along the three-dimensional space, realize the connection and separation of the distribution port of the distribution valve 112 and each liquid inlet 111a of different liquid preparation assemblies 111, and complete the liquid preparation. In the liquid preparation process, the positive pressure liquid pumping interface 111d and the negative pressure liquid pumping interface 111e are both in a closed state.

[0161] In the vacuumizing stage, the second lifting mechanism 125 pushes the base 1211 and drives the first lifting mechanism 124 and the battery monomer 20 to move to the top side to realize the butt joint of the base 1211 and the shell cover 1212, the base 1211 is provided with a locking mechanism 1213, and in the state that the base 1211 is butt jointed with the shell cover 1212, the locking mechanism locks the base 1211 and the shell cover 1212 to increase the sealing property of the containing cavity 121a. The liquid injection port of the battery monomer 20 is spaced apart from the liquid injection nozzle 1222 of the liquid injection assembly 122, the valve 1221 of the liquid injection assembly 122 is closed, and the positive and negative pressure switching interface 123 vacuums the containing cavity 121a and the battery monomer 20 located in the containing cavity 121a to make the inside of the battery monomer 20 in a vacuum environment.

[0162] It can be understood that the liquid preparation stage and the vacuumizing stage can be performed synchronously.

[0163] In the liquid injection stage, the driving rod 1241 drives the top plate 1242 to drive the battery monomer 20 to move to the top side to realize the butt joint of the liquid injection port of the battery monomer 20 and the liquid injection nozzle 1222, the valve 1221 of the liquid injection assembly 122 is opened, the liquid injection nozzle 1222 is communicated with the liquid outlet 111b of the liquid preparation assembly 111, the gas is introduced into the liquid storage space 111c through the positive pressure liquid injection interface 111d, and the liquid injection body is flowed to the battery monomer 20 through the liquid injection nozzle 1222 under the action of the gas. At this time, the positive and negative pressure switching interface 123 introduces the gas into the containing cavity 121a to make the pressure inside and outside the battery monomer 20 equal, thereby reducing the probability of battery swelling. If the positive pressure liquid injection is smooth, the positive pressure liquid injection is continuously performed until the battery monomer 20 is full of liquid. If the positive pressure liquid injection is blocked, the positive pressure liquid injection interface 111d and the negative pressure liquid injection interface 111e are alternately operated to improve the smoothness of the positive pressure liquid injection until the battery monomer 20 is full of liquid. When the battery monomer 20 is full of liquid, the driving rod 1241 drives the top plate 1242 to drive the battery monomer 20 to move to the bottom side to realize the separation of the liquid injection port of the battery monomer 20 and the liquid injection nozzle 1222, and the second lifting mechanism 125 drives the base 1211 to move downward to realize the separation of the base 1211 and the shell cover 1212, thereby facilitating the removal of the battery monomer 20 full of liquid and the replacement of the new batch of battery monomers 20 to be injected.

[0164] Therefore, the battery liquid injection system 1 provided by the embodiment of the present disclosure does not interfere with the vacuumizing path and the liquid injection path of the battery monomer 20, reduces the probability of electrolyte crystallization and blockage of the vacuumizing path, and can synchronously perform the vacuumizing and liquid preparation of the battery monomer 20 without interference, thereby increasing the overall working efficiency of the battery liquid injection system 1.

[0165] The second aspect of the embodiment of the present disclosure provides a battery liquid injection method.

[0166] It can be understood that the battery liquid injection method of the embodiments of the present disclosure can be applied to the battery liquid injection system 1 of any embodiment of the first aspect.

[0167] Referring to FIG. 6, the battery liquid injection method comprises:

[0168] S101: liquid preparation step: injecting the to-be-injected liquid into the liquid storage space 111c of the liquid preparation assembly 111.

[0169] S201: vacuumizing step: sealing the accommodation cavity 121a, and controlling the positive-negative pressure switching interface 123 to vacuumize the accommodation cavity 121a in a state that the injection port of the battery monomer 20 is separated from the injection assembly 122, wherein the battery monomer 20 is accommodated in the accommodation cavity 121a.

[0170] S102: liquid injection step: controlling the battery monomer 20 to move so as to make the injection port of the battery monomer 20 be in butt joint with the injection assembly 122, and injecting the to-be-injected liquid in the liquid preparation assembly 111 into the battery monomer 20 through the injection assembly 122, and controlling the positive-negative pressure switching interface 123 to introduce gas into the accommodation cavity 121a during the liquid injection process.

[0171] Wherein, the positive-negative pressure switching interface 123 and the injection assembly 122 are not in communication with each other.

[0172] Here, the liquid preparation step refers to injecting the liquid storage space 111c of the liquid preparation assembly 111, specifically, the liquid preparation can be realized by controlling the distribution valve 112 to be in butt joint with the liquid inlet 111a of the liquid preparation assembly 111 through the moving mechanism 113.

[0173] Here, the vacuumizing step refers to vacuumizing the battery monomer 20. Specifically, the second lifting mechanism 125 can drive the base 1211 to move to realize butt joint with the shell cover 1212 to seal the accommodation cavity 121a, and the injection port of the battery monomer 20 is separated from the injection nozzle 1222 of the injection assembly 122, so that when the positive-negative pressure switching interface 123 is vacuumized, the battery monomer 20 can also be vacuumized, so that the battery monomer 20 is in a vacuum state.

[0174] It can be understood that the liquid preparation step and the vacuumizing step at least have a time period intersection, that is, the liquid preparation step and the vacuumizing step can be almost simultaneously performed, that is, in the same time period, the liquid preparation can be performed, and the vacuumizing operation can also be performed.

[0175] Here, the liquid injection step refers to liquid injection on the battery monomer 20. Specifically, the battery monomer 20 can be moved by the first lifting mechanism 124 to make the liquid injection port of the battery monomer 20 dock with the liquid injection nozzle 1222, the liquid injection nozzle 1222 is in communication with the liquid outlet 111b of the liquid preparation assembly 111, the liquid to be injected in the liquid preparation assembly 111 is injected into the battery monomer 20 through the liquid injection assembly 122, and the positive and negative pressure switching interface 123 introduces gas into the containing cavity 121a to make the pressure inside and outside the battery monomer 20 equal.

[0176] Here, the positive and negative pressure switching interface 123 and the liquid injection assembly 122 are not in communication, that is, the positive and negative pressure switching interface 123 and the liquid injection assembly 122 do not interfere with each other, and the liquid to be injected in the liquid injection assembly 122 will not enter the positive and negative pressure switching interface 123.

[0177] In this embodiment, the liquid preparation step and the vacuum extraction step do not interfere with each other, the liquid injection path and the vacuum extraction path are separated, the electrolyte crystallization probability is low, and during the liquid injection process, the positive and negative pressure switching interface 123 can assist in balancing the pressure inside and outside the battery monomer 20, and improve the liquid injection efficiency and reliability of the battery monomer 20.

[0178] In some embodiments, the liquid to be injected in the liquid preparation assembly 111 is injected into the battery monomer 20 through the liquid injection assembly 122, which includes:

[0179] Positive pressure liquid injection: control the positive pressure liquid injection interface 111d of the liquid preparation assembly 111 to introduce gas into the liquid storage space 111c of the liquid preparation assembly 111, so as to inject all the required amount of electrolyte into the battery monomer 20.

[0180] Here, the positive pressure liquid injection interface 111d is used to introduce gas into the liquid storage space 111c, so that the electrolyte flows to the battery monomer 20 under the action of the gas through the liquid injection nozzle 1222 until the battery monomer 20 is full of liquid.

[0181] In this embodiment, the positive pressure liquid injection mode can further improve the liquid injection efficiency and shorten the time required for the battery monomer 20 to be full of liquid.

[0182] In some embodiments, the liquid to be injected in the liquid preparation assembly 111 is injected into the battery monomer 20 through the liquid injection assembly 122, which includes alternating positive pressure liquid injection and negative pressure suction.

[0183] Positive pressure liquid injection: close the negative pressure liquid injection interface 111e of the liquid preparation assembly 111, and control the positive pressure liquid injection interface 111d of the liquid preparation assembly 111 to introduce gas into the liquid storage space 111c of the liquid preparation assembly 111.

[0184] Negative pressure suction: close the positive pressure liquid injection interface 111d of the liquid preparation assembly 111, and control the negative pressure liquid injection interface 111e of the liquid preparation assembly 111 to vacuum the liquid storage space 111c of the liquid preparation assembly 111.

[0185] Here, the alternately executed positive pressure liquid injection and negative pressure suction refer to that the positive pressure liquid injection and the negative pressure suction are performed alternately, the positive pressure liquid injection is stopped after a first preset time, the negative pressure suction is stopped again after a second preset time, and the positive pressure liquid injection is started. In this way, the cycle is repeated.

[0186] Specifically, when the positive pressure liquid injection is performed, the negative pressure liquid injection interface 111e is closed, and gas is introduced into the liquid storage space 111c, so that the electrolyte flows to the battery monomer 20 under the action of the gas. When the flow smoothness of the electrolyte decreases during the positive pressure liquid injection, the positive pressure liquid injection interface 111d is closed, the negative pressure liquid injection interface 111e is opened, and the liquid storage space 111c is vacuumed to adjust the flow smoothness of the electrolyte. Then, the negative pressure liquid injection interface 111e is closed again, and the liquid injection to the battery monomer 20 is continued in the positive pressure liquid injection mode. In this way, the alternation is performed until the battery monomer 20 is filled with liquid.

[0187] It can be understood that the alternation times of the positive pressure liquid injection and the negative pressure suction can be one time or multiple times, which is not limited herein.

[0188] In the embodiment, the flow of the electrolyte can be adjusted in time by the combination of the positive pressure liquid injection and the negative pressure suction, so that the positive pressure liquid injection is smoother, and the liquid injection efficiency of the battery monomer 20 is increased.

[0189] It can be understood that the positive pressure liquid injection or the combination of the positive pressure liquid injection and the negative pressure suction can be determined according to the model of the battery.

[0190] The battery liquid injection method of an application embodiment of the present disclosure will be briefly described below in combination with FIG. 7.

[0191] S301: control the blocking piece 1112 to open the liquid inlet 111a, and inject liquid into the liquid storage space 111c of the liquid preparation assembly 111 in a state that the liquid distribution port of the liquid distribution valve 112 is connected to the liquid inlet 111a of the liquid preparation assembly 111.

[0192] Here, the movement mechanism 113 can be used to control the liquid distribution valve 112 to move in the three-dimensional space, so as to connect or separate the liquid distribution port and the liquid inlet 111a of the liquid preparation assembly 111, and then complete the liquid preparation of the liquid preparation assembly 111, so that the liquid storage space 111c of the liquid preparation assembly 111 stores the electrolyte required for the battery monomer 20 to be filled with liquid.

[0193] S302: control the blocking piece 1112 to close the liquid inlet 111a.

[0194] Here, after the preparation of the liquid, the control of the blocking member 1112 closes the liquid inlet 111a to reduce the probability of impurities entering the liquid storage space 111c.

[0195] S401: Control the second lifting mechanism 125 to drive the base 1211 to move in the first direction to be in butt joint with the shell cover 1212, and control the locking mechanism 1213 to lock the shell cover 1212 and the base 1211 to seal the accommodation cavity 121a.

[0196] Here, the second lifting mechanism 125 drives the first lifting mechanism 124, the battery monomer 20 and the base 1211 to move together, and when the base 1211 is in butt joint with the shell cover 1212, the locking mechanism 1213 locks the shell cover 1212 and the base 1211 to make the accommodation cavity 121a in a sealed state. At this time, the liquid inlet of the battery monomer 20 is separated from the liquid injection nozzle 1222 of the liquid injection assembly 122.

[0197] S402: Close the valve 1221 of the liquid injection assembly 122, and in the case that the liquid inlet of the battery monomer 20 is separated from the liquid injection assembly 122, control the positive and negative pressure switching interface 123 to vacuumize the accommodation cavity 121a, wherein the positive and negative pressure switching interface 123 and the liquid injection assembly 122 are not in communication with each other.

[0198] Here, the positive and negative pressure switching interface 123 vacuums the accommodation cavity 121a, thereby completing the vacuumization of the battery monomer 20. The positive and negative pressure switching interface 123 and the liquid injection assembly 122 are not in communication with each other, the electrolyte in the liquid injection assembly 122 will not flow to the positive and negative pressure switching interface 123, and the electrolyte crystallization probability is low.

[0199] It can be understood that the preparation steps S301 and S302 and the vacuumization steps S401 and S402 can be performed synchronously.

[0200] S303: Control the first lifting mechanism 124 to drive the battery monomer 20 to move in the first direction to be in butt joint with the liquid injection nozzle 1222 of the liquid injection assembly 122, open the valve 1221 of the liquid injection assembly 122, control the positive pressure liquid injection interface 111d to introduce air into the liquid storage space 111c, inject the liquid to be injected in the liquid preparation assembly 111 into the battery monomer 20, and control the positive and negative pressure switching interface 123 to introduce gas into the accommodation cavity 121a.

[0201] Here, when the battery monomer to be injected needs to be injected once by positive pressure injection, the positive pressure injection method is adopted. At this time, the negative pressure liquid injection interface 111e is always in a closed state, and the gas introduced through the positive pressure liquid injection interface 111d makes the electrolyte flow towards the battery monomer 20.

[0202] S304: Control the first jacking mechanism 124 to drive the battery monomer 20 to move along the first direction to the liquid injection port and the liquid injection nozzle 1222 of the liquid injection assembly 122 to dock, open the valve 1221 of the liquid injection assembly 122, control the positive pressure liquid injection interface 111d and the negative pressure liquid injection interface 111e to run alternately, inject the liquid in the standby liquid assembly 111 into the battery monomer 20, and control the positive and negative pressure switching interface 123 to introduce gas into the accommodation cavity 121a.

[0203] Here, when the battery monomer required for liquid injection is blocked by the positive pressure injection and cannot meet the full liquid injection requirement, the positive pressure injection and negative pressure suction are alternately executed to increase the liquid injection smoothness and complete the liquid injection of the battery monomer 20.

[0204] S305: Control the first jacking mechanism 124 to drive the battery monomer 20 to move to separate from the liquid injection nozzle 1222, control the locking mechanism 1213 to unlock, and control the second jacking mechanism 125 to drive the base 1211 to move to separate from the shell cover 1212.

[0205] Here, after the battery monomer is full of liquid, the first jacking mechanism 124 is used to separate the battery monomer 20 from the liquid injection nozzle 1222, the locking mechanism 1213 is used to unlock the shell cover 1212 and the base 1211, and the second jacking mechanism 125 is used to drive the battery monomer 20 and the first jacking mechanism 124 to move to separate the base 1211 from the shell cover 1212.

[0206] S306: Take out the battery monomer 20 and enter the next round of liquid injection.

[0207] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present disclosure, and they should be covered in the scope of the present disclosure. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the present disclosure.

Claims

1. A battery liquid injection system, comprising: a rack; a liquid preparation device connected to the rack, the liquid preparation device comprising a liquid preparation assembly for storing liquid to be injected, the liquid preparation assembly having a liquid outlet; a liquid injection device connected to the rack, the liquid injection device comprising a housing having a receiving cavity for accommodating a battery cell, a liquid injection assembly, and a positive-negative pressure switching interface, the liquid injection assembly and the positive-negative pressure switching interface being arranged in the housing and not in communication with each other, the positive-negative pressure switching interface being configured to evacuate the receiving cavity and the battery cell in the receiving cavity in a sealed state or to introduce gas into the receiving cavity in a vacuum state, the liquid outlet of the liquid preparation assembly being in communication with the liquid injection assembly, the liquid injection assembly being configured to inject the liquid to the battery cell accommodated in the receiving cavity; the liquid preparation device comprising a moving mechanism and a liquid distribution valve, the liquid distribution valve having a liquid distribution outlet, the liquid distribution valve being arranged on a top side of the liquid preparation assembly, the moving mechanism being configured to drive the liquid distribution valve to move so that the liquid distribution outlet is detachably docked with a liquid inlet of the liquid preparation assembly.

2. The battery liquid injection system according to claim 1, wherein the liquid injection assembly comprising a valve and a liquid injection nozzle, the valve connecting the liquid outlet and the liquid injection nozzle, the liquid injection nozzle being configured to be detachably docked with a liquid injection outlet of the battery cell, the valve being configured to open or close a passage between the liquid injection nozzle and the liquid outlet.

3. The battery liquid injection system according to any one of claims 1-2, wherein, the liquid injection device comprising a first lifting mechanism, the first lifting mechanism being configured to drive the battery cell to move towards the liquid injection assembly or away from the liquid injection assembly in a first direction so that the liquid injection outlet of the battery cell is docked with or detached from the liquid injection nozzle of the liquid injection assembly.

4. The battery liquid injection system according to claim 3, wherein the housing comprising a shell cover and a base arranged in two parts, the shell cover and the base being detachably docked together in the first direction to jointly define the receiving cavity, the liquid injection assembly and the positive-negative pressure switching interface being arranged on a top side of the shell cover; the liquid injection device comprising a second lifting mechanism connected to the base, the second lifting mechanism being configured to drive the base to move in the first direction to be docked with or detached from the shell cover.

5. The battery liquid injection system according to claim 4, wherein the housing comprising a locking mechanism arranged on the base or the shell cover, the locking mechanism being configured to lock the shell cover and the base when the base is moved to be docked with the shell cover so that the receiving cavity is in a sealed state.

6. The battery liquid injection system according to any one of claims 4-5, wherein, the first lifting mechanism comprising a driving rod and a top plate, the top plate being arranged in the receiving cavity and configured to support the battery cell, one end of the driving rod being arranged in the receiving cavity and connected to the top plate, the other end of the driving rod being arranged on a bottom side outside the base, the top plate being configured to move the battery cell in the first direction under the driving of the driving rod so that the liquid injection outlet of the battery cell is docked with or detached from the liquid injection nozzle of the liquid injection assembly.

7. The battery liquid injection system according to any one of claims 1 to 6, wherein the housing having a rectangular shape in a cross section perpendicular to the first direction, wherein the first direction is parallel to a top-bottom direction of the battery liquid injection system.

8. The battery liquid injection system according to any one of claims 1 to 7, wherein The liquid preparation assembly comprises a liquid preparation cup and a positive pressure liquid injection interface. The liquid preparation cup has a liquid inlet, a liquid storage space and a liquid outlet. The liquid inlet is configured to introduce a liquid to be injected into the liquid storage space. The positive pressure liquid injection interface is not in communication with the liquid inlet but is in communication with the liquid storage space. The positive pressure liquid injection interface is configured to introduce a gas to transport the liquid to be injected in the liquid storage space to the battery cell through the liquid outlet and the liquid injection assembly.

9. The battery liquid injection system according to claim 8, wherein The liquid preparation assembly comprises a sealing member configured to open or seal the liquid inlet.

10. The battery liquid injection system according to claim 8 or 9, wherein The liquid preparation assembly further comprises a negative pressure liquid injection interface. The negative pressure liquid injection interface is not in communication with the liquid inlet but is in communication with the liquid storage space. The negative pressure liquid injection interface is configured to vacuumize the liquid storage space.

11. The battery liquid injection system according to claim 10, wherein The positive pressure liquid injection interface is in communication with the liquid storage space through a first channel. The negative pressure liquid injection interface is in communication with the liquid storage space through a second channel. At least a portion of the first channel and the second channel overlap.

12. The battery liquid injection system according to claim 10 or 11, wherein After the negative pressure liquid injection interface vacuumizes the liquid storage space, the pressure in the liquid storage space is not less than -90 kpa. After the positive and negative pressure switching interface vacuumizes the accommodating cavity and the battery cell, the pressure in the accommodating cavity and the battery cell is not greater than -95 kpa.

13. The battery liquid injection system according to any one of claims 1 to 12, wherein The liquid preparation assembly comprises a plurality of liquid preparation cups arranged in a second direction. The number of the liquid preparation assemblies is multiple. The multiple liquid preparation assemblies are fixed to the rack and arranged side by side in a third direction. The moving mechanism comprises a first moving module, a second moving module and a third moving module. The liquid distribution valve is connected to the first moving module. The first moving module is configured to drive the liquid distribution valve to move in a first direction. The second moving module extends in the second direction. The first moving module is arranged in the second moving module. The second moving module is configured to drive the first moving module to move in the second direction. The third moving module is connected to the rack and extends in the third direction. The second moving module is arranged in the third moving module. The third moving module is configured to drive the second moving module to move in the third direction. The first direction, the second direction and the third direction are perpendicular to each other.

14. A battery liquid injection method applied to the battery liquid injection system of any one of claims 1-13. The battery liquid injection method comprises: a liquid preparation step of injecting a liquid to be injected into a liquid storage space of a liquid preparation assembly; a vacuumizing step of sealing an accommodating cavity and controlling a positive and negative pressure switching interface to vacuumize the accommodating cavity in a state that a liquid injection port of a battery cell is separated from a liquid injection assembly, wherein the battery cell is accommodated in the accommodating cavity; a liquid injection step of controlling the battery cell to move so that the liquid injection port of the battery cell is connected to the liquid injection assembly, and injecting the liquid to be injected in the liquid preparation assembly into the battery cell through the liquid injection assembly, and controlling the positive and negative pressure switching interface to introduce a gas into the accommodating cavity during the liquid injection process; wherein the positive and negative pressure switching interface is not in communication with the liquid injection assembly.

15. The battery liquid injection method according to claim 14, wherein The injection of the liquid to be injected in the liquid preparation assembly into the battery cell through the liquid injection assembly comprises: Positive pressure injection: the positive pressure liquid injection interface of the liquid preparation assembly is controlled to introduce gas into the liquid storage space of the liquid preparation assembly, so as to inject all the required amount of the liquid to be injected into the battery monomer.

16. The battery liquid injection method according to claim 14, wherein The injection of the liquid to be injected in the liquid preparation assembly into the battery monomer through the liquid injection assembly includes alternately executed positive pressure injection and negative pressure suction, wherein, Positive pressure injection: the negative pressure liquid injection interface of the liquid preparation assembly is closed, and the positive pressure liquid injection interface of the liquid preparation assembly is controlled to introduce gas into the liquid storage space of the liquid preparation assembly; Negative pressure suction: the positive pressure liquid injection interface of the liquid preparation assembly is closed, and the negative pressure liquid injection interface of the liquid preparation assembly is controlled to vacuumize the liquid storage space of the liquid preparation assembly.

Images