Energy storage battery liquid injection mechanism, liquid injection method and energy storage battery

Abstract

The application relates to an energy storage battery liquid injection mechanism, a liquid injection method and an energy storage battery, which can improve the liquid injection speed. The energy storage battery liquid injection mechanism comprises a liquid injection assembly, a liquid inlet pipeline, first, second and third liquid injection needles connected in parallel with the liquid inlet pipeline, and a vertical driving assembly. The vertical driving assembly is used for driving the first, second and third liquid injection needles to ascend and descend so as to be capable of extending into the liquid injection hole of the energy storage battery to perform liquid injection. The first, second and third liquid injection needles are arranged in a straight line in sequence and are spaced apart. The flow cross sections of the first and third liquid injection needles are smaller than that of the second liquid injection needle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium batteries, in particular to a kind of energy storage battery liquid injection mechanism, liquid injection method and energy storage battery. BACKGROUND

[0002] In the production process of lithium ion battery, electrolyte infiltration is an important link in battery design and production process.Electrolyte infiltration is directly related to the performance of the battery.Electrolyte infiltration for too long will affect the production efficiency of lithium ion battery and increase production cost.

[0003] Therefore, the liquid injection process is a very important process, which directly affects the performance of the battery.The liquid injection process is to quantitatively inject electrolyte into the battery after the battery is assembled.During the liquid injection process, too much liquid injection can cause the battery to bulge, resulting in uneven thickness of the battery, too little liquid injection can reduce the capacity and cycle life of the battery, and uneven liquid injection can cause inconsistent capacity and cycle performance. SUMMARY

[0004] Therefore, it is necessary to provide an energy storage battery liquid injection mechanism, liquid injection method and energy storage battery to solve the problem of how to ensure the electrolyte infiltration effect.

[0005] An energy storage battery liquid injection mechanism includes a liquid injection assembly, a liquid inlet pipeline, a first liquid injection needle, a second liquid injection needle and a third liquid injection needle connected in parallel to the liquid inlet pipeline, and a vertical driving assembly.The vertical driving assembly drives the first liquid injection needle, the second liquid injection needle and the third liquid injection needle to move up and down to extend into the liquid injection hole of the energy storage battery for liquid injection.The first liquid injection needle, the second liquid injection needle and the third liquid injection needle are arranged in a straight line in sequence.The cross-sectional area of the first liquid injection needle and the third liquid injection needle is smaller than that of the second liquid injection needle.

[0006] In some embodiments, the second liquid injection needle is uniformly provided with a plurality of spray holes in the circumferential direction of the second liquid injection needle, so that the second liquid injection needle sprays uniformly in all directions.

[0007] In some embodiments, the area of the spray hole on the first liquid injection needle opening towards the side of the second liquid injection needle is greater than that of the spray hole opening in other directions;The area of the spray hole on the third liquid injection needle opening towards the side of the second liquid injection needle is greater than that of the spray hole opening in other directions.

[0008] In some embodiments, the energy storage battery liquid injection mechanism further comprises a horizontal driving assembly, which drives at least one of the first liquid injection needle, the second liquid injection needle and the third liquid injection needle to move in the arrangement direction of the first liquid injection needle, the second liquid injection needle and the third liquid injection needle.

[0009] The application discloses an injection method applied to the injection mechanism of the energy storage battery, and the method comprises the following steps: controlling the first injection needle, the second injection needle and the third injection needle to be inserted into the corresponding first injection port, the second injection port and the third injection port of the energy storage battery respectively; and controlling the flow of the first injection needle and the third injection needle to be smaller than the flow of the second injection needle.

[0010] In some embodiments, the step of controlling the flow of the first injection needle and the third injection needle to be smaller than the flow of the second injection needle comprises the following steps: controlling the liquid inlet amount of the first injection needle and the third injection needle to be smaller than the liquid inlet amount of the second injection needle.

[0011] The application discloses an energy storage battery, which comprises a shell, an electrode assembly arranged in the shell, a top cover arranged at an opening of the shell, a first injection port, a second injection port and a third injection port arranged on the outer side of the top cover along the length direction of the top cover, wherein the second injection port is arranged at the middle part of the top cover, and the first injection port and the third injection port are arranged on the two sides of the second injection port; the shell is provided with a first liquid outlet part, a second liquid outlet part and a third liquid outlet part which are arranged in the shell and correspond to the first injection port, the second injection port and the third injection port respectively; the first liquid outlet part and the third liquid outlet part are both provided with injection holes on the side facing the second liquid outlet part, and the injection holes of the second liquid outlet part are arranged at multiple positions in the circumferential direction of the second liquid outlet part.

[0012] In some embodiments, the first injection port and the third injection port are respectively deviated from the two ends of the shell along the length direction of the top cover.

[0013] In some embodiments, the top cover comprises a cover plate and an injection molding part, the cover plate is connected with the shell, the injection molding part is arranged on the side of the cover plate facing the opening, and the first liquid outlet part, the second liquid outlet part and the third liquid outlet part are arranged on the injection molding part.

[0014] In some embodiments, the first liquid outlet part, the second liquid outlet part and the third liquid outlet part are respectively provided with a float and an elastic part, the float is kept in the position shielding the injection hole under the elastic force of the elastic part, and the float overcomes the elastic force to at least partially expose the injection hole under the action of external force.

[0015] In the application, the first injection needle, the second injection needle and the third injection needle inject liquid into the energy storage battery from different positions at the same time, so that the electrolyte can be injected at a high speed and uniformly, and then the electrolyte can be uniformly infiltrated. The time required for injection is obviously reduced, and the cycle number of the battery is superior to that of the prior art. In addition, under the same standing time, the battery has smaller AC internal resistance and better infiltration effect. Therefore, the infiltration time can be reduced to a certain extent, and the production cycle of the battery is shortened. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1 is a schematic view of the relative position relationship between the liquid injection mechanism of the energy storage battery and the energy storage battery to be injected with liquid according to an embodiment of the present application.

[0017] Figure 2 Fig. 2 is a sectional view of the first liquid injection needle in the liquid injection mechanism of the energy storage battery according to an embodiment of the present application.

[0018] Figure 3 Fig. 3 is a sectional view of the second liquid injection needle in the liquid injection mechanism of the energy storage battery according to an embodiment of the present application.

[0019] Figure 4 Fig. 4 is a flowchart of the liquid injection method according to an embodiment of the present application.

[0020] Figure 5 Fig. 5 is a sectional view of the first liquid outlet or the third liquid outlet of the energy storage battery according to an embodiment of the present application.

[0021] Figure 6 Fig. 6 is a sectional view of the second liquid outlet of the energy storage battery according to an embodiment of the present application.

[0022] Figure 7 Fig. 7 is a sectional view of another embodiment of the second liquid outlet.

[0023] Reference signs:

[0024] 1. liquid injection mechanism of energy storage battery; 10. liquid injection assembly; 110. liquid inlet pipeline; 120. first liquid injection needle; 121. first injection hole; 130. second liquid injection needle; 131. second injection hole; 140. third liquid injection needle; 150. first speed regulating valve; 160. second speed regulating valve; 170. third speed regulating valve; 20. vertical driving assembly; 30. horizontal driving assembly; 2. energy storage battery; 201. first liquid injection port; 202. second liquid injection port; 203. third liquid injection port; 204. first liquid outlet; 205. second liquid outlet; 2051. accommodating groove; 206. third liquid outlet; 207. liquid injection hole; 210. shell; 220. electrode assembly; 230. top cover; 231. cover plate; 232. injection molding; 240. float; 250. elastic member. DETAILED DESCRIPTION

[0025] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways other than those described herein without departing from the spirit of the present application, and those skilled in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0026] In the description of the application, it should be understood that, if there are these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0027] In addition, if there are these terms "first", "second", these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise explicitly specified and limited, if there are terms such as "mounting", "connecting", "connecting", "fixing" and the like, these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0029] In this application, unless otherwise explicitly specified and limited, if there are similar descriptions such as "first feature on or under second feature", the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0030] It is to be noted that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it is to be understood that when a layer is referred to as being "connected", "coupled", or "adjacent" to another element, it can be directly connected, coupled, or adjacent to the other element, or intervening elements can also be present. As used herein, the term "vertical", "horizontal", "up", "down", "left", "right", and the like are merely used for the purpose of explanation and are not to be construed as limiting.

[0031] Referring to Figure 1 An embodiment of the first aspect of the present application provides a mechanism 1 for injecting electrolyte into a battery 2. The electrolyte contains electrolyte, which is the carrier of ion transmission in the battery, and is generally composed of lithium salt and organic solvent. During the charging and discharging process of the battery 2, lithium ions move back and forth between the positive and negative electrodes, and the electrolyte is the medium for the migration and transmission of lithium ions, causing a potential difference between the positive and negative electrodes of the battery, thereby generating an electric current, and thus enabling the battery to work normally.

[0032] The mechanism 1 for injecting electrolyte into a battery 2 includes an injection assembly 10. The injection assembly 10 includes a liquid inlet pipe 110, a first injection needle 120, a second injection needle 130, and a third injection needle 140 connected in parallel to the liquid inlet pipe 110, and a vertical driving assembly 20. The vertical driving assembly 20 is used to drive the first injection needle 120, the second injection needle 130, and the third injection needle 140 to ascend and descend so as to be able to extend into the injection port of the battery 2 for injection. The first injection needle 120, the second injection needle 130, and the third injection needle 140 are arranged in a straight line in sequence and at intervals, and the flow cross section of the first injection needle 120 and the third injection needle 140 is smaller than that of the second injection needle 130.

[0033] As Figure 1 shown, the liquid inlet pipe 110 is used to be connected to an electrolyte providing device (not shown). The first injection needle 120, the second injection needle 130, and the third injection needle 140 are each connected at one end to the liquid inlet pipe 110 and at the other end to inject electrolyte into the battery 2. The first injection needle 120, the second injection needle 130, and the third injection needle 140 are arranged in sequence along the axial direction of the liquid inlet pipe 110 to form a parallel effect. In the axial direction of the liquid inlet pipe 110, the second injection needle 130 is located between the first injection needle 120 and the third injection needle 140.

[0034] In the present application, the flow cross section of the first injection needle 120 and the third injection needle 140 is smaller than that of the second injection needle 130. Thus, when the mechanism 1 for injecting electrolyte into a battery 2 is used to inject electrolyte into the battery 2, the amount of electrolyte sprayed by the second injection needle 130 is the largest.

[0035] The flow cross section of the first liquid injection needle 120 and the third liquid injection needle 140 is smaller than the flow cross section of the second liquid injection needle 130, and the specific implementation is not limited. Optionally, the inner diameter of the first liquid injection needle 120 and the third liquid injection needle 140 is smaller than the inner diameter of the second liquid injection needle 130.

[0036] The vertical driving assembly 20 is used to drive the first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 to ascend and descend, so that the first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 can be inserted into the corresponding first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 of the energy storage battery 2. Optionally, the driving source of the vertical driving assembly 20 is a pneumatic cylinder, and a bracket is connected to the output end of the pneumatic cylinder. The liquid inlet pipeline 110, the first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 are all arranged on the bracket.

[0037] When the energy storage battery liquid injection mechanism 1 is used to inject liquid into the energy storage battery 2, the liquid inlet pipeline 110 is located above the energy storage battery 2 in the vertical direction. The first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 are arranged in the horizontal direction. In the vertical direction, the first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 correspond to the first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 of the energy storage battery 2 respectively. The second liquid injection port 202 of the energy storage battery 2 is located in the middle of the energy storage battery 2 in the horizontal direction. In this way, the second liquid injection needle 130 can inject liquid into the middle of the energy storage battery 2, and the first liquid injection needle 120 and the third liquid injection needle 140 can inject liquid into the two ends of the energy storage battery 2.

[0038] When the energy storage battery liquid injection mechanism 1 of the present application is used to inject liquid into the energy storage battery 2, the first liquid injection needle 120, the second liquid injection needle 130 and the third liquid injection needle 140 inject liquid into the energy storage battery 2 from different positions at the same time, so that the electrolyte can be injected at a high speed and uniformly, and then the electrolyte can be uniformly soaked, and the required time is less.

[0039] In addition, the flow cross section of the second liquid injection needle 130 is larger, so that more electrolyte flows to the middle of the energy storage battery 2, and the electrolyte can flow from the middle of the energy storage battery 2 to the periphery, thereby facilitating the uniform soaking of the electrolyte.

[0040] In some embodiments, the second liquid injection needle 130 is uniformly provided with a plurality of injection holes in the circumferential direction of the second liquid injection needle 130, so that the second liquid injection needle 130 uniformly sprays in all directions.

[0041] Specifically, as shown in Figure 2 , the first liquid injection needle 120 is provided with a first injection hole 121. The structure of the third liquid injection needle 140 can be completely the same as that of the first liquid injection needle 120. As shown in Figure 3As shown, the second injection needle 130 is provided with a second injection hole 131. The second injection hole 131 is uniformly distributed along the circumference of the second injection needle 130, and the second injection needle 130 can uniformly spray electrolyte in all directions, so that the electrolyte is uniformly dispersed, and then the electrolyte fully wets the inner pole piece and the separator of the energy storage battery 2.

[0042] In some embodiments, the area of the injection hole on the first injection needle 120 that is open to the side of the second injection needle 130 is greater than the area of the injection hole that is open in other directions; the area of the injection hole on the third injection needle 140 that is open to the side of the second injection needle 130 is greater than the area of the injection hole that is open in other directions.

[0043] Taking the first injection needle 120 as an example, optionally, as shown in Figure 2 As shown, the first injection needle 120 is provided with a plurality of first injection holes 121 in the circumferential direction of the first injection needle 120. The area of the first injection hole 121 on the right side is greater than the area of the first injection hole 121 in other directions. In this way, in the case that the first injection needle 120 can spray electrolyte in all directions to uniformly disperse the electrolyte, the amount of electrolyte sprayed by the first injection needle 120 towards the middle of the energy storage battery 2 is relatively large, so that more electrolyte is injected into the middle of the energy storage battery 2, and then the electrolyte spreads to all directions, so that the electrolyte fully wets the inner pole piece and the separator of the energy storage battery 2.

[0044] Optionally, the first injection needle 120 is provided with a first injection hole 121 only on the side facing the second injection needle 130. In this way, the amount of electrolyte sprayed by the first injection needle 120 towards the middle of the energy storage battery 2 is relatively large.

[0045] The structure of the third injection needle 140 can be exactly the same as that of the first injection needle 120. It is easy to understand that the third injection needle 140 can also achieve the above-mentioned effects, and will not be described again.

[0046] In some embodiments, the energy storage battery liquid injection mechanism 1 further comprises a horizontal driving assembly 30, which is used to drive at least one of the first injection needle 120, the second injection needle 130 and the third injection needle 140 to move in the arrangement direction of the first injection needle 120, the second injection needle 130 and the third injection needle 140. Thus, the energy storage battery 2 of different specifications can be matched.

[0047] Optionally, the horizontal driving assembly 30 is arranged on the output end of the vertical driving assembly 20. The first injection needle 120, the second injection needle 130 and the third injection needle 140 are all arranged on the horizontal driving assembly 30. In this way, the horizontal driving assembly can drive the three injection needles to move in the horizontal direction to adjust the position.

[0048] Optionally, the first liquid injection needle 120 and the third liquid injection needle 140 are arranged in the transverse driving assembly 30. The first liquid injection needle 120 and the third liquid injection needle 140 are respectively communicated with the liquid inlet pipeline 110 through a hose.

[0049] In some embodiments, a first speed regulating valve 150 is arranged between the first liquid injection needle 120 and the liquid inlet pipeline 110, a second speed regulating valve 160 is arranged between the second liquid injection needle 130 and the liquid inlet pipeline 110, and a third speed regulating valve 170 is arranged between the third liquid injection needle 140 and the liquid inlet pipeline 110. In this way, the spraying amount of electrolyte at different positions in the horizontal direction can be ensured by adjusting the speed regulating valves, so that the electrolyte can be sprayed more uniformly.

[0050] The advantages of the energy storage battery liquid injection mechanism of the present application in injecting electrolyte into an energy storage battery will be described below in combination with an embodiment and a comparative example.

[0051] Embodiment 1: Select 280 batteries, and inject electrolyte into the batteries by using the energy storage battery liquid injection mechanism of the present application.

[0052] Specifically, the battery design capacity of the 280 batteries is 280 Ah, and the nominal voltage is 3.2 V. Three liquid injection ports are arranged on the battery shell.

[0053] Comparative Example 1: Select 280 batteries of the same type as the batteries in Embodiment 1 to inject electrolyte. Specifically, the battery design capacity is 280 Ah, and the nominal voltage is 3.2 V. One liquid injection port is arranged on the battery shell, and electrolyte is injected by using a traditional method.

[0054] Embodiment 1 and Comparative Example 1 are injected with the same electrolyte. After injection, Embodiment 1 and Comparative Example 1 are both placed at a temperature of 45℃, and the time for the alternating current resistance to decrease to 0.145 mΩ-0.146 mΩ is observed.

[0055] (1) The comparison of battery injection time and battery cycle number is shown in the following table:

[0056] Table 1

[0057]

[0058] (2) The comparison of the alternating current resistance of the battery with the change of the standing time is shown in the following table:

[0059] Table 2

[0060]

[0061] As can be seen from Table 1 and Table 2, the time required for liquid injection of Example 1 is significantly reduced; the number of battery cycles is superior to that of Comparative Example 1. In addition, under the same standing time, the time required for the battery of Example 1 to reduce to the required AC resistance is less, thereby the soaking time can be reduced to a certain extent, and the battery manufacturing cycle is shortened.

[0062] An embodiment of the second aspect of the application provides a liquid injection method applied to the liquid injection mechanism 1 of any of the above embodiments.

[0063] Reference Figure 4 The liquid injection method comprises:

[0064] S10, control the first injection needle 120, the second injection needle 130 and the third injection needle 140 to be inserted into the corresponding first injection port 201, the second injection port 202 and the third injection port 203 of the energy storage battery 2 respectively.

[0065] Specifically, the first injection needle 120, the second injection needle 130 and the third injection needle 140 are vertically lowered by the vertical driving assembly, and then inserted into the first injection port 201, the second injection port 202 and the third injection port 203 of the energy storage battery 2.

[0066] S20, control the flow rate of the first injection needle 120 and the third injection needle 140 to be less than that of the second injection needle 130. For example, the flow rate of the first injection needle 120 and the third injection needle 140 can be controlled to be less than that of the second injection needle 130 by controlling the liquid injection amount and the opening area of the injection hole of each injection needle.

[0067] By controlling the flow rate of the first injection needle 120 and the third injection needle 140 to be less than that of the second injection needle 130, more electrolyte is sprayed to the middle part of the energy storage battery 2, and the electrolyte can flow from the middle part of the energy storage battery 2 to the surrounding, thereby facilitating uniform soaking of the electrolyte.

[0068] In some embodiments, S20 comprises: controlling the liquid injection amount of the first injection needle 120 and the third injection needle 140 to be less than that of the second injection needle 130.

[0069] Optionally, the three outlets of the liquid injection pipeline 110 connected to each injection needle are provided with different areas, so that the liquid injection amount of the second injection needle 130 is the largest.

[0070] The advantages of using the energy storage battery liquid injection mechanism of the application to inject liquid into the energy storage battery will be described below in combination with an embodiment and a comparative example.

[0071] Example 2: A 280 battery was selected to be injected by the injection method of the application. The flow rate of the second injection needle was 25 g / s, and the flow rates of the first injection needle and the third injection needle were 70% of the flow rate of the second injection needle.

[0072] Specifically, the battery design capacity of the 280 battery was 280 Ah, and the nominal voltage was 3.2 V. Three injection ports were provided on the battery shell.

[0073] Comparative Example 2: A 280 battery of the same type as the battery of Example 1 was selected for injection. Specifically, the battery design capacity was 280 Ah, and the nominal voltage was 3.2 V. One injection port was provided on the battery shell, and the battery was injected using a conventional method.

[0074] Example 2 and Comparative Example 2 were injected with the same electrolyte. After injection, both Example 2 and Comparative Example 2 were allowed to stand at a temperature of 45℃, and the time for the AC resistance to decrease to 0.143 mΩ-0.144 mΩ was observed.

[0075] (1) The battery injection time and battery cycle number comparison is shown in the following table:

[0076] Table 3

[0077]

[0078] (2) The battery AC resistance change with standing time comparison is shown in the following table:

[0079] Table 4

[0080]

[0081] As can be seen from Table 3 and Table 4, the injection time of Example 2 is significantly reduced; the battery cycle number is superior to that of Comparative Example 2. In addition, under the same standing time, the time required for the battery of Example 2 to decrease to the required AC resistance is less, thereby the soaking time can be reduced to a certain extent, and the battery production cycle can be shortened.

[0082] An embodiment of the third aspect of the application proposes a energy storage battery 2, which has good soaking effect and good battery performance in a short time after injection.

[0083] As shown in Figure 1 , Figures 5 to 7 , the energy storage battery 2 includes a shell 210, an electrode assembly 220 arranged in the shell 210, and a top cover 230 arranged at the opening of the shell 210. The outer side of the top cover 230 is along the length direction of the top cover 230. Figure 1The first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 are arranged at intervals along the length direction of the top cover 230. The second liquid injection port 202 is located at the middle of the top cover 230, and the first liquid injection port 201 and the third liquid injection port 203 are located at the two sides of the second liquid injection port 202. In this way, when injecting liquid into the energy storage battery 2, the electrolyte is injected from the middle and the two sides of the top cover 230.

[0084] The electrode assembly 220 is arranged in the shell 210. The positive and negative tabs of the electrode assembly 220 are connected to the positive and negative columns through the adapter plates respectively. The top cover 230 is arranged at the opening of the shell 210 to enclose the electrode assembly 220 in the shell 210. The top cover 230 is provided with the positive and negative columns. The outer side of the top cover 230 refers to the side surface of the top cover 230 facing away from the electrode assembly 220.

[0085] The first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 are arranged at intervals along the length direction of the top cover 230. The second liquid injection port 202 is located at the middle of the top cover 230, and the first liquid injection port 201 and the third liquid injection port 203 are located at the two sides of the second liquid injection port 202. In this way, when injecting liquid into the energy storage battery 2, the electrolyte is injected from the middle and the two sides of the top cover 230.

[0086] The first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 are arranged at intervals along the length direction of the top cover 230. The second liquid injection port 202 is located at the middle of the top cover 230, and the first liquid injection port 201 and the third liquid injection port 203 are located at the two sides of the second liquid injection port 202. In this way, when injecting liquid into the energy storage battery 2, the electrolyte is injected from the middle and the two sides of the top cover 230.

[0087] Optionally, the top cover 230 includes a cover plate 231 and an injection molding part 232. The cover plate 231 is connected to the shell 210, and the injection molding part 232 is arranged on the side of the cover plate 231 facing the opening of the shell 210. The first liquid injection port 201, the second liquid injection port 202 and the third liquid injection port 203 are arranged on the injection molding part 232. The injection molding part and the cover plate 231 are integrally formed. The cover plate 231 and the shell 210 are usually welded. Optionally, the materials of the cover plate 231 and the shell 210 are both aluminum.

[0088] In the embodiment, the first liquid outlet portion 204 and the third liquid outlet portion 206 are provided with liquid injection holes 207 on the side facing the second liquid outlet portion 205, and the second liquid outlet portion 205 is provided with multiple liquid injection holes 207 in the circumferential direction. In this way, when the energy storage battery 2 is injected with electrolyte by the liquid injection mechanism, the electrolyte flowing into the second liquid outlet portion 205 can uniformly spray electrolyte in all directions, so that the electrolyte is uniformly dispersed, and then the electrolyte fully wets the inner pole piece and the separator of the energy storage battery 2.

[0089] At the same time, the electrolyte flowing into the first liquid outlet portion 204 and the third liquid outlet portion 206 is sprayed from the side of the first liquid outlet portion 204 and the third liquid outlet portion 206 facing the second liquid outlet portion 205, so that more electrolyte is injected into the middle of the energy storage battery 2, and then the electrolyte spreads to all directions, so that it fully wets the inner pole piece and the separator of the energy storage battery 2.

[0090] Further, the first liquid outlet portion 204 is provided with multiple liquid injection holes 207 in the circumferential direction, and the area of the liquid injection hole 207 on the side of the first liquid outlet portion 204 facing the second liquid outlet portion 205 is larger than that of the liquid injection hole 207 in other opening directions; the third liquid outlet portion 206 is provided with multiple liquid injection holes 207 in the circumferential direction, and the area of the liquid injection hole 207 on the side of the third liquid outlet portion 206 facing the second liquid outlet portion 205 is larger than that of the liquid injection hole 207 in other opening directions. In this way, under the condition that the first liquid outlet portion 204 and the third liquid outlet portion 206 can uniformly spray electrolyte in all directions to make the electrolyte uniformly dispersed, the amount of electrolyte sprayed towards the middle of the energy storage battery 2 is more, so that more electrolyte is injected into the middle of the energy storage battery 2, and then the electrolyte spreads to all directions, so that it fully wets the inner pole piece and the separator of the energy storage battery 2.

[0091] In some embodiments, in the length direction of the top cover 230, the first liquid injection port 201 and the third liquid injection port 203 are respectively deviated to the two ends of the shell 210.

[0092] With the central axis in the length direction of the top cover 230 as the reference, the first liquid injection port 201 and the third liquid injection port 203 are respectively deviated to the two ends of the shell 210. Specifically, the first liquid injection port 201 is closer to one end of the top cover 230 relative to the central axis. The first liquid injection port 201 is closer to the other end of the top cover 230 relative to the central axis.

[0093] In some embodiments, the first liquid outlet portion 204, the second liquid outlet portion 205, and the third liquid outlet portion 206 are respectively provided with a float 240 and an elastic member 250. The float 240 is kept in a position shielding the liquid injection hole 207 under the elastic force of the elastic member 250, and under the action of external force, the float 240 overcomes the elastic force to at least partially expose the liquid injection hole 207.

[0094] Take the second liquid outlet portion 205 as an example. As shown inFigure 7 As shown, the second liquid outlet 205 is provided with a containing groove 2051 which is in communication with the first liquid injection port 201. The circumferential sidewall of the containing groove 2051 is provided with a liquid injection hole 207.

[0095] The float 240 and the elastic member 250 are arranged in the containing groove 2051. The elastic member 250 is located between the float 240 and the bottom wall of the containing groove 2051. The top of the containing groove 2051 is provided with a stepped surface for limiting the float 240. The elastic member 250 is, for example, a spring. The elastic member 250 provides an elastic force to the float 240 upwardly, so that the float 240 is kept at a position for shielding the liquid injection hole 207 under the elastic force of the elastic member 250.

[0096] When injecting the electrolyte into the energy storage battery 2, the second liquid injection needle 130 is inserted into the second liquid injection port 202, and the second liquid injection needle 130 abuts against the top of the float 240, so that the float 240 moves downwardly against the resistance of the elastic member 250, and then partially or completely exposes the second liquid injection port 202. Thus, by controlling the pressing force of the second liquid injection needle 130 on the float 240, the amount of the electrolyte sprayed into the shell 210 by the first liquid outlet 204 can be controlled. The first liquid outlet 204 and the third liquid outlet 206 are arranged in a similar manner and have a similar effect.

[0097] Further, the stiffness coefficients K of the elastic members 250 in the first liquid outlet 204, the second liquid outlet 205 and the third liquid outlet 206 are different. Specifically, the stiffness coefficient K1 of the elastic member 250 in the first liquid outlet 204 and the stiffness coefficient K3 of the elastic member 250 in the third liquid outlet 206 are equivalent, but greater than the stiffness coefficient K2 of the elastic member 250 in the second liquid outlet 205. Thus, when the three liquid injection needles of the liquid injection mechanism are pressed with the same force, the amount of the electrolyte discharged by the second liquid outlet 205 is greater than that of the other two liquid outlets, so that the movement of the three liquid injection needles can be controlled synchronously, and the design of the vertical driving assembly 20 is simplified.

[0098] In addition, when injecting the electrolyte into the energy storage battery 2, one or more of the three liquid injection needles can be adjusted according to experience, so as to adjust the spraying amount of the three liquid injection needles, and the infiltration effect of the electrolyte is better.

[0099] As known from the foregoing embodiments 1 and 2, the energy storage battery of the present embodiment receives the electrolyte through the three liquid injection ports, and the time required for the liquid injection is significantly reduced; and the cycle number of the battery is superior to that of the conventional technology. In addition, under the same standing time, the AC internal resistance of the energy storage battery of the present embodiment is smaller, and the infiltration effect is better. Thus, the infiltration time can be reduced to a certain extent, and the production cycle of the battery is shortened.

[0100] The energy storage battery of the present embodiment can use the liquid injection mechanism of the energy storage battery of the foregoing embodiments, and the liquid injection is performed by using the liquid injection method of the foregoing embodiments.

[0101] In the process of injecting liquid, the three injection needles have different flow cross-sectional areas, so the second injection needle 130 has a larger flow cross-sectional area, and thus more electrolyte flows to the middle of the energy storage battery 2, which can flow from the middle of the energy storage battery 2 to the periphery, thereby facilitating uniform electrolyte soaking.

[0102] In addition, the electrolyte flowing into the second injection port 202 from the second injection needle 130 is sprayed through the plurality of injection holes 207 on the periphery of the second liquid outlet 205 to disperse the electrolyte to the periphery and then diffuse outward, thereby facilitating uniform electrolyte soaking.

[0103] It is easy to understand that the energy storage battery 2 of the present embodiment can be injected by the energy storage battery liquid injection mechanism of the foregoing embodiments, but is not limited thereto. Other structures of the injection mechanism with three injection needles can also be used to inject the energy storage battery at the same time.

[0104] Similarly, the energy storage battery liquid injection mechanism and the liquid injection method of the foregoing embodiments can also be used to inject other energy storage batteries with three injection ports.

[0105] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0106] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. An energy storage battery liquid injection mechanism, characterized in that, Comprising The liquid injection assembly comprises a liquid inlet pipeline, a first liquid injection needle, a second liquid injection needle and a third liquid injection needle connected in parallel to the liquid inlet pipeline, and a vertical driving assembly for driving the first liquid injection needle, the second liquid injection needle and the third liquid injection needle to ascend and descend so as to be capable of corresponding to the first liquid injection port, the second liquid injection port and the third liquid injection port of the energy storage battery, wherein the first liquid injection needle, the second liquid injection needle and the third liquid injection needle are arranged in a straight line in sequence and are spaced apart, the cross-sectional area of the first liquid injection needle and the third liquid injection needle is smaller than that of the second liquid injection needle, and the inner diameter of the first liquid injection needle and the third liquid injection needle is smaller than that of the second liquid injection needle, so that when the energy storage battery liquid injection mechanism is used to inject electrolyte into the energy storage battery, the amount of electrolyte sprayed by the second liquid injection needle is the largest; the second liquid injection needle is uniformly provided with a plurality of spray holes in the circumferential direction of the second liquid injection needle, so that the second liquid injection needle uniformly sprays in all directions; The area of the spray hole on the first liquid injection needle opening towards the side of the second liquid injection needle is greater than that of the spray hole opening in other directions; the area of the spray hole on the third liquid injection needle opening towards the side of the second liquid injection needle is greater than that of the spray hole opening in other directions.

2. The energy storage cell liquid injection mechanism of claim 1, wherein, The energy storage battery liquid injection mechanism further comprises a horizontal driving assembly for driving at least one of the first liquid injection needle, the second liquid injection needle and the third liquid injection needle to move in the arrangement direction of the first liquid injection needle, the second liquid injection needle and the third liquid injection needle.

3. A liquid injection method characterized by comprising: The method applied to the energy storage battery liquid injection mechanism of any one of claims 1-2 comprises: Controlling the first liquid injection needle, the second liquid injection needle and the third liquid injection needle to be respectively inserted into the corresponding first liquid injection port, the second liquid injection port and the third liquid injection port of the energy storage battery; Controlling the flow rate of the first liquid injection needle and the third liquid injection needle to be smaller than that of the second liquid injection needle.

4. The method of claim 3, wherein, Controlling the flow rate of the first liquid injection needle and the third liquid injection needle to be smaller than that of the second liquid injection needle comprises: controlling the liquid injection amount of the first liquid injection needle and the third liquid injection needle to be smaller than that of the second liquid injection needle.

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