Battery monomer and battery

Abstract

The utility model discloses a single battery. The single battery comprises a battery cell, a battery cover and a battery cover, the protective film is coated on the outer side of the battery cell; the battery cell and the protective film are arranged in the shell; the capillary hose comprises a vertical section and a bent section, the vertical section is positioned between the battery cell and the protective film, and the bent section convexly extends above the battery cell; the capillary hose comprises a liquid suction port and a liquid outlet, the liquid suction port is formed in the vertical section, the liquid outlet is formed in the bent section, and the orthographic projection of the liquid outlet in the direction parallel to the vertical section is located on the upper end face of the battery cell. The utility model has the beneficial effects that the free electrolyte can be absorbed and stored in the capillary hose, when the battery is charged, the cell expands to extrude the capillary hose, and the free electrolyte stored in the capillary hose is extruded from the opening at the upper end of the capillary hose and is injected into the cell in a'spraying 'manner.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy battery technical field, specifically, relate to a battery monomer and battery. BACKGROUND

[0002] With the continuous improvement of the cycle life requirement of lithium ion battery, in order to ensure the reliability of long-term cycle of battery, sufficient electrolyte needs to be injected into the battery to maintain the demand of electrolyte in the battery cycle process.

[0003] If sufficient electrolyte is injected into the battery at the beginning, the electrolyte in the free state is easy to be extracted when the battery is negative pressure, causing the waste of electrolyte, if the electrolyte is added by the way of supplementing electrolyte, the newly injected electrolyte is difficult to be timely and fully absorbed by the battery, and further causes the 'liquid spray' phenomenon, which affects the subsequent process of the battery. UTILITY MODEL CONTENT

[0004] To solve the above problems, the purpose of the utility model is to provide a battery monomer and battery.

[0005] On the one hand, the utility model provides a battery monomer, the battery monomer includes:

[0006] Battery cell;

[0007] Protective film, the protective film is wrapped on the outside of the battery cell;

[0008] Shell, the battery cell and the protective film are arranged in the shell;

[0009] Capillary hose, the capillary hose includes vertical section and bending section, wherein the vertical section is located between the battery cell and the protective film, and the bending section protrudes above the battery cell;The capillary hose includes liquid suction port and liquid outlet, the liquid suction port is arranged on the vertical section, the liquid outlet is arranged on the bending section, and the normal projection of the liquid outlet in the direction parallel to the vertical section is located on the upper end surface of the battery cell.

[0010] As an optional implementation, the capillary hose is provided with a plurality of capillary hoses, and the plurality of capillary hoses are arranged in parallel along the width direction of the battery cell;A plurality of capillary hoses are arranged on the surface of the protective film close to the battery cell.

[0011] As an optional implementation, the diameter of the capillary hose gradually decreases from the liquid suction port to the liquid outlet, the diameter of the liquid suction port is 0.5-6mm, and the diameter of the liquid outlet is 0.2-5mm.

[0012] As an optional embodiment, the distance between the edge of the protective film close to the liquid suction port and the liquid suction port is 0.5-10mm in the direction parallel to the vertical section.

[0013] As an optional embodiment, the capillary tube satisfies: l

[0014] wherein, l is the height of the battery cell, h is the height of the capillary tube, and H is the height of the protective film.

[0015] As an optional embodiment, the capillary tube satisfies:

[0016] 0.9≤t1 / (n-2m-2D)≤1.0

[0017] t2 / (n-2m-2D)>1.0

[0018] wherein, n is the thickness of the space in the shell, m is the thickness of the protective film, D is the pipe diameter of the liquid suction port, t1 is the thickness of the battery cell when it is not charged, and t2 is the thickness of the battery cell when it is fully charged.

[0019] As an optional embodiment, the capillary tube satisfies:

[0020] D≤w≤0.5t1

[0021] wherein, w is the distance between the center of the liquid outlet and the outer wall of the bending section close to the protective film.

[0022] As an optional embodiment, the capillary tube satisfies:

[0023] 0.2≤vx / V≤0.8

[0024] wherein, v is the volume of electrolyte that each capillary tube can hold, x is the number of capillary tubes, and V is the volume of the space in the shell that can be used to hold electrolyte.

[0025] As an optional embodiment, the material of the capillary tube is one of PET, PP, PE, PVC, TPE and TPR.

[0026] The capillary tube is filled with a liquid-retaining material, and the liquid-retaining material is at least one of porous foam, sponge and gel.

[0027] As an optional embodiment, the capillary tube is integrally formed with the protective film; or

[0028] The capillary tube is compounded on the protective film.

[0029] In another aspect, the utility model provides a kind of battery, including the battery cell as described above.

[0030] The utility model has the advantages that: by being provided with capillary hose with vertical section and bending section, and making vertical section between protective film and electric core, bending section is above electric core, free electrolyte in the liquid suction port of capillary hose is absorbed and stored in capillary hose, when battery is charged, electric core expands and extrudes capillary hose, free electrolyte stored in capillary hose is extruded from its liquid outlet and injected into electric core in the mode of "shower".Thus, free electrolyte is avoided to be wasted, and enough electrolyte is provided for the circulation process of battery. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0032] Figure 1 It is the structural schematic diagram of battery cell of an embodiment of the utility model;

[0033] Figure 2 It is the structural schematic diagram of electric core of an embodiment of the utility model;

[0034] Figure 3 It is Figure 2 The sectional view of A-A direction;

[0035] Figure 4 It is Figure 3 The position relation schematic diagram of protective film and capillary hose;

[0036] Figure 5 It is the structural schematic diagram of protective film after unfolding of an embodiment of the utility model;

[0037] Figure 6 It is the structural schematic diagram of capillary hose of an embodiment of the utility model;

[0038] Figure 7 It is Figure 6 The enlarged view of I.

[0039] In the drawing,

[0040] 100, battery cell;

[0041] 10, protective film;

[0042] 20, cell; 21, negative electrode sheet; 22, positive electrode sheet; 23, separator;

[0043] 30, housing;

[0044] 40, capillary tube; 41, liquid retaining material; 42, vertical section; 421, liquid suction port; 43, bending section; 431, liquid outlet. DETAILED DESCRIPTION

[0045] In the related art, in order to improve the cycle life of the battery, a sufficient amount of electrolyte needs to be provided to the battery. If a sufficient amount of electrolyte is injected into the cell at one time during the preparation of the battery, the electrolyte cannot be fully infiltrated and absorbed by the cell, resulting in the presence of some electrolyte in a free state at the bottom of the cell. When the cell is subjected to negative pressure formation, the electrolyte in the free state will be extracted, causing waste of the electrolyte. At the same time, at the initial stage of the cycle of the battery, if there is too much electrolyte in a free state, the part of the electrolyte will react with the positive and negative electrode materials at the interface between the two during the charging and discharging process, not only increasing the internal resistance of the battery, but also consuming too much active lithium, which adversely affects the cycle life and performance of the battery.

[0046] If the electrolyte is injected in several times during the preparation of the cell, that is, a sufficient amount of electrolyte is provided by the way of secondary liquid supplement. This way will cause the cell to be unable to timely and fully absorb the supplemented electrolyte, resulting in the phenomenon of "liquid spraying", which affects the subsequent preparation process of the cell.

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] It should be noted that if the present application embodiments involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), if the certain posture changes, the directional indications will also change accordingly.

[0049] Furthermore, the terminology used in the description of this utility model is for illustrative purposes only and is not intended to limit the scope of this utility model. The terms "comprising" and / or "including" are used to specify the presence of the said elements, steps, operations, and / or components, but do not exclude the presence or addition of one or more other elements, steps, operations, and / or components. The terms "first," "second," etc., may be used to describe various elements, do not represent an order, and do not limit these elements. In addition, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more. These terms are used only to distinguish one element from another. These and / or other aspects become apparent in conjunction with the following drawings, and those skilled in the art will more readily understand the description of the embodiments of this utility model. The drawings are used for illustrative purposes only to depict the embodiments of this utility model. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods shown in this utility model can be employed without departing from the principles of this utility model.

[0050] A battery cell according to an embodiment of this utility model includes a battery cell, a protective film, a casing, and a capillary tube. The protective film covers the outside of the battery cell; the battery cell and the protective film are disposed inside the casing; the capillary tube includes a vertical section and a bent section, the vertical section being located between the battery cell and the protective film, and the bent section protruding above the battery cell; the capillary tube includes a suction port and an outlet port, the suction port being located on the vertical section, and the outlet port being located on the bent section, with the orthographic projection of the outlet port in a direction parallel to the vertical section located on the upper end face of the battery cell. The capillary tube is filled with a liquid-retaining material; the capillary tube is configured to absorb the electrolyte located between the battery cell and the casing, and when the battery cell expands during charging, the capillary tube is squeezed to inject the absorbed electrolyte into the battery cell.

[0051] by Figure 1 Let's take an example to illustrate: Figure 1 This is a structural diagram of a single battery cell 100. For ease of understanding, Figure 1 The X-axis represents the thickness of the battery cell 100, the Y-axis represents the width of the battery cell 100, and the Z-axis represents the height of the battery cell 100.

[0052] The battery cell 100 includes a housing 30 and a battery cell 20 located within the housing 30. The battery cell 20 may include one or more bare cells, and the number of battery cells 20 may be one or more. If there are multiple battery cells 20, they may be arranged in an overlapping manner along the thickness direction of the battery cell 100. In use, the number of battery cells 20 can be determined according to the required capacity of the battery cell 100; this application does not impose a specific limitation on this number.

[0053] As shown in Figures 2-3 The electric core 20 comprises a negative electrode sheet 21, a positive electrode sheet 22 and a diaphragm 23 which are stacked, and the negative electrode sheet 21, the positive electrode sheet 22 and the diaphragm 23 form a flat structure in a winding manner or a stacking manner, for example. The flat structure has two end faces which are parallel to each other and a circumferential side face between the two end faces, wherein the two end faces are in a height direction of the electric core 20 and are an upper end face and a lower end face of the electric core 20, respectively. The negative electrode sheet 21, the positive electrode sheet 22 and the diaphragm 23 may, for example, also form a laminated structure in a stacking manner, and the present application does not make a specific limitation in this regard.

[0054] Referring to Figure 3 and Figure 5 The protective film 10 is wrapped around the circumferential side face and the lower end face of the electric core 20, for example, to package the electric core 20 and play a certain protective and fixing role. It can be understood that the protective film 10 wrapped around the lower end face of the electric core 20 is provided with a plurality of through holes for the electrolyte to pass through. The protective film 10 is, for example, a mylar film.

[0055] As shown in Figures 3-6As shown, a plurality of capillary tubes 40 are arranged between the circumferential surface of the battery cell 20 and the protective film 10. Specifically, the capillary tube 40 comprises a vertical section 42 and a bent section 43, wherein: the vertical section 42 is arranged between the protective film 10 and the battery cell 20, and the bent section 43 protrudes above the battery cell 20, i.e. the height of the bent section 43 is higher than the height of the battery cell 20. A liquid suction port 421 is arranged at the lower end of the vertical section 42, and a liquid outlet port 431 is arranged at the upper end of the bent section 43, and the liquid outlet port 431 is located above the upper end surface of the battery cell 20. At the same time, the capillary tube 40 is filled with a liquid storage material 41. It can be understood that the electrolyte is injected into the battery cell 20 from the upper end surface of the battery cell 20, and part of the electrolyte is soaked between the negative electrode sheet 21 and the positive electrode sheet 22 by the battery cell 20 and participates in the chemical reaction in the battery cycle process; and the electrolyte that is not soaked by the battery cell 20 will fall below the battery cell 20 under the action of gravity and exist between the lower end surface of the battery cell 20 and the shell 30, and this part of the electrolyte is called free electrolyte. The electrolyte in the free state is absorbed into the capillary tube 40 from the liquid suction port 421 under the action of the capillary tube 40, and is stored in the liquid storage material 41. Thus, even if a sufficient amount of electrolyte is added at one time, there will be no large amount of free electrolyte in the battery cell 20, which not only avoids the free electrolyte being absorbed away in the formation process, but also avoids the side reaction between the free electrolyte and the positive and negative active materials to cause the loss of active lithium. In addition, when the battery is charged, the battery cell 20 will swell, which will squeeze the vertical section 42 of the capillary tube 40, and the electrolyte stored in the liquid storage material 41 will flow through the bent section 43 and be squeezed out of the liquid outlet port 431 of the capillary tube 40, and the electrolyte will drop to the upper end surface of the battery cell 20, so as to re-inject the electrolyte into the battery cell 20 to maintain the demand for electrolyte in the battery cycle process. At the same time, the process of squeezing the capillary tube 40 is a relatively slow process, and the electrolyte in the liquid storage material 41 will also be injected into the battery cell 20 at a relatively slow speed, which ensures that the electrolyte has sufficient soaking time and avoids the occurrence of "liquid spraying" phenomenon.

[0056] In an alternative embodiment, the diameter of the capillary tube gradually decreases from one end to the other end; wherein the end with a larger diameter is the liquid suction port of the capillary tube, and the end with a smaller diameter is the liquid outlet port of the capillary tube.

[0057] Specifically, as shown in FIG. 2, the capillary tube 40 comprises a vertical section 42 and a bent section 43, wherein: the vertical section 42 is arranged between the protective film 10 and the battery cell 20, and the bent section 43 protrudes above the battery cell 20, i.e. the height of the bent section 43 is higher than the height of the battery cell 20. A liquid suction port 421 is arranged at the lower end of the vertical section 42, and a liquid outlet port 431 is arranged at the upper end of the bent section 43, and the liquid outlet port 431 is located above the upper end surface of the battery cell 20. At the same time, the capillary tube 40 is filled with a liquid storage material 41. It can be understood that the electrolyte is injected into the battery cell 20 from the upper end surface of the battery cell 20, and part of the electrolyte is soaked between the negative electrode sheet 21 and the positive electrode sheet 22 by the battery cell 20 and participates in the chemical reaction in the battery cycle process; and the electrolyte that is not soaked by the battery cell 20 will fall below the battery cell 20 under the action of gravity and exist between the lower end surface of the battery cell 20 and the shell 30, and this part of the electrolyte is called free electrolyte. The electrolyte in the free state is absorbed into the capillary tube 40 from the liquid suction port 421 under the action of the capillary tube 40, and is stored in the liquid storage material 41. Thus, even if a sufficient amount of electrolyte is added at one time, there will be no large amount of free electrolyte in the battery cell 20, which not only avoids the free electrolyte being absorbed away in the formation process, but also avoids the side reaction between the free electrolyte and the positive and negative active materials to cause the loss of active lithium. In addition, when the battery is charged, the battery cell 20 will swell, which will squeeze the vertical section 42 of the capillary tube 40, and the electrolyte stored in the liquid storage material 41 will flow through the bent section 43 and be squeezed out of the liquid outlet port 431 of the capillary tube 40, and the electrolyte will drop to the upper end surface of the battery cell 20, so as to re-inject the electrolyte into the battery cell 20 to maintain the demand for electrolyte in the battery cycle process. At the same time, the process of squeezing the capillary tube 40 is a relatively slow process, and the electrolyte in the liquid storage material 41 will also be injected into the battery cell 20 at a relatively slow speed, which ensures that the electrolyte has sufficient soaking time and avoids the occurrence of "liquid spraying" phenomenon. Figure 6As shown, the tube diameter of the capillary tube 40 gradually decreases from bottom to top along the height direction of the battery cell 20, that is, the liquid suction port 421 of the capillary tube 40 is close to the lower end surface of the battery cell 20, and the liquid outlet port 431 of the capillary tube 40 is close to the upper end surface of the battery cell 20. When the battery is charged, the battery cell 20 expands, and the capillary tube 40 is arranged with a tube diameter gradually decreasing from bottom to top, so that the lower part of the capillary tube 40 is first pressed by the battery cell 20, so that the electrolyte stored in the liquid storage material 41 is subjected to a downward extrusion force, and finally the electrolyte is extruded from the liquid outlet port 431 at the upper part of the capillary tube 40 and dripped onto the upper end surface of the battery cell 20 and absorbed by the battery cell 20. At the same time, the tube diameter of the capillary tube 40 gradually decreases from bottom to top, so that the pressure in the capillary tube 40 gradually increases, and when the electrolyte overflows from the liquid outlet port 431 at the upper part, it will be dripped onto the upper end surface of the battery cell 20 in a manner similar to "spraying", so that the electrolyte can be sprayed to as many positions as possible on the upper end surface of the battery cell 20, so that the electrolyte can be supplied to all parts of the battery cell 20, and the electrolyte can be more quickly soaked and absorbed by the battery cell 20.

[0058] In an alternative embodiment, the capillary tube satisfies:

[0059] 0.9≤t1 / (n-2m-2D)≤1.0(1)

[0060] t2 / (n-2m-2D)>1.0(2)

[0061] wherein n is the thickness of the space in the shell, m is the thickness of the protective film, D is the tube diameter of the liquid suction port 421, t1 is the thickness of the battery cell when not charged, and t2 is the thickness of the battery cell when fully charged.

[0062] For example, the number of the battery cell 20 in the square battery can be one or multiple. When the number of the battery cell 20 is multiple, the multiple battery cells 20 are arranged in the thickness direction of the battery, and then the multiple battery cells 20 arranged in the overlapping manner are encapsulated by the protective film 10, and then the encapsulated battery cell 20 is accommodated in the shell 30. The thickness n of the accommodation space in the shell 30 can be understood as the distance between the inner surface of the first side (for example, the front side) and the inner surface of the second side (for example, the rear side) in the thickness direction of the battery, for example, in mm. The thickness m of the protective film 10 can be understood as the film thickness of the single mylar film wrapped outside the battery cell 20, for example, in mm. The pipe diameter D of the liquid suction port 421 can be understood as the outer diameter of the lower end of the capillary tube 40, for example, in mm. The thickness t1 of the battery cell 20 when not charged can be understood as the distance between the outer surface of the first side (for example, the front side) and the outer surface of the second side (for example, the rear side) in the thickness direction of the battery cell 20 when not charged, for example, in mm. The thickness t2 of the battery cell 20 when fully charged can be understood as the distance between the outer surface of the first side (for example, the front side) and the outer surface of the second side (for example, the rear side) in the thickness direction of the battery cell 20 when fully charged, for example, in mm. When the number of the battery cell 20 is multiple, t1 can be understood as the thickness of the entire electrode assembly when not charged, and t2 can be understood as the thickness of the entire electrode assembly when charged.

[0063] It can be understood that when the capillary tube 40 satisfies formula (1), the battery cell 20 with the added capillary tube 40 can be accommodated in the shell 30. When the capillary tube 40 satisfies formula (2), it can be ensured that the battery cell 20 expanded during charging can always exert a squeezing effect on the capillary tube 40, so as to squeeze out the electrolyte stored in the liquid storage material 41 to supplement the battery cell 20. Therefore, when the capillary tube 40 satisfies the above two inequalities at the same time, not only can it be ensured that the battery cell 20 is easy to enter the shell 30 during the preparation of the battery, but also it can be ensured that the capillary tube 40 can exert a supplementing effect on the battery cell 20 during the cycle of the battery to meet the demand for electrolyte during the cycle of the battery.

[0064] Preferably, the tube diameter of the liquid suction port 421 is 0.5-6mm, for example, the tube diameter of the liquid suction port 421 is 0.75mm, 1.2mm, 2mm, 2.6mm, 3.2mm, 3.8mm, 4.1mm, 4.8mm, 5mm or 5.6mm, etc. The tube diameter of the liquid outlet port 431 is 0.2-5mm, for example, the tube diameter of the liquid outlet port 431 is 0.6mm, 0.8mm, 1.2mm, 1.8mm, 2mm, 2.6mm, 3mm, 3.5mm, 4mm, 4.5mm or 4.8mm, etc. In use, the tube diameter of the liquid suction port 421 and the liquid outlet port 431 of the capillary tube 40 can be adaptively adjusted according to the processing technology of the capillary tube 40, the size of the battery cell 20, the size of the shell 30 and the battery capacity, etc. without being limited to the above-mentioned sizes, which are not limited herein.

[0065] In an alternative embodiment, the capillary tube is provided with a bend near the liquid outlet port 431 so that the orthographic projection of the liquid outlet port 431 is located on the end face of the battery cell.

[0066] Continuing to refer to Figure 6 , the capillary tube 40 is provided with a bend towards the battery cell 20 at the position near the liquid outlet port 431, i.e. the upper part of the capillary tube 40, and the bend makes the liquid outlet port 431 of the capillary tube 40 located above the upper end face of the battery cell 20. In this way, when the electrolyte stored in the liquid storage material 41 is squeezed out of the liquid outlet port 431, it can be just dropped on the upper end face of the battery cell 20 and can be more effectively absorbed by the battery cell 20, avoiding the electrolyte from falling into the lower part of the battery cell 20 again to become free electrolyte.

[0067] Further, the capillary tube satisfies:

[0068] D≤w≤0.5t1

[0069] wherein w is the distance between the center of the liquid outlet port and the outer wall of the bend section of the capillary tube near the protective film.

[0070] Please refer to Figure 7 , the center of the liquid outlet port 431 can be understood as the center of the circular end face of the liquid outlet port 431. Therefore, w can be understood as the distance between the center of the circular end face of the liquid outlet port 431 and the tube wall of the bend section 43 of the capillary tube 40 near the protective film 10, with the unit of mm. As mentioned above, D can be understood as the outer diameter of the lower end of the capillary tube 40, with the unit of mm. t1 can be understood as the distance between the outer surface of the first side (e.g. the front side) and the outer surface of the second side (e.g. the back side) of the battery cell 20 in the thickness direction when the battery cell 20 is not charged, with the unit of mm.

[0071] It can be understood that when the capillary tube 40 satisfies the above inequality, the horizontal distance of the bending of the upper part of the capillary tube 40 extending towards the battery cell 20 is moderate, that is, the length of the bending of the capillary tube 40 projected on the upper end surface of the battery cell 20 is moderate. When the liquid outlet 431 supplements the electrolyte to the battery cell 20 in a "spraying" manner, the area covered by the spraying liquid can be comparable to the area of the upper end surface of the battery cell 20, so that the battery cell 20 at each position can be fully supplemented with electrolyte. Avoiding that the horizontal extension distance of the bending is too small, so that the liquid outlet 431 is far away from the center position of the upper end surface of the battery cell 20, and the battery cell 20 at the center position cannot be effectively supplemented with electrolyte; it can also avoid that the horizontal extension distance of the bending is too large, so that the battery cell 20 at the center position is supplemented with too much electrolyte, which cannot be effectively absorbed, and the battery cell 20 at the edge position cannot be effectively supplemented with electrolyte.

[0072] In an alternative embodiment, the capillary tube satisfies:

[0073] l < h < H

[0074] Wherein, l is the height of the battery cell, h is the height of the capillary tube, and H is the height of the protective film.

[0075] As shown in Figure 3 , the height l of the battery cell 20 can be understood as the distance between the two end surfaces of the battery cell 20 parallel to each other, that is, the distance between the lower end surface and the upper end surface of the battery cell 20, in mm. The height h of the capillary tube 40 can be understood as the distance between the liquid inlet 421 and the liquid outlet 431 of the capillary tube 40, in mm. The height H of the protective film can be understood as the distance from the bottom edge to the top edge of the mylar film wrapped around the side surface of the battery cell 20, in mm.

[0076] It can be understood that when the capillary tube 40 satisfies the above inequality, the capillary tube 40 and the battery cell 20 can be ensured to be encapsulated inside the protective film 10 to play a protective and fixing role on the battery cell 20 and the capillary tube 40; at the same time, the liquid outlet 431 of the capillary tube 40 can also be located above the upper end surface of the battery cell 20 to play a liquid supplementing role on the battery cell 20.

[0077] Preferably, the distance between the edge of the protective film close to the liquid inlet 421 and the liquid inlet 421 is 0.5-10 mm.

[0078] Continuing to refer to Figure 3A certain gap is provided between the bottom edge of the protective film 10 and the liquid inlet 421 of the capillary tube 40 to prevent the liquid inlet 421 from contacting the inner surface of the housing 30. This ensures that free electrolyte can be drawn into the capillary tube 40 from the liquid inlet 421. The distance between the bottom edge of the protective film 10 and the liquid inlet 421 of the capillary tube 40 is, for example, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or 9mm. The capillary tube 40 meeting the above range can ensure that the electrolyte located below the battery cell 20 can be drawn into the capillary tube 40, and as the electrolyte is consumed during battery cycling, the capillary tube 40 can also replenish the electrolyte in the battery cell 20. In use, provided that manufacturing feasibility is met, the distance between the bottom edge of the protective film 10 and the liquid inlet 421 of the capillary tube 40 can be made as small as possible to effectively exert the replenishing function of the capillary tube 40, and is not limited to the ranges listed above.

[0079] In one alternative embodiment, multiple capillary tubes are provided, and the multiple capillary tubes are arranged in parallel along the width direction of the battery cell.

[0080] like Figure 5 As shown, capillary tubes 40 are disposed, for example, on the inner surfaces of two surfaces parallel to the XOY plane of the protective film 10, such as the front and rear surfaces of the protective film 10. Multiple capillary tubes 40 are provided on both the front and rear surfaces of the protective film 10, and are arranged parallel to each other along the width direction of the battery cell 20. The multiple capillary tubes 40 on the front surface can be arranged one-to-one with the multiple capillary tubes 40 on the rear surface; or, the multiple capillary tubes 40 on the front surface and the multiple capillary tubes 40 on the rear surface can be staggered. Preferably, the number of capillary tubes 40 on both the front and rear surfaces of the protective film 10 is equal, and the spacing between adjacent capillary tubes 40 is equal. In use, the number and spacing of the capillary tubes 40 can be determined comprehensively based on factors such as the width of the battery cell 20 and the diameter of the capillary tubes 40; this application does not impose specific limitations on this.

[0081] Furthermore, the capillary tube satisfies:

[0082] 0.2 ≤ vx / V ≤ 0.8

[0083] Where v is the volume of electrolyte that each capillary can hold, x is the number of capillary tubes, and V is the internal volume of the casing that can be used to hold electrolyte.

[0084] Still taking the square battery as an example, the volume of each capillary tube 40 can be understood as the capacity of the electrolyte absorbed and stored by the liquid-retaining material 41 filled in each capillary tube 40, in milliliters. The number x of capillary tubes 40 can be understood as the total number of capillary tubes 40 on the front and back surfaces of the protective film 10. The volume V available for accommodating electrolyte in the shell 30 can be understood as the volume inside the shell 30 minus the volume occupied by the battery cell 20 and the protective film 10, i.e., the space available for accommodating free electrolyte, in milliliters.

[0085] It can be understood that the above inequality can be understood as the amount of free electrolyte that can be absorbed by the capillary tube 40. The capillary tube 40 satisfying the above range not only continuously replenishes the electrolyte for the battery cell 20 during the battery cycle, but also ensures that the amount of electrolyte replenished each time is moderate, so that the battery cell 20 cannot timely absorb the free electrolyte again due to excessive replenishment of electrolyte, and the number of capillary tubes 40 is not too large to affect the energy density of the battery. The amount of free electrolyte that can be absorbed by the capillary tube 40 can be, for example, 0.25, 0.3, 0.35, 0.4, 0.5, 0.55, 0.6, 0.65, 0.7, or 0.75, etc. In use, it can be adjusted as appropriate, and the present application does not make specific limitations thereto.

[0086] Preferably, the material of the capillary tube 40 is, for example, one of PET, PP, PE, PVC, TPE, and TPR insulating materials. The material of the liquid-retaining material 41 is, for example, at least one of porous foam, sponge, and gel porous materials. In use, it can be selected as appropriate, and the present application does not make specific limitations thereto.

[0087] In an alternative embodiment, the capillary tube 40 is integrally formed with the protective film 10, i.e., the capillary tube 40 is integrally formed with the mylar film, which is beneficial to the fixing effect between the capillary tube 40 and the protective film 10, and can avoid subsequent compounding process between the capillary tube 40 and the protective film 10, thereby simplifying the processing steps.

[0088] Alternatively, the capillary tube 40 is compounded on the protective film 10. For example, the capillary tube 40 and the protective film 10 are separately manufactured as separate bodies, and the two can be connected and fixed by compounding methods such as hot melt compounding, lamination compounding, and adhesive bonding.

[0089] In use, the forming method between the capillary tube 40 and the protective film 10 can be determined according to the material and processing technology of the capillary tube 40 and other comprehensive factors, and is not limited to the forming methods listed above.

[0090] The battery provided in the embodiment of the utility model, comprising the battery monomer as described above. It can be understood that the battery comprises one or more battery monomers as described above, when the battery monomers are multiple, the multiple battery monomers are connected in series with each other, or the multiple battery monomers are connected in parallel with each other, or the multiple battery monomers are connected in series and in parallel with each other.

[0091] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the utility model can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0092] In addition, those having ordinary skill in the art will appreciate that while certain embodiments described herein include some but not other features included in other embodiments, the description as to each embodiment applies mutatis mutandis to each of the other embodiments, as is apparent when those embodiments are read with reference to this description. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0093] Those of skill in the art will understand that, although the utility model has been described by reference to the example embodiments, the utility model descends to changes and modifications without departing from the scope thereof, the elements of which can be substituted by other equally effective elements. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the utility model without departing from its central scope. Accordingly, the utility model is not limited to the specific embodiments described and shown.

Claims

1. A battery cell, characterized in that, include: Battery cell; A protective film, which covers the outside of the battery cell; The housing, the battery cell, and the protective film are disposed inside the housing; The capillary tube includes a vertical section and a bent section, wherein the vertical section is located between the battery cell and the protective film, and the bent section protrudes above the battery cell; the capillary tube includes a suction port and a discharge port, the suction port is located on the vertical section, the discharge port is located on the bent section, and the orthographic projection of the discharge port in a direction parallel to the vertical section is located on the upper end surface of the battery cell.

2. The battery cell as described in claim 1, characterized in that, The capillary tubes are provided in multiple ways, and the multiple capillary tubes are arranged in parallel along the width direction of the battery cell; the multiple capillary tubes are provided on the surface of the protective film near the battery cell.

3. The battery cell as described in claim 1, characterized in that, The diameter of the capillary tube gradually decreases from the suction port to the outlet port, with the suction port having a diameter of 0.5-6 mm and the outlet port having a diameter of 0.2-5 mm.

4. The battery cell as described in claim 1, characterized in that, In the direction parallel to the vertical section, the distance between the side of the protective film near the liquid suction port and the liquid suction port is 0.5-10 mm.

5. The battery cell as described in claim 1 or 4, characterized in that, The capillary tube satisfies: l < h < H Wherein, l is the height of the battery cell, h is the height of the capillary tube, and H is the height of the protective film.

6. The battery cell as described in claim 1, characterized in that, The capillary tube satisfies: 0.9≤t1 / (n-2m-2D)≤1.0 t² / (n-2m-2D)>1.0 Wherein, n is the thickness of the internal space of the shell, m is the thickness of the protective film, D is the diameter of the liquid suction port, t1 is the thickness of the battery cell when it is not charged, and t2 is the thickness of the battery cell when it is fully charged.

7. The battery cell as described in claim 6, characterized in that, The capillary tube satisfies: D≤w≤0.5t1 Where w is the distance between the center of the liquid outlet and the outer wall of the bent section near the protective membrane.

8. The battery cell as described in claim 2, characterized in that, The capillary tube satisfies: 0.2 ≤ vx / V ≤ 0.8 Where v is the volume of electrolyte that each capillary can hold, x is the number of capillary tubes, and V is the internal volume of the housing that can be used to hold electrolyte.

9. The battery cell as described in claim 1, characterized in that, The capillary tube is made of one of the following materials: PET, PP, PE, PVC, TPE, and TPR. The capillary tube is filled with a liquid-retaining material, which is at least one of porous foam, sponge and gel.

10. The battery cell as described in claim 1, characterized in that, The capillary tube is integrally formed with the protective film; or The capillary tube is laminated onto the protective film.

11. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-10.

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