CN221782947U

CN221782947U - Insulating film, battery cell, battery and electrical device

Info

Publication number: CN221782947U
Application number: CN202322815463.0U
Authority: CN
Inventors: 阎晓洁; 卓为荣; 左永涛; 李彦朋
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-10-19
Filing date: 2023-10-19
Publication date: 2024-09-27
Anticipated expiration: 2033-10-19

Abstract

The application discloses an insulating film, a battery monomer, a battery and an electric device, wherein the insulating film comprises a bottom and a plurality of side walls with one end connected with the bottom, one side of at least one side wall far away from the bottom is provided with a thickening area, and a plurality of liquid storage holes are formed in the thickening area. Through setting up the thickening district, wrap up the part that bare cell top was thinned to the setting up of stock solution hole can make the bare cell when using the in-process expand, can extrude the electrolyte of storing in the stock solution hole, thereby improve the electrolyte infiltration of bare cell top pole piece, prevent the condition of lithium evolution.

Description

Insulating film, battery cell, battery and electricity utilization device

Technical Field

The application belongs to the field of batteries, and particularly relates to an insulating film, a battery cell, a battery and an electric device.

Background

In some electric devices, particularly electric or hybrid vehicles, a large number of batteries are required to power the vehicle. The main composition of the battery is a battery cell, and the battery cell comprises a bare cell, an insulating film wrapping the bare cell and a shell for placing the bare cell and the insulating film. The top of the bare cell is provided with a pole piece, and a part of the side wall of the top connected with the bare cell is usually thinned.

After the battery monomer works for a period of time, the top of the bare cell drives part of the side wall connected with the top to expand, so that electrolyte is not immersed enough, and lithium precipitation is easy to occur.

Disclosure of utility model

The application provides an insulating film, a battery cell, a battery and an electricity utilization device, which can solve the problems that electrolyte is not immersed enough and lithium is easy to separate after the top of a bare cell expands.

In order to solve the technical problems, the application adopts a technical scheme that: the utility model provides an insulating film, the insulating film include bottom and one end with a plurality of lateral walls that the bottom is connected, at least one lateral wall keep away from one side of bottom is provided with the thickening district, be formed with a plurality of stock solution holes on the thickening district.

Through setting up the thickening district, wrap up the part that bare cell top was thinned to the setting up of stock solution hole can make the bare cell when using the in-process expand, can extrude the electrolyte of storing in the stock solution hole, thereby improve the electrolyte infiltration of bare cell top pole piece, prevent the condition of lithium evolution.

In some embodiments, the thickened region is a thickened film disposed on the side wall of the insulating film, the thickened film is disposed on an inner side surface of the side wall of the insulating film, and one side opening of the liquid storage hole is disposed away from the side wall of the insulating film connected with the thickened film.

The insulation film is easy to open holes, so that incomplete insulation exists, and the thick film is arranged without forming liquid storage holes in the insulation film, so that the insulation film can be ensured to have good insulation effect.

In some embodiments, the side wall of the insulating film abuts the reservoir hole against an opening of the side wall of the insulating film.

When the electrolyte storage device is used, the thick film is clamped between the insulating film and the bare cell, one side of the liquid storage hole is sealed by the insulating film, and electrolyte in the liquid storage hole can flow out towards the bare cell when the liquid storage hole is extruded, so that electrolyte infiltration of a pole piece at the top of the bare cell is improved.

In some embodiments, the thickened film gradually increases in thickness in a direction away from the bottom of the insulating film.

The arrangement mode can enable the thickened film to be attached to the bare cell more.

In some embodiments, the height of the thick film is 5-30 millimeters.

The thick film and the bare cell are thinned to realize high synchronization, so that the thick film is better attached to the bare cell.

In some embodiments, the height of the thick film is 6-12 millimeters.

The thick film and the bare cell are thinned to be highly synchronous, so that the thick film is better attached to the bare cell.

In some embodiments, the maximum thickness of the thick film is 0.1 to 5 millimeters.

Too small thickness of the thick film can not be used, and too large thickness can enable the insulating film to form bulges or too tight clamping bare cells when wrapping the bare cells at positions corresponding to the thick film.

In some embodiments, the thickening film is an elastic structure.

The elastic structure can be compressed, and as the service time is prolonged, the expansion of the pole piece of the bare cell is aggravated, the compression amount is increased, and the expansion of the pole piece of the bare cell is not blocked, so that the pole piece gap is flexibly adjusted.

In some embodiments, the maximum compression of the thick film is not less than 20%.

The highest compression of the thick film needs to be greater than the expansion degree of the top of the bare cell so that the top of the bare cell can be freely expanded without being limited.

In some embodiments, the pore size of the reservoir is no less than 10 ^-6 mm and no greater than 1 mm.

When the size of the liquid storage hole is moderate, the electrolyte can be sucked through capillary action, so that the purpose of storing the electrolyte is achieved.

In some embodiments, the opening of the side of the reservoir hole that abuts the insulating film is larger than the opening of the side of the reservoir hole that is remote from the insulating film.

Because the opening of the side of the liquid storage hole, which is close to the insulating film, is blocked by the insulating film, leakage cannot occur, and the opening of the side of the liquid storage hole, which is close to the insulating film, is made large so that the liquid storage hole can store more electrolyte.

In some embodiments, the opening of the side of the reservoir remote from the insulating film has a diameter of no less than 10 ^-6 mm and no more than 1 mm.

The side of the liquid storage hole far away from the insulating film is the side of the liquid storage hole facing the bare cell, and when the size of the opening at the side is moderate, the electrolyte can be sucked through capillary action, so that the purpose of storing the electrolyte is achieved.

In some embodiments, the thickened area is provided with at least two, respectively located at least two of the side walls which are oppositely arranged.

The structure is matched with the thinned area of the bare cell, so that the structure is matched with the bare cell better.

In some embodiments, the length of the thickened region is equal to or less than the length of the junction of the side wall provided with the thickened region and the bottom.

The length of the thickening area is moderate, so that the cost can be saved.

In order to solve the technical problems, the application adopts a technical scheme that: the utility model provides a battery monomer, the battery monomer includes casing, naked electric core and insulating film, naked electric core with the insulating film set up in the casing, the insulating film is above-mentioned arbitrary one insulating film, the insulating film parcel naked electric core, the thickening district corresponds the top of the lateral wall of naked electric core.

In order to solve the technical problems, the application adopts a technical scheme that: there is provided a battery comprising the battery cell of any one of the above.

In order to solve the technical problems, the application adopts a technical scheme that: an electricity utilization device is provided, and the electricity utilization device comprises the battery, and the battery is used for supplying power to the electricity utilization device.

Drawings

For a clearer description of the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

FIG. 1 is a simplified schematic illustration of a vehicle according to some embodiments;

fig. 2 is an exploded view of a battery according to some embodiments;

fig. 3 is an exploded view of a battery according to other embodiments;

fig. 4 is a schematic diagram of a tiling of insulating films according to some embodiments;

Fig. 5 is a schematic front view of a three-dimensional structure of an insulating film according to some embodiments;

FIG. 6 is a schematic cross-sectional view taken along line A-A of FIG. 5;

FIG. 7 is an enlarged schematic view of the area B in FIG. 6;

Fig. 8 is an enlarged view of a partial sectional structure of an insulating film according to other embodiments;

fig. 9 is a schematic view of a tiling structure of an insulating film according to still other embodiments;

Fig. 10 is a schematic perspective view of an insulating film according to still other embodiments;

Fig. 11 is a schematic cross-sectional structure of an insulating film according to still other embodiments;

fig. 12 is a schematic cross-sectional structure of a battery cell according to some embodiments.

Marking:

vehicle 1, battery 10, battery cell 20, controller 30, motor 40;

The box body 11, the cover body 111, the box shell 112, the bottom plate 112a, the electric cavity 11a, the bus component 12, the supporting beam 114, the shell 21 and the bare cell 22;

Insulating film 50, bottom 51, sidewall 52, thickening film 53, reservoir 54.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings showing various embodiments according to the present application, and it should be understood that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art without undue burden on the person of ordinary skill in the art based on the embodiments described herein, are intended to be within the scope of the present application.

Unless defined otherwise, 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 application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising," "including," "having," "containing," and the like in the description of the present application and in the claims and drawings are used for open ended terms. Thus, a method or apparatus that "comprises," includes, "" has "or" has, for example, one or more steps or elements, but is not limited to having only the one or more elements. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be understood that the terms "center", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly understand that the described embodiments of the application may be combined with other embodiments.

As noted above, it should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The terms "a" and "an" in this specification may mean one, but may also be consistent with the meaning of "at least one" or "one or more". The term "about" generally means that the value mentioned is plus or minus 10%, or more specifically plus or minus 5%. The term "or" as used in the claims means "and/or" unless explicitly indicated to the contrary, only alternatives are indicated.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

Reference to a battery in the presently disclosed embodiments refers to a single physical module that includes one or more battery cells to provide a predetermined voltage and capacity. For example, the battery referred to in the present application may include a battery module, a battery pack, or the like. The battery cells are basic units in the battery, and can be generally divided into: cylindrical battery cells, prismatic battery cells, and pouch battery cells. Hereinafter, it will be mainly spread around the prismatic battery cells. It should be understood that the embodiments described hereinafter are also applicable in certain respects to cylindrical battery cells or pouch battery cells.

The battery cell comprises a positive pole piece, a negative pole piece, electrolyte and a separation film. The lithium ion battery cell mainly relies on movement of lithium ions between the positive electrode sheet and the negative electrode sheet. For example, lithium ion battery cells use an intercalated lithium compound as an electrode material. The positive electrode materials currently used as lithium ion batteries are mainly commonly: lithium cobalt oxide (LiCoO ₂), lithium manganate (LiMn ₂O ₄), lithium nickelate (LiNiO ₂), and lithium iron phosphate (LiFePO ₄). The separator is disposed between the positive pole piece and the negative pole piece to form a thin film structure having three layers of materials. The membrane structure is generally manufactured into an electrode assembly having a desired shape by winding or stacking. For example, a three-layer material film structure in a cylindrical battery cell is wound into a cylindrical shape of an electrode assembly, while a prismatic battery cell is wound or stacked into an electrode assembly having a substantially rectangular parallelepiped shape.

Multiple cells may be connected in series and/or parallel via electrode terminals for use in various applications. In some high power applications, such as electric vehicles, the application of batteries includes three levels: battery cell, battery module and battery. The battery module is formed by electrically connecting a certain number of battery cells together and putting the same into one frame in order to protect the battery cells from external impact, heat, vibration, etc. The battery is the final state of the battery system incorporated in the electric vehicle. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells. The case is generally composed of a cover and a case, which generally includes a bottom plate and an outer side plate. The outer side plate extends from the edge of the bottom plate and is generally perpendicular to the bottom plate, and the bottom plate and the outer side plate form a containing space with an opening for containing the battery cells or the battery modules. The cover body covers the opening of the accommodating space, is arranged opposite to the bottom plate and is connected with the outer side plate. The case shell and the cover body can be detachably connected or can be in sealed connection. Most of the current batteries are manufactured by assembling various control and protection systems such as a Battery Management System (BMS), a thermal management unit, etc., on one or more battery modules. With the development of technology, this level of battery modules may be omitted, i.e., the battery is directly formed of the battery cells. And a plurality of battery cells are connected together so as to be called a battery module. This improvement results in a significant reduction in the number of components while the gravimetric energy density, volumetric energy density of the battery system is improved. The battery referred to in the present application includes a battery module or a battery.

In some cases, the battery cell includes a bare cell, an insulating film surrounding the bare cell, and a case housing the bare cell and the insulating film. The top of the bare cell is provided with a pole piece, and a part of the side wall of the top connected with the bare cell is usually thinned. The insulating film is usually a plastic film, and when the insulating film is wrapped at the top of the bare cell, incomplete wrapping is likely to occur. In addition, the top of the bare cell can bring the pole piece to expand after continuous working for a period of time. And along with the expansion of the top of the bare cell, the electrolyte infiltration condition of the top of the bare cell and the pole piece is poor, so that the lithium precipitation phenomenon occurs.

In order to solve the problem that the electrolyte infiltration condition of the top of the bare cell and the pole piece is poor, so that the lithium precipitation phenomenon occurs, it can be noted that the main reason is that the top of the bare cell lacks the supplement of the electrolyte after expansion. Therefore, the electrolyte infiltration condition of the top of the bare cell and the pole piece can be improved by supplementing electrolyte to the top of the expanded bare cell, the lithium precipitation condition is reduced, and the performance of the battery cell is improved. Therefore, the top end of the side wall of the insulating film far away from the bottom can be provided with a thickening area, and a plurality of liquid storage holes are formed in the thickening area. The reservoir may store electrolyte. When the top of the bare cell expands, the thickened area is extruded, and when the thickened area is extruded, the liquid storage hole is formed on the thickened area, so that the liquid storage hole can be extruded, and electrolyte stored in the liquid storage hole can flow out due to extrusion. The electrolyte flowing out can realize the supplement of the electrolyte to the top of the bare cell and the pole piece, improve the electrolyte infiltration condition of the top of the bare cell, reduce the occurrence of lithium precipitation phenomenon, and further improve the performance of the battery cell.

Based on the above consideration, in order to solve the problem that the electrolyte infiltration condition of the top of the bare cell and the pole piece is poor, thereby generating a lithium precipitation phenomenon, an insulating film, a battery cell, a battery and an electric device are designed.

For example, as shown in fig. 1, which is a simplified schematic diagram of an electric device according to some embodiments as a vehicle 1, the vehicle 1 may be a fuel-oil vehicle, a gas-fired vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended range vehicle, etc. The battery 10 may be provided in the interior of the vehicle 1, and for example, the battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may serve as an operating power source of the vehicle 1. And the vehicle 1 may further include a controller 30 and a motor 40. The controller 30 is used to control the power supplied by the battery 10 to the motor 40, for example, for operating power requirements during start-up, navigation and travel of the vehicle 1. In another embodiment of the present application, the battery 10 may be used not only as an operating power source for the vehicle 1 but also as a driving power source for the vehicle 1, instead of or in part instead of fuel oil or natural gas, to supply driving power to the vehicle 1. The battery 10, which is referred to hereinafter, may also be understood as a battery including a plurality of battery cells 20.

Fig. 2 and 3 illustrate exploded views of battery 10 according to some embodiments, respectively. As shown in fig. 2 and 3, the battery 10 includes a plurality of battery cells 20 and a bus member 12 for electrically connecting the plurality of battery cells 20. In order to protect the battery cell 20 from the invasion or corrosion of external liquid or foreign matter, the battery 10 includes a case 11 for enclosing a plurality of battery cells and other necessary components, as shown in fig. 2 and 3. In some embodiments, the case 11 may include a cover 111 and a case 112, and the battery 10 may further include a support beam 114 extending between the cover 111 and the case 112, and the support beam 114 may extend from a bottom plate 112a of the case 112 toward the cover 111 in a direction perpendicular to the bottom plate 112 a. The cover 111 and the case 112 are hermetically combined to collectively enclose the electric chamber 11a for accommodating the plurality of battery cells 20. In other embodiments, the cover 111 and the case 112 may be combined with each other without sealing.

As shown in fig. 4 and 5, fig. 4 is a schematic view of a tiling structure of an insulating film according to some embodiments, and fig. 5 is a schematic view of a front structure of a three-dimensional structure of an insulating film according to some embodiments. In some embodiments, the insulating film 50 includes a bottom 51 and a plurality of sidewalls 52 having one end connected to the bottom 51. At least one side wall 52 is provided with a thickening area on a side remote from the bottom 51, and a plurality of liquid storage holes 54 are formed in the thickening area.

The insulating film 50 is used for wrapping the bare cell, and realizes insulation between the bare cell and the shell. The bare cell is formed by a mode of winding or laminating by matching an anode pole piece and a cathode pole piece with an isolating film. And one end of the bare cell is also provided with a pole piece extending out of the isolating film and connected with a pole post of the shell. The end of the bare cell extending out of the pole piece is called the top. In some embodiments, the insulating film 50 is a plastic film. The bottom 51 of the insulating film 50 is correspondingly attached to the bottom of the bare cell. The bottom of the bare cell is a part which is arranged opposite to the top of the bare cell. The side wall 52 of the insulating film 50 is correspondingly attached to the side wall of the bare cell, which is the outer wall of the portion between the top and bottom of the bare cell. The side wall 52 of the insulating film 50 is far from the bottom 51, i.e., the portion where the side wall of the corresponding die connects to the top of the die. The side wall of the bare cell is thinned at the portion connected to the top of the bare cell, and the thickened region of the insulating film 50 is processed exactly with the thinned portion of the bare cell. The thickness of the thickened region is greater than the thickness of the sidewall 52 of the isolation diaphragm. The extending direction of the portion of the side wall 52 of the isolation film connected with the bottom wall of the isolation film is the length direction of the side wall 52 of the isolation film, namely the X direction in the figure; the direction in which the isolation film extends in the direction away from the bottom wall is the height direction of the side wall 52 of the isolation film, i.e., the Y direction in the drawing, the height direction of the isolation film being perpendicular to the length direction of the side wall 52 of the isolation film; the thickness direction of the separator is perpendicular to the length direction of the separator and perpendicular to the height direction of the separator, i.e., the Z direction in the drawing. The liquid storage hole 54 is a hole arranged on the thickening area, and the liquid storage hole 54 is used for storing electrolyte. The bare cell is wrapped by the insulating film 50, and immersed in the electrolyte, the reservoir hole 54 may absorb the electrolyte into the reservoir hole 54 by capillary action.

Through setting up the thickening district, wrap up the part that bare cell top was thinned to the setting up of stock solution hole 54 can make the bare cell when expanding in the use, can extrude the electrolyte that stores in the stock solution hole 54, thereby improve the electrolyte infiltration of bare cell top pole piece, prevent the condition of lithium evolution.

As shown in fig. 6 and 7, fig. 6 is a schematic cross-sectional view along A-A in fig. 5, and fig. 7 is an enlarged schematic view of a region B in fig. 6. In some embodiments, the thickened region is a thickened film 53 disposed on a sidewall 52 of the insulating film 50. The thick film 53 is provided on the inner side surface of the sidewall 52 of the insulating film 50. One side opening of the liquid storage hole 54 is provided away from the side wall 52 of the insulating film 50 connected to the thickening film 53.

The thick film 53 is a film layer attached to the inner surface of the sidewall 52 of the insulating film 50 and located on the side of the sidewall 52 of the insulating film 50 away from the bottom 51. The provision of the thick film 53 corresponds to the thinned portion of the bare cell. The thickening film 53 is disposed on the inner surface of the sidewall 52 of the insulating film 50, that is, the thickening film 53 is disposed on the surface of the sidewall 52 of the insulating film 50 facing the bare cell. After the insulating film 50 is assembled with the bare cell, the thickened film 53 is sandwiched between the side wall 52 of the insulating film 50 and the bare cell. The opening of the liquid storage hole 54 on one side needs to be directed to the bare cell to release the stored electrolyte to the bare cell when pressed, and therefore the opening of the liquid storage hole 54 on one side needs to be disposed away from the side wall 52 of the insulating film 50 connected to the thickening film 53. The reservoir 54 may be blind, i.e., have only one opening. In some embodiments, the thickening film 53 needs to be chemically inert to the electrolyte, i.e., the thickening film 53 does not react with the electrolyte. This arrangement ensures that the chemical reaction within the battery cell 20 proceeds properly.

The insulation film 50 is easy to be incompletely insulated, and the thickened film 53 is arranged without forming the liquid storage hole 54 on the insulation film 50, so that the insulation film 50 can be well insulated.

In some embodiments, the sidewall 52 of the insulating film 50 closes the reservoir 54 against the opening of the sidewall 52 of the insulating film 50.

As shown in fig. 8, fig. 8 is an enlarged view of a partial cross-sectional structure of an insulating film according to other embodiments. In fig. 8, a thickening film 53 is provided on a side wall 52 of an insulating film 50, and a plurality of liquid storage holes 54 are provided on the thickening film 53. The uppermost two liquid storage holes 54 are of blind hole structures, and the liquid storage holes 54 and the uppermost two liquid storage holes are of through hole structures. The liquid storage hole 54 may also be a through hole, i.e. have two openings. When the liquid storage hole 54 is a through hole, the liquid storage hole 54 penetrates the thick film 53, and the opening at the other side of the liquid storage hole 54 abuts against the side wall 52 of the insulating film 50. In this case, the side wall 52 of the insulating film 50 closes the reservoir hole 54, preventing the electrolyte in the reservoir hole 54 from flowing out. Closing the side wall 52 of the insulating film 50 against the opening of the side wall 52 of the insulating film 50 by the liquid storage hole 54 is also understood as covering the side wall 52 of the insulating film 50 against the opening of the side wall 52 of the insulating film 50 by the side wall 52.

In use, the thick film 53 is sandwiched between the insulating film 50 and the bare cell, the insulating film 50 closes one side of the reservoir 54, when the reservoir hole 54 is squeezed, the electrolyte therein can flow out toward the bare cell, thereby improving electrolyte infiltration of the top pole piece of the bare cell.

In some embodiments, the thickening film 53 gradually increases in thickness in a direction away from the bottom 51 of the insulating film 50.

The thickness of the thickening film 53 increases gradually in a direction away from the bottom 51 of the insulating film 50 and in a height direction of the insulating film 50, thereby forming a wedge-shaped structure. When the bare cell is thinned, the thinner the bare cell is, the greater the thinning degree is, and a slope structure is formed. And the wedge-shaped structure of the thickened film 53 is matched with the slope structure of the bare cell. The thickness of the thick film 53 is greatest at the end portion of the sidewall 52 of the insulating film 50 distant from the bottom 51 of the insulating film 50.

This arrangement enables the thickened film 53 to more closely conform to the bare cell.

In some embodiments, the height of thickened film 53 is 5-30 millimeters.

The height direction of the thick film 53 is the same as the height direction of the side wall 52 of the insulating film 50. The height of the thick film 53 may be 5 mm, 6mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm or 30 mm. It may also be in a range between any two of the above values, for example 5 mm to 10 mm, 6mm to 20 mm, 20 mm to 30 mm, etc.

The thickened film 53 and the bare cell are thinned to be highly synchronous, so that the thickened film 53 is better attached to the bare cell.

In some embodiments, the height of thickened film 53 is 6-12 millimeters.

The height of the thick film 53 is, for example, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm or 12 mm. It may also be in a range between any two of the above values, for example 6 mm to 10 mm, 6.5 mm to 9.5 mm, etc.

The arrangement mode can further enable the thickening film 53 and the bare cell to be thinned in high synchronization, so that the thickening film 53 can be better attached to the bare cell.

In some embodiments, thickened film 53 has a maximum thickness of 0.1-5 millimeters.

When the thickening film 53 has a wedge structure, the maximum thickness of the thickening film 53 may be the thickness of the position of the thickening film 53 farthest from the bottom 51 of the insulating film 50, and when the thicknesses of the thickening films 53 are equal, the maximum thickness of the thickening film 53 is the normal thickness of the thickening film 53. The maximum thickness of the thick film 53 may be 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm. The maximum thickness of the thick film 53 may also range between any two of the values mentioned above, for example 1 mm to 5mm, 0.5 mm to 2.5 mm, etc.

Too small a thickness of the thick film 53 may not function, and too large a thickness may cause the insulating film 50 to form a protrusion when wrapping the bare cell at a position corresponding to the thick film 53, or to clamp the bare cell too tightly.

In some embodiments, thickened film 53 is an elastic structure.

The elastic structure is an elastic structure which can be compressed and changes its thickness by elastic deformation or reduction. The thickening film 53 is of an elastic structure, i.e., the thickening film 53 can be compressed to deform, thereby reducing its thickness. When the top of the bare cell expands, the side wall 52 of the insulating film 50 is matched with the thickened film 53, and the thickened film 53 is of an elastic structure, so that deformation can occur when the thickened film 53 is extruded, the force generated when the bare cell expands is not completely transmitted to the insulating film 50, and the insulating film 50 can be prevented from being broken to a certain extent. Meanwhile, the thickening film 53 can be compressed, so that the top of the bare cell is not fixed, and the expansion of the bare cell is not blocked. In addition, the thickening film 53 has an elastic structure, so that the liquid storage hole 54 thereon can be more easily compressed, thereby more easily releasing the electrolyte stored in the liquid storage hole 54. The thick film 53 is made of, for example, silica gel.

In some embodiments, the maximum compression of thickened film 53 is not less than 20%.

The highest compression amount of the thickening film 53 is that the thickness variation range of the thickening film 53 is not less than 20% when the thickening film is compressed to be unable to deform. For example, the thickness of the thickened film 53 before compression is 1mm, and when the maximum compression amount of the thickened film 53 is reached, the thickness of the thickened film 53 is not more than 0.8 mm, i.e., the thickened film 53 may be compressed by a distance of not less than 20% of the thickness.

The maximum compression of the thick film 53 needs to be greater than the expansion of the top of the die to allow the top of the die to expand freely without restriction.

In some embodiments, the aperture of the reservoir 54 is no less than 10 ^-6 millimeters and no greater than 1 millimeter.

When the reservoir hole 54 is a circular hole, the aperture of the reservoir hole 54 is the radius of the reservoir hole 54 or the diameter of the reservoir hole 54. When the reservoir hole 54 is an elliptical hole, the aperture of the reservoir hole 54 is the length of the major or minor axis of the ellipse. When the reservoir aperture 54 is a rectangular aperture, the aperture of the reservoir aperture 54 may be the length of the diagonal of the rectangle. The aperture of the reservoir 54 may be 10 ^-6 mm, 10 ^-5 mm, 10 ^-4 mm, 0.001 mm, 0.005 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0, 08 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm. The pore diameter of the thick film 53 may also range between any two of the above values, for example, 10 ^-6 mm to 0.1 mm, 10 ^-4 mm to 1 mm, 10 ^-5 mm to 0.5 mm, etc.

When the size of the liquid storage hole 54 is moderate, the electrolyte can be sucked up through capillary action, so that the purpose of storing the electrolyte is achieved.

In some embodiments, the opening of the side of the reservoir hole 54 that abuts the insulating film 50 is larger than the opening of the side of the reservoir hole 54 that is remote from the insulating film 50.

The opening of the side of the reservoir hole 54 against the insulating film 50 is larger than the opening of the side of the reservoir hole 54 away from the insulating film 50, i.e., the opening of the side of the reservoir hole 54 against the insulating film 50 has a larger aperture than the opening of the side of the reservoir hole 54 away from the insulating film 50.

Since the opening of the side of the reservoir hole 54 near the insulating film 50 is blocked by the insulating film 50, no leakage occurs, and making the opening of the side of the reservoir hole 54 near the insulating film 50 large allows the reservoir hole 54 to store more electrolyte.

In some embodiments, the opening of the side of the reservoir 54 remote from the insulating film 50 has a diameter of no less than 10 ^-6 mm and no more than 1 mm.

The diameter of the opening of the side of the liquid storage hole 54 remote from the insulating film 50 may be 10 ^-6 mm, 10 ^-5 mm, 10 ^-4 mm, 0.001 mm, 0.005 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0, 08 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm. The pore diameter of the thick film 53 may also range between any two of the above values, for example, 10 ^-6 mm to 0.1 mm, 10 ^-4 mm to 1 mm, 10 ^-5 mm to 0.5 mm, etc.

The side of the liquid storage hole 54 far away from the insulating film 50 is the side of the liquid storage hole 54 facing the bare cell, and when the size of the opening at the side is moderate, the electrolyte can be sucked through capillary action, so that the purpose of storing the electrolyte is achieved.

In some embodiments, the thickened region is provided with at least two, at least two side walls 52 disposed opposite each other.

When the insulating film 50 wraps one bare cell or two bare cells, two thickened areas are arranged on the two opposite side walls 52 respectively. As shown in fig. 9 and 10, fig. 9 is a schematic view of a tiling structure of an insulating film according to still other embodiments; fig. 10 is a schematic perspective view of an insulating film according to still other embodiments. In some embodiments, the insulating film 50 needs to wrap around two bare cells, and the length of the side wall 52 of the insulating film 50 is longer, so that one side wall 52 for isolating two bare cells can be formed at an intermediate position after folding. At this time, the thick film 53 is provided on both side walls 52 of the insulating film 50. Similarly, the thickening film 53 has a liquid storage hole 54 formed therein. As shown in fig. 11, fig. 11 is a schematic cross-sectional structure of an insulating film according to still other embodiments. When the insulating film 50 wraps two bare cells, the thickened regions are provided with three or more, respectively located on the side walls 52 of the oppositely disposed three or more insulating films 50. When the insulating film 50 wraps the two bare cells, a thickened area is provided on the sidewall 52 of the insulating film 50 corresponding to the sidewall 52 away from each other, and a thickened area may also be provided on the sidewall 52 facing each other. At this time, the thickened film 53 may be provided with three or more on the side walls 52 of the oppositely disposed three or more insulating films 50, respectively. Meanwhile, two thickening films 53 may be provided on one side wall 52 of the insulating film 50, that is, the thickening films 53 are provided on opposite sides of one side wall 52 of the insulating film 50.

In some embodiments, the length of the thickened region is equal to or less than the length of the junction of the side wall 52 provided with the thickened region and the bottom 51.

The length of the junction of the side wall 52 provided with the thickened region and the bottom 51 is generally greater than or equal to the length of the bare cell in this direction. The length of the thickened region is the length of the thickened region in the length direction of the side wall 52 of the insulating film 50. And the length of the thickened area is optimally consistent with the length of the bare cell in the direction. If the length of the thickened area exceeds the length of the bare cell, the cost performance is not as good as that of the thickened area and the length of the bare cell in the direction, and the cost is correspondingly increased.

The length of the thickening area is moderate, so that the cost can be saved.

As shown in fig. 12, fig. 12 is a schematic cross-sectional structure of a battery cell according to some embodiments. The present application also provides a battery cell 20. The battery cell 20 includes a case 21, a bare cell 22, and an insulating film 50. The bare cell 22 and the insulating film 50 are provided in the case 21, and the insulating film 50 is any one of the insulating films 50 described above. The insulating film 50 wraps the bare cell 22, and the thickened region corresponds to the top end of the side wall of the bare cell 22. The top of the bare cell 22 is in a thinned structure, and a thickened region is disposed on a side of the side wall 52 of the insulating film 50 away from the bottom 51. The thickened region may be a thickened film 53 attached to the side wall 52 of the insulating film 50 toward the bare cell 22.

When the thickened region is the thickened film 53, the thickened film 53 is sandwiched between the bare cell 22 and the insulating film 50. To ensure tightness of the thickened film 53 against the bare cell 22, the thickened film 53 may be in a compressed state.

Through setting up the thickening district, wrap up the part of bare cell top in the battery monomer 20 by the shavings to when the setting up of stock solution hole 54 can make the bare cell expand in the use, can extrude the electrolyte that stores in the stock solution hole 54, thereby improve the electrolyte infiltration of bare cell top pole piece, prevent the condition of lithium evolution.

The application also provides a battery. In some embodiments, the battery comprises a cell as described in any one of the above.

Through the mode, the thickened area can be arranged to wrap the thinned part of the top of the bare cell in the battery cell, and the electrolyte stored in the liquid storage hole can be extruded out when the bare cell expands in the use process by the arrangement of the liquid storage hole, so that the electrolyte infiltration of the pole piece at the top of the bare cell is improved, and the lithium precipitation is prevented.

In some embodiments, the power device comprises a battery as described above for powering the power device. The powered device may include, but is not limited to, a cell phone, tablet, notebook computer, electric toy, electric tool, battery car, electric car, energy storage device, ship, spacecraft, and the like. The energy storage device can be applied to a power grid system, stores electric energy when the power supply amount of the power grid is larger than the demand amount, and releases the electric energy when the power supply amount of the power grid is smaller than the demand amount.

In some specific application scenarios, the battery cell 20 of the present application includes a bare cell 22, a housing 21 and an insulating film 50, aiming at the problem that the electrolyte infiltration condition of the top of the bare cell and the pole piece is poor, so that a lithium precipitation phenomenon occurs. The battery cell 20 includes a case 21, a bare cell 22, and an insulating film 50. The bare cell 22 and the insulating film 50 are provided in the case 21, and the insulating film 50 is any one of the insulating films 50 described above. The insulating film 50 is used for wrapping the bare cell 22, and realizes insulation between the bare cell 22 and the housing 21. The thickened region corresponds to the top of the side wall of the die 22. The top of the bare cell 22 is in a thinned structure, and a thickened region is disposed on a side of the side wall 52 of the insulating film 50 away from the bottom 51. The thickened region may be a thickened film 53 attached to the side wall 52 of the insulating film 50 toward the bare cell 22. The thickening film 53 is provided with a liquid storage hole 54, and the thickening film 53 is of an elastic structure. The bare cell 22 is formed by winding or laminating a positive electrode sheet and a negative electrode sheet with a separator. The pole piece extends out of the isolating film at one end of the bare cell 22 and is connected with the pole post of the shell 21. The end of the bare cell 22 extending out of the pole piece is referred to as the top. In some embodiments, the insulating film 50 is a plastic film. The bottom 51 of the insulating film 50 is correspondingly attached to the bottom of the bare cell 22. The bottom of the bare cell 22 is a portion disposed opposite to the top of the bare cell 22. the side wall 52 of the insulating film 50 is correspondingly attached to the side wall of the bare cell 22, and the side wall of the bare cell 22 is the outer wall of the portion between the top and the bottom of the bare cell 22. The side wall 52 of the insulating film 50 is far from the bottom 51, i.e., the portion corresponding to the side wall of the die 22 that connects the top of the die 22. The side wall of the bare cell 22 is thinned at the portion connecting the top of the bare cell 22, and the thickened region of the insulating film 50 is processed exactly with the thinned portion of the bare cell 22. The thickness of the thickened region is greater than the thickness of the sidewall 52 of the isolation diaphragm. The extending direction of the portion of the side wall 52 of the isolation film connected with the bottom wall of the isolation film is the length direction of the side wall 52 of the isolation film, namely the X direction in the figure; the direction in which the isolation film extends in the direction away from the bottom wall is the height direction of the side wall 52 of the isolation film, i.e., the Y direction in the drawing, the height direction of the isolation film being perpendicular to the length direction of the side wall 52 of the isolation film; the thickness direction of the separator is perpendicular to the length direction of the separator and perpendicular to the height direction of the separator, i.e., the Z direction in the drawing. The liquid storage hole 54 is a hole arranged on the thickening area, and the liquid storage hole 54 is used for storing electrolyte. The bare cell 22 is wrapped by the insulating film 50, and the bare cell 22 is immersed in the electrolyte, so that the electrolyte is absorbed into the reservoir hole 54 by capillary action through the reservoir hole 54. The thick film 53 is a film layer attached to the inner surface of the sidewall 52 of the insulating film 50 and located on the side of the sidewall 52 of the insulating film 50 away from the bottom 51. The provision of the thick film 53 corresponds to the thinned portion of the bare cell 22. The thickening film 53 is disposed on the inner surface of the sidewall 52 of the insulating film 50, that is, the thickening film 53 is disposed on the surface of the sidewall 52 of the insulating film 50 facing the bare cell 22. After the insulating film 50 is assembled with the bare cell 22, the thickened film 53 is sandwiched between the side wall 52 of the insulating film 50 and the bare cell 22. The opening of the liquid storage hole 54 on one side needs to be directed to the bare cell 22 to release the stored electrolyte to the bare cell 22 when pressed, and therefore, the opening of the liquid storage hole 54 on one side needs to be disposed away from the side wall 52 of the insulating film 50 connected to the thickening film 53. The reservoir 54 may be blind, i.e., have only one opening. In some embodiments, the thickening film 53 needs to be chemically inert to the electrolyte, i.e., the thickening film 53 does not react with the electrolyte. This arrangement ensures that the chemical reaction within the battery cell 20 proceeds properly.

Through setting up the thickening district, wrap up the part that bare cell top was thinned to the setting up of stock solution hole 54 can make the bare cell when expanding in the use, can extrude the electrolyte that stores in the stock solution hole 54, thereby improve the electrolyte infiltration of bare cell top pole piece, prevent the condition of lithium evolution. The insulation film 50 is easy to be incompletely insulated, and the thickened film 53 is arranged without forming the liquid storage hole 54 on the insulation film 50, so that the insulation film 50 can be well insulated. The elastic structure can be compressed, and as the service time is prolonged, the expansion of the pole piece of the bare cell is aggravated, the compression amount is increased, and the expansion of the pole piece of the bare cell is not blocked, so that the pole piece gap is flexibly adjusted.

The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application or directly or indirectly applied to other related technical fields are included in the scope of the present application.

Claims

1. An insulating film of a battery cell, characterized in that the insulating film comprises a bottom and a plurality of side walls connected to the bottom at one end, at least one side wall is provided with a thickened area on a side away from the bottom, and a plurality of liquid storage holes are formed on the thickened area.

2. The insulating film according to claim 1 is characterized in that the thickened area is a thickened film arranged on the side wall of the insulating film, the thickened film is arranged on the inner surface of the side wall of the insulating film, and one side opening of the liquid storage hole is arranged away from the side wall of the insulating film connected to the thickened film.

3 . The insulating film according to claim 2 , wherein the side wall of the insulating film places the liquid storage hole close to the opening of the side wall of the insulating film.

4 . The insulating film according to claim 2 , wherein the thickness of the thickened film gradually increases in a direction away from the bottom of the insulating film. 5 .

5 . The insulating film according to claim 2 , wherein the height of the thickened film is 5-30 mm.

6 . The insulating film according to claim 2 , wherein the height of the thickened film is 6-12 mm.

7. The insulating film according to any one of claims 2 to 6, characterized in that the maximum thickness of the thickened film is 0.1-5 mm.

8 . The insulating film according to claim 2 , wherein the thickened film is an elastic structure.

9 . The insulating film according to claim 8 , wherein the maximum compression amount of the thickened film is not less than 20%.

10. The insulating film according to any one of claims 2 to 9, characterized in that the diameter of the liquid storage hole is not less than ^10-6 mm and not more than 1 mm.

11 . The insulating film according to claim 2 , wherein an opening of the liquid storage hole on a side close to the insulating film is larger than an opening of the liquid storage hole on a side away from the insulating film.

12 . The insulating film according to claim 11 , wherein a diameter of an opening of the liquid storage hole on a side away from the insulating film is not less than 10 ⁻⁶ mm and not more than 1 mm.

13 . The insulating film according to claim 1 , wherein at least two thickened regions are provided, respectively located at at least two of the side walls that are arranged opposite to each other.

14 . The insulating film according to claim 1 , wherein the length of the thickened region is equal to or less than the length of a connection between the side wall where the thickened region is provided and the bottom.

15. A battery cell, characterized in that the battery cell comprises a shell, a bare cell and an insulating film, the bare cell and the insulating film are arranged in the shell, the insulating film is the insulating film according to any one of claims 1-14, the insulating film wraps the bare cell, and the thickened area corresponds to the top of the side wall of the bare cell.

16 . A battery, characterized in that the battery comprises a battery cell, and the battery cell is the battery cell according to claim 15 .

17. An electrical device, characterized in that the electrical device comprises a battery, the battery is the battery according to claim 16, and the battery provides electrical energy for the electrical device.