CN220209239U - Insulating sheet and battery cell having the same - Google Patents

Abstract

The utility model discloses an insulating sheet and a battery cell having the same. The insulating sheet is provided between the casing of the battery cell and the current collector. The surface of the side of the insulating sheet away from the current collector is At least part of it is formed as a flow guide surface, and the flow guide surface is an inclined surface extending downward. According to the insulating sheet of the present invention, a downwardly inclined flow guide surface is formed on the side surface of the insulating sheet away from the current collector, so that the electrolyte accumulated between the insulating sheet and the case can be discharged, thereby lowering the case. The probability of the body being corroded can improve the safety of the battery.

Description

Insulating sheet and battery cell having the same

Technical field

The utility model relates to the field of battery technology, and in particular to an insulating sheet and a battery cell having the same.

Background technique

As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used in the field of electric vehicles as power batteries. The insulating sheet of lithium-ion battery is also an important part of lithium-ion power battery. It is located inside the battery cell and connected to the casing and current collecting plate. It is used to maintain the circuit open state and ensure the insulation of the battery. The electrolyte in the lithium-ion battery has volatile characteristics. When it appears between the insulating sheet and the casing, due to the flat structure of the insulating sheet itself, the electrolyte cannot be effectively discharged, which will cause the accumulation of electrolyte, and then It will easily cause side reactions between the electrolyte and the metal case, causing corrosion of the case and even affecting the safe use of the battery core.

Utility model content

The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an insulating sheet that can reduce the probability of corrosion of the casing and improve the safety of the battery.

The utility model also provides a battery cell with the above-mentioned insulating sheet.

According to the insulating sheet of the first aspect of the present invention, the insulating sheet is disposed between the casing of the battery cell and the current collector, and at least part of the side surface of the insulating sheet facing away from the current collector is formed as a flow guide. surface, and the guide surface is an inclined surface extending downward.

According to the insulating sheet of the present invention, a downwardly inclined flow guide surface is formed on the side surface of the insulating sheet away from the current collector, so that the electrolyte accumulated between the insulating sheet and the casing can be discharged, thereby lowering the casing. The probability of the body being corroded can improve the safety of the battery.

According to some embodiments of the present invention, a through hole penetrating the insulating sheet along a thickness direction of the insulating sheet is formed on the insulating sheet.

According to some embodiments of the present invention, the flow guide surface extends downwardly and obliquely in a radial direction of the through hole from the inside to the outside.

According to some embodiments of the present invention, the one side surface of the insulating sheet is provided with a groove, the groove passes through the edge of the insulating sheet, and the bottom wall of the groove is formed as the flow guide surface. .

According to some embodiments of the present invention, the number of the grooves is multiple, and the plurality of grooves are arranged around the through hole.

According to some embodiments of the present invention, the groove extends along a radial direction of the through hole, and the width of the groove gradually increases in a radial direction from the inside to the outside of the through hole.

According to some embodiments of the present invention, the through hole is a circular hole and includes a first hole segment and a second hole segment that are coaxially connected, and the first hole segment is connected at a point away from the second hole segment. One side of the current collector, and the diameter of the first hole segment is smaller than the diameter of the second hole segment.

According to some embodiments of the present invention, in a projection plane perpendicular to the axis of the through hole, the flow guide surface is located radially outside the second hole section.

The battery cell according to the second aspect of the present invention includes a casing, a current collector and an insulating sheet according to the first aspect of the present invention. The insulating sheet is disposed between the current collector and the inner wall surface of the casing. .

According to the battery cell of the present invention, by providing the insulating sheet of the first aspect, the overall performance of the battery cell is improved.

According to some embodiments of the present invention, the current collector has a welding area, and the flow guide surface and the welding area are arranged oppositely in the thickness direction of the insulating sheet.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

Figure 1 is a schematic diagram of an insulating sheet according to an embodiment of the present invention;

Figure 2 is a top view of an insulating sheet according to an embodiment of the present invention;

Figure 3 is a cross-sectional view of an insulating sheet according to an embodiment of the present invention;

Figure 4 is a top view of a current collector according to an embodiment of the present invention.

Reference signs:

10. Insulating sheet; 11. Groove; 12. Guide surface; 13. Through hole; 131. First hole section; 132. Second hole section;

20. Current collector; 21. Welding area; 22. Non-welding area; 23. Protrusion.

Detailed ways

The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and intended to explain the present invention, but should not be understood as limiting the present invention.

The insulating sheet 10 according to the first embodiment of the present invention is described below with reference to FIGS. 1-4 .

As shown in FIG. 1 , according to the insulating sheet 10 according to the first embodiment of the present invention, the insulating sheet 10 is disposed between the casing of the battery cell and the current collector 20 , and the side surface of the insulating sheet 10 facing away from the current collector 20 At least part of is formed as a flow guide surface 12, and the flow guide surface 12 is an inclined plane extending downward.

Specifically, the insulating sheet 10 is a thin sheet that keeps the circuit in a disconnected state and mainly plays an insulating role; the insulating sheet 10 has the properties of high temperature resistance, insulation and electrolyte corrosion resistance, and insulating materials with high temperature resistance and electrolyte corrosion resistance can be used. For example, the insulating sheet 10 can be made of materials such as PP, PET, or PBT. The insulating sheet 10 is disposed between the casing and the current collector 20. The bottom surface of the insulating sheet 10 is in contact with the current collector 20, and a certain gap is formed between the upper end surface of the insulating sheet 10 and the casing. Therefore, the volatilized electrolyte Liquid will accumulate between the insulating sheet 10 and the casing, causing corrosion of the casing. At this time, at least part of the side surface of the insulating sheet 10 away from the current collector 20 is formed as the flow guide surface 12 , that is, the flow guide surface 12 is formed on the side surface where the electrolyte collects, and the flow guide surface 12 is The slope extending downward can cause the accumulated electrolyte to flow downward along the guide surface 12 and away from the surface of the case, thereby reducing corrosion of the case and thereby improving the safety of the battery. Among them, the surface of the side of the insulating sheet 10 that is away from the current collector 20 may be partially formed with the flow guide surface 12 , or may be completely formed with the flow guide surface 12 .

According to the insulating sheet 10 according to the embodiment of the present invention, a flow guide surface 12 extending obliquely downward is formed on the side surface of the insulating sheet 10 away from the current collector 20, so that the electrolyte accumulated between the insulating sheet 10 and the case can be The liquid is discharged, thereby reducing the probability of corrosion of the casing, thereby improving the safety of the battery.

According to some embodiments of the present invention, as shown in FIG. 1 , the insulating sheet 10 is formed with a through hole 13 penetrating the insulating sheet 10 along the thickness direction of the insulating sheet 10 . Specifically, the through hole 13 is used to install the pole, and the pole can extend out of the housing through the through hole 13. The pole serves as the electrical connection part of the battery and is used to output or input the electric energy of the battery cell. Furthermore, in The insulating sheet 10 is formed with a through hole 13 penetrating the insulating sheet 10 along the thickness direction of the insulating sheet 10, which can ensure the normal use of the battery. At the same time, the pole can be sleeved inside the insulating sheet 10, thereby realizing the pole and the shell. The insulation seal of the body can improve the safety of the battery.

According to some embodiments of the present invention, as shown in FIG. 3 , the flow guide surface 12 extends downward and obliquely in the radial direction of the through hole 13 from the inside to the outside. Among them, the flow guide surface 12 and the through hole 13 form a certain angle in the axial direction, and the through hole 13 is arranged at the center of the insulating sheet 10, thereby allowing the electrolyte to spread from the center of the insulating sheet 10 to the surroundings. In turn, the discharge time of the electrolyte can be reduced and the discharge efficiency of the electrolyte can be improved, thereby reducing the corrosion of the casing and improving the safety of the battery.

According to some embodiments of the present invention, as shown in FIG. 1 , a groove 11 is provided on one side surface of the insulating sheet 10 , the groove 11 passes through the edge of the insulating sheet 10 , and the bottom wall of the groove 11 is formed as a flow guide surface 12 . Among them, a groove 11 is formed on the side of the insulating sheet 10 away from the current collector 20. The groove 11 can form a certain distance between the insulating sheet 10 and the inner wall of the top of the case, thereby allowing the electrolyte condensed on the top wall of the case to The liquid is collected into the groove 11 and does not contact the top wall of the housing, thereby reducing the probability of corrosion of the housing; at the same time, the groove 11 penetrates the edge of the insulating sheet 10 and the bottom wall of the groove 11 is formed as a flow guide surface 12. The electrolyte can be collected and drained through the guide surface 12, which can effectively reduce the accumulation of electrolyte between the insulating sheet 10 and the case, thereby reducing the probability of case corrosion and improving the safety of the battery.

According to some embodiments of the present invention, as shown in FIGS. 1 and 2 , the number of grooves 11 is multiple, and the plurality of grooves 11 are arranged around the through hole 13 . For example, the number of grooves 11 can be two, three or more, and multiple grooves 11 are arranged around the through hole 13, which can increase the receiving and collecting area of the grooves 11, thereby increasing the discharge amount of electrolyte, so that Effectively prevent casing corrosion and improve battery safety.

According to some embodiments of the present invention, as shown in FIG. 1 , the groove 11 extends along the radial direction of the through hole 13 , and the width of the groove 11 gradually increases from the inside to the outside along the radial direction of the through hole 13 . Among them, the cross section of the groove 11 in the radial direction from the inside to the outside of the through hole 13 is formed into a fan shape, which can increase the area of the groove 11 and thereby increase the collection amount of electrolyte, thereby increasing the discharge amount of electrolyte. , reducing the probability of case corrosion and improving the safety of the battery; at the same time, it can also slow down the flow rate of the electrolyte to ensure that the electrolyte can be smoothly discharged through the gap between the edge of the groove 11 and the case, thereby reducing electrolyte accumulation. , which can reduce the probability of case corrosion and improve the safety of the battery.

According to some embodiments of the present invention, as shown in Figure 3, the through hole 13 is a circular hole and includes a first hole section 131 and a second hole section 132 that are coaxially connected. The first hole section 131 is connected to the second hole section. 132 away from the current collector 20 , and the diameter of the first hole section 131 is smaller than the diameter of the second hole section 132 . Among them, the through hole 13 is used to install the pole, and the pole passes through the inside of the through hole 13. The inner wall of the first hole section 131 interferes with the pole. That is, the insulating sheet 10 generates a force on the pole through the first hole section 131. The extrusion sealing can increase the sealing effect of the insulating sheet 10 on the pole, prevent impurities from entering the battery through the through hole 13 and causing damage to the battery, thereby improving the safety of the battery; the pole and the current collector 20 are fixed by the fixing block connection, and then the size of the connection position between the pole and the current collector 20 is larger than the diameter of the pole itself, and further the diameter of the second hole section 132 is larger than the diameter of the first hole section 131, which can ensure the convenience of installation of the insulating sheet 10; at the same time, the third hole section 132 is larger than the diameter of the first hole section 131. The two hole sections 132 are in contact and sealed with the fixed block, and the lower end surface of the first hole section 131 is in contact and sealed with the fixed block, thereby further increasing the sealing effect of the insulating sheet 10 and improving the safety of the battery.

According to some embodiments of the present invention, as shown in Figure 3, in the projection plane perpendicular to the axis of the through hole 13, the flow guide surface 12 is located radially outside the second hole section 132, which can ensure that the insulating sheet 10 is opposite to the pole. The sealing and insulating properties of the pole can prevent impurities from entering the battery through the gap between the pole and the casing, thereby improving the safety of the battery.

The battery cell according to the second embodiment of the present invention includes a casing, a current collector 20 and an insulating sheet 10 according to the first embodiment of the present invention. The insulating sheet 10 is provided on the inner wall surface of the current collector 20 and the casing. between.

Among them, the casing is the main carrying component of the battery cell, providing carrying space for the electrode assembly, current collector 20, insulating sheet 10 and electrolyte, and can be used to protect the safety of the electrode assembly; the casing is made of various materials. For example, aluminum, steel, etc. The current collector 20 is used to electrically connect the pole pieces and poles, guide the electrodes inside the electrode assembly to the outside, connect the inside and outside of the electrode assembly, and realize the electrical connection of the battery.

According to the battery cell according to the embodiment of the present invention, the overall performance of the battery cell is improved by providing the insulating sheet 10 of the first embodiment.

According to some embodiments of the present invention, as shown in FIG. 4 , the current collector 20 has a welding area 21 , and the flow guide surface 12 and the welding area 21 are arranged oppositely in the thickness direction of the insulating sheet 10 . Specifically, the welding area 21 of the current collector 20 is used to connect the pole pieces, the non-welding area 2221 of the current collector 20 is formed with a protrusion 23, the insulating sheet 10 is in contact with the protrusion 23 of the current collector 20, and the welding of the current collector 20 is Areas 21 and non-welding areas 2221 are arranged alternately. Among them, the welding zone 21 and the flow guide surface 12 are arranged oppositely in the thickness direction of the insulation sheet 10 , that is, the welding zone 21 and the flow guide surface 12 correspond one to one, and then the welding zone 21 and the flow guide surface 12 are arranged in the through hole 13 They are arranged relative to each other in the axial direction, which can avoid the contact part between the insulating sheet 10 and the current collector 20, ensuring the insulation effect of the insulating sheet 10.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis" ", "radial direction", "circumferential direction", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply what is meant. Devices or components must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically limited.

In this utility model, unless otherwise expressly stipulated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integration; it can be a mechanical connection, an electrical connection, or communication; it can be a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two elements or an interaction between two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "an example," "specific examples," or "some examples" or the like means that specific features are described in connection with the embodiment or example. , structures, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification unless they are inconsistent with each other.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, substitutions and changes can be made to these embodiments without departing from the principles and purposes of the present invention. Modifications, the scope of the present invention is defined by the claims and their equivalents.

Claims (10)

1. The insulating sheet is arranged between the shell of the battery cell and the current collector, and is characterized in that at least part of one side surface of the insulating sheet, which is away from the current collector, is formed into a diversion surface, and the diversion surface is an inclined surface extending downwards in an inclined manner.

2. The insulating sheet according to claim 1, wherein a through hole penetrating the insulating sheet in a thickness direction of the insulating sheet is formed in the insulating sheet.

3. The insulating sheet according to claim 2, wherein the flow guiding surface extends obliquely downward in a direction from inside to outside in a radial direction of the through hole.

4. An insulating sheet as claimed in claim 3, in which the one side surface of the insulating sheet is provided with a recess which passes through the edge of the insulating sheet, the bottom wall of the recess being formed as the flow guiding surface.

5. The insulating sheet of claim 4, wherein the number of said grooves is plural, and a plurality of said grooves are arranged around said through hole.

6. The insulating sheet as claimed in claim 4, wherein the grooves extend in a radial direction of the through-hole, and the width of the grooves gradually increases in a direction from inside to outside in the radial direction of the through-hole.

7. The insulating sheet of claim 2, wherein the through hole is a circular hole and comprises a first hole section and a second hole section coaxially connected, the first hole section is connected to a side of the second hole section facing away from the current collector, and the diameter of the first hole section is smaller than that of the second hole section.

8. The insulating sheet of claim 7, wherein the flow guiding surface is located radially outward of the second hole section in a projection plane perpendicular to an axis of the through hole.

9. A battery cell characterized by comprising a case, a current collector, and the insulating sheet according to any one of claims 1 to 8, the insulating sheet being provided between the current collector and an inner wall surface of the case.

10. The battery cell according to claim 9, wherein the current collector has a welding region, and the current guiding surface is disposed opposite to the welding region in a thickness direction of the insulating sheet.