CN211045591U - Battery cell and battery - Google Patents

Abstract

The utility model discloses an electricity core and battery, electricity core includes: the pole piece comprises a current collector, a first substance layer and a second substance layer, wherein the first substance layer is coated on the first surface of the current collector, the second substance layer is coated on the second surface of the current collector, the first surface and the second surface are oppositely arranged, and the first substance layer is provided with a first groove; the tab is arranged in the first groove and is electrically connected with the current collector; and the electrolyte layer is arranged above the lug to prevent the lug from being electrically connected with other conductive substances. From this, through first recess, utmost point ear and electrolyte layer cooperation, can avoid the inside short circuit that takes place of electric core, can promote the security performance of electric core to, through with utmost point ear embedded in first recess, can reduce the electric core thickness of occupying because of utmost point ear leaks outward, thereby can promote the volume energy density of electric core.

Description

Cells and batteries

technical field

The utility model relates to the field of batteries, in particular to an electric core and a battery with the electric core.

Background technique

Lithium-ion batteries are widely used in existing energy storage devices due to their high energy density per unit volume, high average output voltage, long life, and wide operating temperature range.

In the related art, in order to make the battery have a higher energy density, more active materials need to be carried in a limited size space, however, it is usually necessary to reserve an area uncoated with active materials at the head of the pole piece for welding. tabs for connection to external circuits.

There are usually problems such as high solder print height and solder burrs at the welded tabs, which will bring the risk of piercing the isolation film 8 and causing a short circuit in the cell. Paste thick tape on the ears, and paste the thick tape on the corresponding anode diaphragm, which will additionally lose the volumetric energy density of the cell.

Utility model content

The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to provide a battery cell, which can avoid short circuits inside the battery core and can also increase the volume energy density of the battery core.

The utility model further provides a battery.

The battery core according to the present invention includes: a pole piece, including a current collector, a first material layer and a second material layer, the first material layer is coated on the first surface of the current collector, and the second material layer Coated on the second surface of the current collector, the first surface and the second surface are arranged oppositely, the first material layer is provided with a first groove; the tab is provided in the first groove inside, and electrically connected with the current collector; and an electrolyte layer, disposed above the tabs to prevent the tabs from being electrically connected with other conductive substances.

According to the battery cell of the present invention, through the cooperation of the first groove, the tab and the electrolyte layer, short circuit inside the cell can be avoided, the safety performance of the cell can be improved, and the tab is embedded in the first groove. Inside, the thickness of the cell occupied by the external leakage of the tab can be reduced, so that the volume energy density of the cell can be improved.

In some examples of the present invention, the electrolyte layer has a projected area on the first substance layer.

In some examples of the present invention, the electrolyte layer is disposed on the surface of the tab, and there is no projected area on the first substance layer.

In some examples of the present invention, the current collector is further formed with a first empty foil region that is not coated with the first substance layer, and the first empty foil region is provided with the electrolyte layer.

In some examples of the present invention, the electrolyte layer is connected to the first substance layer, or the electrolyte layer has a projected area on the first substance layer.

In some examples of the present invention, the second substance layer is provided with a second groove opposite to the first groove, the electrolyte layer is provided in the second groove, or the electrolyte layer The second groove is partially or completely covered.

In some examples of the present invention, the current collector is further formed with a second empty foil region that is not coated with the second substance layer, and the second empty foil region is provided with the electrolyte layer.

In some examples of the present invention, the electrolyte layer is connected to the second substance layer, or the electrolyte layer has a projected area on the second substance layer.

In some examples of the present invention, the ionic conductivity of the electrolyte layer is greater than or equal to 10 ^-5 s/cm, and the material of the electrolyte layer includes crystalline lithium ion solid electrolyte, glass solid electrolyte or organic polymer solid electrolyte at least one of them.

In some examples of the present invention, the crystalline lithium ion solid electrolyte has at least one of a LISICON structure, a NASICON structure or a perovskite structure, and the glassy solid electrolyte includes at least one of oxides or sulfides A sort of.

The battery according to the present invention comprises a battery cell and a packaging case for accommodating the battery cell, and the battery core is the above-mentioned battery cell.

Additional aspects and advantages of the invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

1 is a schematic diagram of a winding structure of an electric core according to an embodiment of the present invention;

2 is a schematic diagram of a winding structure according to an embodiment of the present utility model in which the tabs of the battery core are arranged at another position;

3 is a cross-sectional view of an embodiment of a pole piece, tab and electrolyte layer of a cell according to an embodiment of the present invention;

Fig. 4 is the top view of Fig. 3;

5 is a cross-sectional view of another embodiment of a pole piece, a tab, and an electrolyte layer of a cell according to an embodiment of the present invention;

Fig. 6 is the top view of Fig. 5;

7 is a cross-sectional view of another embodiment of a pole piece, tab and electrolyte layer of a cell according to an embodiment of the present invention;

FIG. 8 is a plan view of FIG. 7 .

Reference number:

Cell 10;

pole piece 1; collector 11;

the first material layer 12; the first groove 121;

The second material layer 13; the second groove 131;

Electrolyte layer 3 ; first empty foil area 4 ; second empty foil area 5 ; cathode pole piece 6 ; anode pole piece 7 ; separator 8 .

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as a limitation of the present invention.

The battery cell 10 according to the embodiment of the present invention will be described below with reference to FIGS. 1 to 8 .

As shown in FIGS. 1-8 , the battery cell 10 according to the embodiment of the present invention includes: a pole piece 1 , a pole tab 2 and an electrolyte layer 3 . The pole piece 1 can be a cathode pole piece (or a positive pole piece) 6, or it can be an anode pole piece (or a negative pole piece) 7, for example: the pole piece 1 can be a cathode pole piece 6, and the pole piece 1 includes a current collector 11, The first material layer 12 and the second material layer 13, the first material layer 12 is coated on the first surface of the current collector 11, the second material layer 13 is coated on the second surface of the current collector 11, the first surface and the second material layer 13 The surfaces are oppositely arranged. It should be noted that when the upper surface of the current collector 11 is the first surface, the lower surface of the current collector 11 is the second surface, and when the upper surface of the current collector 11 is the second surface, the The lower surface is the first surface, for example, the upper surface of the current collector 11 is the first surface, the lower surface of the current collector 11 is the second surface, and the first material layer 12 is provided with a first groove 121 . The tab 2 is arranged in the first groove 121, and the welding position of the tab 2 can be adjusted. For electrical connection, the electrolyte layer 3 is disposed above the tab 2, and the electrolyte layer 3 can prevent the tab 2 from being electrically connected with other conductive substances.

Specifically, the lithium ion battery includes a battery cell 10, and the battery core 10 can be formed by winding or stacking the cathode pole piece 6, the separator 8, and the anode pole piece 7 in sequence. The function of the separator 8 is to realize the connection between the cathode and the anode. The electronic insulation and ion conduction between the cells are thus ensured that the battery cells 10 can be safely and effectively charged and discharged.

By arranging the electrolyte layer 3 above the tab 2 to replace the original sticking method (such as sticking adhesive tape on the top of the tab 2 , etc.), the electrolyte layer 3 has the characteristics of conducting lithium ions but not conducting electrons. , can make effective use of the cathode active material at the bonding place of the original adhesive tape, and can improve the energy density of the battery cell 10; in addition, the electrolyte layer 3 also has the characteristics of high strength, high temperature and high voltage, oxidation resistance, etc. During welding, the height of the solder print exceeds the specification and the risk of piercing the diaphragm caused by the burr of the solder print can also avoid the shrinkage of the separator 8 and the oxidation of the adhesive tape inside the cell under high temperature conditions. The occurrence of a short circuit can greatly improve the safety and reliability; at the same time, it can also avoid the high requirements of the equipment for the dimensional accuracy of the glue and the detection of the leakage of the glue, and improve the production efficiency of the battery.

In addition, by arranging the tabs 2 in the first grooves 121, the empty foil area of the welding tabs in the prior art (eg, disposed at the beginning or the end of the current collector) can be eliminated, and the tabs 2 can be lowered. The thickness of the battery cell 10 occupied by the external leakage can further increase the volume energy density of the battery cell 10 , and by providing the electrolyte layer 3 , short-circuiting inside the battery cell 10 can be avoided, and the internal resistance and charging and discharging of the battery cell 10 can be reduced. The temperature rise of the battery cell 10 can prevent the temperature of the battery cell 10 from being too high, thereby preventing the battery cell 10 from burning, and further improving the safety performance of the battery cell 10 .

In some embodiments of the present invention, as shown in FIG. 3 , the electrolyte layer 3 has a projected area on the first material layer 12 in the up-down direction, that is, in the up-down direction shown in FIG. 3 , the electrolyte layer 3 has a projection area on the first material layer 12 The projection of the layer 3 and the projection of the first material layer 12 have an overlapping area, and this setting can ensure that the tab 2 and the empty foil area at the welding tab 2 are fully covered, which can prevent the tab 2 from being electrically connected to other conductive substances. , so that the short circuit of the battery cell 10 can be better prevented.

In some embodiments of the present invention, as shown in FIGS. 5-7 , the electrolyte layer 3 may be disposed on the surface of the tab 2, and the electrolyte layer 3 has no projected area on the first material layer 12, which can also be understood as , in the up-down direction, the projection of the electrolyte layer 3 and the projection of the first material layer 12 do not have an overlapping area (or there is no connection area between the electrolyte layer 3 and the first material layer 12 ), at this time, the electrolyte layer 3 can cover At the opening of the first groove 121 , this arrangement can prevent the tab 2 from being electrically connected to other conductive substances, and can further prevent the battery cell 10 from being short-circuited.

In some embodiments of the present invention, as shown in FIG. 3 , the current collector 11 may also be formed with a first empty foil region 4 that is not coated with the first material layer 12 , and the first empty foil region 4 may be provided with an electrolyte layer 3. For example, the first empty foil area 4 can be coated or pasted with the electrolyte layer 3, and the electrolyte layer 3 can be partially or completely coated on the first empty foil area 4. The electrolyte layer 3 can conduct lithium ions and not conduct electricity. Electrolyte can make effective use of the cathode active material at the bonding place of the adhesive tape, so as to further improve the energy density of the battery cell 10, and the electrolyte layer 3 has the characteristics of high strength and oxidation resistance, which can avoid the welding height during welding. The risk of piercing the isolation film 8 caused by exceeding the specification and soldering burrs avoids the occurrence of a short circuit between the aluminum foil current collector 11 and the anode sheet 71 inside the cell 10 .

In some embodiments of the present invention, as shown in FIG. 3 , the electrolyte layer 3 is connected to the first material layer 12 . At this time, in the up-down direction, the projection of the electrolyte layer 3 and the projection of the first material layer 12 do not have the same The overlapping area, or the projection area of the electrolyte layer 3 on the first material layer 12, can further avoid the risk that the height of the solder print exceeds the specification during welding and the risk of piercing the isolation film 8 caused by the burr of the solder print, which can further avoid the interior of the cell 10. The anode pole piece 71 and the cathode pole piece 61 are short-circuited, so that the use safety of the battery cell 10 can be further ensured.

In some embodiments of the present invention, as shown in FIGS. 3 and 5 , the second material layer 13 may be provided with a second groove 131 opposite to the first groove 121 , and the electrolyte layer 3 may be provided in the second groove In the groove 131, or the electrolyte layer 3 partially or completely covers the second groove 131, this arrangement can avoid the electrical connection between the pole piece 1 and other conductive substances, and can avoid the short circuit of the battery cell 10, thereby ensuring the operation of the battery core 10. reliability. Of course, as shown in FIG. 8 , the electrolyte layer 3 may not be provided at the second groove 131 .

In some embodiments of the present invention, as shown in FIG. 3 , the current collector 11 may further be formed with a second empty foil region 5 that is not coated with the second material layer 13 , and the second empty foil region 5 may be provided with an electrolyte layer 3. This setting can make better use of the cathode active material at the bonding place of the original adhesive tape, so as to further improve the volume energy density of the battery cell 10, and can further avoid the welding mark height exceeding the specification and the welding mark during welding. The burrs lead to the risk of piercing the isolation membrane 8 , thereby further avoiding short circuits inside the cells 10 .

In some embodiments of the present invention, the electrolyte layer 3 is connected to the second material layer 13 . At this time, as shown in FIG. 3 , the projection of the electrolyte layer 3 and the projection of the second material layer 13 in the up-down direction do not have the same The overlapping area, or the electrolyte layer 3 has a projection area on the second material layer 13, at this time, in the up-down direction, the projection of the electrolyte layer 3 and the projection of the second material layer 13 have an overlapping area, which can further avoid the welding process. The height of the solder print exceeds the specification and the risk of puncturing the isolation film 8 caused by the burr of the solder print can further avoid the short circuit between the anode electrode 7 and the cathode electrode 6 inside the battery cell 10 , thereby further ensuring the safety of the battery cell 10 .

It should be noted that the thickness of the first material layer 12 and the second material layer 13 can be in the range of 0.1 μm-500 μm. For the material layer on the side of the tab 2, the thickness of the material layer needs to be greater than the thickness of the welded tab 2. On the non-tab 2 side, the thickness of the material layer should be greater than 0.1 μm. The length dimension of the first groove 121 and the second groove 131 are both in the range of 3mm-100mm, and the width dimension of the first groove 121 and the second groove 131 are both in the range of 3mm-100mm.

In some embodiments of the present invention, the electrolyte layer 3 may be a lithium ion solid electrolyte, the ionic conductivity of the electrolyte layer 3 is greater than or equal to 10 ^-5 s/cm, and the material of the electrolyte layer 3 includes crystalline lithium ion solid electrolyte, glass At least one of a solid state electrolyte or an organic polymer solid electrolyte, such arrangement can ensure that the electrolyte layer 3 conducts lithium ions and does not conduct electrons, and can ensure the working reliability of the electrolyte layer 3 . It should be noted that the ionic conductivity test method can be tested by the AC impedance method after the electrolyte is pressed, and the voltage stability window of the cyclic voltammetry test should be greater than or equal to 3.5V vs. Li+.

In some embodiments of the present invention, the crystalline lithium ion solid electrolyte may have at least one of a LISICON (lithium fast ion conductor) structure, a NASICON (sodium fast ion conductor) structure or a perovskite structure, and the glassy solid state The electrolyte may include at least one of oxides or sulfides.

The battery according to the embodiment of the present invention includes a battery cell 10 and a packaging case for accommodating the battery cell 10. The battery cell 10 is the battery cell 10 of any of the above-mentioned embodiments, and the battery cell 10 is arranged in the packaging shell. Replacing the original tape can improve the volume energy density of the battery and improve the safety performance of the battery.

Specifically, when preparing the battery, the above-mentioned cathode pole piece 6, separator 8 and anode pole piece 7 are rolled or stacked according to production requirements, and the separator 8 is used to separate the cathode pole piece 6 and the anode pole piece 7, and the roll The wound or stacked cell 10 is housed in an aluminum-plastic film, and then injected with electrolyte, vacuum-baked and formed into a finished cell 10 , and the cell 10 is processed to obtain a battery.

To sum up, compared with the battery cell 10 in the prior art, the battery cell 10 of the present application uses the electrolyte layer 3 to replace the original adhesive tape, because the electrolyte layer 3 has the properties of conducting lithium ions, non-conducting electrons, high strength, The characteristics of high voltage oxidation resistance, no shrinkage at high temperature, and higher safety can effectively utilize the active material layer where the adhesive tape is attached, which can improve the energy density of the battery cell 10 and improve the safety performance of the battery core 10; in addition, It can also avoid the high requirements of the dimensional accuracy of the glue and the detection of the leakage of glue on the equipment, and improve the production efficiency of the battery.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention. Variations, the scope of the present invention is defined by the claims and their equivalents.

Claims (11)

1. A battery cell, comprising:

the pole piece comprises a current collector, a first substance layer and a second substance layer, wherein the first substance layer is coated on the first surface of the current collector, the second substance layer is coated on the second surface of the current collector, the first surface and the second surface are oppositely arranged, and the first substance layer is provided with a first groove;

the tab is arranged in the first groove and is electrically connected with the current collector; and

and the electrolyte layer is arranged above the lug to prevent the lug from being electrically connected with other conductive substances.

2. The cell of claim 1, wherein the electrolyte layer has a projected area on the first substance layer.

3. The cell of claim 1, wherein the electrolyte layer is disposed on a surface of the tab and has no projected area on the first substance layer.

4. The cell of claim 1, wherein the current collector is further formed with a first empty foil region that is not coated with the first substance layer, the first empty foil region being provided with the electrolyte layer.

5. The electrical core of claim 4, wherein the electrolyte layer is coupled to the first substance layer or has a projected area on the first substance layer.

6. The cell of claim 1, wherein the second material layer is provided with a second groove opposite the first groove, wherein the electrolyte layer is disposed within the second groove, or wherein the electrolyte layer partially or completely covers the second groove.

7. The electrical core of claim 1, wherein the current collector is further formed with a second empty foil region that is not coated with the second layer of material, the second empty foil region being provided with the electrolyte layer.

8. The electrical core of claim 7, wherein the electrolyte layer is connected to the second material layer, or wherein the electrolyte layer has a projected area on the second material layer.

9. The battery cell of claim 1, wherein the ionic conductivity of the electrolyte layer is 10 "5 s/cm or greater, and the material of the electrolyte layer comprises at least one of a crystalline lithium ion solid electrolyte, a glassy solid electrolyte, or an organic polymer solid electrolyte.

10. The cell of claim 9, wherein the crystalline lithium ion solid electrolyte has at least one of an L ISICON structure, an NASICON structure, or a perovskite structure, and the glassy solid electrolyte comprises at least one of an oxide or a sulfide.

11. A battery comprising a cell and a package housing containing the cell, the cell being according to any one of claims 1-10.

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