CN115663404A

CN115663404A - Battery core and battery

Info

Publication number: CN115663404A
Application number: CN202211259776.6A
Authority: CN
Inventors: 王浩; 李枝贤; 龚祖祯; 李明
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2018-01-22
Filing date: 2018-01-22
Publication date: 2023-01-31
Also published as: CN110071320A

Abstract

The application discloses electricity core and have its battery. The battery cell comprises a first pole piece, a diaphragm and a first bonding piece. The first pole piece comprises a first area, the first area is not coated with a first active substance, the first area is located on the inner side of the outermost ring of the battery cell, the first bonding piece is arranged between the first area and the diaphragm, and the first bonding piece is bonded with the first area and the diaphragm. According to the battery cell, the first pole piece and the diaphragm can be bonded together by the first bonding piece, so that the battery cell is prevented from moving relatively when being subjected to external force, the probability of tearing the first pole piece is effectively reduced, the first pole piece is protected, and the battery cell is prevented from being damaged or short-circuited due to the fact that the first pole piece is torn.

Description

Battery cell and battery

The application is a divisional application of an original invention patent application (the application date is 2018, 01, month and 22, the application number is 201810060923.4, and the invention and creation name is 'cell and battery').

Technical Field

The application relates to the technical field of electrochemical devices, in particular to a battery cell and a battery with the battery cell.

Background

Due to its mobility, batteries are widely used in various portable devices, such as mobile phones, notebooks, power tools, electric vehicles, and the like. Among the performances of batteries, safety performance is increasingly receiving attention. If the safety performance of the battery cannot be guaranteed, the battery can be subjected to accidents with large harmfulness, such as combustion, explosion and the like. The battery falls or receives the process of external force striking, and the outer lane mass flow body of the inside electric core of battery takes place easily to tear, damage such as fold, and the mass flow body can produce burr or closed angle to can cause the short circuit danger.

Disclosure of Invention

The application provides an electricity core, electricity core has simple structure, advantage that the security performance is good

The application also provides a battery, which is provided with the battery core.

According to this application embodiment's electric core includes: a first pole piece comprising a first region, the first region not coated with a first active material, the first region located inside an outermost circle of the cell; a diaphragm; and a first adhesive member disposed between the first region and the diaphragm, the first adhesive member being adhered to the first region and the diaphragm.

According to electric core of this application embodiment, through set up first bonding piece in the first region of first pole piece, can utilize first bonding piece to bond first pole piece and diaphragm together, prevent that electric core from receiving external force (for example falling or striking), avoid taking place relative movement between first pole piece and the diaphragm to can reduce first pole piece effectively and take place tearing probability, and then can protect first pole piece effectively, prevent to tear because of first pole piece and lead to electric core impaired or short circuit.

In some embodiments, the cell further comprises a second pole piece, the membrane being disposed between the first pole piece and the second pole piece.

In some embodiments, the first pole piece is a cathode pole piece and the second pole piece is an anode pole piece.

In some embodiments, the second pole piece comprises a second region, the second region being uncoated with a second active, the first region and the second region being directly opposite.

In some embodiments, the first pole piece further includes a third region located outside of an outermost circle of the cell; the battery cell further comprises a second bonding piece, and the second bonding piece is bonded with the third area.

In some embodiments, the first adhesive is completely non-overlapping with the second adhesive.

In some embodiments, the first adhesive at least partially overlaps the second adhesive.

In some embodiments, the first adhesive completely overlaps the second adhesive.

In some embodiments, the length of the first adhesive is greater than or equal to the length of the second adhesive along the winding direction of the first pole piece.

In some embodiments, the width of the first adhesive is greater than the width of the second adhesive in the width direction of the first pole piece.

In some embodiments, the first adhesive and the second adhesive are each selected from glue, tape, or double sided tape.

In some embodiments, the first pole piece further comprises a fourth region, the fourth region being uncoated with the first active, the fourth region being directly opposite the first region.

In some embodiments, the first adhesive member has a length of 10-12mm.

In some embodiments, the first adhesive has a width of 84-86mm.

The battery comprises a packaging shell and the battery core, wherein the battery core is arranged in the packaging shell.

According to the battery of the embodiment of the application, the first bonding piece is arranged in the first area of the first pole piece, the first area of the first pole piece can be bonded with the diaphragm by the first bonding piece, and the impact force, which is received by the first area of the first pole piece, can be relieved when the battery cell is subjected to external force (such as falling or impact), so that the probability of tearing of the first pole piece can be effectively reduced, the first pole piece can be effectively protected, and the damage or short circuit of the battery cell caused by the tearing of the first pole piece is prevented. In addition, the first area of the first pole piece and the diaphragm are prevented from moving relatively, the diaphragm is prevented from shrinking, and therefore the electric core is prevented from being short-circuited.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a battery cell according to an embodiment of the present application, wherein a first region is provided with a first adhesive layer;

fig. 2 is a front view of a first pole piece of the cell of fig. 1;

FIG. 3 is a bottom view of the first pole piece of FIG. 2;

fig. 4 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

fig. 5 is a partially enlarged schematic view of the cell in fig. 4;

fig. 6 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

fig. 7 is a partially enlarged schematic view of the cell in fig. 6;

FIG. 8 is a front view of the first pole piece of FIGS. 4 and 6;

FIG. 9 is a top view of the first pole piece of FIG. 8;

fig. 10 to 13 are schematic views of the positional relationship between the first adhesive member 130 and the second adhesive member 114.

Reference numerals:

the thickness of the battery cell 100, the uncoated region 150,

a first pole piece 110, a first region 111, a first active material 112, a third region 113, a second adhesive member 114, a fourth region 115,

the diaphragm 120 is provided with a diaphragm portion,

the first adhesive member 130 is formed of a first adhesive material,

a second pole piece 140, a second region 141, and a second active material 142.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

A battery cell 100 according to an embodiment of the present application is described below with reference to fig. 1 to 7, and includes a first pole piece 110, a diaphragm 120, and a first adhesive 130.

Specifically, as shown in fig. 1 to 3, the first pole piece 110 may include a first region 111, the first region 111 is not coated with the first active material 112, the first region 111 is located inside an outermost circle of the battery cell 100, the first adhesive 130 is disposed between the first region 111 and the separator 120, and the first adhesive 130 is adhered to the first region 111 and the separator 120.

According to the battery cell 100 of the embodiment of the application, the first adhesive member 130 is disposed in the first region 111 of the first pole piece 110, the first pole piece 110 and the diaphragm 120 can be adhered together by using the first adhesive member 130, and the impact force on the first region 111 of the first pole piece 110 can be relieved, so that the probability that the first pole piece 110 is torn at the first region 111 can be effectively reduced. If the first pole piece 110 is torn in the first region 111, a burr may be generated, and the burr may puncture the separator and contact with the second pole piece 140 to cause a short circuit, and when the battery cell 100 falls or is impacted by an external force, a current collector at the tail of the first pole piece 110, which is not coated with an active material, may wrinkle to generate a sharp corner, and there is also a risk of contact with the second pole piece 140 to cause a short circuit. Therefore, in the present embodiment, the first adhesive member 130 is disposed in the first region 111, so as to effectively protect the first pole piece 110 and prevent the first pole piece 110 from being torn to damage or short circuit the battery 100. In addition, the first area 111 of the first pole piece 110 is prevented from moving relative to the diaphragm, and the diaphragm is prevented from contracting, so that the battery core 100 is prevented from being short-circuited. It should be understood that the positions of the first pole piece 110 inside the trailing end where the first active material 112 is not coated are the first regions 111, and the first adhesive member 130 may be disposed at any position of the first regions 111. The first adhesive 130 may be smaller than the length of the first region 111 or equal to the length of the first region 111 along the winding direction of the first pole piece 110.

According to some embodiments of the present application, as shown in fig. 1 to 3, the battery cell 100 may further include a second pole piece 140, and the separator 120 is disposed between the first pole piece 110 and the second pole piece 140. It is noted that the separator 120 may be an insulating member that may space the first and

second pole pieces

110 and 140 apart to prevent a short circuit caused by contact of the first and

second pole pieces

110 and 140.

Further, the first pole piece 110 may be a cathode pole piece and the second pole piece 140 may be an anode pole piece. Further, the first pole piece 110 may be a pole piece made of aluminum foil (AL foil) on which the first active material 112 is disposed as a current collector, and the second pole piece 140 may be a pole piece made of copper foil (CU foil) on which the second active material 142 is disposed as a current collector. The first active material may be lithium iron phosphate, lithium cobaltate, or lithium manganate, and the second active material may be graphite or the like.

As shown in fig. 2 and 3, in this embodiment, the first pole piece 110 is wound up from one end of the first pole piece 110 and wound to the other end of the first pole piece 110 in the winding direction of the first pole piece 110, i.e., the direction indicated by the arrow a. The first pole piece 110 includes a tail portion of the active material-uncoated current collector, the tail portion current collector includes a first region 111, and the first adhesive member 130 is disposed in the first region 111. It should be noted that the first adhesive member 130 may be adhered to the first region 111 before winding, or the first adhesive member 130 may be adhered to the first region 111 after winding.

As shown in fig. 4, in this embodiment, the second pole piece 140 may include a second region 141, the second region 141 being not coated with the second active material 142, the first region 111 and the second region 141 being opposite, that is, the outermost region of the battery cell 100 includes an uncoated region 150, and the uncoated region 150 is formed by the first region 111, the separator 120, and the second region 141. Since the first region 111 and the second region 141 belong to pole pieces with different polarities, it is assumed that the battery cell 100 is punctured from the uncoated region 150 in a relatively safe short circuit manner, and therefore, due to the presence of the uncoated region 150 in this embodiment, the safety performance of the battery cell 100 is enhanced. Of course, the battery cell 100 may have an uncoated region 150 at the center in addition to the outermost uncoated region 150.

As shown in fig. 4 and 6, in these embodiments, the first pole piece 110 may further include a third region 113. The third region 113 is located outside the outermost circle of the battery cell 100, that is, the first region 113 is located on the back of the first region 111. The battery cell 100 may further include a second adhesive member 114, and the second adhesive member 114 is adhered to the third region 113. It should be noted that the second adhesive member 114 may be used to adhere the battery core 100 to a package cover (not shown) of a battery, and adhere the battery core 100 to the package cover, so as to prevent relative movement between the battery core 100 and the package cover. Because the first region 111 is bonded to the diaphragm 120 through the first bonding member 130, when the battery cell 100 is subjected to an external force, the first bonding member 130 located in the first region 111 generates a force F1 to the first pole piece 110, and the second bonding member 114 located in the third region generates a force F2 to the first pole piece 110, where the two forces are opposite in direction, and at least a part of the force F1 and the force F2 may cancel each other out, so that the probability that the first pole piece 110 is torn due to an excessively large local force can be reduced, and the safety performance of the battery cell 100 is effectively improved.

Fig. 5 is a partial enlarged view of fig. 4, and as shown in fig. 5, the first region 111 is the inner side surface of the tail current collector of the first pole piece 110, and the third region 113 is the outer side surface of the tail current collector of the first pole piece 110.

As shown in fig. 6, in this embodiment, the first pole piece 110 may further include a fourth region 115, the fourth region 115 is not coated with the first active material 112, and the fourth region 115 is opposite to the first region 111, i.e., the fourth region 115 is located outside the penultimate turn of the first pole piece 110. That is, the outer side of the battery cell 100 includes an uncoated region 150, and the uncoated region 150 is formed of the first region 111, the separator 120, and the fourth region 115. When the first pole piece 110 is wound along the winding direction of the first pole piece 110 (the direction indicated by the arrow a in fig. 8), the fourth region is wound first, and then the first region 111 is wound, the fourth region 115 is located at the inner circle of the first region 111, and the fourth region 115 is opposite to the first region 111. Fig. 7 is a partially enlarged view of fig. 6, and as can be seen from fig. 7, the fourth region 115 is a region of the first pole piece 110 and is an outer surface of the current collector located at an inner ring of the first region 111.

As shown in fig. 8 and 9, in this embodiment, the first adhesive member 130 is wound up from one end of the first pole piece 110 to the other end of the first pole piece 110 along the winding direction of the first pole piece 110, i.e. the direction of arrow a, and the length of the first adhesive member 130 is equal to or greater than the length of the second adhesive member 114. As shown in fig. 8, the longitudinal direction of the first adhesive member 130 is a longitudinal dimension in a c-c direction as shown in fig. 8 and 9, i.e., a dimension along the winding direction of the first pole piece 110. Therefore, the first pole piece 110 can be further protected, and the first pole piece 110 is prevented from being torn due to uneven stress. Experiments prove that when the length of the first adhesive member 130 is 10-12mm, the first pole piece 110 can be better protected.

As shown in fig. 8, in this embodiment, the width of the first adhesive member 130 is greater than the width of the second adhesive member 114 in the width direction (b-b direction shown in fig. 9) of the first pole piece 110. Therefore, the first pole piece 110 can be further protected, and the first pole piece 110 is prevented from being torn due to uneven stress. Experiments prove that when the width of the first adhesive member 130 is 84-86mm, the first pole piece 110 can be better protected.

According to some embodiments of the present application, the first adhesive member 130 may be selected from glue, tape, or double-sided tape. In one aspect, the membrane 120 and the first pole piece 110 may be bonded together with a first adhesive 130 and the first pole piece 110 and other components (e.g., a package) may be bonded together with a second adhesive 114. On the other hand, the production process can be simplified, and the production cost can be saved. According to some embodiments of the present application, the second adhesive member 114 may be selected from glue, tape, or double-sided tape.

The battery according to the embodiment of the present application includes a package case and the battery cell 100 as described above, and the battery cell 100 is disposed in the package case. In the package, the battery cell 100 may be bonded to the package through the second adhesive member 114, or may not be bonded to the package.

In some embodiments, the first adhesive member 130 may be a double-sided tape, a hot melt adhesive, or other similar functional adhesive paper, coating; in some embodiments, the second adhesive member 114 may be double-sided tape, hot melt adhesive, or other similarly functioning adhesive paper, coating.

In some embodiments, the number of double-sided adhesive tape, hot melt adhesive, or other adhesive paper or coating with similar functions is not limited, and the shape may be rectangular, square, or other shapes.

In some embodiments, the cell may be applied in a wound structure of a lithium ion battery, and may also be applied in a laminated structure.

In some embodiments, the first adhesive 130 and the second adhesive 114 have a thickness between 1u and 100 u.

In some embodiments, the double-sided adhesive tape, the hot melt adhesive, or other adhesive paper or coating with similar functions may cover the blank aluminum foil or copper foil completely or partially.

As shown in fig. 4 and 6, the first adhesive member 130 and the second adhesive member 114 have the same length and width, and are completely overlapped. As shown in fig. 10 to 12, the first adhesive member 130 and the second adhesive member 114 may be partially overlapped.

As shown in fig. 13, the first adhesive member 130 and the second adhesive member 114 may not overlap with each other at all. Example (b):

the lithium ion battery with model number of 495196 is manufactured by taking commercially produced lithium cobaltate, graphite, electrolyte, diaphragm and packaging shell as raw materials and adopting a conventional winding structure, and the capacity of the battery is 4000mAh.

The experimental protocol was as follows:

control group a: the outermost circle of the battery cell is a first pole piece 110, the tail end of the first pole piece 110 is a current collector which is not coated with the first active material 112, the first region 111 of the first pole piece 110 is not provided with the first bonding member 130 (for example, a double-sided tape), and the third region 113 is not provided with the second bonding member 114 (for example, a double-sided tape).

Comparative group B: the first region 111 of the first pole piece 110 is not provided with the first adhesive member 130 (e.g., double-sided tape), the third region 113 is provided with the second adhesive member 114 (e.g., double-sided tape), and the rest are the same as the group a.

Experimental group C: the first region 111 of the first pole piece 110 is provided with a first adhesive member 130 (e.g., double-sided tape), the third region 113 is provided with a second adhesive member 114 (e.g., double-sided tape), and the rest are the same as the group a of the comparison group.

Experimental group D: the first region 111 of the first pole piece 110 is provided with the first adhesive member 130 (e.g., double-sided tape), and the third region 113 is not provided with the second adhesive member 114 (e.g., double-sided tape), which are otherwise the same as the group a of the comparative group.

The four ABCD groups of batteries are subjected to the following drop test respectively:

the drop test conditions were: height: 1.5m;

dropping sequence: the 6 faces and the 4 angles are 1 wheel;

total 6 falls (60 times);

the battery core after falling is disassembled, and the battery core of the group A can freely move in a packaging shell because no double-sided adhesive exists, the top and the tail of the cathode and anode pole pieces are seriously deformed due to impact, and the outermost diaphragm has a contraction phenomenon.

In the battery core of the B group, because the double faced adhesive tape is pasted on the outer layer of the AL foil, an acting force exists between the battery core and the packaging shell, the top and the bottom of the pole piece have no problem of deformation and damage of the pole piece caused by impact, but the empty AL foil has an obvious tearing phenomenon.

In the group C, because the inner side and the outer side of the AL foil are both provided with the double faced adhesive tapes, in the falling process, the double faced adhesive tapes on the outer sides inhibit the free movement of the battery cell in the packaging shell, and the top and the tail of the pole piece have no deformation phenomenon caused by impact; the double-sided adhesive tape on the inner side of the Al foil enables the Al foil and the diaphragm of the inner layer to be tightly bonded together, and the diaphragm has certain toughness, so that the Al foil of the battery cell in the group C does not tear or shrink.

The battery core of the group D has no double-sided adhesive on the outer layer, so that the Al foil is not torn, and the diaphragm is adhered to the empty Al foil due to the double-sided adhesive on the inner side of the Al foil, so that the diaphragm shrinkage phenomenon is avoided.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above 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.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A cell, comprising:

a first pole piece comprising a first region, the first region not coated with a first active material, the first region located inside an outermost circle of the cell;

a diaphragm;

a first adhesive member disposed between the first region and the diaphragm, the first adhesive member being adhered to the first region and the diaphragm, respectively;

the first pole piece further comprises a third area, and the third area is located on the outer side of the outermost ring of the battery cell;

the battery core further comprises a second bonding piece, and the second bonding piece is bonded with the third area and a packaging shell of the battery respectively;

the first bonding piece and the second bonding piece are respectively arranged on two surfaces of a current collector of the outermost ring of the battery core and are opposite in position, and the first bonding piece and/or the second bonding piece are/is selected from double-sided adhesive tape.

2. The cell of claim 1, further comprising a second pole piece, the membrane being disposed between the first pole piece and the second pole piece.

3. The cell of claim 2, wherein the first pole piece is a cathode pole piece and the second pole piece is an anode pole piece.

4. The cell of claim 2, wherein the second pole piece comprises a second region, the second region being uncoated with a second active, the first region and the second region being opposite, the cell comprising an uncoated region formed by the first region, the separator, and the second region.

5. The cell of claim 1, wherein the first adhesive and the second adhesive are completely non-overlapping.

6. The battery cell of claim 1, wherein the first adhesive at least partially overlaps the second adhesive.

7. The cell of claim 1, wherein the first adhesive completely overlaps the second adhesive.

8. The cell of claim 1, wherein, in a winding direction of the first pole piece, a length of the first adhesive member is greater than or equal to a length of the second adhesive member.

9. The battery cell of claim 1, wherein a width of the first adhesive is greater than or equal to a width of the second adhesive in a width direction of the first pole piece.

10. The electrical core of claim 1, wherein the first pole piece further comprises a fourth region, the fourth region being uncoated with the first active material, the fourth region being opposite the first region.

11. The cell of claim 1, wherein the first bonding member has a length of 10-12mm.

12. The cell of claim 1, wherein the first bonding member has a width of 84-86mm.

13. A battery comprising a package and the cell of any of claims 1-12 disposed within the package.