CN217848038U - Lithium ion battery and power device with same - Google Patents

Abstract

The utility model discloses a lithium ion battery and power device who has it, lithium ion battery includes: the tab comprises an insulating layer and a conductive layer coated on the periphery of the insulating layer; the welding part is connected with the lug; a connection tab connected with the weld and configured as an output of the lithium ion battery. The novel tab structure in the lithium ion battery can be directly welded with the connecting sheet, the qualification rate is high in the welding process, the welding area can be designed according to the requirement of the discharge multiplying power of the battery core, the welding effect of the novel tab and the connecting sheet is improved, the contact internal resistance of the lithium ion battery is reduced, the temperature rise of the lithium ion battery is reduced, and the reliability of the lithium ion battery is improved.

Description

Lithium ion battery and power device with same

Technical Field

The utility model belongs to the technical field of the battery technique and specifically relates to a lithium ion battery and have its power device is related to.

Background

Lithium batteries have been widely used due to their advantages of high energy density, long cycle performance, high discharge rate, and the like. However, the current collector of the conventional lithium ion battery generally employs a metal aluminum foil for the positive electrode, and a metal copper foil for the negative electrode, but once a short circuit occurs inside the battery, the current cannot be cut off, and finally heat accumulation and thermal runaway are caused. Since the safety issues caused by thermal runaway are evident, in recent years, researchers have replaced conventional metal current collectors with a new class of current collectors. The novel current collector generally adopts a non-conductive polymer film as a substrate, and a layer of metal is plated on two sides of the substrate in a vacuum evaporation mode, an electroplating mode and the like. For example, a positive electrode current collector is formed by plating aluminum on both sides of a PET (polyethylene terephthalate) film, and a negative electrode current collector is formed by plating copper on both sides of a PP (polypropylene ester) film. These novel current collectors can improve the energy density and safety of the battery to some extent. However, these novel current collectors also have some problems in the welding process, and because the polymer film is adopted in the middle of the novel current collector, the insulating layer formed by the polymer film can not conduct the metal coatings on the two sides, so that the traditional welding mode is not suitable any more. The present application is directed to a lithium ion battery to solve the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, an object of the present invention is to provide a lithium ion battery. The novel tab structure in the lithium ion battery can be directly welded with the connecting sheet, the qualification rate is high in the welding process, the welding area can be designed according to the requirement of the discharge multiplying power of the battery core, the welding effect of the novel tab and the connecting sheet is improved, the contact internal resistance of the lithium ion battery is reduced, the temperature rise of the lithium ion battery is reduced, and the reliability of the lithium ion battery is improved.

The utility model also provides a power device with lithium ion battery.

The lithium ion battery comprises a pole lug, wherein the pole lug comprises an insulating layer and a conductive layer coated on the periphery of the insulating layer; the welding part is connected with the lug; a connection tab connected with the weld and configured as an output of the lithium ion battery.

The utility model relates to a lithium ion battery is provided with the weld part on the utmost point ear, and connection piece accessible weld part is connected with utmost point ear, need not to weld on utmost point ear, and the qualification rate is high in the welding process to can discharge multiplying power demand design welding area according to electric core, not only improve the welding effect of novel utmost point ear and connection piece, reduce lithium ion battery's contact internal resistance. The energy transmission is fast in the welding process, the temperature rise of the lithium ion battery can be effectively reduced, and the reliability of the lithium ion battery is improved.

According to some embodiments of the present invention, the welding part includes a first welding part and a second welding part, and the first welding part and the second welding part are disposed at intervals on both sides of the tab along the first direction; and connecting support legs are arranged on the connecting pieces along two sides of the first direction and are connected with the corresponding welding part I or welding part II.

According to the utility model discloses a some embodiments, be formed with welding area on the welding part in order to be suitable for with the connection piece with welding part connection.

According to some embodiments of the invention, the connecting piece further comprises: a body part disposed at one side of the connection leg in a second direction to configure an output terminal of the lithium ion battery; a transition region disposed between the connection leg and the body portion, the transition region including a conductive portion to electrically connect the body portion and the connection leg.

According to the utility model discloses a some embodiments, the conductive part includes a plurality of edges the conducting strip that first direction interval was arranged, adjacent two be formed with the via hole between the conducting strip.

According to some embodiments of the invention, the transition region further comprises an insulating portion, the insulating portion coating the periphery of the conductive portion.

According to some embodiments of the present invention, the length of the body portion along the first direction is a, the length of the connection leg along the first direction is B, and a is equal to or greater than B; the length of the conducting strip along the first direction is C, and B is larger than C.

According to the utility model discloses a some embodiments, the via hole is followed the length of first direction is D, and satisfies 2D and is less than or equal to B and is less than or equal to 0.5A.

According to some embodiments of the invention, the connecting sheet includes a plurality of connecting layers laminated to each other in a thickness direction.

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.

Drawings

The above and/or additional aspects and advantages of the present invention 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 lithium ion battery according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a lithium ion battery according to another embodiment of the present invention;

FIG. 3 is a schematic structural view of a connecting sheet according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of the transition region of FIG. 3;

FIG. 5 is a cross-sectional view taken along PP' of FIG. 4.

Reference numerals:

1000: a lithium ion battery; 1100: a tab; 1410: an insulating layer; 1420: a conductive layer; 1430: coating; 1300: connecting sheets; 1210: welding one part; 1220: welding the second part; 1310: connecting support legs; 1230: a welding zone; 1320: a transition zone; 1322: a conductive portion; 1321: an insulating section; 1330: a body portion; 1400: a positive plate; 1500: a diaphragm; 1600: and a negative plate.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like 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 drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

As mentioned above, the polymer film is used in the middle of the novel current collector, and the insulating layer formed by the polymer film makes the metal coatings on the two sides unable to be conducted, so that the traditional welding mode is no longer applicable. Particularly, the tab welding mode is mainly ultrasonic welding or laser welding, but the laser welding temperature is too high, so that metal shrinkage deformation on two sides of the insulating layer is easily caused, and the defective rate is high. When the conventional ultrasonic welding is adopted, the structural pressure of a welding machine is insufficient in the welding process, the difference between the material property of the lug and the material property of a novel current collector is large, welding energy is absorbed by a polymer layer in the welding process, the cold joint phenomenon occurs, the alternating current internal resistance of the battery cell is 20% -30% higher than that of the conventional battery cell, the conductivity is poor, the charging and discharging temperature rise rate is high, and the battery cell cannot meet the requirement of high-rate discharge.

A lithium ion battery 1000 according to an embodiment of the present invention is described below with reference to fig. 1-5.

According to the utility model discloses lithium ion battery 1000, referring to fig. 1 and fig. 2, this lithium ion battery 1000 includes utmost point ear 1100, weld part and connection piece 1300.

The tab 1100 includes an insulating layer 1410, the insulating layer 1410 may be a polymer thin film, and a conductive layer 1420 covers the periphery of the insulating layer 1410, and the material forming the conductive layer 1420 includes but is not limited to at least one of aluminum, copper, nickel, titanium, silver, stainless steel, nickel-copper alloy, and aluminum-zirconium alloy.

The welding part is connected to the tab 1100 for welding the tab 1100 to other structures, and particularly, the welding part may be a structure in which the conductive layer 1420 of the tab 1100 itself is extended.

The connection tab 1300 is connected to the welding portion and configured as an output terminal of the lithium ion battery 1000.

The utility model relates to a lithium ion battery 1000 is provided with the weld part on utmost point ear 1100, and connection piece 1300 accessible weld part is connected with utmost point ear 1100, need not to weld on utmost point ear 1100, and the qualification rate is high in the welding process to can discharge multiplying power demand design welding area according to electric core, not only improved novel utmost point ear 1100 and connection piece 1300's welding effect, reduced lithium ion battery 1000's internal resistance of contact. The energy transmission is fast in the welding process, the temperature rise of the lithium ion battery 1000 can be effectively reduced, and the reliability of the lithium ion battery 1000 is improved.

According to some embodiments of the present invention, referring to fig. 1, the lithium ion battery 1000 further comprises a positive plate 1400, a separator 1500, and a negative plate 1600.

According to some embodiments of the present invention, referring to fig. 2, the positive plate 1400 includes an insulating layer 1410 and a conductive layer 1420 coated on the periphery of the insulating layer 1410, the one layer of the conductive layer 1420 departing from the insulating layer 1410 is provided with a coating 1430, and the two sides of the tab 1100 of the positive plate 1400 are provided with a welding portion and welded with the connection plate 1300.

According to some embodiments of the present invention, referring to fig. 1 and 3, the welding portion may include one welding portion 1210 and two welding portions 1220, the one welding portion 1210 and the two welding portions 1220 are disposed at intervals on both sides of the tab 1100 along the first direction, the connection piece 1300 is provided with the connection support pin 1310 along both sides of the first direction, and the connection support pin 1310 is connected with the corresponding one welding portion 1210 or two welding portions 1220. Specifically, the first welding part 1210 and the second welding part 1220 can be respectively disposed on two sides of the tab 1100 in the width direction, the connecting plate 1300 is correspondingly provided with two connecting support legs 1310 on two sides of the tab 1100 in the width direction, and the two connecting support legs 1310 are respectively welded with the first welding part 1210 and the second welding part 1220, so that the tab 1100 and the connecting plate 1300 can be welded on two sides of the tab 1100 in the width direction, and the welding on the top of the tab 1100 is avoided, thereby saving the space of the lithium ion battery 1000 and improving the energy density of the lithium ion battery 1000.

According to some embodiments of the invention, with reference to fig. 1, a welding zone 1230 is formed on the welding portion suitable for connecting the connection piece 1300 with the welding portion. The size of the welding area 1230 can be designed according to the discharge rate requirement of the battery cell, and the larger the discharge rate of the battery cell is, the larger the area of the welding area 1230 is.

According to some embodiments of the present invention, referring to fig. 3, the connection sheet 1300 may further include a body portion 1330 and a transition region 1320, the body portion 1330 is disposed at one side of the connection leg 1310 along the second direction to configure an output end of the lithium ion battery 1000, the transition region 1320 is disposed between the connection leg 1310 and the body portion 1330, and the transition region 1320 includes a conductive portion 1322 to electrically connect the body portion 1330 and the connection leg 1310. Specifically, the connection leg 1310 is disposed inside the battery cell, the connection plate 1300 is connected to the tab 1100 through the connection leg 1310, the body 1330 is exposed outside the battery, and the transition region 1320 is disposed between the connection leg 1310 and the body 1330, so that the connection leg 1310 is electrically connected to the body 1330 for electrical conduction. According to some embodiments of the present invention, the conductive portion 1322 may be a metal sheet, and the metal may be at least one selected from aluminum, copper, nickel, titanium, silver, stainless steel, nickel-copper alloy, and aluminum-zirconium alloy.

According to some embodiments of the present invention, the body 1330 of the connecting sheet 1300, the conductive portion 1322 of the transition region 1320, and the connecting leg 1310 may be formed in a single-step stamping process or may be welded to each other to form the connecting sheet 1300.

According to some embodiments of the present invention, the structure of the conductive portions 1322 is not particularly limited as long as the body portion 1330 and the connection legs 1310 are electrically connected, and particularly, the conductive portions 1322 may include a plurality of conductive sheets arranged at intervals along the first direction. Therefore, when the discharge current is too large, the highest temperature that the transition region can endure is low, so that the metal in the transition region 1320 can be melted, and the current between the connection leg 1310 and the body 1330 can be disconnected, thereby further protecting the battery.

According to some embodiments of the present invention, referring to fig. 3-5, in order to prevent the risk of electric shock from occurring when a person touches the conductive portion 1322 of the transition region 1320, the transition region 1320 further includes an insulating portion 1321, and the insulating portion 1321 covers the periphery of the conductive portion 1322. Specifically, since the via holes are formed between the conductive sheets, the insulating portion 1321 may fill the via holes and wrap the outer peripheries of the conductive sheets. According to some embodiments of the present invention, the insulating portion 1321 may be a plastic material, and the selection of the plastic material is not particularly limited, including but not limited to at least one of poly (terephthalate), polyamide, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, poly (paraphenylene terephthalamide), polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl formal, polyvinyl butyral, polyurethane, polyacrylonitrile, polyvinyl acetate, polyoxymethylene, phenol resin, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber, polycarbonate, polysulfone, polyethersulfone, polyphenylene oxide. It should be noted that the metal sheet and the plastic material in the transition region may be formed into an integral structure by injection molding, or the plastic material may be bonded to the metal sheet by coating a glue layer on the surface of the metal sheet, and then the metal sheet is rolled to a desired thickness.

According to some embodiments of the present invention, referring to fig. 3, the body 1330 is a along the length of the first direction, the connection leg 1310 is B along the length of the first direction, and satisfies that a is not less than B, the conductive sheet is C along the length of the first direction, and satisfies that B is greater than C. According to other embodiments of the present invention, 2C is not less than B and not more than 0.5A. Specifically, the length a of the body 1330 along the first direction is 10 to 60mm, the length B of the connection leg 1310 along the first direction is 10 to 30mm, and the length C of the conductive sheet along the first direction is 1 to 10mm.

According to other embodiments of the present invention, the thickness of the body portion 1330, the transition region 1320, and the connection leg 1310 are each independently 0.1-5 mm.

According to some embodiments of the present invention, referring to FIG. 3, the length of the transition region along the second direction is E, and E satisfies 1mm ≦ E ≦ 10mm, the length of the connection leg 1310 along the second direction is F, and F satisfies 10mm ≦ E ≦ 30mm.

According to some embodiments of the present invention, the connecting sheet 1300 may be a whole, and may include a plurality of connecting layers stacked on each other in the thickness direction, and the connecting sheets 1300 may be formed by welding the plurality of connecting layers.

To sum up, the utility model relates to a lithium ion battery 1000 has following advantage:

(1) The tab 1100 and the connecting sheet 1300 can be welded in a conventional ultrasonic welding mode, and the qualification rate is high in the welding process;

(2) The welding area can be designed according to the discharge multiplying power requirement of the battery cell;

(3) The contact internal resistance of the lithium ion battery 1000 is reduced, the heating rate of the lithium ion battery 1000 in the welding process is reduced, and the reliability and the safety of the lithium ion battery 1000 are improved;

(4) The stacking height of the lithium ion battery 1000 in the second direction is reduced, the space utilization rate of the lithium ion battery 1000 in the first direction is increased, and the energy density of the lithium ion battery 1000 is further improved.

The utility model also provides a power device of having above-mentioned lithium ion battery 1000. The tab 1100 and the connecting sheet of the power device can be welded in a conventional ultrasonic welding mode, the battery is low in heating rate and high in safety in the welding process, and meanwhile, the welding area is adjustable, so that the requirement of high-rate discharge can be met.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean 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 present invention. 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 invention 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 invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A lithium ion battery, comprising:

the tab comprises an insulating layer and a conducting layer coated on the periphery of the insulating layer;

the welding part is connected with the lug;

a connection tab connected with the weld and configured as an output of the lithium ion battery.

2. The lithium ion battery of claim 1, wherein the weld comprises a first weld portion and a second weld portion, the first weld portion and the second weld portion being spaced apart on opposite sides of the tab in the first direction;

and connecting support legs are arranged on the two sides of the connecting sheet along the first direction and are connected with the corresponding welding part I or welding part II.

3. The lithium ion battery of claim 2, wherein the weld is formed with a weld area adapted to connect the tab to the weld.

4. The lithium ion battery of claim 3, wherein the tab further comprises:

a body part disposed at one side of the connection leg in a second direction to configure an output terminal of the lithium ion battery;

a transition region disposed between the connection leg and the body portion, the transition region including a conductive portion to electrically connect the body portion and the connection leg.

5. The lithium ion battery of claim 4, wherein the conductive portion comprises a plurality of conductive sheets arranged at intervals along the first direction, and a via hole is formed between two adjacent conductive sheets.

6. The lithium ion battery of claim 5, wherein the transition region further comprises an insulating portion that wraps around an outer perimeter of the conductive portion.

7. The lithium ion battery of claim 6, wherein the length of the body portion along the first direction is A, the length of the connection leg along the first direction is B, and A ≧ B is satisfied;

the length of the conducting strip along the first direction is C, and B is larger than C.

8. The lithium ion battery of claim 7, wherein the via has a length D along the first direction, and satisfies 2D ≦ B ≦ 0.5A.

9. The lithium ion battery according to claim 1, wherein the connection tab comprises a plurality of connection layers laminated to each other in a thickness direction.

10. A power plant comprising the lithium ion battery according to any one of claims 1 to 9.

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