CN202150519U - Lithium ion secondary battery without polar ears - Google Patents

Abstract

The utility model relates to an electrodeless lithium ion secondary battery, which comprises an electrode core formed by sequentially stacking and winding a positive electrode, a diaphragm, and a negative electrode, a battery case and a battery cover, the electrode core is put into the battery case, and the battery case It is filled with non-aqueous electrolyte solution and sealed by the battery cover. The positive and negative terminal surfaces of the electrode core are provided with exposed metal current collector substrates, and the positive electrode collectors are respectively arranged between the positive terminal surface and the battery cover. Drainage with the negative collector located between the negative terminal surface and the bottom of the battery case. The electrodeless lithium-ion secondary battery described in the utility model has the characteristics of low internal resistance and long cycle life, and is especially suitable for large-capacity lithium-ion batteries that require high-current and high-power work.

Description

A lithium-ion secondary battery without tabs

technical field

The utility model relates to a lithium-ion secondary battery, typically a lithium-ion battery represented by a circular shape, and focuses on its internal structure, in particular to a lithium-ion secondary battery without tabs. the

Background technique

In recent years, with the rapid development of electric tools, electric toys, electric bicycles, hybrid electric vehicles, pure electric vehicles, etc., higher and higher requirements have been put forward for the high-power discharge capacity of batteries. Due to the advantages of good high-power working performance, high energy density and lightness, power lithium-ion batteries are gradually being applied to the above fields. the

FIG. 1 is a schematic structural diagram of a wound pole group in the prior art, as shown in the figure. The positive electrode sheet 1 contains positive active materials on both sides of the aluminum foil substrate, and there is at least one aluminum tab 2 on the aluminum foil; the negative electrode sheet 3 contains negative active materials on both sides of the copper foil substrate, and there is at least one negative electrode on the copper foil. The tab 4; the positive electrode, the separator, and the negative electrode are stacked in sequence, the positive electrode and the negative electrode are completely wrapped by the separator 5, and the positive electrode is completely wrapped by the negative electrode. the

FIG. 2 is a schematic structural diagram of a lithium-ion secondary battery in the prior art, as shown in the figure. The pole core shown in Figure 1 is rolled and wound into the battery case 6, the negative electrode tab 4 protrudes from the diaphragm 5, and is in contact with or welded to the bottom of the battery case, and the positive electrode aluminum tab 2 extends Out of the diaphragm 5, contact or weld with the battery cover. the

After the electrode core is dried and dehumidified, it is injected with a non-aqueous electrolyte solution, and after processes such as sealing, formation, and volume separation, a lithium-ion battery is produced. the

It can be seen from this that the electrode core of the lithium-ion secondary battery without tabs is sequentially stacked by the positive electrode, the diaphragm, and the negative electrode, and is wound into a cylindrical-like pole core, wherein the positive electrode sheet and the negative electrode sheet are provided with tabs for current flow. lead out. However, with the increase of battery capacity, the length of the pole piece increases rapidly. In order to meet the requirements of high-power work, it is necessary to increase the number of tabs. The number of tabs increases, the difficulty of making the pole piece increases, and the consistency of the entire pole core decreases. . Due to the difficulty in extracting current and heat from lithium-ion secondary batteries, it is difficult to increase the capacity and power of lithium-ion secondary batteries, which hinders the development of lithium-ion secondary batteries. the

Utility model content

The purpose of this utility model is a solution developed to overcome the above shortcomings, and its purpose is to provide a low-cost tabless lithium-ion secondary battery that can work at high power. the

The technical solution of the utility model: a lithium-ion secondary battery without tabs, including an electrode core formed by sequentially stacking and winding a positive electrode, a diaphragm, and a negative electrode, a battery case and a battery cover, and the electrode core is put into the battery case. The battery casing is filled with a non-aqueous electrolyte solution and is sealed by the battery cover. The positive and negative terminal surfaces of the electrode core are provided with exposed metal current collector substrates. The positive electrode collector and the negative electrode collector arranged between the negative electrode surface and the bottom of the battery casing conduct drainage. the

In the utility model, the metal current collecting substrate is a positive electrode plate, a diaphragm, and a negative electrode plate in which one end exceeds the edge of the diaphragm by 0.1-50mm among the positive plate, the diaphragm, and the negative plate that are stacked in sequence. the

In the present utility model, the positive electrode sheet and the negative electrode sheet exceed the edge of the diaphragm by 1-10mm. the

In the present utility model, the metal current collector base of the positive plate and the metal current collector base of the negative plate are metal base foils of the electrode plates themselves, or metal foils with high conductivity connected by welding or riveting. the

In the utility model, the positive plate is aluminum, titanium or stainless steel; the negative plate is copper, nickel or tin. the

In the utility model, the metal-based fluid substrate on the positive end surface of the electrode core is aluminum foil, and the metal current-collecting substrate on the negative end surface of the electrode core is copper foil. the

In the utility model, the negative collector is composed of one or more metal materials such as stainless steel, iron, nickel-plated iron, copper, nickel, nickel-plated copper, and copper-plated nickel. the

In the present invention, the positive collector is composed of one or more metal materials such as stainless steel, aluminum and titanium. the

In the present invention, the shapes of the negative collector and the positive collector are sheet-like, strip-like, spring-like, disk-like, foam-like, or a combination thereof. the

In the utility model, the positive terminal surface where the metal current collecting base is located is the positive current collecting end surface, and the positive current collecting end surface is welded or closely contacted with the battery cover through the positive current collecting body; the negative terminal surface where the metal current collecting base is located is The negative electrode current collecting end face is welded or closely contacted with the bottom of the battery case through the negative electrode current collecting body. the

The utility model has the beneficial effects: the electrodeless lithium ion secondary battery described in the utility model, since the positive terminal surface is composed of a positive metal current collector base, and the negative terminal surface is composed of a negative metal current collector base, and then passes through the vortex Flat, forming a whole with a certain strength, the current collection uniformity of the entire positive electrode sheet and negative electrode sheet has been greatly improved. In addition, a positive collector is also provided between the positive end surface and the battery cover, especially after the positive electrode collector is welded to the battery cover and the positive end surface, the current collecting effect of the positive electrode has been qualitatively improved. Between the negative electrode surface and the bottom of the battery case, a negative electrode collector is arranged, especially after the negative electrode collector, the negative electrode surface and the bottom of the battery case are welded, the current collecting effect of the negative electrode is also qualitatively improved. Both the positive and negative current collection effects are improved, and the current collection effect of the entire battery is also greatly improved. the

At the same time, since there is no need to provide lugs on the positive electrode sheet and the negative electrode sheet, the manufacturing process of the entire positive electrode sheet and the negative electrode sheet is greatly simplified and the difficulty is greatly reduced. The uniformity and consistency of the pole piece are greatly improved, and the consistency of the pole core is improved. the

Therefore, the non-tab lithium-ion secondary battery of the present invention has the characteristics of low internal resistance and long cycle life, and is especially suitable for large-capacity lithium-ion batteries that require high current and high power. The overall performance of the battery is improved while the manufacturing cost is also reduced. the

Description of drawings

Fig. 1 is a schematic view of the structure of the winding pole group in the prior art;

Fig. 2 is the structural representation of the lithium-ion secondary battery of prior art;

Fig. 3 is a structural schematic diagram of the winding pole group of the present utility model;

Fig. 4 is a structural schematic diagram of the tabless lithium-ion secondary battery of the present invention. the

[Description of drawing number comparison]

1 Positive plate 2 Positive tabs

3 Negative pole piece 4 Negative pole ear

5 Diaphragm 6 Battery case

7 Positive electrode dressing area 8 Negative electrode dressing area

9 Negative current collecting end face 10 Positive current collecting end face

11 Battery cover 12 Positive collector body

13 Negative collector

Detailed ways

In order to have a further understanding and understanding of the structural features of the present utility model and the achieved effects, a detailed description is provided in conjunction with preferred embodiments and accompanying drawings, as follows:

Fig. 3 is a schematic diagram of the wound pole group of the present invention, as shown in the figure. The positive electrode sheet 1, the separator 5, and the negative electrode sheet 3 are stacked in sequence. The positive electrode sheet 1 is divided into a dressing area and a non-dressing area. The dressing area contains positive electrode active materials on both sides of the positive electrode base aluminum foil, and the non-dressing area is the positive electrode base aluminum foil. The dressing area of the positive electrode sheet is completely wrapped within the length and width of the separator before winding, part of the non-dressing area is within the range of the separator wrapping, and the other part exceeds the width of the separator, with 0.5 mm to 20 mm exposed, preferably 2 mm to 10 mm exposed . If the exposed width is too small, it is not conducive to the subsequent vortex leveling, and it is difficult to form an effective whole on the entire end surface of the pole core, and the strength is not enough, so it is difficult to support subsequent welding or contact with the positive sink. If the exposed width is too large, the strength of the positive end surface is high, but it takes up a lot of height space, which is not conducive to high capacity. the

The negative plate is divided into a dressing area and a non-dressing area. The coating area contains negative electrode active materials on both sides of the negative electrode base copper foil, and the non-dressing area is the negative electrode base copper foil. Before winding, the negative electrode dressing area is completely wrapped within the length and width of the separator, part of the non-dressing area is within the wrapping range of the separator, and the other part exceeds the width of the separator, with 0.1 mm to 50 mm exposed, preferably 1 mm to 10 mm exposed. If the exposed width is too small, it is not conducive to the subsequent vortex leveling, and it is difficult to form an effective whole on the entire end surface of the pole core, and the strength is not enough, so it is difficult to support subsequent welding or contact with the negative electrode sink. If the exposed width is too large, the surface strength of the negative terminal is high, but it takes up a lot of height space, which is not conducive to high capacity. the

The width of the negative electrode dressing area 8 is greater than that of the positive electrode dressing area 7, and the positive electrode dressing area is required to be completely covered and wrapped by the negative electrode dressing area. Otherwise, lithium dendrites will be precipitated on the negative electrode sheet corresponding to the positive electrode area without the negative electrode dressing area during charging, and battery safety problems will occur. the

Fig. 4 is a schematic structural diagram of the tabless lithium-ion secondary battery of the present invention. As shown in the figure, it adopts the winding electrode group shown in Fig. 3 and forms a cylindrical pole core after winding. the

The electrodeless lithium ion secondary battery of the preferred embodiment of the utility model includes an electrode core formed by stacking a positive electrode 1, a diaphragm 5, and a negative electrode 3 in sequence, a battery case 6, and a battery cover 11, and the electrode core is loaded into the battery case 6 , and inject non-aqueous electrolyte solution into the battery case 6, and seal it with the battery cover 11. Both the positive end surface and the negative end surface of the electrode core have metal current collector substrates exposed, which are respectively drained by the positive electrode collector 12 and the negative electrode collector. the

In a preferred embodiment of the present invention, the metal-based fluid substrate on the positive end surface of the electrode core is aluminum foil, and the metal current-collecting substrate on the negative end surface of the electrode core is copper foil. the

The aluminum foil at the positive end of the electrode core is exposed, and the copper foil at the negative end of the electrode core is exposed. When the electrode core is wound, both the base aluminum foil of the positive electrode sheet and the base copper foil of the negative electrode sheet exceed a certain distance from the end face of the diaphragm (the distance range is 0.1-50mm, and the preferred distance range is 1-10mm), and then the electrode core is wound into an electrode core. The positive electrode aluminum foil and the negative electrode copper foil beyond the end face of the separator are vortexed to form a flat end face, that is, the positive electrode current collecting end face and the negative electrode current collecting end face are formed. the

Negative collector body 13 is arranged between the negative terminal face and the bottom of battery case 6, and negative electrode collector body 13 is made of one or more metal materials such as stainless steel, iron, nickel-plated iron, copper, nickel, nickel-plated copper, copper-plated nickel, etc. The composition and shape structure can be sheet, strip, spring, disc, foam, etc., or a combination of the above. The bottom of the negative electrode collector 13 and the battery case 6 may be welded or in close contact. the

The negative end surface where the metal current collector base is located is the negative electrode current collector end surface 9, and the negative electrode current collector end surface 9 and the negative electrode current collector 13 may be welded or in close contact. the

A positive electrode collector 12 is arranged between the positive electrode surface and the battery cover 11. The positive electrode collector 12 is composed of one or more metal materials such as stainless steel, aluminum, titanium, etc., and its shape and structure can be sheet, strip, spring, disk, etc. Shape, foam, etc., or a combination of the above. The lower part of the positive electrode collector 12 and the battery cover 11 may be welded or in close contact. the

The positive end surface where the metal current collector base is located is the positive electrode current collector end surface 10, and the positive electrode current collector end surface 10 and the positive electrode current collector 12 may be welded or in close contact. the

After the electrode core is dried and dehumidified, it is injected with a non-aqueous electrolyte solution, and after processes such as sealing, formation, and volume separation, a lithium-ion battery is produced. the

The utility model electrodeless lithium ion secondary battery, since the positive terminal surface is composed of the positive metal current collecting base, and the negative terminal surface is composed of the negative metal current collecting base, and then passes through the vortex to form a whole with a certain strength. The current collection uniformity of the entire positive electrode sheet and the negative electrode sheet has been greatly improved. Between the positive terminal surface and the battery cover, a positive electrode collector is also provided, especially after the positive electrode collector, the battery cover, and the positive terminal surface are welded, the current collecting effect of the positive electrode has been qualitatively improved. Between the negative electrode surface and the bottom of the battery case, a negative electrode collector is arranged, especially after the negative electrode collector, the negative electrode surface and the bottom of the battery case are welded, the current collecting effect of the negative electrode is also qualitatively improved. Both the positive and negative current collection effects are improved, and the current collection effect of the entire battery is also greatly improved. the

At the same time, since there is no need to provide lugs on the positive electrode sheet and the negative electrode sheet, the manufacturing process of the entire positive electrode sheet and the negative electrode sheet is greatly simplified and the difficulty is greatly reduced. The uniformity and consistency of the pole piece are greatly improved, and the consistency of the pole core is improved. the

Therefore, the actual effect of the utility model is that on the one hand, the overall performance of the battery is improved, and on the other hand, the manufacturing cost is reduced. the

Although the utility model takes lithium-ion secondary batteries without tabs as the object of description, obviously, it is also applicable to lithium-ion batteries of other shapes, such as square lithium-ion batteries, which can also be formed by forming positive current-collecting end surfaces and negative-electrode current-collecting end surfaces. The positive sink body and the negative sink body are set to achieve the purpose of reducing internal resistance and improving discharge power characteristics. the

Although the utility model takes the lithium-ion battery as the object of description, it is obvious that the principles and methods thereof are equally applicable to other types of batteries, such as nickel-metal hydride batteries, which can be adopted equally. the

In summary, it is only a preferred embodiment of the present utility model, and is not used to limit the scope of the utility model implementation. All the shapes, structures, features and spirits described in the scope of the claims of the utility model are equal. Changes and modifications should be included in the scope of the claims of the present utility model. the

Claims (8)

1. electrodeless ear-lithium ion secondary cell; Comprise by positive pole, barrier film, negative pole and stack gradually the electrode cores of reeling and forming; Battery container and battery cover, electrode cores are packed in the battery container, and battery container is equipped with non-aqueous electrolytic solution; And seal by battery cover; It is characterized in that the anodal end face of said electrode cores and negative pole end face are equipped with the metal afflux matrix that exposes, respectively by be located at positive pole between anodal end face and the battery cover conflux body and be located at the negative pole end face and the battery container bottom between the negative pole body that confluxes carry out drainage.

2. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 1 is characterized in that, this metal afflux matrix is positive plate, the negative plate that an end exceeds diaphragm edge 0.1-50mm in the positive plate that stacks gradually placement, barrier film, the negative plate.

3. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 2 is characterized in that it is 1-10mm that said positive plate, negative plate exceed diaphragm edge.

4. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 2; It is characterized in that; Said positive plate metal afflux matrix and said negative plate metal afflux matrix are the metallic matrix foil of battery lead plate self, the high metal foil of conductivity that perhaps connects with welding or riveted joint mode.

5. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 4 is characterized in that said positive plate is aluminium, titanium or stainless steel; Said negative plate is copper, nickel or tin.

6. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 1 is characterized in that the metal base flow matrix of the anodal end face of electrode cores is an aluminium foil, and the metal afflux matrix of the negative pole end face of electrode cores is a Copper Foil.

7. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 1 is characterized in that, said negative pole the conflux profile structure of body of body and said positive pole that confluxes is sheet, band shape, spring-like, plate-like, foam-like, or above combination.

8. a kind of electrodeless ear-lithium ion secondary cell as claimed in claim 1 is characterized in that, the anodal end face at said metal afflux matrix place is the anode collection end face, and this anode collection end face welds or closely contacts with battery cover through the positive pole body that confluxes; The negative pole end face at said metal afflux matrix place is the negative pole currect collecting end face, and this negative pole currect collecting end face welds or closely contacts with the battery case bottom through the negative pole body that confluxes.

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