CN210006846U - A lithium battery suitable for a round battery compartment - Google Patents

Abstract

The utility model relates to an lithium cells suitable for round battery compartment, the lithium cell is the cake type, the lithium cell lateral wall outside is encircleed there is the kink, the kink with wherein terminal surface body coupling of lithium cell, the anodal utmost point ear of lithium cell, negative pole utmost point ear are passed through by the lithium cell is inside the kink is drawn forth the lithium cell and the round battery compartment phase-match that removes portable electronic product, the packing into in the round battery compartment of the same diameter the utility model provides a cake type lithium cell is compared in packing into current square lithium cell, and battery capacity can improve at least 25%.

Description

A lithium battery suitable for a round battery compartment

technical field

The invention relates to the field of electrochemistry, in particular to a lithium ion battery and a manufacturing method thereof.

Background technique

As a form of energy in chemical power sources, lithium-ion batteries have the advantages of high working voltage, high energy density, light weight, small size, good safety, good cycle life, and green environmental protection. with broadly application foreground.

Small lithium-ion batteries are widely used in mobile and portable electronic products such as smart watches, wireless Bluetooth headsets, etc. However, most of the battery compartments used to install small lithium-ion batteries in existing mobile and portable electronic products are round battery compartments. , and the existing small lithium-ion batteries are square, resulting in the remaining space in the round battery compartment, and the battery compartment is not fully utilized, the capacity of the installed lithium-ion battery is too small, which affects the battery life of electronic products. The battery compartments of mobile and portable electronic products are generally made in a circular shape because in the mass production process, the circular structure is simpler to process, has a lower cost and has the best yield compared with other structures. Therefore, in order to improve the endurance of mobile and portable electronic products, it is of great significance to develop a lithium battery with excellent performance and suitable for round battery compartments.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a lithium battery suitable for a circular battery compartment. The lithium battery is a round cake type, which matches the circular battery compartment of a mobile and portable electronic product, and is installed in a circular battery compartment of the same diameter Compared with the existing square lithium battery, the battery capacity can be increased by at least 25% when the round cake type lithium battery provided by the present invention is loaded. The specific technical solutions are as follows:

A lithium battery, the lithium battery is in the shape of a round cake, a bending part is surrounded on the outer side of the side wall of the lithium battery, the bending part is integrally connected with one end surface of the lithium battery, and the positive electrode tab and the negative electrode tab of the lithium battery are formed by the inside of the lithium battery. Lead out through the bending part. In order to match the connection points of the positive and negative electrodes set in the circular battery compartment, the angle between the positive electrode tab and the negative electrode tab of the lithium battery can be any angle.

Further, the battery cell of the lithium battery is of a winding structure. When winding, the separator and the pole piece can be assembled in a way that the separator bag can be used to wrap the positive electrode piece and then wound with the negative electrode, or a roll-to-roll double-layer separator can be used with the negative electrode. Positive and negative pole piece winding method.

Further, the lithium battery packaging shell is made of aluminum or aluminum alloy.

Further, the electrolyte used in the lithium battery may be a gel polymer solid electrolyte or a conventional liquid electrolyte.

The invention discloses a method for making the above-mentioned round cake-shaped lithium battery, which specifically includes the following steps:

Step 1: Prepare the positive electrode slurry according to the conventional method. The positive electrode current collector is made of rectangular aluminum foil, and then the positive electrode slurry is coated on both ends of the positive electrode current collector aluminum foil along the width direction. The aluminum foil is used to connect the positive electrode tab, and the positive electrode sheet is obtained by drying and rolling. It is also possible to apply gap coating on a large piece of aluminum foil first, and then dry, roll film, slit and cut to obtain a positive electrode sheet;

Step 2, prepare the negative electrode slurry according to the conventional method, and then carry out gap coating on the current collector copper foil of the negative electrode piece along the width direction, after drying, rolling, slitting and cutting, the leakage of 1- A negative electrode piece of 4mm current collector copper foil, preferably, a leak is provided at the tail of the negative electrode piece for connecting the negative electrode tab;

Step 3, connect the positive electrode tabs and the negative electrode tabs to the leaking parts of the positive electrode sheet and the negative electrode sheet, respectively, and then stick tapes on both ends of the leaking parts of the positive electrode sheet and the negative electrode sheet;

Step 4: Insulate the positive electrode sheet, put the positive electrode sheet in the middle of the two layers of separators, seal the edges of the two layers of the separators, and cover the part of the positive electrode sheet except for the tail end. The end of the sealed diaphragm is provided with a gap of 1-5mm, and the gap is set to prevent the expansion of the positive electrode sheet when the lithium battery is cyclically charged and discharged, causing the diaphragm to be punctured;

Step 5: winding, stacking the insulated positive electrode sheet and the negative electrode sheet, separating the positive electrode sheet and the negative electrode sheet for insulation, starting from the head end of the positive electrode sheet to obtain a cylindrical winding core, and ending the winding with tabs . During winding, the positive electrode sheet is wound around the inner negative electrode sheet at the outermost layer, and the tail portions of the positive and negative electrode sheets located on the outer layer of the cylindrical winding core are provided with adhesive tape for fixing. When winding, double negative electrode sheets can also be used to wrap the positive electrode sheets for winding;

Step 6, encapsulate, the lithium battery encapsulation shell is made of aluminum or aluminum alloy sheet, the sheet is provided with a circular groove, the cylindrical winding core is placed in the groove, and the positive electrode tabs in the vertical direction, The negative electrode tab is bent at 90°, and the sheet is folded in half and pressed to close the groove. The conventional technical means applied to soft-pack lithium batteries can be used for pressing and sealing. Top sealing and side sealing are performed in sequence. Both ends of the part between the two layers of sheets are pasted with adhesive tape, and then the conventional technical means are used to carry out flaring, liquid injection, formation and two sealing in sequence;

Step 7: Lithium battery is formed, and the folded connecting surface of the sheet is punched into a circular surface by punching. The circular surface and the groove are concentric circles. The diameter of the circular surface is larger than the diameter of the groove. The part whose surface is larger than the groove is bent in the direction of the groove to form a bending part, and the leaked positive electrode tab and the negative electrode tab are bent in a direction away from the groove.

In the eighth step, the battery is charged and discharged according to a conventional method to obtain a round cake type lithium battery product.

Preferably, in step 6, the lithium battery packaging shell is made of aluminum-plastic film, and the thickness of the aluminum-plastic film is between 70-90 microns.

Description of drawings

The accompanying drawings further illustrate the present invention, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention.

FIG. 1 is a schematic structural diagram of a round cake type lithium battery according to Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of a positive electrode sheet of a lithium battery provided in Embodiment 1 of the present invention.

FIG. 3 is a schematic diagram of the packaging of the lithium battery provided in Embodiment 1 of the present invention.

FIG. 4 is a schematic structural diagram of punching and forming a lithium battery according to Embodiment 1 of the present invention.

FIG. 5 is a schematic structural diagram of a round cake type lithium battery provided in Embodiment 2 of the present invention.

FIG. 6 is a schematic structural diagram of a round cake type lithium battery provided in Embodiment 3 of the present invention.

10. Bending part; 2. Positive electrode tab; 3. Negative electrode tab; 4. Insulating tape; 5. Positive electrode sheet; 6. Diaphragm; 7. Aluminum plastic film ; 8. Groove; 9. High temperature insulating tape.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

As shown in FIG. 1, a lithium battery 1, the lithium battery 1 is in the shape of a round cake, a bending part 10 is surrounded on the outer side of the side wall of the lithium battery 1, and the bending part 10 is integrally connected with one end surface of the lithium battery 1, and the lithium battery The positive electrode tab 2 and the negative electrode tab 3 of 1 are drawn out from the inside of the lithium battery 1 through the bending portion 10 . The positive electrode tab 2 and the negative electrode tab 3 are drawn out in parallel.

The production method of the round cake lithium battery provided by Production Example 1, specifically comprises the following steps:

Step 1: Prepare the positive electrode slurry. The current collector of the positive electrode sheet 5 is made of rectangular aluminum foil, and then the positive electrode slurry is coated on both ends of the aluminum foil of the positive electrode sheet 5 along the width direction, and 3mm aluminum foil is leaked on the two ends of the tail end of the positive electrode sheet 5 for connection. The positive electrode tab 3 is dried and rolled to obtain a positive electrode sheet 5;

Step 2, prepare the negative electrode slurry, and then carry out gap coating on the current collector copper foil of the negative electrode sheet along the width direction, and obtain the negative electrode sheet after drying, rolling, slitting and cutting, and set the leakage 3mm current collector copper at the tail of the negative electrode sheet. The foil is used to connect the negative tab 3;

Step 3, connect the positive electrode tab 2 and the negative electrode tab 3 on the leaking part of the positive electrode sheet 5 and the negative electrode sheet respectively, and then stick the high temperature insulating tape 9 on both ends of the leaking part of the positive electrode sheet 5 and the negative electrode sheet;

Step 4, as shown in FIG. 2 , insulating the positive electrode sheet 5, placing the positive electrode sheet 5 in the middle of the two layers of separators 6, sealing the edges of the two layers of the separators 6, and removing the tail end of the positive electrode sheet 5. The outer part is set, the head of the positive electrode sheet 5 and the end of the sealed diaphragm 6 are provided with a gap of 3 mm;

Step 5, winding is carried out, the positive electrode sheet 5 and the negative electrode sheet after the insulation treatment are stacked and arranged, the positive electrode sheet and the negative electrode sheet are separated and insulated by the separator 6, and the head end of the positive electrode sheet 5 starts to be wound to obtain a cylindrical winding core. Pole ends. During winding, the positive electrode sheet 5 is wound around the negative electrode sheet of the inner layer at the outermost layer;

Step 6, as shown in FIG. 3, encapsulate, the lithium battery packaging shell is made of aluminum-plastic film 7, and the aluminum-plastic film 7 is provided with a circular groove 8, and the cylindrical winding core is placed in the groove 8 and will be in a vertical position. The positive electrode tab 2 and the negative electrode tab 3 in the straight direction are bent at 90°, and the aluminum plastic film 7 is folded in half and thermally pressed to close the groove 8. The positive electrode tab 2 and the negative electrode tab 3 are located between the two layers of aluminum plastic film 7. Both ends of the part between the two parts are pasted with insulating tape 4, and then flaring, liquid injection, formation and two sealing are carried out in sequence;

Step 7, as shown in FIG. 4 , forming by punching, punching the folded connecting surface of the aluminum-plastic film 7 into a circular surface, the circular surface and the groove 8 are concentric circles, and the diameter of the circular surface is larger than the concave surface. The diameter of the groove 8, the part of the circular surface larger than the groove 8 is bent in the direction of the groove 8 to form a bending part 10, and the leaked positive electrode tab 2 and the negative electrode tab 3 are bent in the direction away from the groove, and the figure is obtained. 1 shows the lithium battery 1.

In the eighth step, the lithium battery 1 is activated by charging and discharging according to the conventional method.

Compared with the existing square battery, the round cake-shaped lithium battery 1 provided in this Example 1 has a capacity comparison as shown in the following table under the condition that the diameter of the round battery compartment remains unchanged:

Example 2

As shown in FIG. 5, a lithium battery 1, the lithium battery 1 is in the shape of a round cake, a bending part 10 is surrounded on the outside of the side wall of the lithium battery 1, and the bending part 10 is integrally connected with one end face of the lithium battery 1, and the lithium battery The positive electrode tab 2 and the negative electrode tab 3 of 1 are drawn out from the inside of the lithium battery 1 through the bending portion 10 . The positive electrode tab 2 and the negative electrode tab 3 are drawn out at 180°.

Example 3

As shown in FIG. 6, a lithium battery 1, the lithium battery 1 is in the shape of a round cake, a bending part 10 is surrounded on the outside of the side wall of the lithium battery 1, and the bending part 10 is integrally connected with one end face of the lithium battery 1. The lithium battery The positive electrode tab 2 and the negative electrode tab 3 of 1 are drawn out from the inside of the lithium battery 1 through the bending portion 10 . The positive electrode tab 2 and the negative electrode tab 3 are drawn out at 90°.

Claims (3)

1. A lithium battery, characterized in that: the lithium battery is in the shape of a round cake, and a bending portion is surrounded on the outside of the side wall of the lithium battery, and the bending portion is integrally connected with one end face of the lithium battery, The positive electrode tab and the negative electrode tab of the lithium battery are drawn out from the inside of the lithium battery through the bending portion. 2 . The lithium battery according to claim 1 , wherein the battery cell of the lithium battery is of a wound structure. 3 . 3 . The lithium battery according to claim 2 , wherein the lithium battery packaging shell is made of aluminum or aluminum alloy. 4 .

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