CN214625136U

CN214625136U - Cylindrical lithium battery

Info

Publication number: CN214625136U
Application number: CN202120851515.8U
Authority: CN
Inventors: 刘进前; 牟方路
Original assignee: Huaibei Qianliniao New Energy Technology Co ltd
Current assignee: Huaibei Qianliniao New Energy Technology Co ltd
Priority date: 2021-04-25
Filing date: 2021-04-25
Publication date: 2021-11-05
Anticipated expiration: 2031-04-25

Abstract

The utility model provides a cylinder type lithium cell, is in including metal casing, setting electric core in the metal casing sets up block on the metal casing suitable for reading, metal casing with the negative pole of electric core is connected, the block with the positive pole of electric core is connected, electric core is formed by negative pole piece, diaphragm and positive plate coiling, the lower base of negative pole piece is the exposed region of the predetermined height of reserving out, exposed region is in the electric core is rolled up the back, to the central direction bending type of electric core becomes the kink, the lateral surface and the negative pole current collector spot welding of kink are connected, the negative pole current collector with metal casing's interior bottom spot welding is connected. The utility model has the advantages of can improve the lithium cell rate of discharging to and reduce the lithium cell internal resistance and reduce the discharge temperature.

Description

Cylindrical lithium battery

Technical Field

The utility model belongs to the technical field of a lithium ion battery's technique and specifically relates to a cylinder type lithium cell.

Background

Lithium batteries have been widely used in various industries due to their high specific energy, long life, and environmental friendliness. The lithium battery not only needs large capacity, but also needs lower internal resistance and larger discharge rate, and the lower internal resistance ensures that the battery is not easy to generate heat, thereby greatly prolonging the service life of the lithium battery. Most of the existing cylindrical lithium batteries adopt single-pole lug current collection, and a small part of the lithium batteries adopt multi-pole lug current collection. The unipolar lug current collection or the multi-lug current collection is difficult to make further breakthrough in the technical aspects of improving the discharge rate and reducing the internal resistance of the lithium battery, and is a problem which is sought to be solved in the lithium battery manufacturing industry all the time.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model discloses provide one kind to the society and can improve the lithium cell rate of discharging to and reduce the cylinder type lithium cell of lithium cell internal resistance.

The technical scheme of the utility model is that: the utility model provides a cylinder type lithium cell, be in including metal casing, setting electric core in the metal casing sets up block on the metal casing suitable for reading, metal casing with the negative pole of electric core is connected, the block with the positive pole of electric core is connected, electric core is formed by negative pole piece, diaphragm and positive plate coiling, the lower base of negative pole piece is the exposed region of the predetermined height of reserving out, exposed region is in the electric core is rolled up the back, to the central direction bending type of electric core becomes the kink, the lateral surface and the negative pole current collector spot welding of kink are connected, the negative pole current collector with metal casing's interior bottom surface spot welding is connected.

As an improvement of the utility model, the negative current collecting piece is a nickel sheet, a steel sheet or a copper sheet.

As right the utility model discloses an it is the improvement, the upper end of electric core is equipped with insulating spacer, the anodal of electric core passes behind the insulating spacer with the block is connected.

As an improvement to the present invention, the positive electrode of the battery cell is a single-pole positive electrode tab or a multi-pole positive electrode tab.

As a modification to the present invention, the insulating spacer is a plastic spacer.

As right the utility model discloses an it is the improvement be equipped with explosion-proof structure in the block, explosion-proof structure includes first aluminum substrate and second aluminum substrate, connect through the solder joint between first aluminum substrate and the second aluminum substrate, first aluminum substrate with the positive pole of electricity core is connected.

The utility model discloses owing to adopted the lower base of negative pole piece is the exposed region of the predetermined height of reserving out, exposed region is in after electric core is rolled up, to the central direction bending type of electric core becomes the kink, the lateral surface and the negative pole current collector spot welding of kink are connected, the negative pole current collector with metal casing's interior bottom surface spot welding connects the structure, makes the utility model has the advantages of can improve lithium cell discharge rate to and reduce the lithium cell internal resistance.

Drawings

Fig. 1 is a schematic cross-sectional view of an embodiment of the present invention.

Fig. 2 is a schematic plan view of the negative electrode sheet of fig. 1.

Detailed Description

Referring to fig. 1 and 2, fig. 1 and 2 disclose a cylindrical lithium battery, which includes a metal casing 1, a battery cell 2 disposed in the metal casing 1, a cap 3 disposed on an upper opening of the metal casing 1, the metal shell 1 is connected with the negative electrode of the battery core 2, the cap 3 is connected with the positive electrode 22 of the battery core 2, the battery cell 2 is formed by winding a negative electrode sheet 23, a diaphragm 24 and a positive electrode sheet 25, the lower bottom edge of the negative electrode sheet 23 is a reserved exposed area 231 with a predetermined height (see fig. 2, the part below an active material coating area 232), after the battery cell 2 is rolled, the exposed area 231 is bent toward the center 26 of the battery cell 2 to form a bent portion, the outer side surface of the bending part is connected with a negative current collecting piece 27 in a spot welding mode, and the negative current collecting piece 27 is connected with the inner bottom surface of the metal shell 1 in a spot welding mode. The utility model discloses owing to all use as the negative pole ear with the exposed region 231 of negative pole piece 23, and the adoption will exposed region 231 to the 26 direction bending type in center of electric core 2 becomes the kink, connects through kink negative pole current collector 27, has increased the area of contact of negative pole end to can reduce the lithium cell internal resistance, thereby reduce the discharge temperature and improve the multiplying power that discharges of lithium cell. In this embodiment, the outermost surface of the battery cell 2 is further wrapped with a layer of diaphragm 24.

Preferably, the negative current collecting plate 27 is a nickel plate, a steel plate or a copper plate, and the nickel plate, the steel plate or the copper plate has better conductivity.

Preferably, an insulating spacer 28 is disposed at the upper end of the battery cell 2, the positive electrode 22 of the battery cell 2 penetrates through the insulating spacer 28 and then is connected to the cap 3, and the insulating spacer 28 is disposed to prevent a positive short circuit and a negative short circuit at the upper end of the battery cell 2. In this embodiment, the insulating spacer 28 may be a plastic spacer, considering that the insulating spacer 28 has both good insulating property and good cost performance.

Preferably, the positive electrode 22 of the battery cell 2 is a single-pole positive electrode tab or a multi-pole positive electrode tab.

Preferably, an explosion-proof structure 31 is arranged in the cap 3, the explosion-proof structure 31 includes a first aluminum substrate 311 and a second aluminum substrate 312, the first aluminum substrate 311 and the second aluminum substrate 312 are connected by a welding point 313, and the first aluminum substrate 311 is connected with the positive electrode 22 of the battery core 2.

Preferably, the outer surface of the bent portion and the negative current collecting plate 27 are connected by laser spot welding.

Preferably, the metal housing 1 is a steel or aluminum alloy housing.

The cylindrical lithium ion battery of the utility model can be 14500 cylindrical lithium ion battery, 14650 cylindrical lithium ion battery, 16500 cylindrical lithium ion battery, 18500 cylindrical lithium ion battery, 18650 cylindrical lithium ion battery or 26500 cylindrical lithium ion battery, and the diameter is in all height series of 14cm-50 cm.

All equivalent changes made by the contents of the specification and the drawings of the utility model are included in the scope of the claims of the utility model without departing from the idea of the utility model.

Claims

1. The utility model provides a cylinder type lithium cell, is in including metal casing (1), setting electric core (2) in metal casing (1) sets up cap (3) on metal casing (1) the suitable for reading, metal casing (1) with the negative pole of electric core (2) is connected, cap (3) with positive pole (22) of electric core (2) are connected, electric core (2) are formed by coiling negative pole piece (23), diaphragm (24) and positive plate (25), its characterized in that: the lower base of negative pole piece (23) is the naked region (231) of the predetermined height that reserves, naked region (231) are in after electric core (2) are rolled up, to center (26) direction bending type bending portion of electric core (2), the lateral surface and the negative pole current collector piece (27) spot welding of kink are connected, negative pole current collector piece (27) with the interior bottom surface spot welding of metal casing (1) is connected.

2. The cylindrical lithium battery as claimed in claim 1, wherein: the negative current collecting plate (27) is a nickel plate, a steel plate or a copper plate.

3. The cylindrical lithium battery as claimed in claim 1, wherein: an insulating spacer (28) is arranged at the upper end of the battery cell (2), and the positive electrode (22) of the battery cell (2) penetrates through the insulating spacer (28) and then is connected with the cover cap (3).

4. A cylindrical lithium battery as claimed in claim 1, 2 or 3, characterized in that: the positive pole (22) of the battery cell (2) is a single-pole positive pole lug or a multi-pole positive pole lug.

5. A cylindrical lithium battery according to claim 3, characterized in that: the insulating spacer (28) is a plastic spacer.

6. A cylindrical lithium battery as claimed in claim 1, 2 or 3, characterized in that: an explosion-proof structure (31) is arranged in the cap (3), the explosion-proof structure (31) comprises a first aluminum substrate (311) and a second aluminum substrate (312), the first aluminum substrate (311) and the second aluminum substrate (312) are connected through a welding point (313), and the first aluminum substrate (311) is connected with the positive electrode (22) of the battery cell (2).

7. A cylindrical lithium battery as claimed in claim 1, 2 or 3, characterized in that: the outer side surface of the bent part is connected with the negative current collecting piece (27) through laser spot welding.

8. A cylindrical lithium battery as claimed in claim 1, 2 or 3, characterized in that: the metal shell (1) is a steel shell or an aluminum alloy shell.