CN201936925U - Lithium ion secondary battery with circular cores and square casing - Google Patents

Abstract

A round-core square case lithium-ion secondary battery, which includes a housing, an electric core assembled in the housing, and tab connecting pieces, the housing is a square case with a fixed circular cavity, and the electric core is composed of 2- 20 sections of cylindrical winding cores are connected side by side. The cylindrical winding sections connected in parallel are placed in the circular cavity of the square shell. The size of the cylindrical winding cores is the same as the size of the circular cavity of the shell To adapt, the positive lug of the cylindrical winding core is welded on the casing or on the bottom cover plate, and one end of the square casing is provided with a negative electrode connection belt connected to the winding core, and the negative electrode connection strip is connected to the upper cover of the casing. connected to the negative terminal. The utility model has the advantages of simple and stable electrical structure, good reliability, excellent heat dissipation performance, small internal resistance of the battery, stable electrical performance of the battery, and low production cost. It can be widely used in electric tools, electric bicycles, electric motorcycles, mopeds and electric vehicles.

Description

A kind of round core square shell lithium ion secondary battery

technical field

The utility model relates to a lithium ion battery, in particular to a high-power lithium ion power secondary battery.

Background technique

There are usually three structures of existing high-power lithium-ion power batteries: one of them is a cylindrical single 20Ah structure, which includes the upper cover of the casing, the casing, the positive pole lug, the lower gasket, the upper gasket, the negative electrode, and the winding core. . This structure requires the pole pieces to be longer, and the diameter of the cylindrical core after being wound into a cylindrical core is larger. Long, a poor pole piece will lead to more waste, resulting in a higher defective rate. The second one is a winding square monomer 20Ah structure, which is composed of a shell, a tab connecting piece, a lower gasket, an upper gasket, an external connection stud, an external connection gasket, an external connection fastening nut and a rivet. The biggest disadvantage of batteries with this structure is that the multiple winding cores connected in parallel inside are all elliptical structures. The elliptical structure is not the most stable form. In the battery core, it will cause the bonding between the pole pieces in the battery core to be in an unstable state. , resulting in large differences in the consistency of the battery. The third type is the laminated square monomer 20Ah structure. In this structure, except that the winding core is stacked with multi-layer pole pieces, other accessories and assembly methods are the same as the winding square monomer 20Ah structure. Its disadvantage is that the electric core is laminated with multi-layer pole pieces, and its manufacturing efficiency is too low.

Chinese utility model patent CN 201020162903.7 discloses a lithium-ion secondary battery with a round core and a square shell. There are anti-corrosion filling materials. The anti-corrosion filling material used not only increases the production cost, but also has an adverse effect on the structural stability and heat conduction and heat dissipation performance of the battery cell, and is not conducive to fully automatic mechanized production.

Utility model content

The purpose of the utility model is to overcome the above-mentioned defects existing in the existing lithium-ion secondary battery, and provide a round-core square-case lithium-ion secondary battery with large capacity, more stable electrical performance and better heat dissipation performance.

The technical solution of the utility model is: it includes a shell, a cell assembled in the shell, and a positive and negative lug connecting piece (or, when the shell is used as the positive pole, only the negative lug connecting piece is provided), which is characterized in that , the housing is a square shell with a fixed circular cavity, and the battery core is formed by connecting 2-20 cylindrical winding cores side by side. In the circular cavity of the shell, the size of the cylindrical winding core is adapted to the size of the circular cavity of the shell, and the symmetrical ends of the square shell are respectively provided with a positive electrode connection belt connected to the winding core and a Negative pole connecting strip (or only negative lug connecting piece is provided when the shell is used as the positive pole), and the connecting strip is connected with the polarity connecting column welded on the upper cover of the shell.

When the housing is provided with a positive connecting strip, the positive connecting strip and the positive connecting column outside the housing can be riveted with aluminum rivets, or can be welded by super welding or laser welding; when the housing is positively charged, no need to use The positive connection strip and the positive lug of the inner cylindrical core can be directly welded to the shell by super welding or laser welding, or welded to the bottom cover.

The negative connection strip inside the casing and the negative connection column outside the casing can be riveted by copper rivets, or welded by resistance welding or laser welding.

The diameter of the single cylindrical core is preferably 14.0-40.0 mm, and the height is preferably 50.0-100.0 mm.

The gap between the winding cores may be 0-1 mm, preferably 0.5 mm.

An explosion-proof valve should be installed between the positive connecting piece and the negative connecting column.

The housing can be formed by extrusion of aluminum.

The utility model has the advantages: the internal cell of the battery with this structure is a cylindrical cell, which is conducive to the realization of mechanization and automatic production, and improves the consistency of the winding core; the use of a square aluminum shell with a circular cavity makes the battery structure more fixed. For convenience and stability, the electrical performance of the battery is more stable, and the aluminum material is easy to process and low in cost, which greatly reduces the production cost; connecting multiple cylindrical batteries in parallel increases the battery capacity, reduces internal resistance, and makes the battery electrical performance more stable ; while the parallel connection of multiple cylinders makes the battery cells form a flat square shape, which effectively increases the heat dissipation surface of the battery compared with cylindrical batteries of the same capacity. It is more excellent; it can reduce the amount of electrolyte injection in the shell, and at the same time allow the excess electrolyte in the shell to more fully contact and wet the winding core; it also realizes that multiple round cells can be assembled side by side in a square shell, effectively improving The production efficiency of the battery is improved, and at the same time, the external fixing of the battery is more convenient and stable; in addition, the connection between the negative electrode connecting post of the lithium-ion power battery and the negative electrode tab connecting piece in the battery is riveted by copper rivets or laser welding, which can This process is completed before the welding of the winding core tab and the tab connecting piece, so as to better ensure the tightness of the connection between the negative pole and the internal negative tab connecting piece.

The utility model can be widely used in electric bicycles, electric motorcycles, mopeds, automobiles and the like.

Description of drawings

Fig. 1 is a schematic structural view (longitudinal sectional view) of an embodiment of the utility model.

FIG. 2 is a schematic cross-sectional view of the embodiment shown in FIG. 1 .

Detailed ways

Below in conjunction with embodiment the utility model is further described.

Example 1

Referring to the accompanying drawings 1 and 2, this embodiment includes an extruded casing 1 and a battery cell 2 assembled in the inner cavity of the casing. The casing 1 is an aluminum square shell with a fixed circular cavity, and the battery cell 2. It consists of 3 cylindrical cores connected side by side in parallel. The diameter of a single core is 18.0mm, the height is 65.0mm, and the gap between the cores is 0.5mm; the 3 cylindrical cores connected in parallel are placed In the circular cavity of the housing 1, the size of the cylindrical winding core is adapted to the size of the circular cavity of the housing, and the positive tabs of each winding core are directly welded to the bottom plate of the housing 1 by laser welding; The casing 1 is provided with an upper cover 4, and one side of the upper cover 4 is provided with a negative pole connecting post 5, and one end of the square shell is provided with a negative pole connecting strip 3 connected with the winding core negative pole lug, and the negative pole connecting strip 3 is connected with the negative pole connecting post 5 riveted by copper rivets, the negative connection column 5 is equipped with a negative connection piece 6; the upper cover 4 is reserved with a positive connection piece 7; An explosion-proof valve 9 is installed between the negative pole connecting column 5.

Example 2

The symmetrical ends of the housing are respectively provided with a positive connection strip and a negative connection strip connected to the tabs of the winding core. The positive connecting strip and the positive connecting column outside the housing are riveted by aluminum rivets, or welded by super welding or laser welding. The remainder is the same as that of Embodiment 1 (but the tabs of the winding core do not need to be welded on the bottom plate of the housing 1).

Claims (10)

1. round core side case lithium ion secondary cell, comprise housing, be assemblied in the electric core in the housing, the lug brace, it is characterized in that, described housing is that the fixedly square shell of circular cavity is arranged, described electric core is formed in parallel side by side by 2-20 pitch circle column type volume core, described each pitch circle column type volume core in parallel side by side places the circular cavity of described side's shell, the circular cavity size of described column type volume core size and housing adapts, the anode ear of the column type volume heart connects and is welded on the housing or is welded on the bottom plate, the interior end of described side's shell is provided with and rolls up the negative pole connecting band that core is connected, and the negative pole connecting band links to each other with the negative pole joint pin of being located at case top lid.

2. round core side according to claim 1 case lithium ion secondary cell is characterized in that, the single diameter of described column type volume core is 14.0-40.0mm, highly is 50.0-100.0mm.

3. according to claim 1 or 2 or described round core side case lithium ion secondary cell, it is characterized in that the volume core is 0-1mm with the gap of rolling up between the core.

4. round core side according to claim 3 case lithium ion secondary cell is characterized in that, the gap between described volume core and the volume core is 0.5 mm.

5. round core side according to claim 1 and 2 case lithium ion secondary cell is characterized in that, is provided with explosion-proof valve between positive strap and negative pole joint pin.

6. round core side according to claim 1 and 2 case lithium ion secondary cell is characterized in that, rivets by copper rivet between described negative pole connecting band and the negative pole joint pin, or by electric resistance welding or Laser Welding welding.

7. round core side case lithium ion secondary cell, comprise housing, be assemblied in the electric core in the housing, the lug brace, it is characterized in that, described housing is that the fixedly square shell of circular cavity is arranged, described electric core is formed in parallel side by side by 2-20 pitch circle column type volume core, described each pitch circle column type volume core in parallel side by side places the circular cavity of described side's shell, the circular cavity size of described column type volume core size and housing adapts, the two ends of the interior symmetry of described side's shell are respectively equipped with and roll up anodal connecting band and the negative pole connecting band that core is connected, and anodal connecting band links to each other with the negative pole joint pin with the anodal joint pin of being located at case top lid respectively with the negative pole connecting band.

8. round core side according to claim 7 case lithium ion secondary cell is characterized in that, the single diameter of described column type volume core is 14.0-40.0mm, highly is 50.0-100.0mm; Gap between volume core and the volume core is 0-1mm.

9. round core side according to claim 7 case lithium ion secondary cell is characterized in that, rivets by aluminium rivet between the anodal joint pin outside anodal connecting band and the housing, or welds by super weldering or Laser Welding; Rivet by copper rivet between described negative pole connecting band and the negative pole joint pin, or by electric resistance welding or Laser Welding welding.

10. according to Claim 8 or 9 described round core side case lithium ion secondary cells, it is characterized in that, between anodal joint pin and negative pole joint pin, be provided with explosion-proof valve.

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