CN216120429U

CN216120429U - Battery core pole piece and laminated battery core structure

Info

Publication number: CN216120429U
Application number: CN202122677862.6U
Authority: CN
Inventors: 李强; 王丰; 陈伟
Original assignee: Gotion High Tech Co Ltd
Current assignee: Gotion High Tech Co Ltd
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2022-03-22
Anticipated expiration: 2031-11-03

Abstract

The utility model provides an electric core electrode piece, which comprises a current collector and a polar slurry coated on the current collector, wherein two ends of the current collector are respectively provided with polarized slurry on the same side which is deviated from the center position. Pole ear. The utility model also provides a laminated battery core structure, which includes a Z-folded diaphragm, a positive electrode sheet and a negative electrode sheet that are separated and spaced by the diaphragm. A battery tab. The utility model has the advantages that the pole tabs are connected at both ends of the current collector through polar slurry to form a bipolar tab battery pole piece, thereby increasing the pole piece area, reducing the pole piece internal resistance and improving the conversion efficiency. The cell structure is formed by laminating the bipolar tabs. Due to the low internal resistance of the bipolar tabs, the internal resistance of the formed cell will naturally decrease, improving the energy conversion efficiency of the cell and improving the heating of the cell. The problem is that the battery can meet the needs of high current discharge.

Description

Battery core pole piece and laminated battery core structure

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to a battery cell pole piece and a laminated battery cell structure.

Background

With the progress of economic globalization and the increasing demand for energy, finding new energy storage devices has become a focus of attention in the field related to new energy. The lithium ion battery with the advantages of no memory effect, small self-discharge, high energy density, long service life and the like is widely applied to the fields of electric automobiles, hybrid electric automobiles, portable mobile power supplies and the like. With the continuous development of lithium ion batteries and the development of application fields, the requirements of the field of large-current discharge on batteries are higher and higher. In the existing laminated lithium ion battery, in order to meet the requirement of improving the energy or power of a battery monomer, the number of the positive and negative pole pieces required is increased. When the positive pole and the negative pole adopt full lugs, a thick welding area is formed after the lugs are welded, and cold welding is easily caused.

The utility model discloses a utility model patent that publication number is CN201369367Y discloses the naked electric core of power lithium cell of bipolar ear structure, and its negative pole piece both ends set up long utmost point ear and short utmost point ear respectively, twine to be connected long utmost point ear and short utmost point ear behind the electric core to improve battery discharge performance, guarantee the welding stability of utmost point ear. Although the method provides a scheme of reducing the internal resistance through a bipolar lug structure, the scheme only increases the lug area of the negative plate, the internal resistance is still larger for the positive plate, and the bipolar lugs at the two ends of the negative plate are directly connected to be used as the negative electrode of the whole battery cell, when a plurality of battery cells are needed, the negative electrodes of the battery cells are inconvenient to be connected through welding, and when the energy density requirement is larger, the bipolar lugs of the negative plates are stacked at the same position, the requirement on the length of the bipolar lug of the negative plate at the outer side is higher, the welding difficulty is higher, and the problem of insufficient welding caused by the excessively thick lug cannot be effectively solved.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a battery cell pole piece structure capable of reducing the internal resistance of a battery and a battery cell structure obtained by laminating the pole pieces.

The utility model solves the technical problems through the following technical scheme: the utility model provides an electricity core pole piece, includes the mass flow body and coats the polarity thick liquids on the mass flow body, the same one side that the mass flow body both ends deviate central point to put is provided with the utmost point ear of being connected with polarity thick liquids respectively.

The utility model connects the pole lugs at the two ends of the current collector through the polar slurry to form the double-pole-lug battery cell pole piece, thereby increasing the area of the pole piece, reducing the internal resistance of the pole piece and improving the conversion efficiency.

Preferably, the tabs are covered on the polar slurry and connected with the current collector through ultrasonic welding, and the tabs at two ends of the current collector are the same in size.

Preferably, the current collector is an aluminum foil, the polar slurry is a positive electrode slurry, and the tab is a positive tab connected with the positive electrode slurry.

Preferably, the current collector is a copper foil, the polar slurry is a negative electrode slurry, and the tab is a negative electrode tab connected with the negative electrode slurry.

The utility model also provides a laminated cell structure, which comprises a Z-shaped folded diaphragm, and a positive plate and a negative plate which are arranged at intervals through the diaphragm, wherein the positive plate and the negative plate respectively comprise a current collector corresponding to the polarity and polarity slurry coated on the current collector; positive lugs and negative lugs at two ends of the battery cell are respectively stacked at the same position to form four battery cell lugs.

According to the utility model, the battery cell structure is formed by laminating the bipolar lug pole pieces, and the internal resistance of the formed battery cell is naturally reduced due to the lower internal resistance of the bipolar lug pole pieces, so that the energy conversion efficiency of the battery cell is improved, the heating problem of the battery cell is improved, and the battery can meet the requirement of large-current discharge.

Preferably, the negative electrode lugs stacked at the same position at the two ends of the battery core are respectively connected with a copper nickel-plated lug through ultrasonic welding, and the positive electrode lugs stacked at the same position at the two ends of the battery core are respectively connected with an aluminum lug through ultrasonic welding.

Preferably, the thickness of the aluminum tab is 0.4mm, and the thickness of the copper nickel-plated tab is 0.3 mm.

The battery cell pole piece and the laminated battery cell structure provided by the utility model have the advantages that: the two ends of the current collector are connected with the pole lugs through the polar slurry to form the double-pole-lug battery cell pole piece, so that the area of the pole piece is increased, the internal resistance of the pole piece is reduced, and the conversion efficiency is improved.

The battery core structure is formed by laminating the bipolar lug pole pieces, and the internal resistance of the formed battery core can be naturally reduced due to the lower internal resistance of the bipolar lug pole pieces, so that the energy conversion efficiency of the battery core is improved, the heating problem of the battery core is improved, and the battery can meet the requirement of large-current discharge.

Drawings

Fig. 1 is a schematic structural diagram of a cell pole piece according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a positive electrode sheet according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a negative electrode sheet according to an embodiment of the present invention;

fig. 4 is a lamination schematic diagram of a laminated cell structure provided in an embodiment of the present invention;

fig. 5 is a schematic diagram of a laminated cell structure provided in an embodiment of the present invention;

fig. 6 is a schematic diagram of a laminated cell structure encapsulated with tabs according to an embodiment of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described below in detail and completely with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present embodiment provides a cell pole piece, including a current collector 1 and a polar slurry 2 coated on the current collector 1, and with reference to fig. 2 and fig. 3, a tab 3 connected with the polar slurry 2 is respectively disposed on the same side of the two ends of the current collector 1 deviating from the central position.

In the embodiment, the two ends of the current collector 1 are connected with the tabs 3 through the polarity slurry 2 to form the double-tab battery cell pole piece, so that the area of the pole piece is increased, the internal resistance of the pole piece is reduced, and the conversion efficiency is improved.

Utmost point ear 3 is through attached on polarity thick liquids 2 through ultrasonic bonding and mass flow body 1 fixed connection, and the position and the size of the utmost point ear 3 at mass flow body 1 both ends are all the same.

Further, for the positive plate 4 shown in fig. 2, the current collector 1 is made of aluminum foil, the polar slurry 2 is positive slurry, and the tab 3 is a positive tab 41 connected with the positive slurry; for the negative plate 5 shown in fig. 3, the current collector 1 is made of copper foil, the polar slurry 2 is negative slurry, and the tab 3 is a negative tab 51 connected with the negative slurry. The anode slurry comprises lithium iron phosphate or ternary nickel cobalt manganese, a conductive agent and a binder; the negative electrode slurry comprises a CMC binder, a conductive agent and SBR (styrene butadiene rubber).

In this embodiment, a further laminated cell structure using the above cell pole pieces is further provided, with reference to fig. 4, including a Z-shaped folded diaphragm 6 and a positive plate 4 and a negative plate 5 separated by the diaphragm 6 and disposed at an interval, where the positive plate 4 and the negative plate 5 are the structures introduced in the above embodiment, the positive tab and the negative tab at two ends of the cell are stacked at the same position to form four cell tabs, and the cell structure after lamination is as shown in fig. 5.

The battery core structure is formed by laminating the bipolar lug pole pieces, and because the internal resistance of the bipolar lug pole pieces is lower, the internal resistance of the formed battery core can be naturally reduced, the energy conversion efficiency of the battery core is improved, the heating problem of the battery core is improved, and the battery can meet the requirement of high-current discharge.

Referring to fig. 6, the negative electrode tab 51 stacked at the same position at both ends of the battery cell is respectively connected with a copper nickel-plated tab 71 by ultrasonic welding, the positive electrode tab 41 stacked at the same position at both ends of the battery cell is respectively connected with an aluminum tab 72 by ultrasonic welding, in this embodiment, the thickness of the aluminum tab 72 is 0.4mm, and the thickness of the copper nickel-plated tab 71 is 0.3 mm.

Two nickel plating of copper utmost point ear 71 and two aluminium system utmost point ears 72 of electric core both ends that this embodiment provided encapsulate alone after welding respectively, when electric core PACK joined in marriage the group, both sides join in marriage simultaneously and join in marriage mode such as group welding back rethread connecting plate or wire and connect out in unison, and need not reduce the bipolar ear lug at both ends, make things convenient for follow-up connection and equipment.

The positive and negative electrodes are respectively led out from the two ends of the laminated cell structure provided by the embodiment, so that the thickness of a pole lug lamination on one side is reduced, and the probability of the false welding possibly caused by the over-thick pole lug is reduced; compared with the traditional full-lug soft-package lithium ion battery, the internal resistance is reduced, the overall thickness of the positive and negative pole pieces after the lugs are overlapped is effectively reduced, and the battery packaging is facilitated.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. An electric core pole piece, characterized in that: it comprises a current collector and a polar slurry coated on the current collector, and the same side where both ends of the current collector deviate from the center position are respectively provided with a connection with the polar slurry. the polar ear.

2 . The electrode piece of a battery core according to claim 1 , wherein the tabs are covered on the polar slurry and connected to the current collector by ultrasonic welding, and the tabs at both ends of the current collector have the same size. 3 .

3 . The electrode piece of a battery core according to claim 1 , wherein the current collector is an aluminum foil, the polar slurry is a positive electrode slurry, and the electrode tab is a positive electrode tab connected to the positive electrode slurry. 4 .

4 . The electrode piece of a battery cell according to claim 1 , wherein the current collector is a copper foil, the polar slurry is a negative electrode slurry, and the electrode tab is a negative electrode ear connected to the negative electrode slurry. 5 . .

5. A laminated cell structure, characterized in that it comprises a Z-folded diaphragm and a positive electrode sheet and a negative electrode sheet that are separated and spaced by the diaphragm, and the positive electrode sheet and the negative electrode sheet respectively comprise current collectors corresponding to polarities And the polar slurry coated on the current collector, the two ends of the current collector are respectively provided with polar tabs connected to the polar paste on the same side that deviates from the center position; the positive and negative electrodes at both ends of the cell are stacked at the same position. Four cell tabs are formed.

6. A laminated cell structure according to claim 5, characterized in that: the negative tabs stacked at the same position at both ends of the cell are respectively connected with a nickel-plated copper tab by ultrasonic welding, and both ends of the cell are connected by ultrasonic welding. The positive tabs stacked at the same position are respectively connected to an aluminum tab by ultrasonic welding.

7 . The laminated cell structure according to claim 6 , wherein the thickness of the aluminum tab is 0.4 mm, and the thickness of the nickel-plated copper tab is 0.3 mm. 8 .