CN218957975U

CN218957975U - Battery cell

Info

Publication number: CN218957975U
Application number: CN202222690657.8U
Authority: CN
Inventors: 王滨; 于红帅; 张育战
Original assignee: Gp Batteries Dongguan Co ltd
Current assignee: Gp Batteries Dongguan Co ltd
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2023-05-02
Anticipated expiration: 2032-10-13

Abstract

The present utility model relates to a battery, comprising: a housing having a cavity and an opening in communication with the cavity; the battery cell is formed by winding a positive electrode plate, a diaphragm and a negative electrode plate after being stacked, the winding type battery cell is vertically arranged in a cavity, the diaphragm separates the positive electrode plate from the negative electrode plate, the height of the diaphragm is between the positive electrode plate and the negative electrode plate, the height of the negative electrode plate is larger than that of the positive electrode plate, both end surfaces of the negative electrode plate are coated with a negative electrode active material layer, and liquid electrolyte is contained in the cavity; the cover cap is arranged at the opening, and the positive pole piece is connected with the cover cap through the pole lug; sealing rubber rings; an insulating gasket; the conductive connecting layer is arranged at the bottom of the cavity, the conductive connecting layer is connected with the bottom end surface of the cavity and the side wall of the cavity, the conductive connecting layer is connected with one end of the negative electrode pole piece of the battery cell, which is far away from the opening, and the conductive connecting layer is not contacted with the positive electrode pole piece.

Description

Battery cell

Technical Field

The utility model relates to the technical field of power supply devices, in particular to a battery.

Background

The cylindrical full-tab or multi-tab winding battery has high-rate charge and discharge capability. The tab group of the winding battery is connected with the shell or the cap through laser spot welding, if the tab group is not subjected to leveling treatment, the phenomena of cold joint and unstable welding easily occur when the laser spot welding is performed, and the welding stability is reduced. The method for flattening the surface of the tab group to form a flattened plane mainly comprises two methods: firstly, directly rubbing the pole lugs after winding, and pressing down the pole lugs under the action of ultrasonic or external force to form a plane on the uppermost layer of the vertical pole lugs; and secondly, carrying out narrow gap cutting on the tab, dividing the tab into a plurality of small tabs with separated upper parts, and then bending and flattening the cut small tabs to form a plane. The mode that kneads the flat can make the utmost point ear because of receiving external force to push down and rub and produce the metal fillings and enter into the inside unable clear away of battery, causes the battery self discharge easily to arouse the potential safety hazard, simultaneously because the crooked degree of utmost point ear root portion is different, there is the cracked risk of utmost point ear to knead between the flat utmost point ear more compactly, be unfavorable for electrolyte infiltration. The adoption of the bending and flattening mode is easy to cause that the formed plane is not a complete plane, and uneven and unstable gaps exist in the flattened surface after being pressed down, so that welding connection is unstable, current density is uneven or cold welding is generated, and the battery is discharged from the tip.

Disclosure of Invention

Aiming at the technical problems in the prior art, the utility model provides a battery, which comprises:

a housing having a cavity and an opening in communication with the cavity;

the battery cell is formed by winding a positive electrode plate, a diaphragm and a negative electrode plate after being stacked, the winding battery cell is vertically arranged in a cavity of the shell, the diaphragm insulates the positive electrode plate and the negative electrode plate, the height of the diaphragm is between the positive electrode plate and the negative electrode plate, the height of the negative electrode plate is larger than that of the positive electrode plate, and both end surfaces of the negative electrode plate are coated with a negative electrode active material layer;

the cap is arranged at the opening of the shell, the positive pole piece of the battery core is connected with the cap through the pole lug, and the cap can be used as a positive electrode connecting terminal of the battery;

the sealing rubber ring is arranged between the cover cap and the opening of the shell and is used for insulating and isolating the cover cap from the shell;

the insulating gasket is arranged between the battery cell and the cap;

the conductive connecting layer is arranged at the bottom of the cavity, the conductive connecting layer is connected with the bottom end surface of the cavity and the side wall of the cavity, the conductive connecting layer is connected with one end of the negative electrode plate of the battery cell, which is far away from the opening, the conductive connecting layer directly inlays the current collector of the negative electrode plate therein, and the conductive connecting layer is not contacted with the positive electrode plate.

The conductive connecting layer is formed by solidifying paste with electron transmission capability, and the common paste mainly comprises: solder paste, tin alloy paste (tin bismuth alloy, tin lead alloy, tin indium alloy), conductive carbon paste, and conductive silver paste. After the soldering paste is injected into the cavity of the shell, the soldering paste and the shell are heated together to enable the soldering paste to be in a molten state, then one end of a current collector of the negative electrode plate in the battery cell is inserted into the molten soldering paste, and then the instant cooling treatment is carried out to enable the soldering paste to be solidified to form a conductive connecting layer, and at the moment, one end of the negative electrode plate of the battery cell is connected with the conductive connecting layer.

In one embodiment, after the tin alloy paste with low melting point is uniformly injected into the cavity of the shell, one side of the current collector of the negative electrode plate in the battery cell is inserted into the tin alloy paste, and solidification of the tin alloy paste is performed in an instantaneous local heating mode, and at the moment, one end of the negative electrode plate of the battery cell is connected with the conductive connecting layer. Wherein the heating temperature does not change the thermal stability of the membrane, and the membrane can be usedThe membrane is a substrate with higher thermal stability, an inorganic ceramic fiber membrane and a ceramic coating membrane, such as: porous Polytetrafluoroethylene (PTFE) based membrane, porous polyvinylidene fluoride (PVDF) membrane, absorbent Glass Mat (AGM) membrane, al ₂ O ₃ Ceramic coated modified PE separator.

The utility model has the following advantages:

by utilizing the technical scheme of the utility model, one end of the negative electrode plate of the battery cell, which is far away from the opening, is electrically connected with the shell through the conductive connecting layer, and the current collector of the negative electrode plate is directly connected with the shell through the conductive connecting layer. Because the current collector side of the negative electrode plate is used as the electrode lug, the length of the current collector side depends on the length of the negative electrode active layer, and the electron transmission distance in the electrochemical process can be greatly shortened, so that the battery has high-rate charge-discharge performance. The negative electrode plate of the battery cell is electrically connected with the shell through the conductive connecting layer, the negative electrode plate of the battery cell does not need to be subjected to leveling treatment, and the defects of insufficient tab welding and infirm welding existing in the existing welding process are avoided.

The following description is made with reference to specific embodiments.

Drawings

The utility model is further illustrated by the accompanying drawings, which are not to be construed as limiting the utility model in any way.

Fig. 1 is a schematic structural diagram of a battery according to an embodiment of the present utility model;

fig. 2 is a cross-sectional view of a battery according to an embodiment of the present utility model.

Wherein, the reference numerals are as follows: the battery cell comprises a shell 10, a battery cell 20, a positive electrode plate 21, a negative electrode plate 22, a liquid injection channel 23, a cap 30, a sealing rubber ring 40, an insulating gasket 50, a positive electrode lug 60 and a conductive connecting layer 70.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless specifically defined otherwise.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; the connection may be mechanical connection, direct connection or indirect connection through an intermediate medium, and may be internal connection of two elements or interaction relationship of two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific-case.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is less level than the second feature.

As shown in fig. 1 and 2, the battery provided in this embodiment includes a case 10, a battery cell 20, a cap 30, a sealing rubber ring 40, an insulating gasket 50, a positive electrode tab 60, and a conductive connection layer 70. The cap 30 is the positive connection terminal of the battery and the housing 10 is the negative connection terminal of the battery.

The shell 10 is made of nickel-plated steel, tin-plated steel or indium-plated steel, and the shell 10 is of a cylindrical groove body structure. The cap 30 is disposed at the notch of the housing 10, and the packing 40 is disposed between the cap 30 and the notch end of the housing 10, the packing 40 serving to seal and insulate between the cap 30 and the housing 10. The notch end of the housing 10 is provided with a flange, and the edge of the cap 30 is embedded into the flange, so that the cap 30 is fixed at the notch of the housing 10. The top side wall of the housing 10 has a ring-shaped structure, so that the housing 10 forms a cylindrical structure. The battery cell 20 is accommodated in the shell 10, the cap 30 is covered at the notch of the shell 10, and the accommodating space in the shell 10 is further closed by the sealing rubber ring 40.

The battery cell 20 is formed by winding a positive electrode plate 21, a diaphragm and a negative electrode plate 22 after being stacked, wherein the diaphragm is arranged between the adjacent positive electrode plate 21 and the adjacent negative electrode plate 22 and is used for isolating and insulating the adjacent positive electrode plate 21 and the adjacent negative electrode plate 22. The preparation of the coiled cell 20 is within the scope of the prior art and is not described in detail herein. The positive electrode sheet 21 includes a nickel foam and positive electrode material active layers coated on both end surfaces of the nickel foam, and an uncoated region is further provided on the nickel foam for being connected to one end of the positive electrode tab 60 by ultrasonic welding, and the other end of the positive electrode tab 60 is connected to the cap 30. The cap 30 may be any cap disclosed in the prior art as being applied to a cylindrical battery closure. The width of the negative electrode sheet 22 is larger than the width of the separator, and the height of the separator is between the positive electrode sheet 21 and the negative electrode sheet 22. The negative electrode plate 22 comprises a metal base material with a hollow structure or a net-shaped structure and negative electrode material active layers prepared on two end surfaces of the metal base material through a slurry pulling or coating process, and since the negative electrode plate 22 does not need to be connected with a tab, uncoated areas are not arranged on the two end surfaces of the negative electrode plate 22, which is beneficial to improving the capacity of a battery and simplifying the coating process of the negative electrode plate.

The battery cell 20 is vertically placed inside the housing 10, an insulating gasket 50 is disposed between the top end of the battery cell 20 and the cap 30, the insulating gasket 50 is used for preventing the negative electrode tab 22 of the battery cell 20 from contacting the cap, and a through hole (not shown in the drawing) is formed in the insulating gasket 50 for allowing the positive electrode tab 60 to pass through.

The conductive connection layer 70 is disposed on the bottom surface of the groove of the case 10, and the conductive connection layer 70 is connected to the bottom surface of the groove of the case 10 and the inner sidewall of the case 10. The bottom end of the cell 20 is connected to the conductive connection layer 40. It should be noted that, assuming that the height of the conductive connection layer 70 is a, the distance between the bottom end of the positive electrode tab 21 of the battery cell 20 and the bottom surface of the case 10 is b, and the distance between the bottom end of the negative electrode tab 22 of the battery cell 20 and the bottom surface of the case 10 is c, the following conditions are satisfied: c < a < b, in which the negative electrode tab 22 is electrically connected to the conductive connection layer 70 and the positive electrode tab 21 is not in contact with the conductive connection layer 70. The negative electrode tab 22 is electrically connected to the housing 10 by a conductive connecting layer 40.

The conductive connection layer 70 is prepared from solder paste, the solder paste is injected into the interior of the housing 10, the solder paste and the housing 10 are heated together to make the solder paste in a molten state, the heating modes include, but are not limited to, contact heating, infrared heating, laser heating, electromagnetic heating or microwave heating, etc., then the cell 20 is vertically placed into the interior of the housing 10, the bottom end of the cell 20 is inserted into the molten solder paste, and then the temperature is lowered to make the solder paste solidify to form the conductive connection layer 40, and at this time, the bottom of the negative electrode tab 22 of the cell 20 is connected with the conductive connection layer 70. And the conductive connection layer 70 also functions to support the vertical cell 20. The negative electrode 22 of the battery cell 20 is connected with the housing 10 through the conductive connecting layer 70, and the high-rate charge-discharge effect of the battery is equivalent to that of a cylindrical full-tab wound battery connected with the housing through laser spot welding.

The conductive connection layer 70 has conductivity after melting, and the melting temperature thereof is within an acceptable range for ensuring stable material properties of the battery cell 20. The solder paste is melted and then wets the negative electrode material active layer of the negative electrode plate 22, so that the complete electrical connection between the negative electrode plate 22 and the shell 10 is realized, the contact connection area is large, and meanwhile, the connection performance is stable, thereby being beneficial to heat dissipation of the battery.

In the technical solution of this embodiment, the cap 30 is provided with a liquid injection hole, an explosion-proof valve and a plug, the middle part of the cell 20 is formed with a liquid injection channel 23, and the liquid injection hole and the liquid injection channel 23 together form an electrolyte injection channel. The shutoff stopper of block 30 sets up in annotating the liquid hole department, and the explosion-proof valve sets up in the lateral part that seals the shutoff stopper, and the shutoff stopper can play the effect of shutoff to annotating the liquid hole. When the pressure in the case 10 is excessively high, the explosion-proof valve is automatically broken to prevent the explosion of the battery.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. A battery, the battery comprising:

a housing having a cavity and an opening in communication with the cavity;

the battery cell is formed by stacking and placing a positive electrode plate, a diaphragm and a negative electrode plate and then winding, the winding type battery cell is vertically arranged in the cavity, the diaphragm isolates the positive electrode plate from the negative electrode plate, the height of the diaphragm is between the positive electrode plate and the negative electrode plate, the height of the negative electrode plate is larger than that of the positive electrode plate, both end surfaces of the negative electrode plate are coated with a negative electrode active material layer, and liquid electrolyte is contained in the cavity;

the cover cap is arranged at the opening, and the positive pole piece is connected with the cover cap through a pole lug;

the sealing rubber ring is arranged between the cap and the opening of the shell;

an insulating gasket disposed between the battery cell and the cap;

the conductive connecting layer is arranged at the bottom of the cavity, the conductive connecting layer is connected with the bottom end face of the cavity and the side wall of the cavity, the conductive connecting layer is connected with one end of the negative electrode plate of the battery cell, which is far away from the opening, and the conductive connecting layer is not in contact with the positive electrode plate.

2. The battery according to claim 1, wherein the housing has a cylindrical groove structure, a flange is provided at a notch end of the housing, an edge of the cap is embedded into the flange, and a top side wall of the housing has an annular structure, so that the housing forms a cylindrical structure.

3. The battery according to claim 2, wherein the cap is provided with a liquid injection hole, a liquid injection channel is formed in the middle of the electric core, and the liquid injection hole and the liquid injection channel jointly form an electrolyte injection channel.