WO2010124591A1

WO2010124591A1 - Battery and fabricating method thereof

Info

Publication number: WO2010124591A1
Application number: PCT/CN2010/072102
Authority: WO
Inventors: 王伟强; 王春光; 任灿; 陈保同; 刘铭
Original assignee: 深圳市比克电池有限公司
Priority date: 2009-04-29
Filing date: 2010-04-23
Publication date: 2010-11-04
Also published as: CN101877420A

Abstract

A battery comprises a case and a battery unit which is sealed in the case and has a positive electrode lead-out terminal and a negative electrode lead-out terminal. Said case comprises a substrate and a composite plate which both form cavities with openings opposite to each other. Each cavity accommodates one part of the battery unit. Said substrate and composite plate are connected and sealed on their circumferential edges, and then two cavities with openings opposite to each other are united to form a sealed cavity which accommodates the battery unit completely. A battery fabricating method comprises machining a substrate and a composite plate, forming cavities with openings opposite to each other respectively and forming together a sealed cavity which accommodates a battery unit completely. Each cavity accommodates one part of the battery unit. Said method enables that the extension in the machining is equally shared by the substrate and the composite plate and the strength of the case is improved. Using metal substrate not only inherits high explosion-proof safety performance of the soft package battery but also improves the mechanical strength of the case. The battery case is not easy to be punctured, and the mechanical safety of the battery in use and fabrication is greatly improved.

Description

Battery and battery manufacturing method

The present invention relates to flexible packaging batteries and to a method of manufacturing a flexible packaging battery. Background technique

In a lithium ion battery, in addition to the positive and negative electrodes, the electrolyte, and the separator paper, a housing that stores various reaction components of the lithium ion battery is also a very important component. As an effective part, the housing provides the function of storing the lithium ion 1 battery in addition to the storage function, and it also helps the safety of the lithium ion battery.

At present, the materials used in the battery casing are mainly: stainless steel, nickel-plated steel, aluminum alloy and aluminum plastic film. The aluminum plastic film has the characteristics of softness and softness. Therefore, the battery using the aluminum plastic film as the casing is a flexible packaging battery, which has been highly valued for its superior safety in preventing explosion. Aluminum plastic film, also known as aluminum-plastic composite film, is a flexible packaging battery prepared by cutting a piece of aluminum-plastic composite film of a certain size, folding aluminum-plastic composite film, and high-temperature compounding the opening edge of the aluminum-plastic composite film to make the battery pole The group is sealed in the interior and the like to complete the manufacture. The aluminum-plastic composite film is made of multi-layer composite of PP and aluminum foil. It has low mechanical strength and is easily pierced by sharp substances during manufacturing and use, resulting in safety hazards due to scrapping or scratching. In order to solve the above problem of being easily pierced, a metal or plastic case is usually added to the soft packaged battery to improve its puncture resistance. Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a flexible packaging battery having a high mechanical strength.

Another technical problem to be solved by the present invention is to provide a method of processing the above battery. The technical problem of the present invention is solved by the following technical solutions:

A battery comprising a housing and a battery unit sealed therein having a positive electrode lead end and a negative electrode lead end, the case comprising a substrate and a composite plate. The composite plate and the substrate are each formed with a split cavity partially accommodating the battery unit, and the substrate and the periphery of the composite plate are sealed and connected, and the two open cavity bodies are combined to form a sealed cavity in which the battery unit is completely housed.

In order to improve the mechanical strength of the casing, the substrate and the composite plate structure are preferably: the composite plate has a layered structure including at least one metal plate, and the substrate includes a metal plate. The substrate is connected to the composite plate by a heat sealing seal.

The composite sheet described above includes an aluminum-plastic composite film.

The substrate includes any one of an aluminum plate, a steel plate, an aluminum foil, or a copper foil.

The above battery is a lithium ion battery.

The invention also relates to a battery manufacturing method comprising the following steps:

A. preparing a battery unit having a positive electrode lead end and a negative electrode lead end, and cutting a plate-shaped substrate of a certain size and a flat composite plate;

B. stamping the substrate and the composite board respectively, so that the substrate and the composite board form a split cavity and a peripheral edge partially accommodating the battery unit;

c. placing the battery unit into one of the open chambers;

D. After the composite board is connected to the periphery of the substrate, the two pairs of open cavities are combined to completely house the battery unit in the sealed cavity formed by the combination of the opposing cavities, wherein the positive electrode lead end and the negative electrode lead end are fixed on the composite plate and the substrate. Between the circumferences and beyond the circumference.

In order to improve the mechanical strength of the casing, the substrate and the composite plate structure are preferably: the composite plate has a layered structure including at least one metal plate, and the substrate includes a metal plate.

As a first embodiment of the present invention, the above step D further includes a step of forming a liquid injection path at a peripheral connection of the substrate and the composite plate, injecting the electrolyte into the sealing cavity through the liquid injection channel, and closing the liquid injection channel.

As a second embodiment of the present invention, in the case where the battery unit is not impregnated with the electrolyte, the above step B further includes the step of forming the second composite cavity for discharging the exhaust gas in the sealed chamber by stamping the composite plate; The method further includes forming a liquid injection channel at a peripheral connection of the substrate and the composite plate, wherein the liquid injection channel communicates with the sealing cavity and the second cavity, and the second cavity is provided with a second liquid injection channel, and the second liquid injection channel Connecting the second cavity to the outside, the step D further includes the step of injecting the electrolyte into the sealing cavity through the second liquid injection channel, the second cavity and the liquid injection channel, and then closing the liquid injection channel and the second liquid injection channel. .

In order to facilitate the exhaust gas discharge, the above step D further includes the steps of charging the battery and puncturing the second cavity, so that the gas in the sealed cavity is discharged through the liquid injection channel and the second cavity pierced, and the exhausting is completed. A process of closing the above-described liquid injection channel and cutting the second cavity is also included.

The beneficial effects of the present invention compared to the prior art are:

(1) By using a metal substrate as a part of the casing, it not only inherits the high anti-explosion safety performance of the flexible packaging battery, but also improves the mechanical strength of the casing, and the battery casing is not easily pierced, which greatly improves the battery use and manufacture. Mechanical safety in the process: processing substrates and composite panels, Forming a third cavity and a fourth cavity respectively, and jointly forming a first cavity for accommodating the battery unit, so that the stretching during processing is evenly distributed on the basic and composite plates, further improving the strength of the casing;

(2) The manufacturing cost of the substrate relative to the composite board is extremely low, and the production cost of the battery can be reduced;

(3) The sealing method of the reserved liquid injection channel is more operability with the way of completely sealing the battery unit, and the production efficiency is greatly improved;

(4) The manufacturing method of exhausting the exhaust gas from the second cavity to the cavity can greatly reduce the probability of the battery expansion of the drum shell;

(5) The method of puncturing the exhaust gas on the second cavity is more advantageous for exhaust gas removal. DRAWINGS

The present invention will be further described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a structure of a battery according to a specific embodiment of the present invention;

Figure 2 is an enlarged view of C in Figure 1;

3 is a schematic view showing a step 101 of Embodiment 1 of the battery processing method of the present invention;

Figure 4 is an enlarged view of A in Figure 3;

Figure 5 is an enlarged view of B in Figure 3;

6 is a schematic view showing a step 102 of Embodiment 1 of the battery processing method of the present invention;

Figure 7 is a schematic view showing the step 103 of Embodiment 1 of the battery processing method of the present invention. detailed description

A battery, one embodiment of which is a lithium ion battery, as shown in FIG. 1 and FIG. 2, comprising a housing and being sealed therein, having a positive terminal 4 and a negative terminal (with a positive terminal) 4 parallel arrangement, not shown) of the battery unit 3; the housing comprises a substrate 1, a layer of metal layer 11 and a layered structural composite board 2 composed of a hot melt layer 12 laminated on the front and back of the metal layer 11; The positive electrode lead end 4 and the negative electrode lead end are respectively provided with a hot melt layer 10 thereon; the substrate 1 has a C-shaped cross section, and includes a first peripheral edge 61 and a third cavity 51 having an opening; a cross section of the layered structural composite plate 2 The C-shape includes a second peripheral edge 62 and a fourth cavity 52 having an opening. The opening of the fourth cavity 52 is opposite to the opening of the third cavity 51, and the first peripheral edge 61 and the second peripheral edge 62 are integrally connected by fusion. The third cavity 51 and the fourth cavity 52 are combined to form the first cavity 5; the battery unit 3 is disposed in the first cavity 5, and the positive terminal 4 and the negative terminal of the battery unit 3 extend out of the first week The junction between the edge 61 and the substrate 1 is sandwiched between the edge 61 and the second peripheral edge 62. End terminal 4 and the negative electrode lead is also connected to a melt, is fixed between the substrate 1 and the layered structure composite plate 2. In a preferred manner, the substrate 1 is made of aluminum plate, steel plate, aluminum foil or copper foil, and the aluminum plate or stainless steel is used in a preferred manner. In a better manner, the A3003 or A3005 annealed 0-state aluminum alloy piece is used, and the thickness can be set at 0. Between 18~0. 35匪, it is best to use 0. 22~0. 3匪, in this case, use aluminum alloy sheet with model A 3005 and thickness of 0.25 ;; layered composite panel 2釆A layered composite of aluminum foil with two layers of PP and an intermediate interlayer is used, and a plate of an aluminum-plastic composite film of the current flexible packaging battery is used in a more preferable manner.

As shown in Tables 1 and 2, Table 1 shows the results of the puncture test of the aluminum-plastic composite film, and Table 2 shows the tensile strength test results of the aluminum-plastic composite film, which shows that the mechanical strength of the aluminum-plastic composite film is low.

Table 1 Test conditions

Material : Aluminum-plastic composite film 0. 12 + 15 Speed: 50. 00 m/min

Temperature: 26. 00°C Standard: 100. 00 mm

: 60. 00%

Test section maximum force fracture length extension rate sample number ( mm 2 ) ( N ) ( mm ) ( % )

201 1. 80 113. 89 59. 85 59. 85

202 1. 80 115. 57 48. 74 48. 74 203 1. 80 112. 46 44. 46 44. 46

204 1. 80 105. 65 37. 77 37. 77

205 1. 80 61. 92

206 1. 80 126. 60 60. 33 60. 33

207 1. 80 136. 06 71. 41 71. 41 Average 54. 93 54. 93 Table 2 In this case, aluminum and aluminum-plastic composite film are used, and the joint is made of aluminum and aluminum-plastic composite film. It can improve the mechanical strength of the shell while retaining the safety and explosion-proof performance of the aluminum-plastic composite film. Table 3 shows the tensile strength test results of aluminum sheets.

table 3

An embodiment of the battery manufacturing method of the present invention is a method for manufacturing a lithium ion battery, comprising the steps of:

Example 1

Step 101, as shown in FIG. 3, FIG. 4 and FIG. 5, a battery unit 3 having a positive electrode terminal 4 and a negative electrode terminal (not shown in parallel with the positive electrode terminal) is prepared, and the thin plate structure is cut to a certain size. The aluminum plate of the model A3003 is used as the substrate 1 and the aluminum-plastic composite film (also referred to as aluminum-plastic composite film) having the lamellar structure laminated plate as the layered structural composite plate 2; Step 102, as shown in FIG. 6 and FIG. 7, the stamped substrate 1 forms a first peripheral edge 61 and a third cavity 51, and the stamped layered composite panel 2 forms a second peripheral edge 62 and a fourth cavity 52, the third cavity The opening of the body 51 is opposite to the opening of the fourth cavity 52, together forming a first cavity 5 for accommodating the battery unit 3, and then stamping the layered composite panel 2, so that the second cavity 7 is formed;

Step 103, as shown in FIG. 7, the battery unit 3 is placed into the cavity 5 such that the negative electrode lead end of the positive electrode lead end 4 protrudes beyond the first peripheral edge 61 and the second peripheral edge 62; the first peripheral edge 61 and the first The two peripheral edges 62 are thermally fused so that the positive electrode terminal 4 and the negative electrode terminal are fixed between the layered composite plate 2 and the substrate 1, and the battery unit 3 is encapsulated inside the first cavity 5, and the substrate 1 and the layered structure are simultaneously The junction of the composite plate 2 forms a liquid injection channel 8 and a second liquid injection channel 9, wherein the liquid injection channel 8 communicates with the first cavity 5 and the second cavity 7, and the second liquid injection channel 9 connects the second cavity 7 with the outside Connected; due to the presence of PP material in the aluminum plastic film, the melting temperature of the PP material is about 150 ° C, taking into account the machine fluctuations, the temperature of the hot melt composite connection is 90 ° C, the composite pressure is 3 MPa;

Step 104: The electrolyte is injected into the first cavity 5 through the second liquid injection channel 9, the second cavity 7, and the liquid injection channel 8, and then the second liquid injection channel 9 is closed;

Step 105: charging the battery;

Step 106: Piercing the second cavity 7 to exhaust the exhaust gas generated in the first cavity 5 through the injection channel 8 and the second cavity 7;

Step 107: Finally, the liquid injection channel 7 is closed, and the second cavity 7 is cut off to produce a battery as shown in FIG.

The battery processed in this example was tested for peel strength by shell connection. The test results are shown in Table 4.

Table 4

Example 2: This example is basically the same as Example 1, except that the compounding temperature in the step 103 is 120 °C.

The processed battery was tested for peel strength by shell connection, and the test results are shown in Table 5. Sample maximum force (N) maximum deformation ( 匪 ) test time (S)

501 52.916 27.6622 33.6 502 47. 868 30. 2

503 63. 495 6. 4819 8. 2

504 54. 318 23. 7385 28. 8

table 5

Example 3: This example is basically the same as Example 1, except that the compounding temperature in the step 103 is 140 °C. The processed battery was tested for peel strength by shell connection, and the test results are shown in Table 6.

Oo

Table 6

Example 4: This example is basically the same as Example 1, except that the composite temperature in step 103 is 140 ° C, the composite pressure is IMP, and the processed battery is tested by the shell connection peel strength test. 7 is shown.

Table 7

Example 5: This example is basically the same as Example 3 except that the composite temperature in step 103 is 120 ° C and the composite pressure is 5 MPa. The processed battery is tested by the shell connection peel strength test. 8 is shown.

Table 8

Comparative Example: The peel strength test results of a conventional composite aluminum-plastic composite film are shown in Table 9.

Table 9

It can be seen from the comparison of the peel strength test that the pressure at 120 °C is higher at a pressure of 3 MPa, and the pressure at 5 MPa is greater at a temperature of 120 ° C, but it is limited to the long-term use of the equipment, preferably using a pressure of 3 MPa. Compared with the composite strength of the aluminum-plastic composite film, it can be seen that the composite strength of the material used in the present invention can meet the needs of normal production.

Scanning electron microscopy (SEM) test of the composite position of the present invention shows that the composite layer is tightly packed from the composite layer, and the aluminum sheet and the aluminum-plastic composite film are mutually infiltrated, and the composite effect is good.

Another embodiment of the method of fabricating a battery of the present invention for use in nickel-hydrogen battery processing includes the following steps:

Example 6

Step 601, preparing a battery unit having a positive electrode terminal 4 and a negative electrode terminal, and cutting a certain size of an aluminum plate of the type A3005 having a thin plate structure as the substrate 1 and an aluminum-plastic composite film (also referred to as an aluminum plastic film) having a thin plate structure as Layered composite panel 2;

Step 602, the stamped substrate 1 forms a first peripheral edge 61 and a third cavity 51, and the stamped layered composite panel 2 forms a second peripheral edge 62 and a fourth cavity 52, the opening of the third cavity 51 and the fourth cavity The openings of 52 are opposite to each other to form a first cavity 5 capable of accommodating the battery unit 3;

Step 603, the battery unit 3 is placed in the first cavity 5 such that the positive terminal 4 and the negative terminal extend beyond the first periphery 61 and the second periphery 62;

Step 604, hot-melt connecting the first peripheral edge 61 and the second peripheral edge 62, so that the positive electrode terminal 4 and the negative electrode terminal are fixed between the layered composite plate 2 and the substrate 1, and the battery unit 3 is sealed in the first cavity. 5 internal, forming a complete battery.

In this example, the battery unit 3 has been impregnated with the electrolyte so that the battery unit can be completely sealed in the first chamber 5 at one time.

The above is a further detailed description of the present invention in conjunction with specific preferred embodiments. It is to be understood that the specific implementation of the invention is not limited to the description. It will be apparent to those skilled in the art that the present invention may be made without departing from the spirit and scope of the invention.

Claims

Claim

A battery comprising a casing and a battery unit sealed therein, having a positive electrode terminal and a negative electrode terminal, the casing comprising a substrate and a composite plate, wherein: the composite plate and the substrate are formed Partially accommodating the opposing cavity of the battery unit, the substrate and the periphery of the composite plate are sealingly connected, and the two opposing cavities are combined to form a sealed cavity that completely houses the battery unit.

2. The battery according to claim 1, wherein: the composite board has a layered structure including at least one metal plate, and the substrate comprises a metal plate.

3. The battery according to claim 2, wherein: the substrate and the composite board are connected by a heat sealing seal.

The battery according to any one of claims 2 or 3, wherein the composite panel comprises an aluminum-plastic composite film.

The battery according to any one of claims 2 to 3, wherein the substrate comprises any one of an aluminum plate, a steel plate, an aluminum foil or a copper foil.

The battery according to any one of claims 1 to 3, wherein the battery is a lithium ion battery.

A battery manufacturing method, comprising the steps of:

A. preparing a battery unit having a positive electrode lead end and a negative electrode lead end, cutting a plate-shaped substrate of a certain size and a flat composite plate;

C. Put the battery unit into one of the open chambers;

8. The method of manufacturing a battery according to claim 7, wherein the composite plate has a layered structure including at least one metal plate, and the substrate comprises a metal plate.

The battery manufacturing method according to claim 7 or 8, wherein the step D further comprises forming a liquid injection channel at a peripheral connection of the substrate and the composite plate, and injecting the electrolyte through the liquid injection channel. The cavity, the step of closing the injection channel.

The battery manufacturing method according to claim 7 or 8, wherein the step B further comprises the step of forming a second composite cavity for discharging the sealed cavity exhaust gas by stamping the composite plate; The method further includes forming a liquid injection channel at a peripheral connection of the substrate and the composite plate, the liquid injection channel communicates with the sealing cavity and the second cavity, and the second cavity is provided with a second liquid injection channel, the second The liquid injection channel communicates with the second cavity and the outside, and the step D further includes injecting the electrolyte into the sealing cavity through the second liquid injection channel, the second cavity and the liquid injection channel, and then injecting the liquid channel and the second liquid injection The step of closing the channel.

11. The method of manufacturing a battery according to claim 10, wherein: the step D further comprises: charging the battery, and puncturing the second cavity, so that the gas in the sealed cavity passes through the liquid injection channel. And the second cavity of the puncture is discharged, and after the exhausting is completed, the process of closing the liquid injection channel and cutting the second cavity is further included.