CN103733377B

CN103733377B - Secondary cell aluminium pot body and manufacture method thereof

Info

Publication number: CN103733377B
Application number: CN201280039602.7A
Authority: CN
Inventors: 松本刚; 小林一德
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2011-10-28
Filing date: 2012-09-13
Publication date: 2016-06-01
Anticipated expiration: 2032-09-13
Also published as: JP2013097900A; CN103733377A; WO2013061707A1; JP5656802B2; KR101697410B1; KR20140077940A

Abstract

The present invention relates to the lid body and exterior body laser welding the secondary cell aluminium pot body that assembles and manufacture method thereof that form by aluminium alloy plate body. Preparing the alloy sheets body being made up of aluminium alloy, the end face of 2-in-1 gold plate body is docked by the acies portion, side along the 1st alloy sheets body, and described aluminium alloy is by quality ratio at least containing the B of the Si of less than 0.30%, the scope of 2��30ppm; Along what the end face at the 1st alloy sheets body produced, wiring is carried out continuous laser welding. Width W is set to more than 1.5 relative to the ratio of the degree of depth D clipping melting junction surface wiring given herein, and controls Laser Welding Condition in the way of there is the degree of depth D of more than 0.35mm.

Description

Secondary cell aluminium pot body and manufacture method thereof

Technical field

The present invention relates to the lid body formed by aluminium alloy plate body and exterior body welds and the aluminium pot body that assembles and manufacture method thereof.

Background technology

Below, such as, (it is called patent documentation 1 at Japanese Unexamined Patent Publication 11-104866 publication. ) in, disclose following technology: the end face of lid body alloy sheets body is docked by the acies portion, side along the aluminium alloy plate body being made up of the aluminium alloy and JIS-A3000 system that mainly with the addition of Mn, on the other hand, wiring utilizes YAG disk laser carry out laser welding carry out assembling jar body along what the end face at main body alloy sheets body produced.

Below, in addition, (it is called patent documentation 2 at Japanese Unexamined Patent Publication 2009-146645 publication. ) in, to mention: dispersing and weld seam (bead) thickness being reduced of the metal caused by sputtering occurs with the use of high-density thermal source laser, formation there occurs the welding portion of the shape of depression from outside. On the other hand, disclose: along main body alloy sheets body and lid body alloy sheets body, wiring is formed protuberance laterally from two plate bodies, this protuberance is carried out laser welding.

Below, further, (it is called patent documentation 3 at Japanese Unexamined Patent Publication 2009-287116 publication. ) in, although being low strength but the JIS-A1000 system of high conductivity (pure aluminum) is applicable to the tank body of lithium-ion secondary cell of automobile mentioning, if and with aluminium plate described in the pulsed laser welding of high-energy-density, then the width at melting junction surface and the degree of depth are produced bigger impact by the composition such as the impurity in aluminium plate and condition of surface, can produce to run through aluminium plate abruptly such excessively dark thoroughly molten, or produce pore etc., easily cause the acute variation at melting junction surface.

Prior art literature

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 11-104866 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2009-146645 publication

Patent documentation 3: Japanese Unexamined Patent Publication 2009-287116 publication

Summary of the invention

For the lightweight of the battery of lithium-ion secondary cell etc., it is desirable to: the aluminium alloy using high strength in lid body and exterior body, such as, among JIS-A3000 system, they are carried out laser welding to be assembled into aluminium pot body by particularly A3003, A3005. Herein, in order to improve the bond strength of welding, it is preferable that deeper form melting junction surface and obtain wider bonding area. On the other hand, while adopting the aluminium alloy of high strength, the plate of lid body and/or exterior body is thick thinning, so the width at bigger melting junction surface can not be obtained. That is, only wish to make the depth direction at melting junction surface to become big, it is possible to adopt aperture (keyhole) the type welding etc. of high-energy-density. But, as disclosed in going back in patent documentation 1��3, in the laser welding of high-energy-density, it is difficult to give intact melting junction surface when not producing weldering root crackle (rootcrack), pore (porosity) stablely.

Therefore, it is an object of the invention to provide a kind of secondary cell aluminium pot body, its for the lid body and the exterior body laser welding that form by the aluminium alloy plate body of high strength and the secondary cell aluminium pot body assembled, there is provided: can when not producing weldering root crackle, pore, can give stablely the secondary cell aluminium pot body at intact melting junction surface manufacture method and by giving this intact junction surface and higher strength of joint, thus there is high mechanical strength as a whole.

The manufacture method of the secondary cell aluminium pot body of the present invention is characterised in that, its for the lid body and the exterior body laser welding that form by aluminium alloy plate body and the manufacture method of secondary cell aluminium pot body assembled, it comprises configuration step: prepare the alloy sheets body being made up of aluminium alloy, and is docked by the end face of 2-in-1 gold plate body along the acies portion, side of the 1st alloy sheets body; Described aluminium alloy at least contains the B of the scope of the Si and 2��30ppm of by quality ratio less than 0.30%; Welding step: wiring is carried out continuous laser welding along what the end face at above-mentioned 1st alloy sheets body produced, above-mentioned welding step comprises the steps: to control Laser Welding Condition taking width W relative to the mode of the ratio W/D clipping the above-mentioned degree of depth D to the melting junction surface that wiring is given as more than 1.5.

Now, in the assembling of secondary cell aluminium pot body utilizing laser welding, can by controlling the energy density of continuous laser and width W be set to more than regulation relative to the ratio of the degree of depth D at melting junction surface, it is grouped into and the degree of depth D at melting junction surface can be made bigger by adjusting the one-tenth of aluminium alloy plate body simultaneously, and intact melting junction surface can be given when not making crackle, pore produce stablely. That is, the secondary cell aluminium pot body giving intact junction surface and have higher physical strength can be provided.

In above-mentioned the present invention, its feature can be: above-mentioned configuration step prepares the step of the aluminium alloy plate body of following compositions composition including as the one or both of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body, described one-tenth is grouped into and is made up of following, by quality ratio Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.25%, Mn:0.8��1.5%, B:2��20ppm is as must addition element, the scope of below Mg:0.05%, below Ti:0.1% is as any addition element, and surplus is Al and inevitable impurity. Now, the secondary cell aluminium pot body with the physical strength suitable with A3003 material can be provided.

In above-mentioned the present invention, its feature can be: above-mentioned configuration step prepares the step of the aluminium alloy plate body of following compositions composition including as the one or both of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body, described one-tenth is grouped into by forming as follows: by quality ratio Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.3%, Mn:0.8��1.5%, Mg:0.2��0.6%, B:2��30ppm is as must addition element, the scope of below Ti:0.1% is as any addition element, and surplus is Al and inevitable impurity. Now, the secondary cell aluminium pot body with the high mechanical strength suitable with A3005 material can be provided.

In above-mentioned the present invention, its feature can be: above-mentioned configuration step also prepares the step of aluminium alloy plate body as above-mentioned lid body of following compositions composition including as the another one of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body, described one-tenth is grouped into by forming as follows: B:2��10ppm is as necessary addition element by quality ratio, below Si:0.30%, below Fe:0.6%, below Cu:0.1%, below Mn:0.05%, below Mg:0.05%, below Zn:0.1%, the scope of below Ti:0.04% is as any addition element, surplus is Al and inevitable impurity. now, even if optionally adopting the lid body compared exterior body and the physical strength of mother metal reduced, in the assembling of secondary cell aluminium pot body utilizing laser welding, also by control continuous laser energy density and by width W relative to the ratio of the degree of depth D at melting junction surface be set to regulation above while, the degree of depth D allowing to melting junction surface is bigger, and gives intact melting junction surface when not making crackle, pore produce stablely.

In above-mentioned the present invention, its feature can be: the acies portion, side along above-mentioned 1st alloy sheets body has cutting portion. Now, because of can easily and precision carry out the position alignment of plate body well and temporarily fix, so intact melting junction surface can be given stablely.

Further, the secondary cell of the present invention aluminium pot body, it is characterized in that, it is the lid body and exterior body laser welding the secondary cell aluminium pot body that assembles that form by aluminium alloy plate body, above-mentioned aluminium alloy plate body be by quality ratio at least containing less than 0.30% Si, the aluminium alloy of the B of the scope of 2��30ppm, along the acies portion, side of the 1st alloy sheets body, by the end face docking of the 2-in-1 gold plate body, end face at above-mentioned 1st alloy sheets body produces wiring, along this, wiring is carried out continuous laser welding, and width W is more than 1.5 relative to clipping the above-mentioned ratio W/D to the degree of depth D at the melting junction surface that wiring is given, and degree of depth D is more than 0.35mm.

Now, in the secondary cell aluminium pot body utilizing laser welding to assemble, can by control continuous laser energy density and by width W relative to the ratio of the degree of depth D at melting junction surface be set to regulation above while, being grouped into by the one-tenth of adjustment aluminium alloy plate body makes the degree of depth D at melting junction surface be set to more greatly, and gives intact melting junction surface when not making crackle, pore produce stablely. That is, the secondary cell aluminium pot body having intact junction surface and having higher physical strength can be provided.

In above-mentioned the present invention, its feature can be: the one or both of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body has following compositions composition, described one-tenth is grouped into by forming as follows: by quality ratio Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.25%, Mn:0.8��1.5%, B:2��20ppm is as must addition element, the scope of below Mg:0.05%, below Ti:0.1% is as any addition element, and surplus is Al and inevitable impurity. Now, can obtain having the tank body of the physical strength suitable with A3003 material.

In above-mentioned the present invention, its feature can be: the one or both of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body has following compositions composition, described one-tenth is grouped into by forming as follows: by quality ratio Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.3%, Mn:0.8��1.5%, Mg:0.2��0.6%, B:2��30ppm is as must addition element, the scope of below Ti:0.1% is as any addition element, and surplus is Al and inevitable impurity. Now, can obtain having the tank body of the high mechanical strength suitable with A3005 material.

In above-mentioned the present invention, its feature can be: the alloy sheets body of the another one of above-mentioned 1st alloy sheets body or above-mentioned 2-in-1 gold plate body is above-mentioned lid body, and there is following compositions composition, described one-tenth is grouped into by forming as follows: B:2��10ppm is as necessary addition element by quality ratio, the scope of below Si:0.30%, below Fe:0.6%, below Cu:0.1%, below Mn:0.05%, below Mg:0.05%, below Zn:0.1%, below Ti:0.04% is as any addition element, and surplus is Al and inevitable impurity.

Now, even if when the lid body that physical strength is reduced by exterior body is compared in employing, by width W relative to the ratio of the degree of depth D at melting junction surface be set to regulation above while, the degree of depth D at melting junction surface is relatively big, and realizes the effect that secondary cell aluminium pot body can have the few intact melting junction surface of crackle, pore and have high mechanical strength.

In above-mentioned the present invention, it is characterized by: along above-mentioned 1st alloy sheets body acies portion, side give cutting portion and weld. Now, because of can easily and precision carry out the position alignment of plate body well and temporarily fix, therefore intact melting junction surface can be given stablely.

Accompanying drawing explanation

Fig. 1 is stereographic map and the sectional view of the welding joint in welding test.

Fig. 2 is the representative value of the alloying constituent of the welding joint in welding test.

Fig. 3 is the alloying constituent of welding joint in display welding test and the figure of test-results.

Fig. 4 is the alloying constituent of welding joint in display welding test and the figure of test-results.

Fig. 5 is the photo of the pore quality for judging in welding test.

Fig. 6 is the photo of the crackle quality for judging in welding test.

Fig. 7 is the stereographic map of the test body in tension test.

Fig. 8 is the sectional view of other welding joints.

Fig. 9 is the sectional view of another other welding joints.

Embodiment

The present invention relates to the lid body and exterior body laser welding the aluminium pot body that assembles and manufacture method thereof that form by aluminium alloy plate body. In particular, the present invention relates to receive secondary cell aluminium pot body and the manufacture method thereof of secondary cell as lithium-ion secondary cell.

When by laser welding secondary cell for assembling with aluminium pot body, in order to obtain the higher physical strength at melting junction surface, it is necessary to form melting junction surface deeper. But, what be considered to be formed deeper melting junction surface utilizes the pinhole type of high-density laser to weld, and easily occurs weld seam to split the confusion at root and the such defect of pore, melting junction surface. The present inventor has drawn as drawn a conclusion: in the purposes of the intact welding of being aspired for stability of the outward appearance comprising melting junction surface as secondary cell aluminium pot body, it is difficult to apply this welding. Therefore, deeply investigate: while not producing the heat-conducting type laser welding of aperture by reducing energy density and obtaining intact melting junction surface, and the one-tenth as the high-strength aluminium alloy plate body used in the manufacture of the secondary cell aluminium pot body of soldered object is grouped into changes in order to melting junction surface can be made to deepen.

It found that, by among the composition contained by aldural, particularly adjust the content of Si and B, the degree of depth given as melting junction surface as the physical strength needed for secondary cell aluminium pot body can be obtained, and intact melting junction surface can be obtained stablely. Find again: in the aluminium alloy that with the addition of Mg, adjusted in the lump by the addition of related Mg, the melting junction surface being equal to the aluminium alloy not adding Mg can be obtained.

About more than, there is the degree of depth and stable obtain for the purpose of intact melting junction surface, present inventor has performed welding test. About this welding test, it is described in detail with Fig. 1��Fig. 7.

As shown in Fig. 1 (a), in welding test, the docking section of the housing plate 2 suitable with the exterior body of secondary cell tank body and lid body plate 3 this 2 flat aluminium alloy plates suitable with lid body is carried out continuous laser weld, make the welding joint 1 of the L font that weld length is set to 200mm and carried out various test. It should be noted that, housing plate 2 is the aluminium alloy plate that is grouped into of one-tenth described later of the thick 0.5mm of plate, width 50mm, length 200mm, and lid body plate 3 is the aluminium alloy plate that is grouped into of one-tenth described later of the thick 1.0mm of plate, width 50mm, length 200mm.

If with reference to Fig. 1 (b), then in the making of welding joint 1, near the end face 2a of housing plate 2, namely at the end face 3a of acies portion, side docking cover body plate 3 of housing plate 2, and configure, temporarily fix. Herein using the outside edge line of the end face 3a as binding surface with the edge line along the end face 2a residing for edge line outside this as to wiring 5.

Then; utilize multi-mode CW (continuous oscillation) optical fiber laser; along to wiring 5 from the surface irradiating laser 6 of end face 2a; welding speed is set to 5m/ minute, advancing angle be set to 10 ��, while carry out laser welding using 20 liters/min to the supply of welding portion as the nitrogen limit of shielding gas. Melting junction surface 4 clips and wiring 5 is formed across both housing plate 2 and lid body plate 3, and housing plate 2 and lid body plate 3 are engaged, and obtain welding joint 1.

It should be noted that, so that the distance of processing point with focus is set to 0, focusing beam diameter is 0.8mm, and the mode that its power is 2500��3200W adjusts laser. Herein, if with reference to Fig. 1 (c), then in the welding of the laser power density of this heat-conducting type, confirm: although width W is more than 1.5 relative to the ratio of the degree of depth D at melting junction surface 4, but in aftermentioned embodiment, all in the degree of this power range, the degree of depth D at melting junction surface 4 can be set to more than 0.35mm, therefore have adjusted laser power in the way of the degree of depth D at melting junction surface 4 becomes 0.4mm (�� 0.01mm).

In addition, in aftermentioned comparative example, carry out forming the such pinhole type welding of aperture at melting junction surface 4, but herein by the distance of processing point with focus is set to 0, focusing beam diameter is limited to 0.2mm, its power be 600��800W to adjust laser, welded as described above.

It is that one-tenth after the one-tenth of the alloy numbering 3003,3005 and 1050 of regulation in JIS-H4000 is grouped into change is grouped into that the one-tenth of aluminium alloy plate used in the making of welding joint 1 is grouped into, respectively hereinafter referred to as 3003 being, 3005 be, 1050 be. At both middle aluminium alloy plate bodies using these one-tenth to be grouped into of housing plate 2 and lid body plate 3. In fig. 2, show and 3003 it is, 3005 is and the 1050 respective representative compositions being. In addition, in figure 3, the one-tenth of the aluminium alloy used in the welding joint 1 of embodiment 1��15 and comparative example 1��21 illustrate only Si, Mg, B among being grouped into. That is, be grouped into about one-tenth in addition to these, with the 3003 of Fig. 2 be and the 3005 representative compositions being identical. Further, about using in lid body plate 3 1050 it is, uses 3003 to be or the embodiment 16��21 of 3005 situations being and comparative example 22��30 be shown in too in Fig. 4 in housing plate 2. Herein, the content of each composition is all by quality ratio, below, only represents with % or ppm.

Fig. 3 and Fig. 4 has illustrated test-results. It should be noted that, in the hurdle of Laser Welding Condition, " K " represents that the laser power and carrying out when welding speed in pinhole type welding is welded, " H " represents and weld when the laser power of heat-conducting type welding and welding speed.

About the judgement of " outward appearance ", by outward appearance visual observation, the entirety of the weld length 200mm of each welding joint 1 of gained is carried out. Melting junction surface 4 is judged to well without situation that is chaotic and that obtain stable outward appearance, in Fig. 3 and Fig. 4, represents to be "��". The width localized variation at melting junction surface 4 or undercut are locally occurred, the situation only with the part of 1 place's outward appearance confusion be judged to still can, represent for " �� " in Fig. 3 and Fig. 4. The situation with the outward appearance confusion more than 1 place is judged to defective, represents in Fig. 3 and Fig. 4 for "��".

About the judgement of " pore " and " crackle ", cut the sample of the length of 20mm from the weld length 200mm of arbitrary 2 positional distance welding joints 1 and grind, utilize observation by light microscope to carry out. It should be noted that, the section in the welding line direction of the length direction along welding joint 1 observes the center portion at melting junction surface 4. In the judgement of " pore ", as shown in Fig. 5 (a), it is good by the judgement not observing the pore of diameter more than 50 ��m, represents in Fig. 3 and Fig. 4 for "��". As shown in Fig. 5 (b), by relative to weld length 10mm observe the pore before less than 5 diameters reach 100 ��m be judged to still can, represent for " �� " in Fig. 3 and Fig. 4. As shown in Fig. 5 (c), it will be observed that the pore of the size of diameter more than 100 ��m is judged to defective, represent for "��" in Fig. 3 and Fig. 4. In addition, in the judgement of " crackle ", as shown in Fig. 6 (a), it is good by the judgement not observing crackle, represents in Fig. 3 and Fig. 4 for "��". As shown in Fig. 6 (b), it will be observed that the judgement of crackle is defective, represent for "��" in Fig. 3 and Fig. 4.

About the judgement of " strength of joint ", it is that corresponding embodiment 5��12, comparative example 5��16 are undertaken by tension test to 3005. Specifically as shown in Figure 7, housing plate 2b is fixed on fixture 20 and carries out tension test by the test body 1b of the length being cut into 20mm with the weld length 200mm apart from each welding joint 1 in arbitrary position. The interarea making housing plate 2b and the L-type fixture 21 installed on the chuck (chuck) of a side of not shown tensile testing machine above to connecing, by pressing plate 22, housing plate 2b from pressing above and is fixed with bolt 23 and nut 24. Further, in the way of making the center of the lid body plate 3b of test body 1b overlap with the central shaft M of the stretching of not shown tensile testing machine, lid body plate 3b is installed on not shown chuck. Thus, taking its binding surface as boundary, test body 1b is divided into upper and lower mode to stretch. Value tensile strength obtained divided by the sectional area of the lid body plate 3b of test body 1b is than the 110N/mm of the strength of joint as 3003 standards being²High by 10%, i.e. 121N/mm²Above situation is judged to well, by less than 121N/mm²Situation be judged to defective, represent for "��" "��" in Fig. 3 and Fig. 4 respectively.

" evaluation " of the experiment results of each welding joint 1 carries out based on each result of determination of above-mentioned " outward appearance ", " pore ", " crackle " and " strength of joint ". That is, in Fig. 3 and Fig. 4, by expression all intact for above-mentioned result of determination be " well ", by result of determination comprise still can and there is no defective expression for " still can ", comprise defective expression for " defective " by result of determination.

Carry out describing to the test-results of Fig. 3. First, the comparative example 18��21 that the comparative example 10��16,1050 about 3003 comparative examples being 1��4,3005 that Laser Welding Condition is set to " K " being is is all " defective " that " evaluation " of welding test is all " defective " in " outward appearance ". In addition, in " pore ", also there is no the result of " well ". That is, it is difficult to obtain in good condition melting junction surface 4 by pinhole type welding.

Then, in 3003 embodiments being 1 and 2, " evaluation " of the experiment results is " well ", and in embodiment 3 and 4, " evaluation " of the experiment results is " still can ". Utilize in the embodiment that heat-conducting type welds at this, obtain required degree of depth D and intact melting junction surface 4. It should be noted that, about embodiment 3 and 4, the part at melting junction surface 4 is observed slight confusion, be " still can " in " outward appearance ". In the survey, with regard to the content of B, compared with 5.7ppm and 9.7ppm of embodiment 1 and 2, up to 11.0ppm and 17.3ppm in embodiment 3 and 4, which is beyond that 10ppm. Although situation describes later in detail, it is postulated that it is the reason of the confusion at melting junction surface 4. Therefore, although the upper limit of the content of B is 20ppm in 3003 being, but the upper limit of preferred content is 10ppm.

In addition, in 3005 embodiments being 5 and 6, " evaluation " of the experiment results is " well ", and in embodiment 7 and 8, " evaluation " of the experiment results is " still can ". In the embodiment utilizing this heat-conducting type to weld, obtain required degree of depth D and intact melting junction surface 4. It should be noted that, about embodiment 7 and 8, the some at melting junction surface 4 is observed slight confusion, be " still can " in " outward appearance ". In the survey, with regard to the content of B, compared with 9.8ppm and 16.3ppm of embodiment 5 and 6, embodiment 7 and 8, up to 20.9ppm and 26.7ppm, has exceeded 20ppm. Although situation describes later in detail, it is postulated that it is the reason of the confusion at melting junction surface 4. Therefore, although the upper limit of the content of B is 30ppm in 3005 being, but the upper limit of preferred content is 20ppm.

Further, in 1050 embodiments being 13 and 14, " evaluation " of the experiment results is " well ", and in embodiment 15, " evaluation " of the experiment results is " still can ". In the embodiment utilizing this heat-conducting type to weld, obtain required degree of depth D and intact melting junction surface 4. It should be noted that, about embodiment 15, the part at melting junction surface 4 is observed slight confusion, be " still can " in " outward appearance ". In the survey, with regard to the content of B, compared with 2.7ppm and 5.3ppm of embodiment 13 and 14, embodiment 15, up to 9.2ppm, has exceeded 6ppm. Although situation describes later in detail, it is postulated that it is the reason of the confusion at melting junction surface 4. In addition, in comparative example 17, the content of B is up to 13.4ppm, has exceeded 10ppm. Its result is, melting junction surface 4 is observed confusion and in " outward appearance " for " defective ", namely " evaluation " of the experiment results is " defective ". Therefore, in 1050 being, the upper limit of the content of B is 10ppm, it is more preferable to the upper limit of content be 6ppm.

Then, in 3005 embodiments being 9, comparative example 5 and 6, the content of Si is set to 0.25%, 0.32% and 0.45% successively. Its result is, the content of Si is being set in the embodiment 9 of 0.25%, " evaluation " of the experiment results is " well ", but " crackle " is " defective " being set to by the content of Si in the comparative example 5 and 6 more than 0.30%, also not obtaining the result of " well " in " pore ", " evaluation " of the experiment results is " defective ". Although situation describes later in detail, it is postulated that the reason of crackle is the content height of Si, in 3005 being, the upper limit of the content of Si is 0.30%.

Then, in 3005 comparative examples being 7, embodiment 10��12, comparative example 8 and 9, the content of Mg is set to 0.11%, 0.21%, 0.39%, 0.52%, 0.64% and 0.78% successively. Its result is, the content of Mg is being set in the comparative example 7 less than 0.2%, " strength of joint " is " defective ", Mg content is being set in the comparative example 8 and 9 more than 0.6%, " crackle " is " defective ", but " evaluation " of the experiment results is " well " in embodiment 10��12. Although situation describes later in detail, it is postulated that the content that the reason of decrease in intensity is Mg reduces, the reason of crackle is that the content of Mg raises. Therefore, in 3005 being, the content of Mg is in the scope of 0.2��0.6%.

With upper, in the assembling of secondary cell aluminium pot body utilizing laser welding, the adjustment energy density of continuous laser, welding speed etc., to become the welding of the ratio of width W relative to the degree of depth D at melting junction surface 4 as more than 1.5, i.e. heat-conducting type welding, and the degree of depth 0.4mm (�� 0.01mm) of the degree of depth at more than 0.35mm at the melting junction surface 4 of the physical strength required for the plate body thickness for common secondary cell aluminium pot body is given can be obtained. And, the content of Si and B is adjusted by the one-tenth that is corresponding 3003 in being grouped into, 3005 be corresponding one-tenth be grouped in adjust the content of Si, B and Mg, 1050 be corresponding one-tenth be grouped in adjust the content of B, thus can obtain intact melting junction surface 4 respectively. That is, the secondary cell aluminium pot body that can obtain that there is intact junction surface, there is more high mechanical strength.

It should be noted that, about the integrity at melting junction surface, when obtaining requiring among common aluminum alloy welding connection member tighter lithium-ion secondary cell aluminium pot body, not only " evaluation " of above-mentioned welding test be judged to " still can ", and based on being judged to that " well " needs and be specified to the scope that is grouped into. That is, the upper limit of the content of B is: 3003 be corresponding one-tenth be grouped in for 10ppm, 3005 be corresponding one-tenth be grouped in be 20ppm, 1050 be corresponding one-tenth be grouped in be 6ppm.

Then carry out describing to the test-results of Fig. 4. First, Laser Welding Condition is set to " K ", about housing plate 2 being set to 3003 comparative examples being 24 and 25, housing plate 2 is set to 3005 comparative examples being 29 and 30, being all " defective " in " pore ", " evaluation " of welding test is all " defective ". That is, it is difficult to obtain intact melting junction surface 4 by pinhole type welding.

Further, housing plate 2 is being set in 3003 embodiments being 16��18, comparative example 22, with regard to 1050 one-tenth being with regard to using in lid body plate 3 are grouped into, the content of B is set to 2.7ppm, 5.3ppm, 9.2ppm, 13.4ppm successively, and itself and above-described embodiment 13��15, comparative example 17 are identical with about lid body plate 3. The experiment results is also same with embodiment 13 and 14 in embodiment 16 and 17, " evaluation " is " well ", in embodiment 18 similarly to Example 15, " outward appearance " is " still can ", thus " evaluation " is also " still can ", in comparative example 22 same with comparative example 17, " outward appearance " is " defective ", and thus " evaluation " is also " defective ". Think that the different reason of these results is caused by the difference of the content of the B of lid body plate 3. That is, the investigation same with above-described embodiment 13��15, comparative example 17 is given.

In addition, about housing plate 2 being set to 3005 embodiments being 19��21, comparative example 26, also it is the experiment results same with above-described embodiment 16��18 and comparative example 22. About these results, give also the investigation same with above-described embodiment 13��15, comparative example 17.

Further, being set to by housing plate 2 in 3003 comparative examples being 23, the content of the B of housing plate 2, up to 27.2ppm, observes confusion in melting junction surface 4, is " defective " in " outward appearance ", and namely " evaluation " of the experiment results is " defective ". Although the upper limit being described in the content that 3003 one-tenth being are grouped into middle B above is 20ppm, but this is the result becoming its evidence.

Then, in comparative example 27, Si is set to up to 0.45% in being grouped into by 3005 one-tenth being used in housing plate 2. Same with above-mentioned comparative example 6, it is " defective " that the content of Si is set to the result more than 0.30% " crackle ", and " evaluation " of the experiment results is " defective ". Same with above-mentioned comparative example 6, it is believed that the reason of crackle is the content height of Si.

In addition, in comparative example 28, Mg is set to up to 0.78% in being grouped into by 3005 one-tenth being used in housing plate 2. Same with above-mentioned comparative example 9, the content of Mg is set to the result more than 0.6% is " crackle " is " defective ", and " evaluation " of the experiment results is " defective ". Same with comparative example 9, it is believed that the reason of crackle is that the content of Mg is many.

Then, when obtaining with the equal melting junction surface of above-described embodiment, to determining as use in the assembling of secondary cell aluminium pot body 3003 it is and the reason of composition range of necessary addition element of the 3005 aluminium alloy plate bodies being is described.

Si mother mutually in solid solution and make as needed for aluminium alloy plate body physical strength improve, make as assembling after secondary cell aluminium pot body needed for compressive strength improve. In addition, form Al-Fe-Mn-Si series intermetallic compound, the plasticity during formed machining of aluminium alloy plate body is improved. If adding on the other hand excessive, then the thick intermetallic compound easily becoming the starting point of crackle is made to increase and the plasticity of aluminium alloy plate body is reduced, it becomes easily to produce welding crack. Therefore, according to the result of above-mentioned welding test, the addition of Si is in the scope of 0.05��0.30%.

Fe forms Al-Fe-Mn series intermetallic compound, Al-Fe-Mn-Si series intermetallic compound, and this intermetallic compound is precipitated out finely, makes the lubricant effect during formed machining of aluminium alloy plate body improve and plasticity is improved. If it is excessive to add on the other hand, then makes the thick intermetallic compound easily becoming the starting point of crackle increase, the plasticity of aluminium alloy plate body is reduced. Therefore, the addition of Fe is in the scope of 0.05��0.7%.

Cu mother mutually in solid solution and make as needed for aluminium alloy plate body physical strength improve. If it is excessive to add on the other hand, then become easily to produce welding crack. Therefore, the addition of Cu is in the scope of 0.05��0.25% in 3003 is corresponding aluminium alloy, is in the scope of 0.05��0.3% in 3005 is corresponding aluminium alloy.

Mn mother mutually in solid solution and can make to improve with the increase of its addition as the physical strength needed for aluminium alloy plate body, make as assembling after secondary cell aluminium pot body needed for compressive strength improve. By forming Al-Fe-Mn series intermetallic compound, Al-Fe-Mn-Si series intermetallic compound, this intermetallic compound is made to precipitate out finely and make the lubricant effect when the formed machining of aluminium alloy plate body improve and make raising plasticity. If it is excessive to add on the other hand, then makes the thick intermetallic compound easily becoming the starting point of crackle increase, the plasticity of aluminium alloy plate body is reduced. Therefore, the addition of Mn is in the scope of 0.8��1.5%.

B when the slab ingot casting of aluminium alloy, by by cast structure's miniaturization and homogeneous and the casting crack of rolling slab can be prevented. If adding on the other hand excessive, then melting weld seam when welding easily produces pore, further by making pore condense because of the convection current of the molten metal in melting weld seam, thus easily make melting junction surface confusion reigned. It should be noted that, owing to utilizing the interpolation of Mg described later and B can be made the impact of the generation of pore to be reduced, so its addition can be adjusted with the content of Mg. Therefore, also according to the result of above-mentioned welding test, the addition of B is in the scope of 2��20ppm in 3003 is corresponding aluminium alloy, it is more preferable to be in the scope of 2��10ppm, it is in the scope of 2��30ppm in 3005 are, it is more preferable to be in the scope of 2��20ppm.

Mg is necessary addition element 3005 in being, but is any addition element 3003 in being. Mg mother mutually in solid solution and can make to improve with the increase of its addition as the physical strength needed for aluminium alloy plate body, make as assembling after secondary cell aluminium pot body needed for compressive strength improve. In addition, by making Mg₂Si, S ' phase (Al₂CuMg) precipitate out finely, suppress the movement of dislocation and suppress stress relaxation, make to improve as the proof stress slackness needed for aluminium alloy plate body. If containing excessive on the other hand, then promote work hardening, infringement is as the plasticity needed for aluminium alloy plate body. In addition, it becomes easily produce crackle, pore when welding. From this viewpoint, and the result according to above-mentioned welding test, the content of Mg is in the scope of less than 0.05% in 3003 is corresponding aluminium alloy, 3005 be corresponding aluminium alloy be 0.2��0.6% scope in.

Further, to determining as use in the assembling of secondary cell aluminium pot body 3003 it is and the reason of composition range of any addition element of the 3005 aluminium alloy plate bodies being is described.

Ti when the slab ingot casting of aluminium alloy, by by cast structure's miniaturization and homogeneous and the casting crack of rolling slab can be prevented. Contain if excessive on the other hand, then the convection current of molten metal can be made when welding unstable, easily in melting junction surface, pore is remained. From this viewpoint, in the scope of the content of Ti below 0.1%.

As other impurity elements, Zn, Zr, Cr, Ga, V, Ni etc. can be listed, they are all set to the content of less than 0.05%, the total of Ti and B is set to the content of less than 0.15%, thus above-mentioned physical property can not be produced bigger impact.

It should be noted that, if at both middle aluminium alloy plate bodies using same one-tenth to be grouped into of exterior body and lid body, then to physical strength, weldability favorably, the cyclicity after assembling is favourable.

Further, at the Gai Tizhong that physical strength required compared with exterior body is low, it is possible to use pure aluminium. Particularly requiring that the Gai Tizhong of high conductivity is preferably pure aluminium. The one-tenth of pure aluminium is grouped into such as suitably can be selected from the scope of the chemical composition of the alloy numbering 1050,1060,1070,1080,1085 etc. of regulation among JISH4000. Now, same with the embodiment employing the aluminium alloy plate body that above-mentioned 1050 are, using as must the B of addition element be arranged in the scope of 2��10ppm, more preferably it is arranged in the scope of 2��6ppm, the Ti as any addition element is set to less than 0.04% and the chaotic of melting junction surface can be made to reduce. Further, as other any addition element, it is preferable that Si is set to less than 0.30%, Fe is set to less than 0.6%, Cu is set to less than 0.1%, Mn is set to less than 0.05%, Mg is set to less than 0.05%, Zn is set in the scope of less than 0.1%.

In addition, in above-mentioned welding test, although the end face 3a of acies portion, the side docking cover body plate 3 of housing plate 2 and weld, if but the relation docked of housing plate 2 with lid body plate 3 being set to other relations too. Such as, as shown in Fig. 8 (a), it is possible near the end face 3a of lid body plate 3, namely the end face 2a of housing plate 2 is docked by the acies portion, side of lid body plate 3, and the mode making lid body plate 3 be equipped on housing plate 2 configures. Now, configure to make the edge line of the outside edge line of the end face 2a as binding surface and end face 3a residing for edge line outside this become in the way of wiring 5, to weld in the way of the formation melting junction surface 4, position to wiring 5 as Suo Shi Fig. 8 (b).

Further, such as, as shown in Fig. 9 (a), to acies portion, the side imparting of lid body plate 3 and the cutting portion 3b of the thick degree of depth in approximate same size of plate of housing plate 2, and end face 2a butts up against the acies portion, side of lid body plate 3 in the way of embedding housing plate 2 wherein, and it is also same as described above. Namely, now also configure to make the edge line of the outside edge line of the end face 2a as binding surface and end face 3a residing for edge line outside this become in the way of wiring 5, to weld in the way of the formation melting junction surface 4, position to wiring 5 as Suo Shi Fig. 9 (b).

Above, although the description of embodiments of the invention and based on its variation, but the present invention is not necessarily limited to above-mentioned, as long as the technician of this area, so that it may to implement various replacement embodiment and Change Example when the scope of the purport not departing from the present invention or the claim enclosed.

Nomenclature

1 welding joint

2 housing plates

3 lid body plates

4 melting junction surfaces

Claims

1. the secondary cell manufacture method of aluminium pot body, it is characterised in that, it is the lid body and exterior body laser welding that form by aluminium alloy plate body and the manufacture method of secondary cell aluminium pot body assembled, comprising:

Configuration step: prepare the alloy sheets body being made up of aluminium alloy, and along the acies portion, side of the 1st alloy sheets body, the end face of 2-in-1 gold plate body is docked,

It is become the aluminium alloy plate body being grouped into as follows as the one or both in described 1st alloy sheets body or described the 2-in-1 gold plate body:

Described one-tenth is grouped into by forming as follows: by quality ratio, Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.20%, Mn:0.8��1.5%, B:2��20ppm are as necessary addition element, the scope of Mg:0��0.05%, Ti:0��0.1% is as addition element, and surplus is Al and inevitable impurity; With

Welding step: wiring is carried out continuous laser welding along what the end face at described 1st alloy sheets body produced,

Described welding step comprises following rate-determining steps: control Laser Welding Condition in the way of width W being set to more than 1.5 relative to the ratio W/D of the degree of depth D clipping described melting junction surface wiring given.

2. the secondary cell manufacture method of aluminium pot body, it is characterised in that, it is the lid body and exterior body laser welding that form by aluminium alloy plate body and the manufacture method of secondary cell aluminium pot body assembled, comprising:

Described one-tenth is grouped into by forming as follows: by quality ratio, Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.3%, Mn:0.8��1.5%, Mg:0.2��0.6%, B:2��30ppm are as necessary addition element, the scope of Ti:0��0.1% is as addition element, and surplus is Al and inevitable impurity; With

3. the manufacture method of secondary cell aluminium pot body according to claim 1, it is characterized in that, the one-tenth of the one in described 1st alloy sheets body or described the 2-in-1 gold plate body is grouped into when having prepared, and the another one that described configuration step also comprises described 1st alloy sheets body or described 2-in-1 gold plate body prepares to become as follows the aluminium alloy plate body that is grouped into as the step of described lid body:

The one-tenth of described another one is grouped into by forming as follows, by quality ratio, B:2��10ppm is as necessary addition element, the scope of Si:0��0.30%, Fe:0��0.6%, Cu:0��0.1%, Mn:0��0.05%, Mg:0��0.05%, Zn:0��0.1%, Ti:0��0.04% is as addition element, and surplus is Al and inevitable impurity.

4. the manufacture method of secondary cell aluminium pot body according to claim 2, it is characterized in that, the one-tenth of the one in described 1st alloy sheets body or described the 2-in-1 gold plate body is grouped into when having prepared, and the another one that described configuration step also comprises described 1st alloy sheets body or described 2-in-1 gold plate body prepares to become as follows the aluminium alloy plate body that is grouped into as the step of described lid body:

5. the secondary cell manufacture method of aluminium pot body according to any one of Claims 1 to 4, it is characterised in that, along the acies portion, side of described 1st alloy sheets body, there is cutting portion.

6. a secondary cell aluminium pot body, it is characterised in that, it is the lid body and exterior body laser welding the secondary cell aluminium pot body that assembles that form by aluminium alloy plate body,

The end face of 2-in-1 gold plate body is docked by the acies portion, side along the 1st alloy sheets body, and produce wiring at the end face of described 1st alloy sheets body, along this, wiring is carried out continuous laser welding, and width W is more than 1.5 relative to the ratio W/D of the degree of depth D clipping described melting junction surface wiring given, and degree of depth D is more than 0.35mm

The one or both of described 1st alloy sheets body or described 2-in-1 gold plate body has following compositions composition:

Described one-tenth is grouped into by forming as follows: by quality ratio, Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.25%, Mn:0.8��1.5%, B:2��20ppm are as necessary addition element, the scope of Mg:0��0.05%, Ti:0��0.1% is as addition element, and surplus is Al and inevitable impurity.

7. a secondary cell aluminium pot body, it is characterised in that, it is the lid body and exterior body laser welding the secondary cell aluminium pot body that assembles that form by aluminium alloy plate body,

Described one-tenth is grouped into by forming as follows: by quality ratio, Si:0.05��0.30%, Fe:0.05��0.7%, Cu:0.05��0.3%, Mn:0.8��1.5%, Mg:0.2��0.6%, B:2��30ppm are as necessary addition element, the scope of Ti:0��0.1% is as addition element, and surplus is Al and inevitable impurity.

8. secondary cell aluminium pot body according to claim 6, it is characterized in that, the one-tenth of the one in described 1st alloy sheets body or described 2-in-1 gold plate body is grouped into when having prepared, the another one of described 1st alloy sheets body or described 2-in-1 gold plate body is described lid body, and has following compositions composition:

The one-tenth of described another one is grouped into by forming as follows: by quality ratio, B:2��10ppm is as necessary addition element, the scope of Si:0��0.30%, Fe:0��0.6%, Cu:0��0.1%, Mn:0��0.05%, Mg:0��0.05%, Zn:0��0.1%, Ti:0��0.04% is as addition element, and surplus is Al and inevitable impurity.

9. secondary cell aluminium pot body according to claim 7, it is characterized in that, the one-tenth of the one in described 1st alloy sheets body or described 2-in-1 gold plate body is grouped into when having prepared, the another one of described 1st alloy sheets body or described 2-in-1 gold plate body is described lid body, and has following compositions composition:

10. secondary cell aluminium pot body according to any one of claim 6��9, it is characterised in that, the acies portion, side along described 1st alloy sheets body gives cutting portion and is soldered.