CN220492032U - Battery case, battery and battery pack - Google Patents

Abstract

The utility model discloses a battery shell, a battery and a battery pack, wherein the battery shell comprises a first structural member and a second structural member, the first structural member is provided with a first welding structure, the second structural member is provided with a second welding structure, the first welding structure and the second welding structure are oppositely arranged and are mutually attached to form a region to be welded, the first structural member and the second structural member are welded with the second welding structure through the first welding structure, the sealing of the battery shell is realized, and the joint of the first welding structure and the second welding structure can be attached to a welding probe. The joint part is attached to the welding probe, so that the welding contact area is larger, the welding tightness is better, leakage is less likely to occur, and the fire accident caused by electrolyte leakage is effectively slowed down; but also can block the reflected light and scattered light of the laser and prevent the burning of the area around the welding; the probe positioning device can be compatible with probes with all diameters to perform positioning functions, and the welding track is not deviated; the welding surface is smooth, and the integrity of the application can be effectively protected.

Description

Battery case, battery and battery pack

Technical Field

The utility model relates to the field of battery manufacturing, in particular to a battery shell, a battery and a battery pack.

Background

With the continuous development of new energy industry, improving the safety of the lithium battery field is always a hot topic. The battery cell with good sealing performance can prevent leakage of internal electrolyte, effectively reduce corrosion to a battery pack and prolong the service life of the battery. But the structure of the welded part of present casing and top cap adopts right angle design mostly, only welds non-contact edge when the welding, and this edge exists the arc step, owing to be close to blue membrane edge bending part, leads to the edge blue membrane to paste inadequately easily and leads to the top paster to warp the problem, in addition, not only weld back casing and top cap department and weld inadequately, helium leak rate is higher, and the laser welding of welding in the side seal in addition can make the holistic volume increase of battery, has increaseed the degree of difficulty of battery equipment module, still can restrict the biggest volume of going into the shell electric core for the space utilization in battery descends, and then reduces volume energy density.

Disclosure of Invention

In order to overcome the defects, the utility model provides a special structural design between the side edge of the shell and the top cover, which not only can effectively improve the welding tightness of each shell and the passing rate of helium detection, optimize the warping problem of the top patch, but also can reduce the volume of the battery, provide higher utilization rate of the internal space and finally improve the volume energy density of the car-loading battery pack.

The utility model aims to provide a battery shell, a battery and a battery pack.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the utility model provides a battery case, includes first structure and second structure, and first structure is equipped with first welded structure, and the second structure is equipped with second welded structure, and first welded structure and second welded structure set up relatively, and form the welded area after laminating each other, and the welded area is concave in the surface of electric core casing, and first structure and second structure pass through the welding of first welded structure and second welded structure, realize battery case's seal, and first welded structure and second welded structure concatenation department can laminate with welding probe.

The joint part is attached to the welding probe, so that the welding contact area is larger, the welding tightness is better, leakage is less likely to occur, and the fire accident caused by electrolyte leakage is effectively slowed down; but also can block the reflected light and scattered light of the laser and prevent the burning of the area around the welding; the probe positioning device can be compatible with probes with all diameters to perform positioning functions, and the welding track is not deviated; the welding surface is smooth, and the integrity of the application can be effectively protected.

Further, on the section along the width direction of the battery cell casing, the first welding structure comprises a first section and a second section which are sequentially connected, and the first section and the second section are straight lines; the second welding structure comprises a third section and a fourth section which are sequentially connected, the third section and the fourth section are straight lines, and the welding area is an accommodating space surrounded by the first section, the second section, the third section and the fourth section.

Still further, first segmentation forms the right angle with the second segmentation, and the third segmentation forms the right angle with the fourth segmentation, and first welded structure forms "U" font with second welded structure, and welding probe and the concatenation department laminating of second segmentation and fourth segmentation have avoided taking place the rosin joint phenomenon, and the welding seal is directly coated in the welded region of "U" font, and welding tightness is good.

Furthermore, the first section and the second section form an obtuse angle, the third section and the fourth section form an obtuse angle, the first welding structure and the second welding structure form an inverted trapezoid, and the size of the welding probe is usually selected by combining the width of the welding area during welding, so that the welding track is not deviated, and the welding tightness is good.

Furthermore, on the section along the width direction of the battery cell shell, the first welding structure and the second welding structure are cambered surfaces which are concave inwards, the first welding structure and the second welding structure form a U shape, the two side walls of the U shape arc are preferably inclined side walls, and the inclination angle beta of the side wall of the U shape groove is preferably 10-25 degrees, so that the proper welding line width can be obtained, the welding fusion ratio can be reduced, the welding efficiency of the battery shell welding and peripheral welding procedures can be improved, and the laser welding rate can be improved; the U-shaped and other welding mark designs can not only provide a more accurate positioning function for the laser welding probe, but also be used as a moving welding track of the laser probe, so that the problem of non-contact surface probe deflection during conventional welding is solved, and the welding efficiency of the battery shell welding and peripheral welding procedures is improved.

The electrical core has better tightness and higher safety coefficient; compared with the conventional non-contact edge welding, the welding method has the advantages that under the condition of the same welding width, the contact surface between the welding marks of the U-shaped and other designs and the shell or the anode and cathode top covers is larger, the welding effect is better, leakage is less likely to occur, and the fire accident caused by electrolyte leakage is effectively slowed down;

the battery core with larger volume can be compatible to be put into the shell; when the double U-shaped structures are cited on the side surface of the welding shell, the welding height of the inner part is lower than the surface of the inner shell, and is different from the conventional inner laser welding, so that the welding height provides the opportunity of shell entering for more large-volume battery cores, and the utilization rate of the inner space of the battery can be effectively improved;

the problem of lifting of the top patch can be relieved; structural designs such as U style of calligraphy are because the welding seal height is not exceeded casing and top cap edge surface in top cap edge, and its nearby is more even, does not have the radian step that leaves after the laser welding, makes the inhomogeneous phenomenon of blue membrane atress, can effectively alleviate the top paster and warp.

Still further, first structure is the casing, and the second structure is the casing, and first welded structure and second welded structure butt joint welding, welding area are located one side or both sides of casing thickness direction to extend along the X direction, under the circumstances of guaranteeing the welding effect, make the welding seal with the casing surface level, give the chance that the shell was gone into to the bigger electric core, improve the space utilization in battery.

Further, the distance from the splicing part to the outer surface of the shell is a first depth, and the maximum distance between the first welding structure and the second welding structure along the butt joint direction is a first width.

Still further, the first depth is less than 1/2 of the thickness of the first structural member, and the ratio of the first width to the first depth is less than 5:1, forming a narrow and deep weld joint when the forming coefficient of the weld joint is small, and gathering more impurities due to regional segregation in the center of the weld joint, wherein the thermal cracking resistance is poor; the forming coefficient of the welding seam is not too high, and the wide and shallow welding seam is formed by too high width-depth ratio value, so that the welding is not firm, and the surface of a welding area is provided with grooves and the like.

Still further, first structure is the casing, and the second structure is the top cap, and first welded structure and second welded structure corner joint welding, the welded area is located the top cap outside around, welds in casing and top cap corner joint department, and the welding seal is bigger with the contact surface of casing, and the welding effect is better, effectively slows down the electrolyte weeping and the conflagration accident that arouses. The welding marks higher than the surface of the shell are polished after welding, so that the welding marks are leveled with the surface of the shell under the condition of ensuring the welding effect, the blue film is uniformly stressed, and the phenomena of lifting, tilting and the like of the top patch can be effectively relieved. The prepared battery cell has smaller volume; because of the welding mode of U-shaped and the like, the welding height of the welding mode does not exceed the edges of the shell surface and the anode top cover, the total volume of the corresponding battery core is smaller, the difficulty of entering the battery core of the assembled module can be reduced, and the volume energy density of the battery pack is improved.

Further, the distance from the splice to the outer surface of the shell is a second depth, and the maximum distance between the first welding structure and the second welding structure along the corner joint direction is a second width.

Still further, the second depth is less than 2/3 of the thickness of the first structural member, and the ratio of the second width to the second depth is less than 5:1.

a battery comprises a battery core and the battery shell, wherein the battery core is arranged in the battery shell.

A battery pack comprises the battery.

Drawings

FIG. 1 (a) is a prior art welding schematic diagram with the weld area untreated;

FIG. 1 (b) is a schematic diagram of a prior art solder mask structure with no solder area treatment;

FIG. 2 (a) is a schematic view of V-shaped welding in a conventional welding mode;

FIG. 2 (b) is a schematic diagram of a conventional V-shaped weld;

FIG. 3 is a schematic diagram of a first cross-sectional structure of a first welding structure and a second welding structure according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a second cross-sectional structure of a first welding structure and a second welding structure according to an embodiment of the present utility model;

FIG. 5 is a schematic diagram of a third cross-sectional structure of a first welding structure and a second welding structure according to an embodiment of the present utility model;

FIG. 6 is a schematic diagram of a fourth cross-sectional structure of a first welded structure and a second welded structure according to an embodiment of the present utility model;

FIG. 7 is a schematic diagram of a fifth cross-sectional structure of a first welded structure and a second welded structure according to an embodiment of the present utility model;

FIG. 8 is a schematic diagram of a sixth cross-sectional structure of a first welded structure and a second welded structure according to an embodiment of the present utility model;

FIG. 9 is a schematic view of the connection of the housing to the top cover plate according to the embodiment of the present utility model;

FIG. 10 is a schematic view of a bump welded to a side of a housing according to an embodiment of the present utility model;

FIG. 11 (a) is a schematic diagram of a U-shaped weld cross section according to an embodiment of the present utility model;

FIG. 11 (b) is a schematic view of a welding track of a U-shaped welding section;

FIG. 12 (a) is a schematic illustration of the top cover edge blue film being applied loosely resulting in lifting of the top patch;

FIG. 12 (b) is a schematic view of a top patch according to an embodiment of the present utility model without lifting;

FIG. 13 is a schematic view of a first depth and a first width according to an embodiment of the present utility model;

fig. 14 is a schematic view of a second depth and a second width according to an embodiment of the utility model.

In the figure: 1. a first welded structure; 101. a first segment; 102. a second segment; 2. a second welded structure; 201. a third segment; 202. a fourth segment; 3. a housing; 4. a top cover; 5. a welding probe; 6. welding and printing; 7. and (5) welding areas.

Detailed Description

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. It is also to be understood that the terminology used in the examples of the utility model is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the utility model. The test methods in the following examples, in which specific conditions are not noted, are generally conducted under conventional conditions or under conditions recommended by the respective manufacturers.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the utility model, are not intended to be critical to the essential characteristics of the utility model, but are intended to fall within the spirit and scope of the utility model. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the utility model, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the utility model may be practiced.

Referring to fig. 1 (a) and 1 (b), the welding method in the prior art includes that a welding area is not treated, that is, a first welding structure 1 and a second welding structure 2 are abutted and jointed, and then welding is completed at a abutted seam, and in the welding method, the joint between a welding probe 5 and a welding surface is better, but a welding track is easy to deviate, a false welding phenomenon occurs, and the welding strength is poor; meanwhile, after welding is finished, the welding area is smaller, if the welding mark 6 is excessively polished, the welding quality can be affected, if the welding mark 6 is not polished, the welding surface can be protruded due to the welding mark 6, so that the subsequent blue film attaching effect is affected, and therefore, the welding mode is not preferable in welding of the battery shell.

Fig. 2 (a) and 2 (b) show another conventional welding method, V-shaped welding. The welding mode needs to perform V-shaped pretreatment on the first welding structure 1 and the second welding structure 2 in advance, wherein the V-shape can be formed on one side surface of two welded structural members after being butted, and the two side surfaces can also be pretreated simultaneously, namely double V-shape welding. The welding track is straight and does not deviate under the welding mode, but when the welding probe 5 is too large, the welding probe 5 is not attached to the welding surface, the contact surface is small, the false welding condition is obvious, and the welding tightness is poor.

Referring to fig. 3-8, in this embodiment, a battery case includes a first structural member and a second structural member, where the first structural member is provided with a first welding structure 1, the second structural member is provided with a second welding structure 2, the first welding structure 1 and the second welding structure 2 are oppositely arranged, the opposite arrangement in this embodiment may be butt joint or corner joint, the first welding structure 1 and the second welding structure 2 enclose a welding area 7 after being mutually attached, the welding area 7 is recessed in the surface of the battery case, the first structural member and the second structural member are welded by the first welding structure 1 and the second welding structure 2, so as to realize sealing of the battery case, and the joint of the first welding structure 1 and the second welding structure 2 can be attached to the welding probe 5, after attaching, the welding mark 6 can be fully filled, so as to avoid the occurrence of a virtual welding phenomenon.

The laser welding method can improve the rate of merit of laser welding, can provide a more accurate positioning function for the laser welding probe 5, can also be used as a moving welding track of the laser probe, solves the problem of non-contact surface probe deflection during conventional welding, and improves the welding efficiency of the welding and peripheral welding procedures of the battery shell 3; the height of the welding marks 6 does not exceed the surface of the shell 3 and the edges of the anode top cover 4, the total volume of the corresponding battery is smaller, the difficulty of battery entering of the assembled module can be reduced, and the volume energy density of the battery pack is improved.

Compared with the conventional non-contact edge welding, the structural design of the embodiment has the advantages that under the condition of the same width of the welding mark 6, the contact surface between the welding mark 6 and the shell 3 or the anode and cathode top cover 4 is larger, the welding effect is better, leakage is less likely to occur, and the fire accident caused by electrolyte leakage is effectively slowed down; different from the conventional internal laser welding, the welding mark 6 height provides a shell entering opportunity for more large-volume batteries, and the utilization rate of the internal space of the batteries can be effectively improved; the edge of the top cover 4 is not higher than the edge surfaces of the shell 3 and the top cover 4 due to the fact that the height of the welding mark 6 is not higher than that of the edge surfaces of the shell 3 and the top cover 4, the vicinity of the welding mark is smoother, radian steps left after laser welding are avoided, the phenomenon that the stress of a blue film is uneven is caused, and the situation that a top patch is tilted up and the like can be effectively relieved.

In some embodiments, the first welded structure 1 includes a first segment 101 and a second segment 102 connected in sequence, the first segment 101 and the second segment 102 being straight, on a cross section along the width direction of the battery case 3; the second welding structure 2 comprises a third section 201 and a fourth section 202 which are sequentially connected, the third section 201 and the fourth section 202 are straight lines, the welding area 7 is an accommodating space surrounded by the first section 101, the second section 102, the third section 201 and the fourth section 202, and compared with other embodiments, the plane is easier to machine and shape and is more beneficial to later welding.

Referring to fig. 3, 13 and 14, in some embodiments, the first segment 101 forms a right angle with the second segment 102, the third segment 201 forms a right angle with the fourth segment 202, and the first welded structure 1 forms a "U" shape with the second welded structure 2. In the figure, a first section 101 corresponds to a vertical plane, a second section 102 corresponds to a horizontal plane, the two planes are mutually perpendicular to form an L-shaped structure, a third section 201 corresponds to a vertical plane, a fourth section 202 corresponds to a horizontal plane, the two planes are mutually perpendicular to form an L-shaped structure, and after the first welding structure 1 is in butt joint with the second welding structure 2, a U-shaped welding area 7 is formed; the welding probe 5 is attached to the joint of the second segment 102 and the fourth segment 202, so that the phenomenon of cold joint is avoided, the welding mark 6 is formed in the U-shaped welding area 7, and the welding tightness is good.

In the above embodiment, the lengths of the second segment 102 and the fourth segment 202 form the width of the welding area 7, the length of the first segment 101 or the third segment 201 is the depth of the welding area 7, and the width of the welding area 7 is usually considered in the welding process, so that the welding track is not deviated, and the welding tightness is good.

Referring to fig. 4, in some embodiments, the first section 101 forms an obtuse angle with the second section 102, the third section 201 forms an obtuse angle with the fourth section 202, and the first welded structure 1 forms an inverted trapezoid with the second welded structure 2. In the figure, a first section 101 corresponds to an inclined plane, a second section 102 corresponds to a horizontal plane, the two planes form an obtuse angle structure, a third section 201 corresponds to an inclined plane, a fourth section 202 corresponds to a horizontal plane, the two planes form an obtuse angle structure, and after the first welding structure 1 is in butt joint with the second welding structure 2, an inverted trapezoid welding area 7 is formed; the welding probe 5 is attached to the joint of the second segment 102 and the fourth segment 202, so that the phenomenon of cold joint is avoided, the welding mark 6 is directly coated in the inverted trapezoid welding area 7, and the welding tightness is good.

In the above embodiment, the lengths of the second segment 102 and the fourth segment 202 form the width of the welding area 7, the length of the first segment 101 or the third segment 201 is the depth of the welding area 7, and the width of the welding area 7 is usually considered in the welding process, so that the welding track is not deviated, and the welding tightness is good.

In some embodiments, the first welding structure 1 and the second welding structure 2 further comprise a combination of line segments and arcs, the first segment 101 of the first welding structure 1 is a vertical plane, the second segment 102 is an arc surface, the third segment 201 of the second welding structure 2 is a vertical plane, the fourth segment 202 is an arc surface, and after the first welding structure 1 is butted with the second welding structure 2, a welding area 7 is formed; the welding probe 5 is attached to the joint of the second segment 102 and the fourth segment 202, so that the welding marks 6 can be fully filled, the phenomenon of cold welding is avoided, the welding marks 6 are directly coated in the welding area 7, and the welding tightness is good.

Similar to the structure of the above embodiment, the first segment 101 of the first welding structure 1 is a plane inclined to the outside, the second segment 102 is an arc surface, the third segment 201 of the second welding structure 2 is a plane inclined to the outside, the fourth segment 202 is an arc surface, and after the first welding structure 1 is butted with the second welding structure 2, the formed welding area 7 can be fully filled with the welding marks 6, so that the occurrence of the cold joint phenomenon is avoided.

In some embodiments, the first welding structure 1 and the second welding structure 2 are arc surfaces concave inward, and the first welding structure 1 and the second welding structure 2 may form a semicircle, "U" shape or other arc surfaces in a cross section along the width direction of the battery case 3. Wherein, the two side walls of the U-shaped arc are preferably inclined side walls, and the inclination angle of the side wall of the U-shaped groove is preferably 10-25 degrees, thus obtaining proper weld width and reducing welding fusion ratio. The arc radius R of the U-shaped arc corresponds to the size of the welding probe 5, and when the arc radius R is too small, welding vacuum can occur, so that welding defects such as unfused layers and the like exist; when the arc radius R is too large, the welding locus of the welding probe 5 in the welding area 7 is liable to deviate, resulting in poor welding tightness.

On the U-shaped welding section, the welding probe 5 is attached to the butt joint of the shell 3, so that the laser welding probe 5 with any diameter can provide accurate positioning function, the moving welding track of the laser probe can be provided, the problems of cold welding and probe deflection during conventional welding are solved, the welding efficiency of the welding process of the battery shell 3 and the welding process of the periphery of the shell 3 is improved, and as shown in fig. 11 (a) and 11 (b), the welding track of the U-shaped welding section is straight and has no deflection, and the welding tightness is good.

In some embodiments, the first structural member is a shell, the second structural member is a shell, the first welded structure 1 and the second welded structure 2 are butt welded, and the welded region 7 is located on one side or both sides of the thickness direction of the shell 3 and extends in the X direction shown in fig. 9. In this embodiment, the side surface of the housing 3 is welded, and the housing is first press-formed and then placed in a mold and fixed. And (3) performing stamping forming treatment on the shell according to a preset position, and forming an opening on the side face. The welding method in the prior art can form raised welding marks 6 on the inner surface and the outer surface of the shell 3, and excessive polishing can also cause unstable welding. The raised welds 6 limit the maximum volume of the battery to be housed, as shown in fig. 10, so that the space utilization inside the battery is reduced, thereby increasing the volumetric energy density.

In the above embodiments, in some examples, the battery case 3 has a square body structure, and the battery case 3 has a bottom surface and four sides, the four sides being two front surfaces and two sides; two side surfaces are arranged between the two front surfaces, and the aluminum shell is formed by the connection mode and the bottom surface; the welding mode is conventional, the bulges are formed on the side surfaces, the inner bulges are generally arranged on the two side surfaces, when the laminated battery in the battery shell 3 expands, the side surfaces of the laminated battery cannot be extruded by the round corners of the battery shell 3 due to the blocking of the inner bulges, the phenomenon that the laminated battery is subjected to lithium precipitation caused by extrusion deformation of the copper aluminum foil sheets on the side surfaces of the laminated battery is avoided, the risk of lithium precipitation on the side surfaces of the laminated battery is reduced, and the service performance of the battery is further improved.

As shown in fig. 10, when the internal protrusion is formed on the side surface of the battery case, the battery case 3 is placed in the battery cell, and the battery cell with a larger volume cannot be smoothly inserted, so that the width of the battery cell needs to be necessarily reduced, that is, the volume of the battery cell is reduced, so that the space utilization rate in the battery is reduced, and the volume energy density is further improved. In the above embodiment, when the battery case 3 needs to be welded on one side, the two ends to be welded are treated, so that the welding area 7 is recessed in the surface of the battery case 3, and the surface of the welding area 7 is polished and trimmed after the welding is completed, so that the sealing performance of the case 3 is improved, the welding mark 6 is ensured not to protrude out of the surface of the case 3, and the battery cell can smoothly enter the battery case, so that a larger battery cell volume into the case is provided, the utilization rate of the internal space is higher, and the volumetric energy density of the battery pack for loading is finally improved.

In the embodiment, the outer side of the side surface of the shell 3 or the two sides of the thickness direction of the shell 3 are welded, the contact surface between the welding mark 6 and the shell 3 is larger, the welding effect is better, leakage is less likely to occur, and the fire accident caused by electrolyte leakage is effectively slowed down. The welding mark 6 higher than the surface of the shell 3 is polished after welding, so that the welding mark 6 is leveled with the surface of the shell 3 under the condition of ensuring the welding effect, the opportunity of entering a shell of a larger volume of battery core is given, the space utilization rate of the inside of the battery is improved, and meanwhile, the battery is prevented from being extruded by the protrusions of the welding mark 6 when expanding.

In some embodiments, the splice is at a first depth from the outer surface of the housing 3, and the maximum distance between the first welded structure 1 and the second welded structure 2 in the butt direction is a first width, as shown in fig. 13. As shown in fig. 13, after the first welding structure 1 is in butt joint with the second welding structure 2, a groove is formed on the surface of the shell 3, the bottom of the groove is the joint between the first welding structure 1 and the second welding structure 2, and the distance from the bottom of the groove to the surface of the shell 3 is a first depth H1; the upper edge of the groove is the maximum distance between the first welding structure 1 and the second welding structure 2 along the butt joint direction, and the distance is the first width W1.

The ratio of the width of the weld to the depth of the weld in the single pass weld cross section is referred to as the weld forming factor. During welding, the main size parameters of the welding seam are as follows: penetration, width and residual height, wherein the ratio of the width to the penetration is referred to as a weld forming coefficient or a weld form coefficient. The forming coefficient of the welding seam is small, a narrow and deep welding seam is formed, and the forming coefficient of the welding seam cannot be too small because of more concentrated impurities due to regional segregation in the center of the welding seam and poor thermal cracking resistance, for example, the forming coefficient of the welding seam is larger than 1.3 in automatic submerged arc welding, namely, the width of the welding seam is at least 1.3 times of the calculated thickness of the welding seam. Of course, the weld forming coefficient is not too high, and too high a width-depth ratio value forms a wide and shallow weld, so that welding is not firm, and grooves and the like appear on the surface of the welding area 7.

To ensure the welding effect, the diameter of the laser welding probe 5 is generally smaller than the width of the welding track by default, in the above embodiment, the first depth H1 is smaller than 1/2 of the thickness of the first structural member, and the ratio of the first width W1 to the first depth H1 is smaller than 5:1. in the welding of the side face of the housing 3, the welding area 7 may be located at one side or both sides in the thickness direction of the housing 3. The inventor obtains the optimal weld joint forming coefficient through multiple experiments, when the welding area 7 is arranged on two sides of the shell 3, the sum of the first depth H1 of the welding area 7, namely the depth addition of the two sides is smaller than 1/2 of the thickness of the shell 3, and the ratio of the first width W1 to the first depth H1 is smaller than 5:1.

in some embodiments, the first structural member is a housing 3, the second structural member is a top cover 4, the first welded structure 1 is fillet welded to the second welded structure 2, and the welded area 7 is located circumferentially outward of the top cover 4. This embodiment is the welding of casing 3 and top cap 4, and after casing 3 and top cap 4 angle joint, the welding mode among the prior art can accomplish the welding along a week of top cap 4 in the angle joint department, can form bellied welding seal 6 in the angle joint department after the welding, and the too much polishing still can lead to welding insecure. The raised solder marks 6 have arc steps, as shown in fig. 12 (a), the edge blue film is easily applied and not firmly attached to the edge blue film, so that the problem of raising the top patch is easily caused, besides, the housing 3 and the top cover 4 are not firmly welded after welding, and the helium leak detection rate is higher.

In the above embodiment, when the casing 3 and the top cover 4 are welded by laser, the welding area 7 not only can block the reflected light and scattered light of the laser and protect the plastic on the pole, so as to improve the yield of the single battery, but also can receive melted materials because the welding marks 6 generated by welding are accommodated in the concave part, so that the welding marks 6 generated by welding are prevented from being accumulated on the upper surface of the battery casing, and the welding protrusions can not protrude out of the upper surface of the battery casing 3; so as to ensure the flatness of the surface of the battery shoulder and improve the space utilization rate; meanwhile, the problem of rising of the top edge of the envelope can be effectively improved, and the damage of the outer insulating film by the welding bulge is avoided, as shown in fig. 12 (b).

The battery shell is square, the blue film is a high-temperature adhesive tape, when the blue film is wrapped, the two wide sides and the two side surfaces of the battery shell are coated by the U-shaped and return-type blue film, the top and the bottom of the battery shell are exposed by the coated blue film, then the exposed blue film at the top and the bottom of the battery shell is subjected to a flanging process, the exposed blue film is coated on the top and the bottom of the battery shell, and finally an insulating sheet is coated on the battery shell, so that the whole flow of the battery blue film wrapping shearing device of the aluminum-shell lithium battery is completed.

According to the embodiment, the corner joint of the shell 3 and the top cover 4 is welded, the contact surface between the welding mark 6 and the shell 3 is larger, the welding effect is better, and the fire accident caused by electrolyte leakage is effectively slowed down. The welding marks 6 which are higher than the surface of the shell 3 are polished after welding, so that the welding marks 6 are leveled with the surface of the shell 3 under the condition of ensuring the welding effect, the blue film is uniformly stressed, and the phenomena of lifting, tilting and the like of the top patch can be effectively relieved.

In some embodiments, the splice is at a second depth H2 from the outer surface of the housing 3, and the maximum distance between the first welded structure 1 and the second welded structure 2 in the corner joint direction is a second width W2. After the corner joint of the shell 3 and the top cover 4, the shell 3 is vertical to the top cover 4, a groove is formed on the surface of the shell 3 and the side surface of the top cover 4, the bottom of the groove is the corner joint of the first welding structure 1 and the second welding structure 2, and the distance from the bottom of the groove to the surface of the shell 3 is the second depth H2; the upper edge of the groove is the maximum distance between the first welding structure 1 and the second welding structure 2 along the corner joint direction, and the distance is the second width W2.

In some embodiments, the second depth H2 is less than 2/3 of the thickness of the first structural member, and the ratio of the second width W2 to the second depth H2 is less than 5:1. the shell 3 and the top cover 4 are welded at the corner joint, and the welding area 7 is only on the circumferential outer side of the top cover 4, as shown in fig. 6-8, the inventor obtains through multiple tests that the welding seam forming coefficient is smaller than 5 optimally when only one side is welded, the welding depth is not larger than 2/3 of the wall thickness of the shell 3, and if the depth is too large, the welding deformation easily occurs, as shown in fig. 14.

The utility model also provides a battery, which comprises an electric core and a battery shell of any one of the above, wherein the electric core is arranged in the battery shell.

The battery shell mainly plays roles of packaging the winding core, bearing electrolyte and protecting explosion protection in the power battery. The utility model can use the thin aluminum shell to process and manufacture the battery shell, and realizes the switching from side welding to top welding process on the premise of not changing the inherent thickness, weight and metal strength of the aluminum shell, thereby avoiding the problem that the side welding seam is protruded on the side of the shell 3, and simultaneously solving the problem that the top welding process requires the thickness of the aluminum shell and the positioning chamfering to be difficult to process.

The above embodiments are only for illustrating the technical concept and features of the present utility model, and are intended to enable those skilled in the art to understand the content of the present utility model and to implement the same, but are not intended to limit the scope of the present utility model, and all equivalent changes or modifications made according to the spirit of the present utility model should be included in the scope of the present utility model.

Claims (14)

1. The utility model provides a battery case, its characterized in that, includes first structure and second structure, first structure is equipped with first welded structure, the second structure is equipped with second welded structure, first welded structure with second welded structure sets up relatively, and forms the welding area after laminating each other, the welding area concave in battery case's surface, first structure with the second structure passes through first welded structure with second welded structure's welding realizes battery case's seal, first welded structure with second welded structure's concatenation department can laminate with welding probe.

2. The battery case according to claim 1, wherein the first welding structure includes a first segment and a second segment connected in sequence, the first segment and the second segment being straight lines, on a cross section in a width direction of the battery case; the second welding structure comprises a third section and a fourth section which are sequentially connected, the third section and the fourth section are straight lines, and the welding area is an accommodating space surrounded by the first section, the second section, the third section and the fourth section.

3. The battery housing of claim 2, wherein the first segment forms a right angle with the second segment and the third segment forms a right angle with the fourth segment.

4. The battery housing of claim 2, wherein the first segment forms an obtuse angle with the second segment and the third segment forms an obtuse angle with the fourth segment.

5. The battery case according to claim 1, wherein the first welding structure and the second welding structure each include an inwardly recessed arc surface in a cross section in a width direction of the battery case.

6. The battery housing of claim 5, wherein the welded area enclosed by the first and second welded structures is "U" shaped.

7. The battery case according to claim 1, wherein the first structural member is a case, the second structural member is a case, the first welding structure is butt-welded to the second welding structure, and the welding region is located at one side or both sides of the case in the thickness direction and extends in the X direction.

8. The battery housing of claim 7, wherein the splice is a first depth from the housing outer surface and a maximum separation of the first and second weld structures in the mating direction is a first width.

9. The battery housing of claim 8, wherein the first depth is less than 1/2 of the first structural member thickness and the ratio of the first width to the first depth is less than 5:1.

10. the battery housing of claim 1, wherein the first structural member is a shell and the second structural member is a top cover, the first welded structure is fillet welded to the second welded structure, and the welded area is located circumferentially outward of the top cover.

11. The battery housing of claim 10, wherein the splice is a second depth from the housing outer surface and the maximum separation of the first and second welded structures in the corner joint direction is a second width.

12. The battery housing of claim 11, wherein the second depth is less than 2/3 of the thickness of the first structural member and the ratio of the second width to the second depth is less than 5:1.

13. a battery comprising a battery cell and the battery housing of any one of claims 1 to 12, the battery housing having the battery cell mounted therein.

14. A battery pack comprising the battery of claim 13.