CN212571138U

CN212571138U - Single battery and power battery

Info

Publication number: CN212571138U
Application number: CN202021539047.2U
Authority: CN
Inventors: 戴亨伟; 徐卫东; 张立鹏; 何庆庆; 杨伟; 张耀
Original assignee: Sunwoda Electric Vehicle Battery Co Ltd
Current assignee: Xinwangda Power Technology Co ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2021-02-19
Anticipated expiration: 2030-07-29

Abstract

The utility model discloses a single battery and a power battery, wherein the single battery comprises a shell, a pole column and a top cover; the shell is of a structure with an opening at one end, and the top cover is arranged at the opening of the shell and is connected with the shell in a laser welding way; the outer surface of the single battery is provided with a concave part for laser irradiation corresponding to the joint of the top cover and the shell, and the concave part is composed of a first notch arranged on the top cover and/or a second notch arranged at the opening of the shell; wherein, during laser welding, the top cover and the shell collapse towards the recess to fill the recess; the post is arranged on the top cover and is far away from the concave part. Through setting up the depressed part, when casing and top cap pass through laser welding, not only can block the laser of scattering, plastic on the protection utmost point post improves battery cell's yields, because the molten bath that the welding produced holds in the depressed part, the material that melts is restrainted in the receipts, and the molten bath that avoids the welding to produce is piled up at the upper surface of electricity core shell moreover, and the welding arch can not bulge electricity core shell upper surface.

Description

Single battery and power battery

Technical Field

The utility model relates to the technical field of battery especially involves a battery cell and power battery.

Background

With the improvement of the requirements of new energy automobiles on mass energy density, the requirements on the lightweight of a power cell are more and more urgent, and the structural member of the power cell is generally developed towards the trend of lightness and thinness; especially, power electricity core top cap and aluminum hull through reducing top cap and casing wall thickness, reach the purpose that reduces structure weight by a wide margin, promote quality energy density. But has problems that: 1) the bending strength of the top cover is greatly reduced, the top cover is easy to deform, the flatness is difficult to ensure, and the production rate of the top cover is low; 2) the top cover has poor integral strength, and is easy to deform under the condition of gas generation inside the battery cell (particularly serious gas generation inside the ternary battery cell), so that the structural size stability is influenced, and interference and even safety risk are caused; 3) the laser welding heat of the shell cover is large, reflected light or scattered light easily burns plastic on the pole, poor insulation or appearance defects are caused, meanwhile, welding heating is large, heat is conducted to sensitive components such as an explosion-proof valve and an SSD, the explosion value and the turnover value of a functional part are easily influenced, and the safety of a battery cell is influenced; 4) the molten pool formed by laser welding is deformed and solidified on the upper surfaces of the shell and the top cover, so that the upper surfaces of the corner joint positions of the shell and the top cover are provided with bulges.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a single cell and power battery aims at improving among the current single cell that the plastic is gone up to the terminal post of burning easily with casing laser welding, arouses the problem of insulating harmfully or appearance imperfections.

The utility model provides a single battery, which comprises a shell, a pole and a top cover; the shell is of a structure with an opening at one end, and the top cover is arranged at the opening of the shell and is connected with the shell in a laser welding way; the outer surface of the single battery is provided with a concave part for laser irradiation corresponding to the joint of the top cover and the shell, and the concave part is composed of a first notch arranged on the top cover and/or a second notch arranged at the opening of the shell; wherein, during laser welding, the top cover and the shell collapse towards the recess to fill the recess; the post is arranged on the top cover and is far away from the concave part.

Furthermore, an upward fixing bulge is arranged on the upper side surface of the top cover; or the lower side surface of the top cover is provided with a downward fixed bulge.

Furthermore, the fixed bulge is arranged on the outer ring peripheral outline of the top cover; when the fixed bulge is arranged on the upper side surface of the top cover, the concave part at least comprises a second notch; when the fixing protrusion is arranged on the lower side surface of the top cover, the concave part is formed by the first notch and/or the second notch.

Furthermore, the fixing bulge is arranged between the pole and the concave part; the recess is formed by a first notch and/or a second notch.

Further, the fixing projection is in a closed ring shape.

Further, the fixing protrusion comprises a plurality of sectional protrusions which are arranged at intervals and surround to form a ring shape.

Furthermore, the outer side edge of the free end of the fixed protrusion is provided with a chamfer angle or a fillet.

Furthermore, the top cover is provided with a first protruding part in the first gap, and/or the shell is provided with a second protruding part in the second gap.

Furthermore, the profile of the cross section of the concave part is V-shaped, rectangular with a missing upper side, semicircular arc or parabola.

The utility model also provides a power battery, including outer shell and a plurality of above-mentioned battery cell, a plurality of battery cells locate in the outer shell.

The utility model discloses the beneficial effect who brings does: through setting up the depressed part, when casing and top cap pass through laser welding, not only can block laser reflection light and scattered light, plastic on the protection utmost point post improves cell's yields, because the molten bath that the welding produced holds in the depressed part, the material that melts is restrainted in the receipts, and the molten bath that avoids the welding to produce is piled up at the upper surface of electricity core shell, and the welding arch can not bulge electricity core shell upper surface moreover.

Drawings

Fig. 1 is a cross-sectional view of an embodiment of a single battery of the present invention;

FIG. 2 is an enlarged view taken at A in FIG. 1;

FIG. 3 is a schematic structural view of an embodiment of a middle cover part of the present invention;

FIG. 4 is a schematic cross-sectional view of A-A of FIG. 3;

FIG. 5 is an enlarged view at B in FIG. 3;

fig. 6 is an enlarged schematic view of a part of the structure of another embodiment of the middle cap part of the present invention;

fig. 7 is an enlarged schematic view of a part of the structure of a third embodiment of the middle cap part of the present invention;

FIG. 8 is an enlarged schematic view of an embodiment of the central depression of the present invention;

fig. 9 is a schematic structural diagram of an embodiment of a single battery according to the present invention;

fig. 10 is a schematic structural diagram of an embodiment of a middle power battery according to the present invention.

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A single battery, as shown in fig. 1-9, includes a housing 1, a terminal, and a top cover 2; the shell 1 is of a structure with an opening at one end, and the top cover 2 is arranged at the opening of the shell 1 and is connected with the shell 1 in a laser welding mode; the outer surface of the single battery is provided with a concave part 3 for laser irradiation corresponding to the connection part of the top cover 2 and the shell 1, and the concave part 3 consists of a first notch 31 arranged on the top cover 2 and/or a second notch 32 arranged at the opening of the shell 1; wherein, at the time of laser welding, the top cover 2 and the case 1 are collapsed toward the recess 3 to fill the recess 3; the pole is arranged on the top cover 2 and is far away from the concave part 3.

By arranging the concave part 3, when the shell 1 and the top cover 2 are welded by laser, not only can laser reflection light and scattered light be blocked, plastic on the pole is protected, and the yield of the single battery is improved, but also because a molten pool generated by welding is contained in the concave part 3, melted materials are converged, the molten pool generated by welding is prevented from being accumulated on the upper surface of the battery cell shell, and a welding bulge cannot protrude out of the upper surface of the battery cell shell 1; the smoothness of the surface of the shoulder part of the battery cell is ensured, and the space utilization rate is improved; meanwhile, the problem of upwarping of the top folding edge of the envelope can be effectively solved, and the outer insulating film is prevented from being damaged by the welding bulge; the pole far from the concave part 3 plays a role in weakening the effect of baking the pole by heat generated in laser welding.

The molten pool is formed by melting the joint of the top cover 2 and the shell 1 through laser irradiation.

It should be said that, in some embodiments, the single battery includes the casing 1 and the top cap 2, and further includes, an outer insulating film provided outside the casing 1, a top cap 2 patch for insulation provided on the top cap 2, an inner insulating film outside the bare cell, a bottom support plate provided on the bottom surface of the casing 1 and used for placing the bare cell, an electrolyte poured into the casing 1, and the terminal hermetically provided on the top cap 2 includes the first terminal unit 41, the second terminal unit 42, the explosion-proof valve structure 6, the liquid injection hole structure 7, and a lower insulating member. Wherein, first utmost point post unit 41 is provided with the first extension that electrically conducts, and the first extension that electrically conducts is connected with the first utmost point ear electricity of naked electric core, and second utmost point post unit 42 is provided with the electrically conductive extension of second, and the electrically conductive extension of second is connected with naked electric core second utmost point ear electricity.

Further, the upper side surface of the top cover 2 is provided with an upward fixing bulge 21; or the underside of the top cover 2 is provided with a downward fixing projection 21.

Specifically, the strength of the top cover 2 can be obviously improved by arranging the fixing protrusions 21, so that the wall thickness of the top cover 2 is reduced, and the weight is reduced; the bending strength of the top cover 2 is improved, so that the surface flatness of the top cover 2 is improved; the top cover 2 can be isolated from the concave part 3 matched with the shell 1, so that laser reflected light and scattered light during laser welding can be blocked more effectively, and appearance and even poor function caused by burning plastic of the pole can be avoided; on the other hand, the welding heat transfer can be reduced, the thermal deformation of the top cover 2 is reduced, and the influence of the welding heat on functional parts such as the anti-explosion valve turnover valve is reduced.

It should be noted that the fixing projection 21 may be formed integrally with the top cover 2, or may be integrally connected to the top cover 2 by welding, gluing, or the like.

Further, with reference to fig. 3-6, in some embodiments, the fixing projections 21 are provided on the outer circumferential profile of the top cover 2; when the fixing protrusion 21 is disposed on the upper side surface of the top cover 2, the recess 3 at least includes a second notch 32; when the fastening projection 21 is provided on the lower side of the cover 2, the recess 3 is formed by a first recess 31 and/or a second recess 32.

Specifically, in some embodiments, the fixing protrusion 21 is disposed on the outer circumferential profile of the top cover 2, and the fixing protrusion 21 is disposed on the upper side surface of the top cover 2, the recessed portion 3 may be formed by enclosing the second notch 32 and the side wall of the fixing protrusion 21, the recessed portion 3 may be formed by enclosing the second notch 32 and the first notch 31 disposed on the fixing protrusion 21, and in order to ensure that the fixing protrusion 21 blocks the laser reflected light and the scattered light during laser welding, the first notch 31 may be disposed in the middle of the side wall of the fixing protrusion 21; it should be noted that, with the first notch 31 alone, the recess 3 would be blocked by the housing 1, and therefore, the recess 3 at least includes the second notch 32; in some embodiments, the fixing projection 21 is provided on the outer circumferential profile of the top cover 2, and the fixing projection 21 is provided on the lower side of the top cover 2, and the recess 3 is formed by the first notch 31 and/or the second notch 32.

Further, with reference to fig. 7, in some embodiments, a fixing projection 21 is provided between the pole and the recess 3; the recess 3 is formed by a first recess 31 and/or a second recess 32. First breach 31 is established on the outer ring of top cap 2 is all along the profile, and when laser welding casing 1 and top cap 2, fixed protrusion 21 can reduce the welding heat transfer, reduces top cap 2 heat altered shape and reduces the effect that the welding generates heat to the functional part such as explosion-proof valve upset valve, can also reduce the deformation influence to fixed protrusion 21, promotes top cap 2 surface flatness.

Further, the fixing projection 21 has a closed ring shape. Can more show 2 intensity of promotion top cap, the 2 wall thickness attenuate lightweight of top cap of being convenient for.

Further, the fixing protrusion 21 includes a plurality of segment protrusions, and the segment protrusions are spaced apart and arranged to form a ring shape. Can more show and promote 2 intensity of top cap, the 2 wall thickness attenuate lightweight of top cap of being convenient for can slightly warp moreover, makes top cap 2's adaptability stronger.

Further, the outer edge of the free end of the fixing protrusion 21 is provided with a chamfered angle or a rounded corner. The fixing protrusions 21 can be effectively prevented from scratching the hands in the process of moving the single batteries, and a protection effect is achieved.

Further, referring to fig. 8, the top cover 2 is provided with a first protrusion 51 at the first notch 31, and/or the housing 1 is provided with a second protrusion 52 at the second notch 32.

In the present embodiment, the first convex portion 51 and/or the second convex portion 52 constitute a convex portion, the convex portion is made of tin metal, the cross section of the convex portion is triangular, the upper end portion of the convex portion is a smaller end, and the position of the convex portion is set according to the position where the concave portion 3 is set; when the concave part 3 comprises the first notch 31 and the second notch 32, two convex parts are arranged and respectively arranged on the top cover 2 and the shell 1, so that a welding tool firstly contacts the convex parts to melt and weld the convex parts, and the upper end parts of the convex parts are smaller ends, so that the convex parts can be conveniently melted, and the top cover 2 and the shell 1 can be conveniently welded and fixed; and the convex part protrudes out of the corresponding top cover 2 or the corresponding shell 1, so that the top cover 2 and the shell 1 are not easy to deform when the convex part is melted. The protruding part may be a protruding part of the corresponding top cover 2 and the housing 1, or may be a separate part connected to the recessed part 3 through post-processing.

Further, the profile of the cross section of the concave part 3 is V-shaped, rectangular with a broken upper side, semicircular arc or parabola.

In this embodiment, it is preferably configured as a rectangle without upper side, and in other embodiments, configured as a V-shape, a semi-circular arc or a parabola, the concave portion 3 is easy to machine. In some embodiments, the first notch 31 and the second notch 32 are identical in shape, which facilitates the machining of the top cover 2 and the housing 1. In other embodiments, the shape of the first notch 31 and the shape of the second notch 32 may not be consistent, and the molten pool may be guided to a larger volume portion during welding, thereby reducing the accumulation of the molten pool on the upper surface of the roof 2.

In some embodiments, the first notch 31 and the second notch 32 are symmetrically disposed.

In the embodiment, the shapes of the first notch 31 and the second notch 32 are consistent, so that the top cover 2 and the shell 1 can be conveniently machined and formed, and a molten pool can be conveniently accommodated.

In some embodiments, the unit cell further includes a lid body that covers the recess 3 after laser welding. Cover lid and depressed part 3, ensure the planarization of monomer battery upper surface, avoid the material damage outer insulating film after condensing in the depressed part 3.

Referring to fig. 10, the present invention further provides a power battery, which includes an outer casing 8 and a plurality of the above single batteries, wherein the plurality of single batteries are disposed in the outer casing 8. Specifically, in some embodiments, one or more battery modules are arranged in the outer casing of the power battery, and a plurality of single batteries are arranged in each battery module.

The utility model discloses the beneficial effect who brings does: by arranging the concave part 3, when the shell 1 and the top cover 2 are welded by laser, scattered laser can be blocked, plastic on the pole is protected, the yield of the single battery is improved, and a molten pool generated by welding is contained in the concave part 3, so that melted materials are restrained, the molten pool generated by welding is prevented from being accumulated on the upper surface of the battery cell shell, and the welding bulge cannot protrude out of the upper surface of the battery cell shell 1; the strength of the top cover 2 can be obviously improved by arranging the fixing bulges 21, so that the wall thickness of the top cover 2 is reduced and the weight is reduced; the bending strength of the top cover 2 is improved, so that the surface flatness of the top cover 2 is improved; the top cover 2 can be isolated from the joint matched with the aluminum shell, so that laser reflected light and scattered light during laser welding can be effectively blocked, and appearance and even poor function caused by burning plastic of the pole can be avoided; on the other hand, the welding heat transfer can be reduced, the thermal deformation of the top cover 2 is reduced, and the influence of the welding heat on functional parts such as the anti-explosion valve turnover valve is reduced.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims

1. A battery cell, comprising: the terminal comprises a shell, a pole and a top cover; the shell is of a structure with an opening at one end, and the top cover is arranged at the opening of the shell and is connected with the shell in a laser welding mode; the outer surface of the single battery is provided with a depressed part for laser irradiation corresponding to the joint of the top cover and the shell, and the depressed part is composed of a first notch arranged on the top cover and/or a second notch arranged at the opening of the shell; wherein, upon laser welding, the top cover and the housing collapse toward the recess to fill the recess; the pole is arranged on the top cover and is far away from the sunken part.

2. The battery cell according to claim 1, wherein the top cover is provided at an upper side thereof with an upward fixing protrusion; or the lower side surface of the top cover is provided with a downward fixing bulge.

3. The battery cell according to claim 2, wherein the fixing protrusion is provided on an outer circumferential contour of the top cover; when the fixing bulge is arranged on the upper side surface of the top cover, the concave part at least comprises the second notch; when the fixing protrusion is arranged on the lower side surface of the top cover, the concave part is formed by the first notch and/or the second notch.

4. The battery cell according to claim 2, wherein the fixing protrusion is provided between the post and the recess; the recess is formed by the first notch and/or the second notch.

5. The unit cell according to claim 2, wherein the fixing projection is in a closed ring shape.

6. The single-cell battery as claimed in claim 2, wherein the fixing protrusion comprises a plurality of segmented protrusions which are arranged at intervals and form a ring around the segmented protrusions.

7. The unit cell according to claim 2, wherein the outer edge of the free end of the fixing projection is provided with a chamfered or rounded corner.

8. The battery cell as claimed in claim 1, wherein the top cover is provided with a first protrusion at the first notch, and/or the housing is provided with a second protrusion at the second notch.

9. The battery cell according to claim 1, wherein the cross-section of the recessed portion has a V-shaped profile, a truncated rectangle, a semicircular arc or a parabola.

10. A power cell comprising an outer casing and a plurality of cells according to any one of claims 1 to 9, the plurality of cells being disposed within the outer casing.