CN218005184U - Current collecting plate and cylindrical lithium ion battery - Google Patents

Abstract

The utility model provides a current collecting disc and cylinder type lithium ion battery, through die-cut shell fragment on the dish body, and with shell fragment and utmost point post welding, the shell fragment takes place to deform after compressing, thereby support current collecting disc and foil material terminal surface welding department tightly, so, need not to set up the connection piece of buckling, can play the effect of flexible coupling again, even flow dish and foil material terminal surface welding department appear the rosin joint or drop, also enable the two to keep inseparable electric connection; the through hole left by die cutting can be used as an electrolyte injection channel, so that the infiltration of electrolyte between the pole pieces is improved; the elastic piece of the utility model is compressed after being assembled, hardly occupies the height space in the battery shell, and can greatly improve the energy density of the battery compared with the existing collecting tray component; the curved part is arranged, so that the elastic sheet can obtain larger elasticity when the tilting angle is small.

Description

Current collecting plate and cylindrical lithium ion battery

Technical Field

The utility model relates to a lithium ion battery field especially relates to a current collector and cylinder type lithium ion battery.

Background

The full-lug cylindrical lithium ion battery is a key development direction of the conventional power battery, and is characterized in that blank positive and negative foils are reserved at two ends of a winding core respectively, then the foils are radially extruded, the end faces of the foils are flattened, then a current collecting disc and the end faces of the foils are subjected to laser welding, and then the current collecting disc and a pole on a cover plate are electrically connected. At present, the electric connection between the utmost point post on current collection dish and the apron mainly has two kinds of hard joint and flexible coupling:

(1) The hard connection is that the current collecting disc and the pole on the cover plate are directly abutted against each other and then are welded and fixed, for example, patent CN114221073A is such a hard connection structure;

(2) The flexible connection is to lead out a flexible connecting sheet on the current collecting disc, and then connect the connecting sheet with the post on the cover plate to realize electrical conduction, for example, patent CN215070163U is such a flexible connection structure.

When the flexible connection is used, the connecting sheet needs to be bent for multiple times, so that the connecting sheet is thinner and the overcurrent capacity is reduced; in addition, after the connecting sheet is welded with the pole, the cover plate is difficult to align during welding, usually, a guide device is needed to match the cover plate with the shell, the current collecting disc and the foil are easily pulled during the process to rub the flat end face, so that the current collecting disc and the foil are easy to fall off or welding marks are loose, the internal resistance of the battery is increased, and the performance of the battery is affected.

When the hard connection is used, the welding process is complex, and the current collecting disc is difficult to align, so that the cover plate and the shell are dislocated during welding, the shell is slightly deformed, a leak source is caused in the welding process, and the battery is scrapped.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a current collecting plate and cylinder type lithium ion battery need not to set up the connection piece of buckling, can play the effect of flexible coupling again.

The technical scheme of the utility model is realized like this:

the utility model provides a current collecting plate, which comprises a plate body and an elastic sheet, wherein the elastic sheet is formed by die cutting the middle part of the plate body, the die cutting part on the plate body is correspondingly provided with a through hole, the elastic sheet comprises a continuous welding part, a connecting part and a bent arc part,

the welding part is used for abutting against and welding the pole;

the curved portion and the plate body are continuously arranged and integrally formed, and the cross section of the curved portion comprises an arc-shaped section.

In addition to the above technical solution, preferably, the welding portion is in a truncated cone shape and is formed by punching a connecting portion.

In addition to the above technical solution, preferably, the welding portion is in a truncated cone shape and is formed by punching a connecting portion.

In addition to the above technical solution, preferably, the curved portion is formed by stamping the connecting portion.

On the basis of the technical scheme, preferably, the width and the length of the through hole are respectively larger than those of the elastic sheet.

On the basis of the above technical solution, preferably, the disc body includes a plurality of thickened portions and weak portions which are continuously arranged, the weak portions are formed between the thickened portions, the thickness of the thickened portions is greater than that of the weak portions, and the elastic sheet is formed by die-cutting the thickened portions.

Further preferably, the thickened portion includes an outer edge portion provided along an edge of the disk body outer ring, an inner edge portion provided around the through hole, and a rib portion connecting the outer edge portion and the inner edge portion.

On the basis of the technical scheme, preferably, a plurality of positioning notches are formed in the edge of the disc body.

In a second aspect, the utility model provides a cylindrical lithium ion battery, it includes utmost point post, book core, casing and apron, and the apron lid is established at casing end opening part and sealed with it, roll up the core and set up in the casing and roll up the core both ends and be provided with the welding terminal surface respectively, still include the current collector dish of the first aspect of the invention, a dish body terminal surface supports with the welding terminal surface and welds, sets up the hole on the apron, and utmost point post passes the hole and welds sealedly with it, and the shell fragment is in the compression deformation state, and the welding part supports with utmost point post and welds.

On above technical scheme's basis, it is preferred, utmost point post includes utmost point post body and spacing portion, and utmost point post body passes hole and bottom and shell fragment welding, and spacing portion sets up in utmost point post body side and supports and weld seal with the apron counterbalance.

On the basis of above technical scheme, it is preferred, utmost point post bottom is provided with the constant head tank, and the welding part stretches into in the constant head tank.

The utility model discloses a current collection dish and cylindrical lithium ion battery have following beneficial effect for prior art:

(1) The flow disc and the foil end face are tightly connected through the elastic sheet which is cut on the disc body and welded with the pole, and the elastic sheet deforms after being compressed, so that the welding position of the flow disc and the foil end face is abutted tightly, a bent connecting sheet is not needed, the effect of flexible connection can be achieved, and even if the welding position of the flow disc and the foil end face is subjected to false welding or falls off, the flow disc and the foil end face can be kept in tight electrical connection; the through hole left by die cutting can be used as an electrolyte injection channel, so that the infiltration of electrolyte between the pole pieces is improved; the elastic piece of the utility model is compressed after being assembled, hardly occupies the height space in the battery shell, and can greatly improve the energy density of the battery compared with the existing collecting tray component;

(2) The bent arc part is arranged, so that the elastic sheet can obtain larger elastic force when the tilting angle is small;

(3) The thickened part and the weak part are arranged, so that the weight can be reduced on the premise of ensuring the strength of the disc body; meanwhile, the elastic sheet is formed by die cutting of the thickened part, so that the elasticity of the elastic sheet can be ensured;

(4) The positioning notch is arranged, so that the positioning is facilitated when the current collecting disc is welded, and meanwhile, the positioning notch can also be used as an electrolyte filling channel to improve the infiltration of electrolyte between the pole pieces;

(5) The bottom of the pole is provided with a positioning groove, and the welding part extends into the positioning groove, so that the pole and the welding part can be positioned and welded quickly.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a perspective view of a cylindrical lithium ion battery of the present invention;

fig. 2 is a front sectional view of a cylindrical lithium ion battery of the present invention;

FIG. 3 is an enlarged view of the oval area of FIG. 2 rotated 90;

fig. 4 is an exploded view of the cylindrical lithium ion battery of the present invention;

fig. 5 is a perspective view of the current collecting plate of the present invention;

fig. 6 is a perspective view of the current collecting plate of the present invention;

fig. 7 is a perspective view of the column of the cylindrical lithium ion battery of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention.

As shown in fig. 5 and 6, the current collecting plate of the present embodiment includes a plate body 1 and a spring plate 3. As shown in fig. 1 to 4, the cylindrical lithium ion battery of the present embodiment further includes a terminal post 2, a winding core 4, a case 5, and a cover plate 6.

Wherein, the disc body 1 is made of metal material and is electrically connected with the roll core 4. Specifically, as shown in fig. 4, two ends of the winding core 4 are respectively provided with exposed foils, the foils are flattened to form a welding end face 40, and the end face of the winding core body 1 away from the pole 2 abuts against and is welded to the welding end face 40. Specifically, laser welding may be employed.

Just as the utility model discloses the background art introduces, because set body 1 adopts the hard joint with welding terminal surface 40, the rosin joint appears easily in the welding department or drops, leads to the increase of battery internal resistance, or the problem of opening circuit. Therefore, the utility model is provided with the elastic sheet 3 which is electrically connected with the disc body 1 and the pole 2; simultaneously, be in deformation state after the assembly of shell fragment 3 is accomplished, can compress tightly dish body 1 and welding terminal surface 40, even appear the rosin joint or drop in the welding department of dish body 1 and welding terminal surface 40, also enable the two and keep inseparable electric connection.

Specifically, the elastic sheet 3 includes a continuous welding portion 31, a connecting portion 32, and a bent portion 33, wherein:

the welding portion 31 is for abutting against and welding the pole post 2. Specifically, the welding portion 31 is formed in a truncated cone shape by punching a connecting portion 32. The structure of round platform shape is upwards protruding, is convenient for support with utmost point post 2 and holds, and is convenient for find accurate welding position, prevents to weld by mistake.

The connecting portion 32 serves to connect the welding portion 31 and the curved portion 33, and the shape thereof can be designed according to actual use requirements.

The curved portion 33 is continuously provided with the disc body 1 and is integrally formed, and its cross section includes an arc-shaped section. Through setting up the arc section, make shell fragment 3 also can obtain great elasticity when the perk angle is very little. Specifically, the curved portion 33 is formed by stamping the connecting portion 32. It should be noted that the cross section of the curved portion 33 may include an arc segment, or may be configured as a plurality of consecutive arc segments; furthermore, not only circular arcs, but also saw-toothed shapes are actually arc segments, which should be understood as part of the scope of the present invention.

Specifically, in order to facilitate rapid forming, the elastic sheet 3 is formed by die-cutting the middle part of the disc body 1, and the die-cutting part on the disc body 1 is correspondingly provided with a through hole 10. The through hole 10 can be used as a pouring channel of electrolyte, and as is known to be relatively compact after the welding end face 40 is flattened, the problem that the electrolyte is difficult to infiltrate between pole pieces exists in the full-lug cylindrical lithium ion battery, and the problem of the infiltration of the electrolyte can be improved through the through hole 10.

In order to prevent the through hole 10 from being blocked after the elastic sheet 3 is compressed and deformed, so that the electrolyte cannot be poured; or the elastic sheet 3 cannot recover the deformation after being clamped into the through hole 10, as a preferred embodiment, the width and length dimensions of the through hole 10 are respectively larger than those of the elastic sheet 3. Specifically, as shown in the drawings of the present invention, after the end of the connecting portion 32 is compressed to the bottom, there is still a gap between the connecting portion and the through hole 10 for the electrolyte to pass through; similarly, gaps are also formed between both sides of the connection portion 32 and the through-hole 10, and the electrolytic solution passes through the gaps.

For weight saving, the thinner the disc body 1 is, the better. However, if the disc body 1 is too thin, it has low strength and is easily deformed; in addition, the elastic sheet 3 is formed by die cutting from the disc body 1, the thickness of the elastic sheet is the same as that of the disc body 1, and the elastic force of the elastic sheet 3 which is too thin is insufficient. Therefore, as a preferred embodiment, the disc body 1 comprises a plurality of thickened portions 11 and weak portions 12 which are arranged in series, the weak portions 12 are formed between the thickened portions 11, the thickened portions 11 are thicker than the weak portions 12, and the elastic sheet 3 is formed by die cutting the thickened portions 11. Therefore, on the premise of light weight, the strength of the disc body 1 can be ensured, and the elastic force of the elastic sheet 3 can be enough. Specifically, the bottom surface of the weak portion 12 abuts against the welding end surface 40 and is laser-welded, so that the weak portion is thinner, easier to be welded through and more firm to be welded. Specifically, the thickened portion 11 includes an outer edge portion 111, an inner edge portion 112, and a rib portion 113, the outer edge portion 111 being provided along an outer circumferential edge of the disk body 1, the inner edge portion 112 being provided around the through-hole 10, and the rib portion 113 connecting the outer edge portion 111 and the inner edge portion 112. By such arrangement, the outer edge portion 111 can ensure the strength of the outer ring of the disc body 1; the inner edge part 112 can ensure the strength of the inner ring of the disc body 1 along the through hole 10 and ensure the thickness of the elastic sheet 3 cut by the die; further, the rib 113 connects the outer edge portion 111 and the inner edge portion 112, ensuring the overall strength.

In order to facilitate the positioning during the welding of the current collecting disc, the current collecting disc can also be used as an electrolyte filling channel to improve the infiltration of electrolyte between pole pieces, and positioning notches 100 are arranged at the edges around the disc body 1.

The cylindrical lithium ion battery of the present invention is introduced below.

The housing 5 is generally a cylindrical cylinder, and has two open ends or one open end.

And a cover plate 6 which covers and seals the opening at the end part of the shell 5.

The winding core 4 is arranged in the shell 5, exposed foils are arranged at two ends of the winding core 4 respectively, and the foils form welding end faces 40 after being kneaded flat. As the prior art, the winding core 4 is formed by sequentially laminating a positive plate, an isolating film, a negative plate and an isolating film and then winding the positive plate, the isolating film, the negative plate and the isolating film to form a cylindrical barrel structure, and foils on the positive plate and the negative plate are exposed out of two ends of the winding core 4 and are flattened after winding to form a welding end face 40.

The utility model discloses a current collecting plate assembly relation as follows:

a terminal surface of the plate body 1 is abutted to and welded with the welding terminal surface 40, the cover plate 6 is provided with a hole 60, the pole 2 penetrates through the hole 60 and is welded and sealed with the hole 60, the elastic sheet 3 is in a compression deformation state, and the welding part 31 is abutted to and welded with the pole 2. Thus, under the action of the resilience force of the elastic sheet 3, the disc body 1 is ensured to abut against the welding end face 40.

In order to facilitate the limitation of the pole 2 and the hole 60 on the cover plate 6, as shown in fig. 7, the pole 2 comprises a pole body 21 and a limiting part 22, the pole body 21 passes through the hole 60 and the bottom is welded with the elastic sheet 3, and the limiting part 22 is arranged on the side surface of the pole body 21 and is abutted to the cover plate 6. Specifically, the post body 21 is cylindrical, and the limiting portion 22 is annular.

In order to position and further weld the welding part 31 and the pole 2, the bottom of the pole 2 is provided with a positioning groove 20, and the welding part 31 extends into the positioning groove 20. The design of the welding part 31 of the matching circular truncated cone shape can quickly position the welding part 31 and the pole 2 and find the welding position accurately.

The utility model discloses a cylindrical lithium ion battery's assembly process is introduced below, including following step:

s1, welding a current collecting disc and a pole 2: positioning the welding part 31 and the pole 2, and welding from one side of the welding part 31;

s2, welding a current collecting plate: the disc body 1 is propped against and welded with the welding end face 40 of the winding core 4;

s3, welding the pole 2 and the cover plate 6: the pole body 21 penetrates through the hole 60, and the limiting part 22 is abutted against the cover plate 6 and is welded and sealed;

s4, entering a shell: the winding core 4 is plugged into the shell 5;

s5, sealing the shell 5: the cover plate 6 and the cover are arranged at the opening at the end part of the shell 5 and are welded and sealed.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be construed as limiting the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a current collecting plate, its includes dish body (1) and shell fragment (3), and shell fragment (3) are formed by a dish body (1) middle part cross cutting, and the cross cutting position correspondence on the dish body (1) is provided with through hole (10), its characterized in that: the elastic sheet (3) comprises a continuous welding part (31), a connecting part (32) and a bent arc part (33),

a welding part (31) which is used for abutting against and welding the pole (2);

the curved part (33) and the disc body (1) are continuously arranged and integrally formed, and the cross section of the curved part comprises an arc-shaped section.

2. The manifold disk of claim 1, wherein: the welding part (31) is in a circular truncated cone shape and is formed by punching a connecting part (32).

3. The manifold disk of claim 1, wherein: the bent arc part (33) is formed by stamping the connecting part (32).

4. The manifold disk of claim 1, wherein: the width and length of the through hole (10) are respectively larger than those of the elastic sheet (3).

5. The manifold disk of claim 1, wherein: the disc body (1) comprises a plurality of thickened parts (11) and weak parts (12) which are continuously arranged, the weak parts (12) are formed among the thickened parts (11), the thickness of each thickened part (11) is larger than that of each weak part (12), and the elastic sheet (3) is formed by die cutting of the thickened parts (11).

6. The manifold disk of claim 5, wherein: the thickened portion (11) includes an outer edge portion (111), an inner edge portion (112), and a rib portion (113), the outer edge portion (111) being provided along an outer circumferential edge of the disk body (1), the inner edge portion (112) being provided around the through-hole (10), the rib portion (113) connecting the outer edge portion (111) and the inner edge portion (112).

7. The manifold disk of claim 1, wherein: a plurality of positioning notches (100) are formed in the edge of the disc body (1).

8. The utility model provides a cylinder type lithium ion battery, its includes utmost point post (2), rolls up core (4), casing (5) and apron (6), and apron (6) lid is established at casing (5) end opening part and is sealed with it, roll up core (4) and set up in casing (5) and roll up core (4) both ends and be provided with respectively and weld terminal surface (40), its characterized in that: the current collecting plate further comprises the current collecting plate according to any one of claims 1 to 7, one end face of the plate body (1) is abutted to and welded with the welding end face (40), a hole (60) is formed in the cover plate (6), the pole (2) penetrates through the hole (60) and is welded and sealed with the hole, the elastic sheet (3) is in a compression deformation state, and the welding portion (31) is abutted to and welded with the pole (2).

9. The cylindrical lithium ion battery of claim 8, wherein: utmost point post (2) are including utmost point post body (21) and spacing portion (22), and utmost point post body (21) pass hole (60) and bottom and shell fragment (3) welding, and spacing portion (22) set up in utmost point post body (21) side and with apron (6) counterbalance and welded seal.

10. The cylindrical lithium ion battery of claim 8, wherein: the bottom of the pole (2) is provided with a positioning groove (20), and the welding part (31) extends into the positioning groove (20).

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