CN220856710U - Battery unit, annular battery, battery module, electric equipment and welding equipment - Google Patents

Abstract

The utility model belongs to the technical field of lithium batteries, and discloses a battery unit, an annular battery, a battery module, electric equipment and welding equipment, wherein the battery unit comprises a battery shell, and the battery shell comprises an outer shell wall and an inner shell wall arranged in the outer shell wall; the bare cell is sleeved outside the inner shell wall, and a first gap is formed between the inner wall of the bare cell and the outer side wall of the inner shell wall; the first busbar is arranged at one end of the bare cell, which is positioned at the bottom of the shell wall, and comprises a first electric connection part and a second electric connection part; the first electric connection part is electrically connected with the first tab of the bare cell, and the second electric connection part is at least partially positioned in the first gap and is electrically connected with the bottom of the shell wall in the first gap. The scheme at least improves the reliability of the electric connection between one pole of the bare cell and the battery shell.

Description

Battery unit, annular battery, battery module, electric equipment and welding equipment

Technical Field

The utility model belongs to the technical field of lithium batteries, and particularly relates to a battery unit, an annular battery, a battery module, electric equipment and welding equipment.

Background

Lithium ion batteries have been the mainstream batteries with the advantages of light weight, high energy density, long cycle life, high safety, and the like.

The main forms of lithium ion batteries include square shell batteries, columnar batteries and soft package batteries. For the columnar battery, the processing automation degree is high, the production efficiency is high, the consistency is good, and the cost is relatively low.

At present, many industries adopt lithium ion batteries, working condition environments applied by the lithium ion batteries are more and more complex, for example, in certain working condition environments, the lithium ion batteries can be subjected to severe vibration or external force impact and the like, and at least one electrode of a bare cell in the lithium ion batteries is easy to be electrically connected with a battery shell to fail.

Disclosure of utility model

The utility model provides a battery unit, an annular battery, a battery module, electric equipment and welding equipment, which are at least used for improving the reliability of electric connection between one pole of a bare cell and a battery shell.

In a first aspect, the present utility model provides a battery comprising:

a battery housing including an outer housing wall and an inner housing wall disposed within the outer housing wall;

The bare cell is sleeved outside the inner shell wall, and a first gap is formed between the inner wall of the bare cell and the outer side wall of the inner shell wall;

The first busbar is arranged at one end of the bare cell, which is positioned at the bottom of the shell wall, and comprises a first electric connection part and a second electric connection part; the first electric connection part is electrically connected with the first tab of the bare cell, and the second electric connection part is at least partially positioned in the first gap and is electrically connected with the bottom of the shell wall in the first gap.

As an achievable manner, the first electrical connection portion includes a first annular connection portion, the second electrical connection portion includes a second annular connection portion, the first annular connection portion and the second annular connection portion are coaxially disposed, and a second gap is disposed between an outer edge of the second annular connection portion and an inner edge of the first annular connection portion, at least one bridge portion is disposed in the second gap, and the bridge portion is electrically connected with the first annular connection portion and the second annular connection portion respectively, and is configured to disconnect electrical connection of the first annular connection portion and the second annular connection portion when fusing.

As an implementation manner, a plurality of bridging portions are uniformly arranged in the second gap at intervals along the circumferential direction of the inner shell wall.

As an achievable way, an insulating gasket is arranged between the first busbar and the bottom of the shell wall;

In an orthographic projection perpendicular to the axis of the inner housing wall, the first electrical connection and the bridge are both located within the insulating spacer.

As an implementation manner, the second electrical connection part is welded and fixed with the bottom of the housing wall.

As an implementation manner, the device further comprises a protective sleeve, wherein the protective sleeve penetrates through the outer side of the inner shell wall and is positioned in the first gap; and a third gap is arranged between the inner side wall of the protective sleeve and the outer side wall of the inner shell wall.

As an implementation manner, a plurality of through holes are formed in the side wall of the protective sleeve.

As an implementation manner, the second electrical connection part is at least partially located in the third gap, and is welded and fixed with the bottom of the shell wall in the third gap.

As an achievable mode, an insulating layer is disposed on the outer side of the first busbar, and the insulating layer extends from at least the top of the insulating spacer to the bottom of the bare cell, and is wrapped on the outer side of the bottom of the bare cell.

As an implementation, in an orthographic projection perpendicular to the axis of the inner shell wall, the outer edge of the insulating layer coincides with or is located within the outer edge of the insulating spacer.

As an achievable way, one end of the inner shell wall is closed, and the other end is open; or both ends of the inner shell wall are open.

As an implementation manner, an opening is formed in the top of the shell wall, a cover plate is fixed on the opening in a sealing manner, and a pole is arranged on the cover plate;

The other end of the bare cell is electrically connected with a second busbar, and the second busbar is electrically connected with the pole.

As an implementation manner, the second busbar includes a third annular connection portion, and an electrical connection piece extends outwards from the third annular connection portion, and is electrically connected with the pole.

As an realizable form, the inner shell wall is provided with a hole extending along the axis of the inner shell wall.

As an implementation manner, the hole is a heat dissipation hole.

As an implementation, the cross section of the hole is circular, regular polygon, oval or non-equilateral polygon.

As an implementation, the cross section of the outer shell wall and/or the inner shell wall is circular, regular polygonal, elliptical or non-equilateral polygonal.

As an implementation manner, the cross section of the bare cell is a circle, a regular polygon, an ellipse or a polygon with non-equal sides.

As an implementation manner, the maximum value of the linear distance between any two points on the cross section of the hole is 0.11-0.65 of the maximum value of the linear distance between any two points on the cross section of the shell wall

As an implementation manner, a plurality of heat dissipation protrusions are arranged on the wall of the hole.

In a second aspect, the present utility model provides a ring-shaped battery comprising the battery cell described above.

As an implementation manner, the outer shell wall and the inner shell wall enclose a cavity for accommodating the bare cell, and the cross section of the cavity is annular.

In a third aspect, the present utility model provides a battery comprising the above annular battery.

In a fourth aspect, the present utility model provides a battery module, including a plurality of the above-mentioned annular batteries, a plurality of the annular batteries being connected in series and/or in parallel; or, a plurality of the batteries are included, and a plurality of the batteries are connected in series and/or in parallel.

In a fifth aspect, the present utility model provides an electrical device, including a plurality of the annular batteries described above; or, a plurality of the above batteries; or, the battery module comprises the battery module.

In a sixth aspect, the present utility model provides a welding apparatus for preparing a battery cell as described above, or for preparing an annular battery as described above, or for preparing a battery as described above, the welding apparatus comprising a first welding head and a second welding head for movement towards each other, the first welding head comprising an annular welding portion for extending into the first gap for pressing the second electrical connection portion and the bottom of the housing wall towards the second welding head such that the second electrical connection portion is at least partially welded to the bottom of the housing wall.

As an implementation manner, a plurality of welding protrusions are arranged on one side, facing the second welding head, of the annular welding portion, and the welding protrusions are uniformly distributed along the circumferential direction of the annular welding portion.

According to the scheme, the second electric connection part of the first busbar electrically connected with the bare cell is at least partially positioned in the first gap, and the second electric connection part can be welded with the bottom of the shell wall in the first gap through the welding equipment, so that the second electric connection part is reliably electrically connected with the bottom of the shell wall in the first gap, the problem that the second electric connection part is separated from the bottom of the shell wall to cause electric connection failure is avoided, and therefore, the reliability of electric connection between one pole of the bare cell and the battery shell is at least improved.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the accompanying drawings in which:

fig. 1 is a perspective view of a battery according to an embodiment of the present utility model;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a cross-sectional view of the portion A-A of FIG. 1;

FIG. 4 is a schematic diagram of a first bus bar according to another embodiment of the present utility model;

FIG. 5 is a cross-sectional view of a battery according to another embodiment of the present utility model corresponding to the A-A position;

FIG. 6 is a cross-sectional view of a battery according to another embodiment of the present utility model corresponding to the A-A position;

FIG. 7 is a cross-sectional view of a battery according to another embodiment of the utility model, corresponding to the A-A position;

Fig. 8 is a schematic view illustrating a use state of a welding apparatus according to another embodiment of the present utility model.

Reference numerals illustrate:

The electric power source comprises an outer shell wall 1, an inner shell wall 2, a hole 21, a cover plate 3, a pole 31, a second busbar 4, a third annular connecting part 41, an electric connection piece 42, a protective sleeve 5, a through hole 51, a bare cell 6, a pole lug 61, a first busbar 7, a first annular connecting part 71, a second annular connecting part 72, a second gap 73, a bridging part 74 and a central hole 75; insulating gasket 8, insulating layer 9, explosion-proof valve 10, liquid injection hole 20, first bonding tool 101, annular welding part 1011, welding projection 1012, second bonding tool 102, first gap K1, third gap K2.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be noted that, for convenience of description, only the portions related to the utility model are shown in the drawings.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

As at least shown in fig. 1 to 3, a battery unit provided in an embodiment of the present utility model includes:

A battery case including an outer case wall 1 and an inner case wall 2 provided in the outer case wall 1;

Generally, the battery case may be made of metal, such as steel, aluminum alloy, and the like. The battery can protect the bare cell 6 arranged in the battery on one hand and can serve as one of poles of the battery, such as a negative pole or a positive pole on the other hand.

Wherein, the outer shell wall 1 and the inner shell wall 2 may have annular structures, the inner shell wall 2 may form a centrally located hole 21, and the hole 21 extends along the axis of the inner shell wall 2 and may be used as a heat dissipation hole for heat dissipation. Referring to at least fig. 3, the outer shell wall 1 and the inner shell wall 2 may be of unitary construction, such as by casting, or stamping a sheet of metal; referring to fig. 5, 6 or 7, the outer shell wall 1 and the inner shell wall 2 may also be two-piece structures, wherein the two-piece structures refer to the outer shell wall 1 and the inner shell wall 2 as two separate components. For example, the inner shell wall 2 and the outer shell wall 1 may be joined together by means of welding. In the case where the bottom of the outer shell wall 1 has a bottom plate, the inner shell wall 2 may be welded directly to the bottom plate of the outer shell wall 1, and the bottom plate of the outer shell wall 1 is provided with a hole communicating with the hole 21; if the outer shell wall 1 is only an annular wall, the inner shell wall 2 may be connected to the outer shell wall 1 by means of an end cap, for example, one end of the inner shell wall 2 is welded to the end cap, and the end cap is welded to one end of the outer shell wall 1, and at this time, one end of the end cap may be provided with a hole communicating with the hole 21.

In this embodiment, specifically, the cross section of the housing wall 1 may be a circle, a regular polygon, an ellipse, or a polygon having non-equal sides. Correspondingly, the cross section of the inner housing wall 2 may also be circular, regular polygonal, elliptical or non-equilateral polygonal. The cross-section of the aperture 21 may also be circular, regular polygonal, elliptical or non-equilateral polygonal.

A cavity is defined between the outer case wall 1 and the inner case wall 2, the cross-sectional shape of the cavity is annular, and the cavity serves as at least an installation space for the bare cell 6.

The bare cell 6 is sleeved outside the inner shell wall 2, and a first gap K1 is formed between the inner wall of the bare cell 6 and the outer side wall of the inner shell wall 2;

The bare cell 6 referred to herein may be a wound cell composed of a positive electrode sheet, a separator, and a negative electrode sheet laminated in this order, and the three-layer structure is wound to form the bare cell 6 having a hole in the center.

The hole in the center of the bare cell 6 is sleeved outside the inner shell wall 2, and the size of the hole in the center of the bare cell 6 is larger than the size of the inner shell wall 2, so that a first gap K1 is formed between the inner wall of the bare cell 6 and the outer side wall of the inner shell wall 2, and the first gap K1 is at least used for providing a channel for an external tool, such as but not limited to a welding device, to extend into the bottom of the battery shell so as to electrically connect the first busbar 7 with the bottom of the outer shell wall 1.

The cross section of the bare cell 6 may be circular, regular polygon, oval or non-equilateral polygon.

A first busbar 7 disposed at one end of the bare cell 6 at the bottom of the housing wall 1, where the first busbar 7 includes a first electrical connection portion and a second electrical connection portion; the first electrical connection portion is electrically connected with the first tab of the bare cell 6, and the second electrical connection portion is at least partially located in the first gap K1 and is electrically connected with the bottom of the housing wall 1 in the first gap K1.

For example, the first electrical connection portion of the first busbar 7 may be welded to the first tab of the bare cell 6, and the second electrical connection portion of the first busbar 7 may be welded to the bottom of the case wall 1 in the first gap K1, that is, the first tab of the bare cell 6 may be electrically connected to the bottom of the case wall 1 through the first busbar 7, and the case wall 1 may serve as one of the poles of the battery, such as the positive pole or the negative pole.

According to the scheme, the second electric connection part of the first busbar 7 electrically connected with the bare cell 6 is at least partially positioned in the first gap K1, and the second electric connection part can be welded with the bottom of the shell wall 1 in the first gap K1 through welding equipment, so that the second electric connection part is reliably electrically connected with the bottom of the shell wall 1 in the first gap K1, the problem that the second electric connection part is separated from the bottom of the shell wall 1 to cause electric connection failure is avoided, and therefore, the reliability of electric connection between one pole of the bare cell 6 and the battery shell is at least improved.

In addition, the first gap K1 may allow the welding device to extend into the bottom of the battery case, and the second electrical connection portion is welded with the bottom of the housing wall 1 in the first gap K1, so that in the battery charging and discharging process, if the bare cell 6 thermally expands, at least a portion of the expansion position of the bare cell 6 may enter into the first gap K1, that is, at least a portion of the expansion amount of the bare cell 6 is offset by the first gap K1, so that the outward extrusion force of the bare cell 6 to the battery case is reduced, and the problem that the battery case expands and deforms due to the expansion of the bare cell 6 is at least alleviated. In the limit, the entire expansion amount of the bare cell 6 is offset by the first gap K1, and in this case, the bare cell 6 does not exert an outward pressing force on the battery case, that is, the battery case is not deformed due to thermal expansion of the bare cell 6.

As an implementation manner, at least referring to fig. 4, the first electrical connection portion includes a first annular connection portion 71, the second electrical connection portion includes a second annular connection portion 72, the first annular connection portion 71 and the second annular connection portion 72 are coaxially disposed, a second gap 73 is disposed between an outer edge of the second annular connection portion 72 and an inner edge of the first annular connection portion 71, at least one bridge portion 74 is disposed in the second gap 73, and the bridge portion 74 is electrically connected with the first annular connection portion 71 and the second annular connection portion 72 respectively.

For example, but not limited to, the first bus bar 7 may be manufactured by stamping, for example, stamping a metal sheet, removing a portion of the metal material on the metal sheet to form the first annular connecting portion 71 and the second annular connecting portion 72 located in the first annular connecting portion 71, and having a second gap 73 between an outer edge of the second annular connecting portion 72 and an inner edge of the first annular connecting portion 71, wherein a bridge portion 74 is disposed in the second gap 73, and the bridge portion 74 is electrically connected to the first annular connecting portion 71 and the second annular connecting portion 72, that is, a portion of the metal material on the metal sheet is stamped between the first annular connecting portion 71 and the second annular connecting portion 72 to form the second gap 73, and a remaining portion of the metal material on the metal sheet forms the bridge portion 74.

The second electrical connection portion includes the second annular connection portion 72, and this second annular connection portion 72 can cover outside the inner shell wall 2 through its centre bore 75 to be located at least in the first clearance K1, can improve the area that the second electrical connection portion and the bottom electricity of shell wall 1 are connected, along with the increase of electric connection area, can reduce contact resistance on the one hand, avoid appearing unusual the heating because of the resistance is too big in the junction, lead to the condition emergence of electric loss increase, on the other hand can improve the joint strength of second electrical connection portion and the bottom of shell wall 1, reduce the possibility that the separation takes place for second electrical connection portion and the bottom of shell wall 1.

In addition, since the bridge 74 is provided in the second gap 73 between the first annular connecting portion 71 and the second annular connecting portion 72, that is, only a partial region between the first annular connecting portion 71 and the second annular connecting portion 72 is connected (region corresponding to the bridge 74), if the current abnormally increases during charging and discharging, the bridge 74 is fused, one of the poles of the battery is in an open state (that is, the electrical connection between the first annular connecting portion 71 and the second annular connecting portion 72 is disconnected), and occurrence of burning, explosion, and the like due to excessive heat generation of the bare cell 6 caused by excessive current can be avoided, and therefore, by providing the bridge 74 in the second gap 73 between the first annular connecting portion 71 and the second annular connecting portion 72, the safety of the battery can be improved.

As an implementation manner, a plurality of bridging portions 74 are uniformly arranged in the second gap 73 at intervals along the circumferential direction of the inner shell wall 2. In this example 4 bridges 74 are evenly provided.

By uniformly arranging the plurality of bridging portions 74 in the circumferential direction of the inner housing wall 2, the size of the single bridging portion 74 can be reduced under the condition that the current transmission requirement between the first annular connecting portion 71 and the second annular connecting portion 72 is met, the current required for fusing the single bridging portion 74 is correspondingly reduced, and the size of the single bridging portion 74 can be designed to be smaller than the current with smaller proportion than the rated current of the single bridging portion 74 according to the specific condition of the battery, so that the safety performance is improved. Where the current rating of the individual bridge 74 may be considered as the maximum current rating of the battery divided by the current rating of the number of bridges 74, the proportion of the individual bridge 74 fusing current exceeding the current rating of the individual bridge 74 may be determined according to the actual situation, such as, but not limited to, 5%, 8%, 10%, etc., which may exceed the current rating of the individual bridge 74.

As an implementation, see also at least fig. 3, an insulating gasket 8 is arranged between the first busbar 7 and the bottom of the housing wall 1;

In an orthographic projection perpendicular to the axis of the inner housing wall 2, both the first electrical connection and the bridge 74 are located within the insulating spacer 8.

By providing the insulating spacer 8 between the first busbar 7 and the bottom of the case wall 1, after the bridge portion 74 is melted due to abnormal increase of the battery current, the battery case and the first busbar 7 can be brought into an open state, and at this time, one of the poles of the bare cell 6 connected to the first busbar 7 is also brought into an open state with the battery case, thereby avoiding further deepening of the fault.

In addition to providing the insulating spacer 8 between the first busbar 7 and the bottom of the housing wall 1 so that the case and the first busbar 7 are in the open state after the bridge 74 is fused, the first busbar 7 may be provided with an insulating layer other than the position where it is electrically connected, and a structure such as an insulating block may be provided between the first busbar 7 and the bottom of the housing wall 1, which is not illustrated here.

As an implementation, the second electrical connection is welded to the bottom of the housing wall 1.

The welding referred to herein may be performed by laser welding, ultrasonic welding, resistance welding, electromagnetic welding, friction welding, resistance welding, or the like.

As an implementation manner, the device further comprises a protective sleeve 5, wherein the protective sleeve 5 penetrates through the outer side of the inner shell wall 2 and is positioned in the first gap K1; and a third gap K2 is arranged between the inner side wall of the protective sleeve 5 and the outer side wall of the inner shell wall 2.

The protective sheath 5 may be a tubular structure, and the shape of its cross section may be determined according to practice, such as a circle, an ellipse, a quadrangle, or a polygon. As a preferred implementation, the cross-sectional shape of the protective sleeve 5 is generally the same as the cross-sectional shape of the inner shell wall 2, although in some examples it may be different.

The protective sleeve 5 is arranged on the outer side of the inner shell wall 2 in a penetrating way, and the protective sleeve 5 is in clearance fit with the inner shell wall 2 so as to form a third clearance K2 between the protective sleeve 5 and the inner shell wall 2.

The protective sleeve 5 is used for supporting and protecting the inner side of the bare cell 6.

Typically, the protective sheath 5 is an insulating protective sheath. For example, the material can be insulating paper, rubber, plastic, etc. Preferably, the protection sleeve 5 has a certain flexibility, that is, the protection sleeve 5 is a flexible protection sleeve, so that the protection sleeve 5 is beneficial to deform towards the direction of the inner shell wall 2 along with the thermal expansion of the bare cell 6, so as to avoid that the protection sleeve 5 is of a rigid structure, and the thermal expansion of the bare cell 6 towards the direction of the inner shell wall 2 is prevented, so that the thermal expansion of the bare cell 6 towards the direction of the outer shell wall 1 is caused, and the outer shell wall 1 is outwards deformed.

Referring to fig. 2 and 3, the third gap K2 may buffer at least a part of thermal expansion deformation of the bare cell 6, and may further contain a part of electrolyte in the third gap K2, so that in order to make the electrolyte flow on two sides of the protective cover 5, a plurality of through holes 51 are provided on a side wall of the protective cover 5, so that the electrolyte in the third gap K2 may flow toward the bare cell 6 through the through holes 51, or may flow from the direction of the bare cell 6 toward the third gap K2.

As an implementation manner, the second electrical connection part is at least partially located in the third gap K2, and is welded and fixed with the bottom of the housing wall 1 in the third gap K2.

As a preferred implementation, the bare cell 6 is in an interference fit with the protective sheath 5. When the battery is assembled, the protective sleeve 5 can be inserted into the hole in the center of the bare cell 6, and the bare cell 6 and the protective sleeve 5 are in interference fit and can be assembled into the battery shell together, so that the assembly efficiency can be improved, and the protective sleeve 5 is arranged in the hole in the center of the bare cell 6 when the bare cell 6 is assembled into the battery shell, so that the protective sleeve 5 can prevent the hole in the center of the bare cell 6 from colliding with the shell wall 1 in the assembly process, and the problems of short circuit and the like caused by the damage of the center of the bare cell 6 are solved. After the protective sleeve 5 is arranged in the battery shell along with the bare cell 6, a third gap K2 is formed between the protective sleeve 5 and the inner shell wall 2, the welding equipment stretches into the bottom of the battery shell through the third gap K2, and the second electric connection part is at least partially welded and fixed with the bottom of the outer shell wall 1.

As an implementation manner, at least as shown in fig. 3, an insulating layer 9 is disposed on the outer side of the first busbar 7, and the insulating layer 9 extends from at least the top of the insulating spacer 8 to the bottom of the bare cell 6, and is wrapped on the outer side of the bottom of the bare cell 6.

With the above structure, at least the outer side of the first bus bar 7 and the bottom of the bare cell 6 are covered with the insulating layer 9, so that the outer side of the first bus bar 7 and the outer side of the bare cell 6 are insulated from the inner side of the case wall 1, and when the bridge portion 74 is fused, the failure is not further deteriorated due to the electrical connection between the outer side of the first bus bar 7 and the outer side of the bare cell 6 and the inner side of the case wall 1.

As an implementation, in an orthographic projection perpendicular to the axis of the inner housing wall 2, the outer edge of the insulating layer 9 coincides with the outer edge of the insulating spacer 8 or is located within the outer edge of the insulating spacer 8.

The outer side edge of the insulating layer 9 coincides with the outer side edge of the insulating spacer 8, or is located in the outer side edge of the insulating spacer 8, so that a certain distance is formed between the outer side of the first busbar 7 and the outer side of the bare cell 6 and the inner side of the housing wall 1, and the situation that the outer side of the first busbar 7 and the outer side of the bare cell 6 are in conductive connection with the inner side of the housing wall 1 is avoided.

As an achievable way, one end of the inner shell wall 2 is closed and the other end is open; or both ends of the inner housing wall 2 are open.

Wherein, as at least shown in fig. 6, the inner casing wall 2 may be a hole 21 with one closed end and one open end to form a blind hole, the hole 21 is used for dissipating heat from the middle part of the battery, and at this time, the bottom plate or the end cover of the outer casing wall 1 is provided with a hole communicated with the open end of the hole 21, so that the hole 21 dissipates heat from the middle part of the battery; in other examples, at least as shown in fig. 5, the inner casing wall 2 may be open at both ends, and one end thereof is closed by other external components, for example, one end thereof is closed by a battery end cover or a bottom plate of the outer casing wall 1 to form a blind hole, and the blind hole may be used as a hole 21 to dissipate heat from the middle of the battery.

Of course, in other examples, at least as shown in fig. 7, both ends of the inner case wall 2 are opened to form a through hole, which may serve as the hole 21, and the bottom plate or the end cap of the outer case wall 1 is provided with a hole communicating with the hole 21 so that the hole 21 radiates heat to the middle of the battery.

As an achievable way, the maximum value of the linear distance between any two points on the cross section of the hole 21 is between 0.11 and 0.65 of the maximum value of the linear distance between any two points on the cross section of the housing wall 1.

As an achievable way, the linear distance between any two points on the cross section of the hole 21 is a maximum of 5mm-30mm.

As an achievable way, the linear distance between any two points on the cross section of the hole 21 is a maximum of 8mm-25mm.

As an achievable way, the linear distance between any two points on the cross section of the hole 21 is a maximum of 10mm-15mm.

Such as, but not limited to, a maximum value of 5.15mm, 5.3mm, 6.25mm, 7mm, 8.66mm, 13mm, 15.35mm, 18.7mm, 19mm, 22.9mm, 24mm, 28.4mm, 29.46mm, etc., for the linear distance between any two points across the cross-section of the aperture 21. The maximum value of the linear distance between any two points on the cross section of the hole 21 can be determined according to practical needs, as long as the maximum value of the linear distance between any two points on the cross section of the hole 21 is 0.11-0.65 of the maximum value of the linear distance between any two points on the cross section of the shell wall 1 of the battery shell. In addition, generally, the longer the length of the battery unit is, the larger the maximum value of the linear distance between any two points on the cross section of the hole 21 can be selected, i.e. the maximum value of the linear distance between any two points on the cross section of the hole 21 is positively correlated to the length of the battery unit, so that the cooling medium can perform sufficient heat exchange in the hole 21 to take away the heat of the central part of the battery unit to the greatest extent, and the heat dissipation effect on the battery unit is improved. The cooling medium in the hole 21 may be supplied to the cooling medium through a liquid cooling pipe, and the cooling medium may radiate the center of the battery cell, or may radiate the center of the battery cell by heat conduction such as a cooling column.

As an achievable form, in order to improve the heat dissipation capacity of the battery cell, a plurality of heat dissipation protrusions (not shown in the drawings) are provided on the wall of the hole 21. By arranging a plurality of heat dissipation bulges on the hole wall of the hole 21, the surface area of the hole wall of the hole 21 is increased, and along with the increase of the surface area, the contact area of the heat dissipation bulges and the cooling medium is correspondingly increased, so that the heat exchange area is increased, the heat in the middle part of the battery unit can be fully exchanged with the cooling medium flowing in the hole 21, the heat in the middle part of the battery unit is taken away, and the temperature of the battery with the battery unit during charging and discharging is reduced.

As an implementation manner, each of the heat dissipation protrusions is an annular protrusion disposed around the wall of the hole 21. The heat radiation protrusions are provided as annular protrusions surrounding the wall of the hole 21, and can uniformly radiate heat in the circumferential direction of the wall. It will be appreciated that the heat dissipating bump may be a dot, a column, or other shaped bump structure, and is not limited to the annular bump in the above implementation.

As an implementation manner, an opening is formed in the top of the shell wall 1, a cover plate 3 is fixed in a sealing manner to the opening, and a pole 31 is arranged on the cover plate 3; the cover plate 3 can be connected to the housing wall 1 in a sealing and fixed manner by welding.

The end cap 3 may be provided with an explosion-proof valve 10, a liquid injection hole 20, and the like, and electrolyte may be injected into the battery cell through the liquid injection hole 20. In the formation process after the electrolyte is injected, the injection hole 20 may be used as an exhaust hole for exhausting the gas generated by the formation from the battery case, and the injection hole 20 may be plugged after the formation is completed, for example, but not limited to, a sealing nail may be welded in the injection hole 20.

The other end of the bare cell 6 is electrically connected with a second busbar 4, and the second busbar 4 is electrically connected with the pole 31.

For example, the second bus bar 4 is welded to the tab 61 at the other end of the bare cell 6 and the post 31 connected to the cover plate 3.

As an implementation, the second busbar 4 includes a third annular connection portion 41, and an electrical connection piece 42 extends outward from the third annular connection portion 41, and the electrical connection piece 42 is electrically connected to the pole 31.

In connection, the third annular connection portion 41 may be welded to the tab at the other end of the bare cell 6, then the electrical connection piece 42 is welded to the back surface of the post 31 on the cover plate, then the cover plate 3 is turned over and covered on the opening of the battery case, and then the end cap is welded to the case wall 1.

In a second aspect, the present utility model provides an annular battery including the above-described battery cell, and the annular battery includes a battery in which a cross-sectional shape of a cavity defined between an outer case wall 1 and an inner case wall 2 of the battery cell is annular, so that the annular battery having the battery cell is annular as a whole.

In a third aspect, the utility model provides a battery comprising a ring-shaped battery as described above, to achieve a better heat dissipation of the middle of the battery through the holes 21.

In a fourth aspect, the present utility model provides a battery module comprising a plurality of annular batteries as described above, a plurality of said annular batteries being connected in series and/or in parallel.

The number of the adopted annular batteries and the serial-parallel connection relation thereof can be determined according to the output voltage and the capacity of the battery module.

Or the battery module comprises a plurality of batteries which are connected in series and/or in parallel. The number of the adopted batteries and the serial-parallel connection relation thereof can be determined according to the output voltage and the capacity of the battery module.

In a fifth aspect, the present utility model provides an electric device, including the above-mentioned annular battery; or, including the above battery; or, the battery module comprises the battery module.

Electrical consumers such as, but not limited to, new energy vehicles (electric vehicles, hybrid vehicles, etc.), digital products, and the like.

In a sixth aspect, referring at least to fig. 8, the present utility model provides a welding apparatus for preparing the above-described battery cell; or preparing the annular battery; or preparing the battery described above, the welding device comprises a first welding head 101 and a second welding head 102 for movement towards each other, said first welding head 101 comprising an annular welding portion 1011, said annular welding portion 1011 being adapted to extend into said first gap K1 for pressing said second electrical connection and the bottom of said housing wall 1 towards said second welding head 102 for at least partially welding said second electrical connection to the bottom of said housing wall 1.

Wherein first bonding tool 101 and second bonding tool 102, which are moving toward each other, may move one of them, the other of them is fixed, or both of them may move.

Taking the case where one of them is movable and the other is fixed as an example, for example, the second welding head 102 is fixed, the top portion is used for placing the battery to be welded, the first welding head 101 is movable in the vertical direction, the first welding head 101 moves downward when welding is performed, the annular welding portion 1011 extends into the first gap K1 of the battery until the bottom portion of the housing wall 1 and the first busbar 7 are interposed between the first welding head 101 and the second welding head 102, and the bottom portion of the housing wall 1 and the first busbar 7 are welded together by the first welding head 101 and the second welding head 102.

As an implementation manner, a plurality of welding protrusions 1012 are disposed on a side of the annular welding portion 1011 facing the second welding head 102, and the plurality of welding protrusions 1012 are uniformly arranged along a circumferential direction of the annular welding portion 1011.

By providing a plurality of welding projections 1012 on the annular welding portion 1011, spot welding can be performed to weld the bottom of the case wall 1 with the first busbar 7 to improve welding quality.

In addition, the second welding head 102 may be any material that can be energized and that can support the battery to be welded, and the shape thereof is not limited to this, and may be, for example, but not limited to, a columnar shape, a plate shape, a tubular shape, or the like.

It is to be understood that the above references to the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., are for convenience in describing the present utility model and simplifying the description only, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

The above description is only illustrative of the preferred embodiments of the present utility model and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the utility model referred to in the present utility model is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the above-mentioned features and the technical features disclosed in the present utility model (but not limited to) having similar functions are replaced with each other.

Claims (27)

1. A battery cell, comprising:

a battery case including an outer case wall (1) and an inner case wall (2) provided in the outer case wall (1);

the bare cell (6) is sleeved outside the inner shell wall (2), and a first gap (K1) is formed between the inner wall of the bare cell (6) and the outer side wall of the inner shell wall (2);

The first busbar (7) is arranged at one end of the bare cell (6) positioned at the bottom of the shell wall (1), and the first busbar (7) comprises a first electric connection part and a second electric connection part; the first electric connection part is electrically connected with the first tab of the bare cell (6), and the second electric connection part is at least partially positioned in the first gap (K1) and is electrically connected with the bottom of the shell wall (1) in the first gap (K1).

2. The battery cell of claim 1, wherein the first electrical connection portion comprises a first annular connection portion (71), the second electrical connection portion comprises a second annular connection portion (72), the first annular connection portion (71) is coaxially arranged with the second annular connection portion (72), and a second gap (73) is arranged between an outer edge of the second annular connection portion (72) and an inner edge of the first annular connection portion (71), at least one bridge portion (74) is arranged in the second gap (73), the bridge portion (74) is electrically connected with the first annular connection portion (71) and the second annular connection portion (72), respectively, and the bridge portion (74) is configured to disconnect the electrical connection of the first annular connection portion (71) and the second annular connection portion (72) when fused.

3. The battery cell according to claim 2, wherein a plurality of the bridging portions (74) are provided in the second gap (73) at regular intervals in the circumferential direction of the inner case wall (2).

4. A battery unit according to claim 2 or 3, characterized in that an insulating gasket (8) is provided between the first busbar (7) and the bottom of the housing wall (1);

In an orthographic projection perpendicular to the axis of the inner housing wall (2), both the first electrical connection and the bridge (74) are located within the insulating spacer (8).

5. The battery cell according to claim 4, characterized in that the second electrical connection is welded to the bottom of the housing wall (1).

6. A battery unit according to any one of claims 1-3, further comprising a protective sheath (5), said protective sheath (5) being arranged through the outer side of the inner housing wall (2) and being located in the first gap (K1); and a third gap (K2) is arranged between the inner side wall of the protective sleeve (5) and the outer side wall of the inner shell wall (2).

7. The battery cell according to claim 6, characterized in that a plurality of through holes (51) are provided on the side wall of the protective casing (5).

8. The battery cell according to claim 6, characterized in that the second electrical connection is located at least partially within the third gap (K2) and is welded to the bottom of the housing wall (1) within the third gap (K2).

9. The battery unit according to claim 4, characterized in that an insulating layer (9) is provided on the outer side of the first busbar (7), and the insulating layer (9) extends at least from the top of the insulating spacer (8) to the bottom of the bare cell (6) and wraps the outer side of the bottom of the bare cell (6).

10. The battery cell according to claim 9, characterized in that the outer edge of the insulating layer (9) coincides with the outer edge of the insulating spacer (8) or is located within the outer edge of the insulating spacer (8) in an orthographic projection perpendicular to the axis of the inner housing wall (2).

11. A battery unit according to any one of claims 1-3, characterized in that one end of the inner housing wall (2) is closed and the other end is open; or both ends of the inner shell wall (2) are open.

12. A battery unit according to any one of claims 1-3, characterized in that the top of the housing wall (1) is provided with an opening, the opening being sealingly secured with a cover plate (3), the cover plate (3) being provided with a pole (31);

The other end of the bare cell (6) is electrically connected with a second busbar (4), and the second busbar (4) is electrically connected with the pole column (31).

13. The battery cell according to claim 12, wherein the second busbar (4) comprises a third annular connection portion (41), the third annular connection portion (41) extending outwardly with an electrical connection tab (42), the electrical connection tab (42) being electrically connected with the post (31).

14. Cell according to claim 1, characterized in that the inner housing wall (2) is provided with a hole (21), which hole (21) extends along the axis of the inner housing wall (2).

15. The battery cell according to claim 14, wherein the hole (21) is a heat dissipation hole.

16. The battery cell according to claim 15, wherein the cross-section of the aperture (21) is circular, regular polygonal, elliptical or non-equilateral polygonal.

17. The battery cell according to claim 1 or 15, characterized in that the cross section of the outer housing wall (1) and/or the inner housing wall (2) is circular, regular polygonal, elliptical or non-equilateral polygonal.

18. The battery cell according to claim 1 or 15, characterized in that the cross section of the bare cell (6) is a circle, a regular polygon, an ellipse or a non-equilateral polygon.

19. The battery cell according to claim 14, characterized in that the maximum value of the linear distance between any two points on the cross-section of the hole (21) is 0.11-0.65 of the maximum value of the linear distance between any two points on the cross-section of the housing wall (1).

20. The battery cell according to claim 14, wherein a plurality of heat dissipation protrusions are provided on the wall of the hole (21).

21. A ring battery comprising a battery cell according to any one of claims 1-20.

22. The annular battery according to claim 21, characterized in that the outer housing wall (1) and the inner housing wall (2) enclose a cavity which accommodates the bare cell (6), the cross-sectional shape of the cavity being annular.

23. A battery comprising the annular battery of claim 21 or 22.

24. A battery module comprising a plurality of the annular cells of claim 21 or 22, a plurality of the annular cells being connected in series and/or in parallel; or, comprising a plurality of the cells of claim 23, a plurality of the cells being connected in series and/or in parallel.

25. A powered device comprising a plurality of ring cells as defined in claim 21 or 22; or, comprising a plurality of the cells of claim 23; or, comprising the battery module of claim 24.

26. Welding apparatus for preparing a battery unit according to any one of claims 1-20, or for preparing a ring-shaped battery according to claim 21 or 22, or for preparing a battery according to claim 23, characterized in that the welding apparatus comprises a first welding head (101) and a second welding head (102) for movement towards each other, the first welding head (101) comprising an annular welding portion (1011), the annular welding portion (1011) being intended to protrude into the first gap (K1), the second electrical connection and the bottom of the housing wall (1) being pressed against the second welding head (102) such that the second electrical connection is welded at least partly to the bottom of the housing wall (1).

27. The welding apparatus according to claim 26, wherein a side of the annular welding portion (1011) facing the second welding head (102) is provided with a plurality of welding projections (1012), and the plurality of welding projections (1012) are uniformly arranged in a circumferential direction of the annular welding portion (1011).