CN116315468A

CN116315468A - Shell pole fastening electric connection structure, prefabricated battery, battery pack and preparation method

Info

Publication number: CN116315468A
Application number: CN202310150238.1A
Authority: CN
Inventors: 汪子琪; 汪纯
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-02-22
Filing date: 2023-02-22
Publication date: 2023-06-23

Abstract

The invention relates to a shell pole fastening electric connection structure for a cylindrical battery, a prefabricated battery, a battery pack and a preparation method, wherein the shell pole fastening electric connection structure at least comprises a busbar and a locking unit, the busbar can be electrically connected with at least part of the area of a shell pole of the single battery, the locking unit can be sleeved on at least one side part of the area of a shell or a bottom shell of the side face of the single battery, the locking unit has a thermal contraction coefficient similar to that of the shell pole of the single battery, and is preferably made of a conductor with good heat conduction, when the external temperature changes, the locking unit can synchronously stretch and retract with the shell of the single battery, so that the busbar is kept in tight electrical connection with the shell pole of the single battery.

Description

Shell pole fastening electric connection structure, prefabricated battery, battery pack and preparation method

Technical Field

The invention relates to the field of new energy power batteries, in particular to a shell pole fastening electric connection structure, a prefabricated battery, a battery pack and a preparation method.

Background

Fastening one end of the busbar to the housing of the cylindrical battery and achieving a reliable electrical connection is an important engineering goal for battery grouping applications for series-parallel electrical connection. The prior art includes:

1) The thermal welding electric connection, namely the structure fixation and the electric connection are realized through the metal welding between the bus bar and the shell pole; the penetration is large and the connection is of a strong structure. The problem of strong structural connection is that the connection strength between the shells is weaker, and the stress of strong vibration is directly conducted on the electric connection point through the total amount of abnormal movement between the shells, so that the hidden dangers of easy tearing and the like of the electric connection point are easily caused; the penetration is shallower, for weak structure connection, generally through the overall structure fixedly sealed (such as full injecting glue between the battery shells, between the battery shells and outside reinforced structure) of additional battery, through promoting the integrated degree of casing and overall structure, weaken amplitude and stress between the shells under the strong shock, consequently weaken the stress that is conducted to the electricity tie point to improve the reliability of electricity tie point under the vibration condition. The problem of weak structural connection is that the strong structural connection between the shells leads to larger overall weight gain amplitude of the battery pack, and influences the overall weight-to-energy ratio (important group performance index of the battery pack) of the battery pack; the full glue injection mode is not beneficial to the replacement and maintenance of the single battery.

2) The cold welding electric connection ensures the reliability of the electric connection point by keeping the pressure on the cold welding crimping electric connection point stable; the round hoop is usually glued on the surface of the cylindrical shell, so that the bus bar and the single battery shell are firmly connected and reliably electrically connected; because the battery shell is usually metal, the hoop is glued and then corresponds between the inner diameter of the rubber ring of the shell and the outer diameter of the shell, under the condition of changing the external temperature, the coefficient of thermal expansion and cold contraction of the two is different, so that the change of the tightness is generated, the stability of the contact resistance of the electric connection point is further influenced, and the problem needs to be solved.

Disclosure of Invention

The invention discloses a shell pole fastening electric connection structure, a prefabricated battery, a battery pack and a preparation method, which are used for solving the technical problems existing in the prior art.

In a first aspect, the present invention provides a housing pole fastening electrical connection structure, comprising:

-a busbar in the form of a sheet for at least partly abutting against at least part of the area of the housing post of the cylindrical battery cell and being electrically connectable to the housing post;

a locking unit which is annular and can be sleeved and fastened on at least one partial area of the shell pole and the area where the shell pole is abutted against the bus bar, wherein the locking unit is used for enabling the bus bar to be abutted against the shell pole to be electrically connected;

the locking unit has a thermal contraction coefficient similar to that of the shell pole and is used for abutting and electrically connecting the busbar and the shell pole.

In a second aspect, the invention provides a prefabricated battery, which comprises a single battery and a shell pole fastening electric connection structure;

the single battery comprises a shell pole, wherein the shell pole is configured on the side shell and the bottom of the shell;

the shell pole fastening electric connection structure comprises a busbar and a locking unit, wherein the busbar and the locking unit have the same or similar thermal shrinkage coefficient with the shell pole;

The bus bar is sheet-shaped, is electrically connected with at least part of the area of the shell pole, and cold welding glue is arranged at the electric connection part;

the locking unit is annular and comprises a plurality of turns of metal coils which are arranged in parallel and tightly abutted, and the metal coils are tightly wound on at least part of the area of the side shell and are used for keeping the tight electrical connection between the busbar and the shell pole;

the two ends of the metal coil are oppositely wound and fastened;

the maximum tightness produced by the at least one turn of metal coil is used for a tight electrical connection between the busbar and the housing post.

In a third aspect, the present invention provides a method for preparing a prefabricated battery, comprising:

providing a single battery;

the busbar is electrically connected to the shell pole of the single battery through cold welding glue;

setting a maximum fastening degree according to the internal resistance of the single battery, wherein the maximum fastening degree is expressed as the maximum radial pressure of the coil to the shell pole;

winding wires on the side surface shell of the single battery and the outer side surface of the busbar by an automatic winding machine to form a multi-turn coil; the tension regulator of the automatic winding machine is regulated through the set maximum fastening degree, the tension of the wire is kept constant in the winding process of at least part of the turn coils, and the maximum fastening degree of at least part of the turn coils is ensured, so that the contact resistance between the busbar and the shell pole is located at the set value;

And preparing the prefabricated battery.

In a fourth aspect, the present invention provides a prefabricated battery prepared by the method for preparing a prefabricated battery.

In a fifth aspect, the present invention provides a battery pack comprising a plurality of prefabricated batteries as described above, or alternatively, a battery pack comprising a plurality of single batteries and a housing post fastening electrical connection structure as described above.

In a sixth aspect, the present invention provides a method for preparing a battery pack, comprising:

providing a plurality of single batteries, and respectively and electrically connecting a plurality of bus bars to a shell pole of each single battery through cold welding glue;

winding wires on the side surface shell of each single battery and the outer side surface of the busbar by an automatic winding machine to form a multi-turn coil;

the tension regulator of the automatic winding machine is regulated through the set maximum fastening degree, and the tension of the wire is kept constant in the winding process of at least part of the turn coils, so that the contact resistance between the busbar and the shell pole is constant;

forming a plurality of single batteries provided with bus bars and coils into a battery array which is longitudinally arranged in rows and transversely arranged in lines;

All the single batteries in the battery array are electrically connected in series and/or in parallel;

the battery pack is prepared, and the contact resistance between all the single batteries in the battery pack and the corresponding bus bars is kept consistent.

In a seventh aspect, the present invention provides a battery pack obtained by the method for manufacturing a battery pack described above.

Compared with the prior art, the technical scheme adopted by the invention can achieve the following beneficial effects:

the invention mainly provides a shell pole fastening electric connection structure for a cylindrical battery, which at least comprises a busbar and a locking unit, wherein the busbar can be electrically connected with at least partial areas of the shell poles of the single battery, the locking unit can be sleeved on at least one side partial area of a side shell or a bottom shell of the single battery, the locking unit has a heat shrinkage coefficient similar to that of the shell poles of the single battery, and is preferably manufactured by using a conductor with good heat conduction, when the external temperature changes, the locking unit can synchronously stretch and retract with the shell of the single battery, so that the compression joint fastening degree is kept consistent under different temperature states, and the busbar is ensured to be in tight electric connection with the shell poles of the single battery.

In addition, the smaller the inner diameter of the locking unit is, the larger the radial pressure on the side surface shell of the single battery is, at the moment, the contact resistance of the busbar and the shell pole gradually decreases along with the increase of the pressure, and when the pressure is up to a certain value, the contact resistance is kept constant, so that the controllable adjustment of the contact resistance can be realized by adjusting the tightness of the locking unit; when a plurality of single batteries are connected in series, because of the slight difference of the internal resistance of each single battery, the contact resistance of each single battery and the bus bar is adjusted by adjusting the fastening degree of the locking unit, so that the minimization of the resistance difference of each single battery in the series battery row is realized.

The locking unit is self-locked, the fixing unit is arranged outside the locking unit, or the structural adhesive is arranged between the locking unit and the side surface shell, so that the constancy of the contact resistance of the electric connection point of the busbar is ensured, and after the single batteries are grouped, the reliability of the electric connection point can be ensured even if vibration occurs.

Further, be equipped with slice reinforcement unit between busbar and locking unit, slice reinforcement unit can increase the crimping area of locking unit to the busbar on the one hand, and on the other hand can strengthen the anti peel force between busbar and the casing utmost point post to compensate the not enough of locking unit in Z axial bending resistance, prevent that the busbar from receiving the influence under the effect of the external force for the centre of a circle.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments are briefly described below to form a part of the present invention, and the exemplary embodiments of the present invention and the description thereof illustrate the present invention and do not constitute undue limitations of the present invention. In the drawings:

fig. 1 is a schematic structural view of a fastening and electrical connection structure of a housing pole in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 2 is a perspective view of a housing pole fastening electrical connection structure according to a preferred embodiment of the present invention disclosed in example 1;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a second schematic structural view of a fastening electrical connection structure for a housing pole in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 5 is a third schematic structural view of a fastening electrical connection structure for a housing pole in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 6 is a schematic structural diagram of a fastening electrical connection structure for a housing pole in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 7 is a schematic view showing a structure of a fastening and electrical connection structure of a housing pole in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 8 is a schematic structural view of a locking structure in a preferred embodiment disclosed in example 1 of the present invention;

FIG. 9 is a schematic structural view of a fastening and electrical connection structure for a housing pole in accordance with a preferred embodiment of the present invention disclosed in example 2;

FIG. 10 is a schematic view of a structure of a fastening electrical connection structure of a housing pole in a preferred embodiment disclosed in example 3 of the present invention;

FIG. 11 is a second schematic structural view of a fastening electrical connection structure for a housing pole in accordance with a preferred embodiment of the present invention disclosed in example 3;

fig. 12 is a schematic view showing the structure of a prefabricated battery according to a preferred embodiment of the present invention disclosed in example 4;

fig. 13 is a schematic structural view showing a fastening and electrical connection structure of a housing post in a prefabricated battery according to a preferred embodiment of the present invention disclosed in example 4;

FIG. 14 is a graph showing the relationship between the pressure of the metal coil on the side of the housing and the contact resistance between the busbar and the housing post in accordance with a preferred embodiment of the present invention disclosed in example 4;

fig. 15 is a schematic view showing a process of preparing a prefabricated battery according to a preferred embodiment of the present invention disclosed in example 5;

fig. 16 is a schematic view showing the structure of a battery pack according to a preferred embodiment of the present invention disclosed in example 6;

Fig. 17 is a top view of fig. 16.

Reference numerals illustrate:

bus bar 10, extension 11, connection 12, recess 13; a locking unit 20, a metal coil 21, a wire 211, a metal ferrule 22 and a locking structure 23; a single battery 30, a side housing 31, a bottom 32, and a neck 33; a sheet-like reinforcement unit 40; a tension adjuster 50; an insulating flat plate 60; an insulating block 70.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art. In addition, in the description of the present application, the terms "first," "second," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Referring to fig. 1-8, the present embodiment provides a housing pole fastening electrical connection structure applicable to the top of a battery module or a single battery; the shell pole fastening electric connection structure can simultaneously realize the structural connection and reliable abutting electric connection of the fastening between the bus bar and the single battery shell pole, and even if the external environment temperature changes or the bus bar is pulled by the lateral direction of the external force, the stability of the electric connection part is not obviously affected.

In the present embodiment, the housing pole fastening and electrical connection structure does not include the single battery itself, but exists as a structure and an electrical connection structure thereof.

Preferably, the single battery 30 to which the housing pole fastening electrical connection structure is applied in the present embodiment is a single cylindrical battery; alternatively, the unit cell 30 may be selected from 18650 cells, 21700 cells, 46800 cells, etc., but is not limited thereto.

Preferably, the single battery 30 to which the housing pole fastening electrical connection structure is applied in the present embodiment may be a battery with a neck portion or a battery without a neck portion.

In a preferred embodiment, the cell 30 has a housing post comprising a metal housing disposed in the side housing 31 and the bottom housing 32, and a top post disposed in the center of the top cover; it will be appreciated by those skilled in the art that the top and housing poles are two poles of different polarity of the cell 30, respectively. In view of the slight differences in shape/structure/size of the unit cells 30 of different models, the present embodiment is not exemplified.

In a preferred embodiment, the housing post fastening electrical connection structure includes a busbar 10 and a locking unit 20; the busbar 10 is sheet-shaped and is used for being electrically connected with at least partial areas of the shell poles of the single batteries 30, and preferably, the busbar 10 and the shell poles are electrically connected through cold welding glue; the locking unit 20 is ring-shaped and can be sleeved on at least one side partial region of the side housing 31 or the bottom 32 of the unit cell 30, so as to maintain the tight electrical connection between the busbar 10 and the housing post of the unit cell 30.

Preferably, the locking unit 20 has the same or similar thermal shrinkage rate as the shell of the shell pole, and the locking unit 20 is preferably made of a good conductor material, so that when the external temperature changes, the locking unit 20 can still keep the same thermal expansion and contraction rate and degree as the shell pole, synchronous expansion and contraction of the locking unit 20 and the shell pole are realized, the compression joint tightness is kept consistent, the bus bar 10 is kept in tight electrical connection with the shell pole, and the temperature stability of the contact resistance of the compression joint electrical connection point is ensured. More preferably, the bus bar 10, the locking unit 20 and the housing pole have the same or similar thermal shrinkage coefficients, so as to ensure that the three can realize synchronous expansion or shrinkage when the temperature changes, and further ensure the stability of the contact resistance at the electric connection position.

As shown in fig. 2 to 3, in a preferred embodiment, the locking unit 20 is configured as a plurality of turns of metal coils 21 arranged in parallel or stacked, and the metal coils 21 are provided with a plurality of turns along the circumferential direction or the height direction of the housing pole of the unit cell 30, and the locking unit is locked by the locking structure 23.

In a preferred embodiment, adjacent turns of the metal coil 21 are closely arranged to increase the friction between the opposing turns, prevent back-loosening, and avoid causing a decrease in the maximum tightness of the metal coil 21.

Preferably, when the locking unit 20 is disposed along the circumferential direction of the housing pole, the inner diameter of the locking unit 20 satisfies: interference fit or over fit with the housing post.

In a preferred embodiment, at least one turn of the metal coil 21 has a maximum tightness that can be configured as a first abutment force, a second abutment force and a third abutment force; specifically, the pressing force is the radial pressure of the metal coil 21 to the housing pole; the first abutting force, the second abutting force and the third abutting force all represent a certain numerical range, but not a certain numerical value.

Preferably, when the maximum tightening degree is configured as the first tightening force, the contact resistance between the bus bar 10 and the housing pole is kept constant, and at this time, the bus bar 10 and the housing pole correspond to an integrated metal, which does not change with the change of the maximum tightening degree.

Preferably, when the maximum tightening degree is configured as the second tightening force, the contact resistance between the bus bar 10 and the housing post is inversely related to the value of the maximum tightening degree, that is, the greater the maximum tightening degree, the smaller the contact resistance between the bus bar 10 and the housing post within the value interval of the second tightening force.

Preferably, when the maximum tightening is configured as the third tightening force, the contact resistance between the busbar 10 and the housing pole is equal to the air resistance, and the busbar 10 and the housing pole may be regarded as not being in contact.

Preferably, the first tightening force has a value interval greater than that of the second tightening force, and the second tightening force has a value interval greater than that of the third tightening force.

Preferably, the metal coil 21 can be selected from high-strength metal wires such as iron wires, steel wires, copper wires and the like which are easy to self-attach; further, since the weight gain of the wire is limited, the weight energy density is ensured after the case post is fastened to the electrical connection structure and the unit cell 30 is connected.

In an alternative embodiment, the locking unit 20 is a coil wound with carbon fiber wires, which also reduces the overall weight of the entire battery pack or battery bank while maintaining structural strength.

Preferably, the metal coil 21 can be automatically wound by an automatic winding machine, so that the winding of the same tightness of each turn of coil can be quickly realized, and the bending and locking of the head and tail parts can be realized. Specifically, an automatic winding machine for winding a transformer may be selected to achieve automatic winding of the metal coil 21.

In a preferred embodiment, the metal coils 21 are of a relatively thin diameter and are arranged in close parallel proximity to minimize the effect on the expansion of the diameter of the side housing 31. Preferably, when the unit cell 30 is a neckless cell, the metal coil 21 may be provided with only a closely arranged monolayer; preferably, when the unit cell 30 is a necked cell, the metal coil 21 is disposed in the neck 33 and is provided in multiple layers, so that the fastening is ensured without affecting the outer dimension of the case.

In a preferred embodiment, the locking structure 23 of the metal coil 21 is a mechanical locking structure or a self-locking structure; by arranging the locking structure 23, on one hand, the structure of the locking unit 20 is more reliable and is not influenced by the environment of adhesive locking; on the other hand, the expansion and contraction rate of the locking unit 20 is similar to that of all metal, and is not influenced by different expansion and contraction rates of nonmetal solidified adhesive, so that the locking and abutting state is maintained, and the contact resistance is kept unchanged due to environmental temperature change.

In a preferred embodiment, the tightening is achieved by helically winding the wire at both ends of the wire 21 and forming self-locking attachment structures 23; in another preferred embodiment, the wire of the metal coil 21 is bent in the opposite direction in the circumferential direction, and the bent wire is threaded into the bending portion once again around the coil, and is bent in the opposite direction again, so as to achieve self-locking attachment, as shown in fig. 8.

Preferably, the outer portion of the metal coil 21 is further provided with an insulating layer to compensate for the problem of insulation to the outside of the annular exposed region of the housing pole electrically connected between the busbar 10 and the housing. Preferably, the metal coil 21 provided with an insulating layer may be selected from enameled wires, plastic covered wires, and the like.

In a preferred embodiment, the outer side of the locking unit 20 is further provided with an insulating nonmetallic annular sleeve structure, the inner contour of the annular sleeve structure is matched with the outer contour of the locking unit 20, and the annular sleeve structure can be directly sleeved on the outer side of the locking unit 20 to realize insulation reinforcement and connection reinforcement. Preferably, a structural adhesive is also provided between the collar structure and the locking unit 20.

It will be appreciated by those skilled in the art that when the locking structure 23 is provided, the locking force results from the pinching force or pinching friction of the locking structure 23 against the housing post.

In a preferred embodiment, the busbar 10 includes a connection portion 12 and an extension portion 11; the connecting part 12 can be attached to the side housing 31 or the housing bottom 32 for electrical and structural connection to at least part of the housing pole; the extension 11 can extend to the outside of the unit cell 30, and is disposed by bending or tiling extension for electrical connection with the adjacent unit cell 30 or the electrical connection structure.

As shown in fig. 2, at least a portion of the connection portion 12 has an electrical connection section having a lower hardness than other regions, or the electrical connection section has a smaller thickness but a larger surface area than other regions to keep the electrical connection section the same cross-sectional area as other regions and the electric flux the same. When the extension 11 is pulled by an external force to generate a separation and peeling force of the connection 12, the peeling force is blocked at the electrical connection section, and the structural stability of the electrical connection section is maintained.

In a preferred embodiment, the electrical connection section is configured as a flexible sheet metal, a wire-like conductive wire row or a wire-like conductive wire braid, wherein the conductive wire comprises a long carbon wire.

In a preferred embodiment, cold welding glue is arranged on the inner side of the electric connection section, and the cold welding glue can realize electric connection with the shell pole. Because the main component in the cold welding glue is conductive metal powder, and the cold welding glue is very thin after abutting, the gap is mainly filled in the microscopic gaps among the metal surfaces, but not the blocking interlayer is formed among the metal surfaces, therefore, the cold welding glue stretches only in the microscopic gaps and directly abuts against the metal surfaces to conduct electricity mainly by the microscopic contact among the metal surfaces, and the stretching rate of the cold welding glue has little influence on synchronous stretching among the metal surfaces as long as the stretching rates of adjacent conductor surfaces are generally consistent.

As shown in fig. 4, in a preferred embodiment, the metal coil 21 is disposed along the height direction of the unit cell 30, and the bus bar 10 is laterally disposed at the bottom 32 of the case, and preferably, the extension 11 of the bus bar 10 extends laterally outward for making electrical connection with other unit cells 30 or electrical connection structures.

As shown in fig. 5, in a preferred embodiment, the metal coil 21 is disposed along the circumferential direction of the unit cell 30, and the metal coil 21 is disposed at the upper portion of the housing post, at this time, the bus bar 10 is vertically disposed at the side housing 31, and the extension 11 extends vertically upward for electrical connection with other unit cells 30 or electrical connection structures.

As shown in fig. 6, in a preferred embodiment, the single battery 30 is a battery with a neck, where the busbar 10 is vertically disposed on the side housing 31, and the busbar 10 has a recess 13 at the position of the neck 33, which matches the shape of the neck 33, and the electrical connection section is at least partially disposed in the recess 13; the metal coils 21 are stacked in the circumferential direction of the neck portion 33, and even if the extension portion 11 is affected by an external force, the peeling force is hard to be transmitted to the electrical connection section; preferably, the outer diameter of the metal coil 21 is not larger than the outer diameter of the side housing 31. Preferably, the locking structure 23 of the locking unit 20 is also provided at the neck 33 to avoid increasing the external size of the battery.

As shown in fig. 7, in a preferred embodiment, the metal coil 21 is disposed along the circumferential direction of the unit cell 30, and the metal coil 21 is disposed at the lower portion of the housing post; at this time, the busbar 10 is substantially U-shaped, the electrical connection section is vertically disposed on one side of the housing pole, the extension portion 11 is disposed on the opposite side and extends vertically upwards, and even if the extension portion 11 is pulled by an external force, the peeling force does not extend to the electrical connection section, so that the stability of the electrical connection point between the electrical connection section and the housing pole is not affected.

Example 2

Referring to fig. 9, the present embodiment provides a housing pole fastening electrical connection structure including a busbar 10 and a locking unit 20, wherein the features already included in embodiment 1 described above with respect to the busbar 10 are naturally inherited in the present embodiment.

In the present embodiment, the locking unit 20 is configured as a metal ferrule 22, and the metal ferrule 22 is disposed along the circumferential direction or the height direction of the housing post of the unit cell 30 and is locked by the locking structure 23. Preferably, the locking structure 23 is a screw and nut.

Preferably, when the metal ferrule 22 is disposed along the circumferential direction of the housing pole, the inner diameter of the metal ferrule 22 satisfies: interference fit or over fit with the housing post. At this time, the maximum tightness between the metal ferrule 22 and the housing pole can be kept constant, so as to ensure stable tight electrical connection between the busbar 10 and the housing pole, and ensure that the contact resistance between the busbar and the housing pole is kept constant.

In a preferred embodiment, an insulating nonmetallic ring structure is further disposed on the outer side of the metallic ferrule 22, and the inner contour of the ring structure is matched with the outer contour of the metallic ferrule 22, so that the ring structure can be directly sleeved on the outer side of the metallic ferrule 22 to realize insulation reinforcement and connection reinforcement.

In a preferred embodiment, the metal ferrule 22 is disposed along the height of the cell 30, and the bus bar 10 is disposed laterally at the bottom 32, preferably with the extension 11 of the bus bar 10 extending laterally outward for electrical connection with other cells 30 or electrical connection structures.

In a preferred embodiment, the metal ferrule 22 is disposed along the circumferential direction of the unit cell 30, and the metal ferrule 22 is disposed at the upper portion of the housing post, at this time, the bus bar 10 is vertically disposed at the side housing 31, and the extension 11 extends vertically upward for making electrical connection with other unit cells 30 or electrical connection structures.

In a preferred embodiment, the single battery 30 is a battery with a neck, where the busbar 10 is vertically disposed on the side housing 31, and the busbar 10 has a recess 13 at the position of the neck 33, which matches the shape of the neck 33, and the electrical connection section is at least partially disposed in the recess 13, and the metal ferrule 22 is disposed along the circumferential direction of the neck 33, so that the peeling force is difficult to be transmitted to the electrical connection section even if the extension 11 is affected by an external force; preferably, the outer diameter of the metal ferrule 22 is not larger than the outer diameter of the side housing 31. Preferably, the locking structure 23 of the metal ferrule 22 is also provided on the neck 33 to avoid increasing the external size of the battery.

In a preferred embodiment, the metal ferrule 22 is disposed along the circumferential direction of the unit cell 30, and the metal ferrule 22 is disposed at the lower portion of the housing post; at this time, the busbar 10 is approximately U-shaped, the electrical connection section is vertically disposed on one side of the housing pole, the extension portion 11 is disposed on the opposite side and extends vertically upwards, and even if the extension portion 11 is pulled by an external force, the peeling force will not extend to the electrical connection section, so that the stability of the electrical connection point between the electrical connection section and the housing pole will not be affected.

Example 3

Referring to fig. 10 to 11, the present embodiment provides a housing pole fastening electrical connection structure including a busbar 10, a locking unit 20 and a sheet-like reinforcement unit 40, wherein the features of the busbar 10 or the locking unit 20 are naturally inherited in the present embodiment, which have been included in embodiment 1 or embodiment 2 described above.

In a preferred embodiment, the sheet-like reinforcement unit 40 is adapted to the contour of the housing post of the battery cell 30, preferably an arcuate sheet-like metal, the sheet-like reinforcement unit 40 being arranged in at least a partial region between the locking unit 20 and the busbar 10; on the one hand, the sheet-shaped reinforcing unit 40 can increase the crimping area of the locking unit 20 to the busbar 10, and on the other hand, can strengthen the stripping resistance and the friction between the busbar 10 and the shell pole, so as to make up the defect of the bending resistance of the locking unit 20 in the Z-axis direction and prevent the contact resistance of the busbar 10 from being influenced under the action of the external force relative to the circle center.

Preferably, the sheet-like reinforcement unit 40 is a sheet-like metal sheet, which is a material having a relatively large rigidity, such as a thin steel sheet, an iron sheet, or the like.

Preferably, the arc length of the sheet-like reinforcement unit 40 is greater than the lateral width of the connecting portion 12 to increase the crimping area of the locking unit 20 to the bus bar 10; preferably, the height of the sheet-like reinforcement unit 40 is not greater than the width of the locking unit 20, so that the oversized protrusions outside the battery are avoided, and the outer size of the battery is prevented from being affected.

Preferably, the arc length of the sheet-like reinforcement unit 40 is greater than half the circumference of the side case 31 of the unit cell 30, so that the sheet-like reinforcement sheet is not easily peeled off from the side case 31. Preferably, the sheet-like reinforcement unit 40 is provided with structural glue at the opposite region of the side housing 31 for a secure connection with the side housing 31.

In a preferred embodiment, when the arc length of the sheet-like reinforcement unit 40 is greater than half of the circumference of the side case 31 of the unit cell 30, the bus bar 10, the locking unit 20, and the sheet-like reinforcement unit 40 have the same or similar heat shrinkage coefficients; more preferably, the three have the same or similar thermal contraction coefficient with the shell pole, so that when the external temperature changes, the whole shell pole fastening electric connection structure can still keep the same thermal expansion and contraction rate and degree with the shell pole, synchronous expansion and contraction of the shell pole and the shell pole are realized, the compression joint fastening degree is kept consistent, and the temperature stability of the contact resistance of the compression joint electric connection point is further ensured.

As shown in fig. 10, in a preferred embodiment, the locking unit 20 is disposed along the circumferential direction of the unit cell 30, and the locking unit 20 is disposed at the upper portion of the housing post, at which time the bus bar 10 is vertically disposed at the side housing 31, and the extension 11 extends vertically upward; the sheet-like reinforcement unit 40 is disposed at an upper edge of an area where the busbar 10 and the locking unit 20 abut, and the electrical connection section is disposed at a lower edge of an area where the connection portion 12 and the locking unit 20 abut.

When the extension 11 of the busbar 10 is pulled laterally by an external force, the upper edge of the sheet-like reinforcement unit 40 can resist the radially outward peeling force, and the locking unit 20 is sleeved on the outer side of the sheet-like reinforcement unit 40, so that the radial abutting force can be provided for the locking unit, and the electrical connection section of the busbar 10 can not be peeled off outwards, so that the resistance stability of the electrical connection position is ensured.

As shown in fig. 11, in a preferred embodiment, the locking unit 20 is disposed along the circumferential direction of the unit cell 30, and the locking unit 20 is disposed at the upper portion of the housing post, at which time the bus bar 10 is vertically disposed at the side housing 31, and the extension 11 extends vertically upward; the sheet-like reinforcement unit 40 is disposed at the lower edge of the contact area between the busbar 10 and the locking unit 20, and the electrical connection section is also disposed at the lower edge.

When the extension 11 of the bus bar 10 is pulled laterally by an external force, the upper edge of the locking unit 20 first bears a radially outward peeling force, at which time the locking unit 20 provides a first resistance to the outward pulling of the bus bar 10, and the locking unit 20 can block the outward peeling force layer by layer in the vertical direction, only when the locking unit 20 is released, the sheet-like reinforcement unit 40 provides a second resistance; the stability of the electrical connection is jointly ensured by the combination of the first and second resistive forces.

Example 4

Referring to fig. 12 to 13, the present embodiment provides a prefabricated battery including a unit battery 30 and a case post fastening electric connection structure, wherein the features already included in the above-described embodiments 1 to 3 regarding the case post fastening electric connection structure are naturally inherited in the present embodiment.

In a preferred embodiment, the unit cell 30 includes a housing post including a metal housing disposed at the side housing 31 and the housing bottom 32; the housing pole fastening electrical connection structure includes a busbar 10 and a locking unit 20, both of which have the same or similar thermal shrinkage coefficient as the housing pole.

Preferably, the busbar 10 is electrically connected with at least part of the area of the shell pole, and cold welding glue is arranged at the electric connection part so as to realize cold welding and crimping; preferably, the locking unit 20 is ring-shaped, and the locking unit 20 is sleeved on at least one side part area of the side shell 31 or the shell bottom 32, so as to maintain the fastening electric connection between the busbar 10 and the shell pole.

More preferably, the housing pole fastening electrical connection structure further includes a sheet-like reinforcement unit 40, and a structural adhesive is provided between the sheet-like reinforcement unit 40 and the side housing 31; the sheet reinforcement unit 40 is disposed at least in a partial region between the locking unit 20 and the bus bar 10, for improving the peel resistance between the bus bar 10 and the housing post.

In a preferred embodiment, the unit cell 30 is a battery having a neck portion, in which case the locking unit 20 is disposed at the outer periphery of the neck portion 33, and the outer diameter of the locking unit 20 is not greater than the diameter of the housing pole; preferably, the bus bar 10 and the sheet-like reinforcement unit 40 have recesses 13 extending toward the neck portion 33, as shown in fig. 13, and the recesses 13 of the bus bar 10 and the sheet-like reinforcement unit 40 are adapted to the contour of the neck portion 33.

In a preferred embodiment, the locking unit 20 is configured as a plurality of turns of the metal coil 21, the metal coil 21 being disposed in a plurality of turns along the circumferential direction of the side case 31 of the unit cell 30; alternatively, the metal coil 21 may be wound in a single layer or a plurality of layers.

In a preferred embodiment, the inner diameter of the metal coil 21 satisfies: an interference fit or an over fit with the side housing 31; if the inner contour circumference of the metal coil 21 is defined as C1, the circumference of the side case 31 is defined as C2, that is, C1. Ltoreq.C2; specifically:

When c1=c2, the metal coil 21 is in abutting connection with the side surface case 31;

when C1 is less than C2, the metal coil 21 is in abutting connection with the side shell 31;

when C1< < C2, and the side housing 31 is soft metal, the metal coil 21 is moderately stretched and partially embedded in the thickness layer of the housing, and the metal coil 21 and the side housing 31 are also tightly connected.

The tightness of the metal coil 21 to the side case 31 is related to the magnitude of the radial pressure F directed to the center of the single battery 30 from the outside, and the radial pressure F is uniform, and further, the smaller the circumference C2 of the metal coil 21 is, the larger the radial pressure F is, that is, F C1.

Referring to fig. 14, in the cold welding crimping process, the radial pressure F of the metal coil 21 to the side housing 31 is associated with the contact resistance R1 between the busbar 10 and the side housing 31 as follows: in the first constant section, the metal coil 21 is in clearance fit with the side housing 31, and the metal coil and the side housing are not in contact, so that the contact resistance R1 is an air resistance, and is kept constant at this time; in the variation section, the radial pressure F is inversely related to the contact resistance R1, i.e., the larger the radial pressure F, the smaller the contact resistance R1; in the second constant section, the absolute value of the contact resistance R1 of the cold welding and crimping is equal to the contact resistance value of the complete welding between metals (constant value), namely, the contact resistance R1 is always kept constant no matter how the radial pressure F is increased again; defined as the pressure threshold at the inflection points of the variable and constant segments, beyond which the contact resistance R1 no longer decreases with increasing pressure F.

Under the cold welding and crimping process, the high consistency (at least one order of magnitude higher than the thermal welding consistency) of the contact resistance R1 is realized because the tightness can be controlled at the same value of the variation section or in the second constant section manually and accurately.

Because different single batteries 30 have different internal resistances R2, the tightness of the metal coil 21 can be accurately adjusted, so that the slight difference (adjustable 0.1 mu omega level) of the contact resistance R1 in the variation section can be realized, and the consistency of the resistances (contact resistance r1+internal resistance R2) of the different single batteries 30 can be realized.

Therefore, when the plurality of unit cells 30 are electrically connected in series, the internal resistance R2 of each unit cell 30 is first determined, then the busbar 10 is fixed to the housing post of the side housing 31 through the metal coil 21, the tightness is adjusted by adjusting the circumference of the metal coil 21 on each unit cell 30, the value of the contact resistance R1 between the busbar 10 and the housing post is further controlled, and finally it is ensured that the r1+r2 of each cell in the series cell row remains the same, and the resistance difference between the branch resistances of the respective cells is minimized.

Specifically, the metal coil 21 is automatically wound by the automatic winding machine, the winding of the same tightness of each turn of coil can be rapidly realized, and the tension of the metal wire is regulated by regulating the tension regulator in the automatic winding machine, so that the larger the tension is, the higher the tightness is.

Preferably, the degree of retention of C1 of the metallic coil 21 determines the degree of constancy of the contact resistance R1 of the cold-welded electrical connection point.

In a preferred embodiment, the metal coil 21 is wound around each other by an automatic winding machine at the end and the head, and the length of C1 of the metal coil 21 is locked by the strength (non-restorability) and the structural self-locking of the metal bending point.

In a preferred embodiment, the length of C1 of the wire 21 is kept constant by friction between the wire and the side housing 31 between adjacent wires such that the tensioned wire is not easily retracted and loosened.

Preferably, structural glue is provided between the metal coil 21 and the side housing 31 to increase the friction force therebetween.

Preferably, a plurality of layers of metal coils 21 are arranged radially, adjacent metal coils 21 are tightly abutted, and the possibility of retraction loosening of single-strand coils and multi-strand coils is reduced by utilizing mutual friction force.

Preferably, a structural adhesive is provided between adjacent metal coils 21 to increase friction between adjacent coils.

Preferably, a fixing unit is arranged outside the metal coil 21, the fixing unit is configured into a non-metal loop structure, the inner contour of the loop structure is matched with the outer contour of the locking unit 20, the fixing unit can be directly sleeved outside the locking unit 20, and the balanced fastening force of the loop structure on all the metal coils 21 is used for preventing displacement movement or loosening among single-strand coils; more preferably, structural glue may be provided at the interface (at multiple junctions) of the loop structure and the multi-strand coil for friction reinforcement.

Since the metal coil 21 is bound to the side housing 31, the radial pressure F of the electrical connection point is derived from the self coil fastening, and the radial pressure is independent of the squeezing force of the adjacent single battery 30 or the external solid on the single battery 30, that is, the direct influence on the radial pressure F (contact resistance R1) which may be caused by the reverse movement between the adjacent solid and the single battery 30 under the vibration condition is eliminated, and the vibration reliability of the electrical connection point is improved.

Example 5

The present embodiment provides a method for manufacturing a prefabricated battery for manufacturing the prefabricated battery in the above embodiment 4, and the technical features already included in the above embodiment are naturally inherited in the present embodiment.

In a preferred embodiment, the method of preparing a prefabricated battery comprises the steps of:

step s81, providing a single battery 30.

Preferably, the unit cell 30 is a cylindrical unit cell, and the battery described in the above embodiment 1 can be selected specifically, and will not be described herein.

Step s82, electrically connecting the busbar 10 to the housing post of the unit cell 30 by cold welding.

Preferably, the method further comprises the step S821 of determining a contact resistance value R1 according to the internal resistance R2 of the single battery 30, the battery module where the single battery 30 is located and the position where the single battery 30 is located in the battery module, and then determining the maximum fastening degree; based on the preset contact resistance R1, the tension of the wire 211 is reversely adjusted by the tension adjuster 50, as shown in fig. 15, so that the coil reaches a set maximum tightness, at which the coil is wound and both ends are locked.

Step s83, setting a maximum tightness according to the internal resistance R2 of the unit battery 30, where the maximum tightness represents a maximum radial pressure of the coil to the housing pole.

S84, winding the wires 211 on the side surface shell 31 of the single battery 30 and the outer side surface of the busbar 10 through an automatic winding machine to form a multi-turn coil; the tension regulator 50 of the automatic winding machine is adjusted through the set maximum tightness, so that the tension of the wire 211 is kept constant in the winding process of at least part of the turn coils, and the maximum tightness of at least part of the turn coils is ensured, and the contact resistance R1 between the busbar 10 and the shell pole is located at the set value.

Preferably, the method further comprises the step s841 of winding the wire 211 on the side housing 31 of the unit cell 30 and the outer side surface of the bus bar 10 by an automatic winding machine: the radial pressure of the coil to the shell pole is F, and the perimeter of the inner outline of the coil is C1, F-C1; the contact resistance between the busbar 10 and the housing post is R1, R1 gradually decreasing with increasing F, and after exceeding the pressure threshold, R1 tends to be constant. Specifically, the pressure threshold of the coil and the housing pole is represented as the abutment point position in fig. 14.

Preferably, step s842 is further included in which the tension of the wire 211 is set to be equal to or greater than the pressure threshold value in the step of adjusting the tension adjuster 50 of the automatic winding machine by the set maximum tightness.

Preferably, the method further comprises step S843, when the material of the wire 211 is metal wire, after forming a multi-turn coil, winding and bending the head and the tail of the coil by an automatic winding machine to realize self-locking attachment so as to maintain R1 constant; when the material of the wire 211 is carbon fiber, after forming the multi-turn coil, coating UV structural adhesive between the metal coil 21 and the side housing 31; coating UV structural adhesive between the metal coils 21 of adjacent turns; after structural self-locking of the metal coil 21 is achieved, the UV structural adhesive is subjected to ultraviolet fixation to maintain R1 constant.

Preferably, the method further comprises the step S844 of sleeving a nonmetallic loop structure outside the coil after the multi-turn coil is formed, so that the nonmetallic loop structure is mutually abutted with the coil, and the metallic coil is prevented from loosening to maintain R1 constant.

And S85, preparing the prefabricated battery.

Example 6

The present embodiment provides a battery pack and a battery module, both of which include a plurality of prefabricated batteries in embodiment 4 described above, or include a plurality of unit batteries 30 and the housing pole fastening electrical connection structure described in embodiments 1-3, and the technical features already described in embodiments 1-4 are naturally inherited in this embodiment, and are not described again.

In a preferred embodiment, there is provided a series battery pack composed of a plurality of prefabricated batteries arranged in a plane in a row or a matrix, and a parallel battery module composed of a plurality of series battery packs, which are stacked up and down correspondingly and connected in parallel, with plane-adjacent prefabricated batteries being electrically connected in series by a bus bar 10.

In another preferred embodiment, the series battery pack includes a plurality of unit cells 30 arranged in a row or a matrix, each unit cell 30 is connected with a housing pole fastening electrical connection structure, and adjacent unit cells 30 are electrically connected in series through the bus bar 10. Optionally, one or more bus bars 10 may be disposed on each unit cell 30 for serial electrical connection between planar adjacent prefabricated cells and/or parallel electrical connection of housing poles between longitudinally adjacent prefabricated cells, as shown in fig. 16, where two bus bars 10 are disposed on the unit cells 30 disposed at the edges of the battery pack, the bent bus bars can be electrically connected in series with the top poles of the adjacent prefabricated cells, and the vertically disposed bus bars 10 can be electrically connected in parallel with the battery pack above.

Preferably, in the series battery, the bus bars 10 in the case-pole fastening electric connection structure may be connected electrically in parallel with the case poles by being integrated with the bus bars 10 adjacent in the longitudinal direction (the upper and lower long bus bars), or may be connected electrically in series by the bent extension 11 with the top poles of the prefabricated batteries adjacent to the plane in the battery or the electric connection members thereof.

Alternatively, the unit cells 30 in the battery pack may be aligned in an array pattern, or may be staggered. As shown in fig. 16 and 17, in the case of a staggered array, the contact resistance between the side housing 31 of each unit cell 30 and the busbar 10 in the array maintains good uniformity. Preferably, the four corners of the staggered battery pack are further provided with insulating blocks 70, the inner sides of the insulating blocks 70 are matched with the side surface shells 31 of the single batteries 30, and the outer contours of the insulating blocks 70 are used for filling up the gaps at the four corners of the battery pack, so that the outer contour of the whole battery pack is in a regular rectangle, and the tightening constraint of an external fastening structure is facilitated. Preferably, the upper part of the insulating block 70 is further provided with male and female terminals for forming structural stability of the parallel battery modules stacked up and down.

Preferably, whether the unit cells 30 in the series battery are configured in an array arrangement or a staggered arrangement, an insulating plate 60 is further provided outside the electrical connection point of the extension 11 of the busbar 10 and the top post of the adjacent cell, and the insulating plate 60 covers at least the top of the side housing 31 of the adjacent cell to prevent the busbar 10 from making electrical contact with the housing post of the adjacent prefabricated cell in the area outside the electrical connection point, resulting in a short circuit of the series battery.

In a preferred embodiment, the battery pack includes a series battery row and a parallel battery row; in the series battery row, the contact resistance between the bus bar 10 and the side surface shell 31 of the single battery 30 is R1, and the R1 can be indirectly adjusted to an appropriate resistance value by adjusting the pressure of the fastening electric connection structure to the bus bar 10 and the side surface shell 31; the internal resistance of each single battery 30 is different R2, and the value of r1+r2 on each single battery in the adjustable row is kept consistent through the matching between different R1 and R2, so as to minimize the resistance difference between the resistances of the battery branches.

In a preferred embodiment, at least one of the cells 30 has an internal resistance of N, and the other cells 30 have an internal resistance of M, N < M; the unit cell 30 having N internal resistance, the maximum tightness set by the locking unit 20 of which enables the contact resistance K1 to be generated between the bus bar 10 and the housing post; the maximum tightness of the locking unit 20 of the single battery 30 with internal resistance M can enable the contact resistance K2 to be generated between the busbar 10 and the housing post, preferably, K1 > K2, and n+k1=m+k2, so as to minimize the resistance difference between the resistances of the battery branches of the battery pack.

Example 7

The present embodiment provides a method for manufacturing a battery pack for manufacturing the battery pack cell of embodiment 6 described above, and the technical features already included in the above embodiment are naturally inherited in the present embodiment.

In a preferred embodiment, the method of manufacturing a battery pack comprises the steps of:

step s91, providing a plurality of unit cells 30, and electrically connecting the plurality of bus bars 10 to the housing post of each unit cell 30 through cold welding glue.

Step s92, setting a maximum fastening degree according to the internal resistance R2 of the single battery 30, where the maximum fastening degree is represented by a maximum radial pressure of the coil to the housing pole.

Step s93, winding the wire 211 on the side housing 31 of each unit cell 30 and the outer surface of the busbar 10 by an automatic winding machine to form a multi-turn coil.

Step S94, the tension regulator 50 of the automatic winding machine is regulated through the set maximum fastening degree, and the tension of the wire 211 is kept constant in the winding process of at least part of the turn coils, so that the contact resistance between the busbar 10 and the shell pole is constant R1.

Preferably, the contact resistance value R1 is determined according to the internal resistance R2 of the single battery 30, the battery pack where the single battery 30 is located and the position where the single battery 30 is located in the battery pack, so as to determine the maximum tightness; the tension of the wire 211 is reversely adjusted by the tension adjuster 50 based on the preset contact resistance R1 so that the coil reaches a set maximum tightness, and the coil is wound under the tension and both ends are locked.

Step S95, forming a plurality of single batteries 30 provided with the bus bars 10 and the coils into a battery array which is longitudinally arranged in a column and transversely arranged in a row.

Step s96, all the unit cells 30 in the cell array are electrically connected in series and/or in parallel.

Step S97, preparing a battery pack, wherein the contact resistance R1 between all the single batteries 30 in the battery pack and the corresponding bus bars 10 is kept consistent.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are to be protected by the present invention.

Claims

1. A housing pole fastening electrical connection structure, comprising:

-a busbar in the form of a sheet for at least partly abutting against at least part of the area of the housing post of the cylindrical single cell and being electrically connectable with the housing post;

-a locking unit, of annular shape, able to be sleeved with a partial region fastened to at least one side of the housing pole, a region of the housing pole in abutment with the busbar, for making the busbar in abutment electrical connection with the housing pole;

2. The housing pole fastening electrical connection structure of claim 1, wherein the buss bar comprises a connection portion and an extension portion;

the connecting part can be attached to the side surface shell or the bottom of the shell of the single battery and is used for being electrically and structurally connected with at least part of the area of the shell pole;

the extension portion can extend to the outside of the single battery and is configured to be tiled or folded for electrical connection with an adjacent single battery or electrical connection structure.

3. The housing pole fastening electrical connection structure of claim 2 wherein at least a portion of the connection section has an electrical connection section that has a lower hardness than other areas or a smaller thickness and a larger surface area than other areas.

4. A housing pole fastening electrical connection according to claim 3, wherein the electrical connection section is configured as a flexible sheet metal, a wire row of wire leads or a braid of wire leads.

5. The housing pole fastening electrical connection structure of claim 3, wherein the electrical connection section is disposed at a lower portion of the connection portion and the locking unit abutment region.

6. The housing pole fastening electrical connection structure according to claim 1, wherein the locking unit includes a metal coil provided with at least one turn in a circumferential direction or a height direction of the unit cell side housing, and the locking is achieved by the locking structure.

7. The housing pole fastening electrical connection structure of claim 6, wherein at least one turn of the metal coil has a maximum fastening degree configurable as a first tightening force, a second tightening force, and a third tightening force;

when the maximum tightness is configured as the first tightening force, the contact resistance between the busbar and the housing post remains constant;

when the maximum tightness is configured as the second tightening force, the contact resistance between the busbar and the housing post is inversely related to the value of the maximum tightness;

when the maximum tightening is configured as the third tightening force, the contact resistance between the busbar and the housing post is equal to the air resistance.

8. The housing pole fastening electrical connection structure of claim 6, wherein the metal coil is configured as a number of turns, or metal hoops, arranged in parallel and/or stacked.

9. The housing pole fastening electrical connection of claim 6 wherein the metal coils of adjacent turns are arranged in close proximity.

10. The housing pole fastening electrical connection structure of claim 6, wherein the metal coil is externally provided with an insulating layer.

11. The housing pole fastening electrical connection structure of claim 6, wherein the locking structure comprises a mechanical locking structure or a self-locking structure.

12. The housing pole fastening electrical connection structure of claim 6, wherein the outside of the locking unit is provided with an insulating nonmetallic collar structure.

13. The housing pole fastening electrical connection of claim 12, wherein structural adhesive is disposed between the non-metallic collar structure and the locking unit.

14. The housing pole fastening electrical connection structure of claim 8, wherein the metal ferrule is locked by a clamping structure disposed at both ends of the metal ferrule, the clamping structure comprising a screw and a nut.

15. The housing pole fastening electrical connection structure of claim 1, wherein an inner diameter of the locking unit satisfies: interference fit or over fit with the housing post.

16. The housing pole fastening electrical connection structure of claim 2, further comprising a sheet-like reinforcement unit provided in at least a partial region between the locking unit and the bus bar for improving a peel resistance between the bus bar and the housing pole.

17. The housing pole fastening electrical connection structure of claim 16, wherein the sheet reinforcement unit comprises an arcuate sheet metal; the arc length of the sheet-shaped reinforcing unit is larger than the transverse width of the connecting part, and the height of the sheet-shaped reinforcing unit is not larger than the width of the locking unit.

18. The housing pole fastening electrical connection structure of claim 17 wherein the sheet reinforcement unit is adapted to the contour of a cell housing pole.

19. The housing pole fastening electrical connection structure of claim 17, wherein the arc length of the sheet-like reinforcement unit is greater than half of the circumference of the side housing of the unit cell, and the bus bar, the locking unit, and the sheet-like reinforcement unit have the same or similar heat shrinkage coefficients.

20. The housing pole fastening electrical connection structure according to claim 17, wherein the sheet-like reinforcement unit is provided at an upper portion of an abutment region of the busbar and the locking unit, with an upper edge being flush with an upper edge of the abutment region;

or, the sheet-shaped reinforcing unit is arranged at the lower part of the contact area of the busbar and the locking unit, and the lower edge of the sheet-shaped reinforcing unit is flush with the lower edge of the contact area.

21. The prefabricated battery is characterized by comprising a single battery and a shell pole fastening electric connection structure;

the single battery comprises a shell pole, wherein the shell pole is arranged on the side shell and the bottom of the shell;

the shell pole fastening electric connection structure comprises a busbar and a locking unit, wherein the busbar and the locking unit have the same or similar thermal contraction coefficient with the shell pole;

the busbar is sheet-shaped, is electrically connected with at least part of the area of the shell pole, and is provided with cold welding glue at the electric connection part;

the locking unit is annular and comprises a plurality of turns of metal coils which are arranged in parallel and tightly abutted, and the metal coils are tightly wound on at least partial areas of the side surface shell and are used for keeping the tight electrical connection between the bus bar and the shell pole;

The two ends of the metal coil are oppositely wound and fastened;

the maximum tightness produced by at least one turn of the metal coil is used for a tight electrical connection between the busbar and the housing post.

22. The prefabricated battery according to claim 21, wherein the locking unit is sleeved outside the side housing; the circumference of the inner outline of the locking unit is C1, and the circumference of the side shell is C2, wherein C1 is less than or equal to C2.

23. The prefabricated battery according to claim 22, wherein,

when c1=c2, the locking unit is in abutting connection with the side housing;

when C1 is less than C2, the locking unit is in abutting connection with the side shell.

24. The prefabricated battery of claim 21 wherein structural adhesive is disposed between the metal coil and the side housing;

and/or, structural adhesive is arranged between the adjacent metal coils;

and/or the locking unit is externally provided with a fixing unit, and the fixing unit is abutted against the periphery of the locking unit.

25. The prefabricated battery according to claim 21, wherein the case post fastening electrical connection structure further comprises a sheet-like reinforcement unit, a structural adhesive being provided between the sheet-like reinforcement unit and the side case; the sheet-shaped reinforcing unit is arranged in at least part of the area between the locking unit and the bus bar and is used for improving the stripping resistance between the bus bar and the shell pole.

26. The prefabricated battery according to claim 25, wherein an electrical connection provided with the cold welding glue is provided at a lower edge of an abutment region of the busbar and the locking unit;

the sheet-shaped reinforcing unit is abutted against the electric connection part; or the sheet-shaped reinforcing unit is arranged at the upper edge of the contact area between the busbar and the locking unit.

27. The preformed battery of claim 25, wherein the cell further comprises a neck;

the locking unit is arranged on the periphery of the neck, and the outer diameter of the locking unit is not larger than the diameter of the shell pole;

the busbar and the sheet-like reinforcement unit have recesses extending towards the neck, and the busbar and the sheet-like reinforcement unit are adapted to the contour of the neck.

28. A method of manufacturing a prefabricated battery, comprising:

providing a single battery;

setting a maximum tightness according to the internal resistance of the single battery, wherein the maximum tightness is expressed as the maximum radial pressure of the coil on the shell pole;

winding wires on the side surface shell of the single battery and the outer side surface of the busbar by an automatic winding machine to form a multi-turn coil; the tension regulator of the automatic winding machine is regulated through the set maximum tightness, the tension of the wire in the winding process of at least part of the turn coils is kept constant, and the maximum tightness of at least part of the turn coils is ensured, so that the contact resistance between the busbar and the shell pole is located at the set value;

And preparing the prefabricated battery.

29. The method of manufacturing of claim 28, further comprising, after the step of electrically connecting the bus bar to the housing post of the unit cell by cold welding paste:

determining a contact resistance value according to the internal resistance of the single battery, the battery module where the single battery is positioned and the position where the single battery is positioned in the battery module, and further determining the maximum fastening degree;

the wire tension is reversely adjusted based on a preset contact resistance so that the coil reaches a set maximum tightness, and the coil is wound under the tension and both ends are locked.

30. The method of claim 29, wherein in the step of winding the wire around the side housing of the unit cell and the outer surface of the bus bar by an automatic winding machine:

the radial pressure of the coil on the shell pole is F, and the perimeter of the inner outline of the coil is C1, and F is C1;

the contact resistance between the busbar and the housing post is R1, R1 decreases gradually with increasing F, and R1 tends to be constant after the pressure threshold is exceeded.

31. The manufacturing method according to claim 30, wherein in the step of adjusting the tension adjuster of the automatic wire winding machine by the set maximum tightness, the wire tension is set to be equal to or higher than the pressure threshold.

32. The method of manufacturing according to claim 30, wherein the wire comprises a metal wire; after the step of forming the multi-turn coil, further comprising:

the automatic winding machine is used for winding and bending the head and the tail of the coil to realize self-locking attachment so as to maintain R1 constant.

33. The method of manufacturing according to claim 30, wherein the wire comprises a carbon fiber wire; after the step of forming the multi-turn coil, further comprising:

coating UV structural adhesive between the metal coil and the side shell;

coating UV structural adhesive between the metal coils of adjacent turns;

after structural self-locking is achieved on the metal coil, ultraviolet sealing is carried out on the UV structural adhesive so as to maintain R1 constant.

34. The method of manufacturing of claim 30, further comprising, after the step of forming the multi-turn coil:

the nonmetal loop structure is sleeved outside the coil, so that the nonmetal loop structure is mutually abutted with the coil, and the metal coil is prevented from loosening, so that R1 is kept constant.

35. A prefabricated battery manufactured by the method for manufacturing a prefabricated battery according to any one of claims 28 to 34.

36. A battery pack comprising a plurality of prefabricated batteries according to any one of claims 21-27, or a plurality of single cells and a housing post fastening electrical connection structure according to any one of claims 1-20.

37. The battery of claim 36, wherein the battery comprises a series electrical connection direction and a parallel electrical connection direction; in the series electrical connection direction, the contact resistance between the bus bar and the side case of the unit cells is R1, the internal resistance of each unit cell is R2, and the value of each unit cell r1+r2 remains uniform.

38. The battery pack according to claim 36, wherein in the battery pack, the internal resistance of at least one unit cell is N, the internal resistances of the other unit cells are M, N < M;

the maximum tightness set by the locking unit of the single battery with N internal resistance can enable the contact resistance K1 to be generated between the busbar and the shell pole; the maximum tightness set by the locking unit of the single battery with M internal resistance can enable the contact resistance K2, K1 & gtK 2 and N+K1=M+K2 to be generated between the busbar and the shell pole.

39. A method of making a battery comprising:

the tension regulator of the automatic winding machine is regulated through the set maximum fastening degree, and the tension of the wire rod is kept constant in the winding process of at least part of the turn coils, so that the contact resistance between the busbar and the shell pole is constant;

and preparing a battery pack, wherein the contact resistance between all the single batteries in the battery pack and the corresponding bus bars is kept consistent.

40. A battery pack manufactured by the method of manufacturing a battery pack according to claim 39.