CN115714241A - Battery assembly process and battery - Google Patents

Abstract

The invention discloses a battery assembling process, which comprises the following steps: s1: configuring at least two battery cells with lugs on two sides, wherein a positive lug and a negative lug are respectively provided with a connecting sheet, and the pole connecting parts of the connecting sheets are arranged on the side of the lug leading-out end surface of the battery cell main body at intervals; the battery core main body is connected in an overlapped mode to obtain a battery core assembly; s2: abutting the top cover pole with the same polarity of the positive pole and/or the negative pole and the pole connecting part of the cell assembly, injecting laser beams from the spacing part of the pole connecting part and the pole ear leading-out end face, and performing laser welding on the top cover pole and the pole connecting part which are abutted with each other to obtain the cell top cover assembly; s3: and the shell is arranged in the cell top cover assembly, and the shell and the top cover of the cell top cover assembly are welded and connected. The battery assembling process is characterized in that laser beams are incident at intervals of the pole connecting part and the pole lug leading-out end face to weld the pole and the connecting piece of the top cover, so that the utilization rate of the internal space of the battery shell and the battery capacity are improved. The invention also discloses a battery.

Description

A battery assembly process and battery

technical field

The invention relates to the technical field of lithium ion batteries, in particular to a battery assembly process and a battery.

Background technique

According to the protruding position of the tab, the battery is divided into two types: single-side tab and double-side tab. In the double-side tab battery, as disclosed in CN215600419U, the positive tabs and negative tabs of the two batteries are first stacked and gathered, then bent in a "7 shape", and then connected to the poles of the top cover, as shown in Figure 1 shown. The defect of the above tab structure is that the multi-tab lamination thickness of the two winding cores is relatively large, resulting in a multiplied increase in the height of the tab after bending, and the bending height of the tab (H in Figure 1) takes up more space inside the housing. Large, the utilization rate of the internal space of the casing and the battery capacity are low.

Contents of the invention

One of the purposes of the present invention is to overcome the defects existing in the prior art and provide a battery assembly process in which the laser beam is incident from the gap between the pole connection part and the lead-out end face of the tab to avoid stacking and folding of multiple battery tabs. The curved structure reduces the internal space of the battery case occupied by the tabs, which is conducive to improving the utilization rate of the internal space of the case and the battery capacity.

In order to achieve the above technical effects, the technical solution of the present invention is: a battery assembly process, comprising the following steps:

S1: Configure at least two double-sided tab batteries, the positive tab and the negative tab are respectively provided with connecting pieces, and the pole connection parts of the connecting pieces are arranged at intervals on the side of the tab lead-out end face of the main body of the battery; The main body of the core is the cell assembly;

S2: Contact the pole connecting part of the top cover pole with the same polarity of the positive pole and/or negative pole and the battery core assembly, inject the laser beam at the interval between the pole connecting part and the lead-out end surface of the tab, and laser weld each other The abutting pole of the top cover and the connecting part of the pole obtains the battery top cover assembly;

S3: The battery cell and at least one top cover of the battery cell top cover assembly are put into the shell, and the shell and the top cover of the battery cell top cover assembly are welded.

The preferred technical solution further includes: welding the connecting piece to the positive pole lug and the negative pole lug respectively, through the connecting piece having a bent structure or bending the lug or bending the connecting piece, to obtain an electric pole connection part. core.

The preferred technical solution is that the battery cell is a multi-tab battery cell, and the main body of the battery cell is sequentially stacked along the stacking direction; it also includes: stacking and fixing the tabs of the battery cell at the first position, and the second The first position is located directly on the side of the lead-out end surface of the tab, and the first position is away from the superimposed surface of the battery core body along the superimposing direction.

A preferred technical solution is that the pole connection parts of the battery cell assembly in S2 are arranged side by side and abut against the poles of the top cover respectively.

The preferred technical solution is that the top cover is provided with a lower plastic part, and the lower plastic part is provided with a stopper protrusion, and the stopper protrusion in S2 abuts against the lead-out end surface of the tab before laser welding, so that The laser beam is incident from a side opening between adjacent stop protrusions or between the stop protrusion and the tab.

The second object of the present invention is to provide a battery, including:

The cell is a double-sided tab cell, including the cell body, the positive tab and the negative tab;

a housing having opposite end openings; said end openings are provided with a top cover;

At least two battery core bodies of the battery cells are superimposed and arranged in the housing; the positive pole tabs and/or negative pole tabs are respectively provided with connecting pieces, and the pole connecting parts of the connecting pieces are arranged at intervals The lug of the main body of the electric core leads out to the side of the end face; the pole connecting portion of the electric core is connected to at least one pole of the top cover by laser welding with the same polarity.

The preferred technical solution is that the positive tab and/or the negative tab respectively include a lead-out section and a bent section connected in sequence; the lead-out end is connected to the main body of the battery cell, and the bent section is The lead-out direction of the tab is bent toward the side of the main body of the cell, and the connecting piece is connected to the bent section.

The preferred technical solution is that the cell is a multi-tab cell, and the cell bodies are stacked sequentially along the stacking direction; the positive tabs and/or negative tabs are stacked and fixed on their respective first tabs. position, the first position is located directly on the side of the battery core body, and the first position is away from the stacking surface of the battery core body along the stacking direction.

A preferred technical solution is that the pole connecting parts are arranged side by side with each other, and the orthographic projection of the pole connecting parts along the pole axis coincides with the pole.

The preferred technical solution is that the top cover is provided with a lower plastic part, and the lower plastic part is provided with a stop protrusion, and the stop protrusion abuts with the battery core; A side opening is provided, and the side opening is arranged on the front side of the axially extending section of the pole, and the side opening is configured to accommodate the passage of the laser beam for welding the pole connection part and the pole.

A preferred technical solution is that the width direction of the positive pole tab and the negative pole tab is the first direction, and the pole connection part is extended to the side of the first direction corresponding to the positive pole tab and the negative pole tab.

The preferred technical solution is that the connecting piece includes a lug connecting portion and a pole connecting portion, and the distance between the lug connecting portion and the corresponding lug leading end surface is smaller than the distance between the pole connecting portion and the corresponding lug leading end surface .

Advantage and beneficial effect of the present invention are:

The battery assembly process injects the laser beam at the interval between the pole connection part and the tab lead-out end face, and utilizes the characteristics of non-contact and long-distance laser welding to realize the laser welding connection of the top cover pole and the tab connection piece;

Based on the same battery cell, compared with the overall bending height of two or more cell tabs stacked and bent, the distance between the pole connection part required for laser beam incidence and the tab lead-out end face is smaller, which is conducive to further improving the battery case. The utilization rate and battery capacity of the internal space of the body;

It is convenient to set more tab layers in a single battery cell, further improving the overcurrent capability of the battery, and meeting the fast charging demand of higher current.

Description of drawings

Fig. 1 is a structural schematic diagram of tab bending of a double-side tab cell battery (dual cell) in the prior art;

Fig. 2 is a schematic diagram of the three-dimensional structure of a single double-sided tab cell and a connecting piece in the embodiment;

Fig. 3 is a top view of the connection structure between a single double-sided tab cell and a connecting piece in the embodiment;

Fig. 4 is the cell top cover assembly in the embodiment;

Fig. 5 is a partial enlarged view of A in Fig. 4;

Fig. 6 is a schematic diagram of the structure of the cell assembly corresponding to A in Fig. 4;

7 is a schematic diagram of the welding structure of the positive electrode top cover of the battery;

Fig. 8 is a schematic diagram of the welded structure of the negative electrode top cover of the battery;

Fig. 9 is a schematic diagram of the three-dimensional structure of the positive electrode top cover;

Fig. 10 is a three-dimensional structural schematic diagram of a negative electrode top cover;

In the figure: 1, double-side tab battery; 11, positive tab; 12, negative tab; 101, lead-out section; 102, bending section; 13, battery main body; 131, tab lead-out end face; 132, Superimposed surface; 2. Connecting piece; 21. Pole connecting part; 22. Tab connecting part; 3. Positive top cover; 4. Negative top cover; 5. Shell; 6. Stop protrusion; 100. Electric Core assembly; 200. Cell top cover assembly.

Detailed ways

The specific implementation manners of the present invention will be further described below in conjunction with the drawings and examples. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

In the description of this application, it should be noted that, unless otherwise specified, the meaning of "plurality" is more than two; the terms "upper", "lower", "left", "right", "inner", " The orientation or positional relationship indicated by "outside" and so on are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a reference to this application. Application Restrictions.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or a flexible connection. Detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Example

As shown in Figures 1-7, the battery assembly process of the embodiment includes the following steps:

S1: configure at least two double-sided tab cells 1, the positive tab 11 and the negative tab 12 are each provided with a connecting piece 2, and the pole connection part 21 of the connecting piece 2 is arranged at intervals on the tab lead-out end surface of the main body 13 of the battery cell 131 on the side; stack and connect the main body 13 of the battery cell to obtain the battery cell assembly 100, and the structure of the battery cell assembly 100 corresponding to A in Figure 3 is shown in Figure 4;

S2: contact the pole connecting portion 21 of the top cover pole of the same polarity as the positive pole and/or the negative pole and the battery core assembly 100, the laser beam is incident at the interval between the pole connecting portion 21 and the tab lead-out end surface 131, respectively Laser welding the top cover pole of the positive pole and the negative pole and the pole connecting portion 21 to obtain the cell top cover assembly;

S3: The battery cells and at least one top cover of the battery cell top cover assembly are put into the shell, and the casing 5 and the top cover of the battery cell top cover assembly 200 are welded.

Two battery cells, or more than three battery cells, such as three, four, five or even more, can be optionally arranged in the same casing 5 .

Taking the cell assembly 100 provided with two double-side tab cells 1 as an example, the opposite first end and second end of the cell assembly 100 are tab lead-out ends. Wherein, the positive tabs 11 of the two cells are located at the first end of the cell assembly 100 , and the negative tabs 12 are located at the second end of the cell assembly 100 .

The connection sheet 2 is suitable for ternary lithium-ion batteries, and the connection structure between the connection sheet 2 and the tabs is conducive to improving the safety performance of the battery. In S1, the pole connection part 21 of the connecting piece 2 is arranged at intervals on the side of the tab lead-out end surface 131 of the cell main body 13. The end face is away from the side of the cell main body 13 , and the pole connecting portion 21 connected to the negative electrode tab 12 is provided on the side of the lead-out end face of the negative electrode tab 12 away from the cell main body 13 .

It can be understood that, in S2, before the poles of the positive top cover 3 are welded, the positive poles abut against the pole connecting parts 21 of all the positive pole lug connecting pieces in the cell assembly 100, and then the abutting area is laser welded; Similarly, before welding the 4 poles of the negative top cover, the negative poles are in contact with the pole connection portions 21 of all the negative tab connection pieces in the cell assembly 100, and then the abutment area is laser welded.

When two top covers (positive top cover 3 and negative top cover 4 respectively) are connected to the cell top cover assembly 200 obtained in S2, the casing 5 has opposite end openings, and the casing 5 and the top cover in S3 The welding sequence of welding includes two types: first, the positive top cover 3 and the stacked battery cells are put into the shell in sequence; second, the negative top cover 4 and the stacked battery cells are put into the shell sequentially.

Taking the case where the positive top cover 3 and the stacked cells are put into the case in sequence, S3 includes the following steps:

① As shown in Figures 7 and 9, the outer contour size of the positive cover 3 is slightly smaller than the size of the cross-section of the inner cavity of the housing 5; Penetrate into the casing 5 until the positive top cover 3 moves to the predetermined position of the end opening at the other end of the casing 5, at this time, both the positive top cover 3 and the negative top cover 4 meet the welding position requirements;

②The laser beam is incident along the direction of the arrow a in Figure 7, and the positive electrode top cover 3 and the casing 5 are connected by vertical welding; The same laser vertical welding is performed on the positive top cover 3 . In this step, there is no particular limitation on the welding sequence of the positive electrode top cover 3 and the negative electrode top cover 4 .

As an alternative to welding the negative top cover 4, as shown in FIGS. On one side of the battery cell, the outer contour dimension of the second stepped portion 42 is slightly smaller than the outer contour dimension of the first stepped portion 41, and the end opening of the housing 5 is a stepped hole, and the stepped hole is matched with the cover plate, and the laser beam along the The direction of the arrow b in FIG. 8 is incident, and the side welding is used to connect the negative electrode top cover 4 and the casing 5 .

The specific steps of step S3 in which the negative top cover 4 and the laminated cells are put into the case sequentially are the same as the above-mentioned step of putting the positive top cover 3 and the laminated cells into the case sequentially.

When the battery cell top cover assembly 200 obtained in S2 only includes one top cover (positive electrode top cover 3 or negative electrode top cover 4), take the example where only the positive electrode top cover 3 is connected to the cell top cover assembly 200: the negative electrode top cover The connection structure between the cover 4 and the battery core adopts any known connection structure between the tab and the top cover. The positive pole top cover 3 and the negative pole top cover 4 are vertically welded and side welded according to the size of the cross section of the inner cavity of the housing 5 . This solution also has the effect of improving the utilization rate of the internal space of the casing 5 and the battery capacity, but compared with the battery top cover assembly 200 including the positive electrode top cover 3 and the negative electrode top cover 4, the internal space utilization rate of the casing 5 and the battery capacity The increase is small.

Furthermore, the poles of the top cover with the same polarity are in surface contact with the pole connecting portion 21 of the cell assembly 100 , which is beneficial to narrow the lamination gap, improve the quality of laser welding, and reduce the welding failure rate.

In another preferred embodiment, it also includes: welding the connecting piece 2 to the positive pole tab 11 and the negative pole tab 12 respectively, through the connecting piece 2 having a bent structure or bending the tab or bending the connecting piece 2, A cell with a pole connecting portion 21 is obtained.

Preferably, the laminated structure of the connecting piece 2 and the tab is ultrasonically welded. The shaded part in Figure 2 is the position of the welding spot for ultrasonic welding. The connecting piece 2 of the optional bending structure has a first bending part and a second bending part, the first bending part is connected to the lead-out section of the tab from the battery main body 13, part or all of the second bending part As the pole connecting portion 21 . Bending the connecting piece 2 refers to a structure in which the planar connecting piece 2 is bent to have the above-mentioned first bent portion and second bent portion. Compared with the above two bending structures for the connecting piece 2, the more preferable process is: the bending section of the tab is obtained by bending the tab, and the bending section is connected with the connecting piece 2 by ultrasonic welding to obtain a The pole connecting portion 21 on the side of the end face 131 is drawn out. In the specific operation process, the connecting piece 2 can also be connected with the tab by ultrasonic welding first, and then the end of the tab with the connecting piece 2 welded can be bent to obtain the tab bending section with the connecting piece 2, that is, to obtain the The pole connecting portion 21 on the side of the end surface 131 . The bending section of the tab has a large deformation margin, which can reduce the extrusion of the tab pole connection structure on the root of the tab during the assembly welding process and the battery use process, and reduce the risk of short-circuiting the battery caused by the reverse insertion of the tab .

In another preferred embodiment, the battery cell is a multi-tab battery cell, and the battery cell main body 13 is stacked sequentially along the stacking direction; it also includes: stacking and fixing the tabs of the battery cell at the first position, the first position It is located on the front side of the lead-out end face 131 of the tab, and the first position is away from the stacking face 132 of the cell main body 13 along the stacking direction.

When two battery cells are arranged in the casing 5, the first position where the tabs are stacked and gathered is shown in Figure 6. The same-polarity tabs of the two battery cells are arranged away from each other, and the stacked and gathered structure of the tabs is used to form a pair of tops. The effective support of the cover is conducive to maintaining the relative position of the top cover and the battery core when passing through the casing 5, reducing the interaction force between the top cover and the inner surface of the casing 5 and transmitting it to the tab and the root of the tab, resulting in tab deformation or tab deformation. The probability of inversion. Furthermore, the pole lugs arranged far away from each other are bent relative to each other, so that the connecting parts of the two poles are close to each other, which can increase the area of the solder joint connected to the same pole, that is, increase the flow area.

When three battery cells are arranged in the housing 5 , the battery core in the middle has an opposite overlapping surface 132 , and at this time, the first position where the tabs are stacked and gathered is located in the center between the two overlapping surfaces 132 .

In another preferred embodiment, the pole connecting portions 21 of the cell assembly 100 in S2 are arranged side by side and abut against the poles of the top cover. Taking a battery with two batteries as an example, compared with the stacked structure of two pole connecting parts 21, the pole connecting parts 21 are arranged side by side to indicate that the pole connecting parts 21 of the two batteries are of the same height. The position and the bending position of the tab can be realized without considering the thickness of the pole connection part 21 and the influence of the stacking of the pole connection part 21 on the two battery tabs, and the operability is stronger; based on the same laser beam Parameters and welding time, the welding of the single-layer pole connecting portion 21 and the pole can obtain greater penetration; the side-by-side arrangement of the pole connecting portions 21 is also conducive to evenly distributing the solder joints according to the position of the light spot to ensure that the two poles The column connecting portion 21 and the pole have a flow area tending to be equal.

In another preferred embodiment, the top cover is provided with a lower plastic part, and the lower plastic part is provided with a stop protrusion 6. Before laser welding, the stop protrusion 6 abuts against the lead-out end surface 131 of the tab in S2, and the laser beam is driven by the corresponding The side opening between the adjacent stop protrusions 6 or between the stop protrusion 6 and the tab is incident.

As shown in Figures 4, 9, and 10, the two stop protrusions 6 are separately arranged at both ends of the top cover, and the interval opening between the two stop protrusions 6 in Figure 4 is located at the front of the axial extension of the pole. sideways. The tab is led out from the main body 13 of the cell, and the tab is correspondingly arranged on the longer side of the tab lead-out end surface 131. The lead-out part of the tab is located in the above interval opening, and the lateral opening 7 for accommodating the incident laser light is sandwiched between the tab and the stop. Between the moving protrusions 6. As an alternative to realizing the pole connecting portion 21 and the pole laser welding, or when the pole lug completely blocks the above interval opening, the lateral opening can also be correspondingly arranged at the short side of the pole lug lead-out end surface 131, for example, in Fig. A lateral opening is provided on the corresponding stop protrusion 6 at the short side of the top cover in 5 .

As shown in Figures 2-4, 7, and 8, the battery of the embodiment includes a cell and a casing 5; the cell is a double-sided tab cell 1, and the cell includes a cell body 13, a positive tab 11 and a negative tab 12; the housing 5 has opposite end openings; the end openings are provided with a top cover; at least two cell main bodies 13 are stacked in the housing 5; the positive pole tab 11 and the negative pole tab 12 are respectively provided There is a connection piece 2, and the pole connection part 21 of the connection piece 2 is arranged at intervals on the side of the tab lead-out end surface 131 of the cell main body 13; Solder connection.

Further, the pole connection part of the battery is connected with the pole poles of the two top covers by laser welding with the same polarity. It can be understood that one of the opposite end openings of the housing 5 is provided with a positive top cover 3, and the other is provided with a negative top cover 4, the positive top cover 3 is connected to the positive tabs of more than two batteries, and the negative top cover 4 is connected to the negative tabs of more than two batteries, and the two batteries in the housing 5 are connected in parallel.

The connection structure between the positive tab 11 of the two batteries and the positive top cover 3, the negative tab 12 and the negative top cover 4 includes the following three methods:

1. The positive tabs of the two batteries are connected to the positive pole of the positive top cover through their respective connecting pieces, and the negative tab adopts a known tab top cover connection structure (such as shown in Figure 1);

2. The negative tabs of the two cells are connected to the negative pole of the negative top cover through their respective connecting pieces, and the positive tab adopts the known tab top cover connection structure (such as shown in Figure 1);

3. The positive tabs of the two batteries are connected to the positive pole of the positive top cover through their respective connecting pieces, and the negative poles are connected to the negative pole of the negative top cover through their respective connecting pieces.

Compared with the first and second connection structures as alternatives, based on the same casing, the third connection structure has a higher utilization rate of the internal space of the casing and a higher battery capacity.

As shown in FIG. 6, in another embodiment, the positive pole tab 11 and the negative pole tab 12 respectively include a lead-out section 101 and a bent section 102 connected in sequence; The tab lead-out direction of the cell body 13 is bent toward the side of the cell body 13 , and the connecting piece 2 is connected to the bent section 102 . Further, the connecting piece 2 is connected to the bent section 102 by ultrasonic welding. Further, the bending angle between the lead-out section 101 and the bending section 102 is a right angle.

As shown in Figure 6, in another embodiment, the cell is a multi-tab cell, and the cell main body 13 is sequentially stacked along the stacking direction; the positive tab 11 and the negative tab 12 are stacked and fixed on their respective The first position, the first position is located on the front side of the cell body 13 , and the first position is away from the stacking surface 132 of the cell body 13 along the stacking direction. The multi-layer lugs located between the first position and the superimposed surface 132 have a diagonal bracing effect on the stacked and gathered structure of the tabs.

As shown in FIG. 6 , in another embodiment, the pole connecting portions 21 are arranged side by side and the orthographic projection along the pole axis coincides with the pole. Arranging side by side is beneficial to improve laser welding efficiency and welding effect.

As shown in Figure 5, in another embodiment, the top cover is provided with a lower plastic part, and the lower plastic part is provided with a stop protrusion 6, and the stop protrusion 6 abuts with the electric core; between the stop protrusions 6 A side opening 7 is provided, and the side opening 7 is arranged on the front side of the axially extending section of the pole, and the side opening 7 is configured to accommodate the passage of the laser beam for welding the pole connecting portion 21 and the pole. In the combination of the top cover and the battery core, the welding structure of the connecting piece 2 and the pole is kept in the space formed by the lower plastic part and the end surface of the battery core, and the contact surface between the stopper protrusion 6 and the battery core is also conducive to dispersion The resistance of the housing 5 to the top cover when passing through the housing 5 reduces the influence of the resistance on the lug and the root of the lug.

As shown in Figures 5 and 6, in another embodiment, the width direction of the positive pole tab 11 and the negative pole tab 12 is the first direction, and the pole connecting portion 21 is extended to correspond to the positive pole tab 11 and the negative pole tab 12. sideways in the first direction of . The first direction is the X direction, the stacking direction of the cell main body 13 is the Y direction, the direction perpendicular to the square cell tab lead-out end surface 131 is the Z direction, and the pole connecting portion 21 is located on the side of the tab in the X direction. The incident angle of can be chosen to be located parallel to the YZ plane and obliquely incident with respect to the X direction.

Opposite to the position of the pole connecting portion 21 above, when the pole connecting portion 21 is arranged between the positive pole lug 11 and the negative pole pole lug 12, as shown in Figure 6, the incident angle of the laser beam must pass through the upper pole in the Z direction. The distance between the column connection part 21 and the tab lead-out end surface 131, the laser beam is obliquely incident with respect to the X direction, Y direction and Z direction, at this time, it is necessary to pay attention to fully avoiding the tab, and the difficulty of laser welding increases significantly; considering the welding yield On the basis of the above, the distance between the pole connection portion 21 and the tab lead-out end surface 131 will be appropriately increased, which is not conducive to increasing the utilization rate of the internal space of the battery case 5 and the battery capacity.

Further, the connection piece 2 includes a pole connection portion 21 and a tab connection portion 22 , the distance between the pole connection portion 22 and the corresponding tab lead-out end surface 131 is smaller than the distance between the pole connection portion 21 and the corresponding tab lead-out end surface 131 . Optionally, the pole connecting portion 21 has a pole lug connecting portion 22 bent toward a side close to the pole.

As shown in FIG. 2 , the pole connecting portion 21 is thinner than the tab connecting portion 22 . Compared with the tab connection part, the thinned pole connection part also has a larger deformation margin, which buffers the vibration during battery use and is conducive to improving the safety factor of the battery.

Taking the direction perpendicular to the lead-out end surface 131 of the tab of the square cell as the Z direction, based on the same tab and the overall height limit of the connection mechanism of the connecting piece 2, the thinned structure of the connecting piece 2 is conducive to reducing the Z of the lead-out section 101 of the tab. To the height, and/or increase the size of the opening to accommodate the incident laser light in the Z direction, to further improve the stability of the top cover when the cell top cover assembly 200 passes through the casing 5, and improve the yield of the battery assembly process.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (12)

1. A battery assembly process, comprising the steps of:

s1: configuring at least two battery cells with lugs on two sides, wherein the positive lug and the negative lug are respectively provided with a connecting sheet, and the pole connecting parts of the connecting sheets are arranged on the side of the lug leading-out end face of the battery cell main body at intervals; the battery core main body is connected in an overlapped mode to obtain a battery core assembly;

s2: abutting the top cover pole with the same polarity of the positive electrode and/or the negative electrode and the pole connecting part of the electric core assembly, injecting laser beams from the space between the pole connecting part and the pole ear leading-out end surface, and performing laser welding on the top cover pole and the pole connecting part which are abutted with each other to obtain the electric core and top cover assembly;

s3: and the battery core and at least one top cover of the battery core top cover assembly are arranged in the shell, and the shell is welded and connected with the top cover of the battery core top cover assembly.

2. The battery assembly process of claim 1, further comprising: and respectively welding the connecting sheets to the positive electrode lug and the negative electrode lug, and obtaining the battery cell with the pole connecting part through the connecting sheets with the bending structures or bending the lugs or bending the connecting sheets.

3. The battery assembly process of claim 1, wherein the battery cells are multi-tab battery cells, and the battery cell main bodies are sequentially stacked along a stacking direction; further comprising: and the tabs of the battery cell are laminated, gathered and fixed at a first position, the first position is positioned at the positive side of the tab leading-out end face, and the first position is far away from the laminating face of the battery cell main body along the laminating direction.

4. The battery assembly process of claim 1, wherein the terminal post connecting portions of the cell assembly in S2 are arranged side by side and respectively abutted against the terminal posts of the top cover.

5. The battery assembly process according to claim 1, wherein the top cover is provided with a lower plastic part, the lower plastic part is provided with stop protrusions, the stop protrusions abut against the tab leading end surfaces in S2 before laser welding, and the laser beam is incident from a lateral opening between adjacent stop protrusions or between the stop protrusions and the tabs.

6. A battery, comprising:

the battery cell is a battery cell with lugs on two sides and comprises a battery cell main body, a positive lug and a negative lug;

a housing having opposing end openings; the end opening is provided with a top cover; it is characterized in that the preparation method is characterized in that,

the cell main bodies of at least two of the cells are arranged in the shell in an overlapped mode; the positive electrode lug and/or the negative electrode lug are/is respectively provided with a connecting sheet, and the pole connecting parts of the connecting sheets are arranged on the side of the lug leading-out end surface of the cell main body at intervals; and the pole connecting part of the battery cell is connected with at least one pole of the top cover by homopolar laser welding.

7. The battery according to claim 6, wherein the positive electrode tab and/or the negative electrode tab respectively comprise a leading-out section and a bending section which are connected in sequence; the leading-out end is connected with the battery cell main body, the bending section is bent towards one side of the battery cell main body along the leading-out direction of the lug of the battery cell main body, and the connecting sheet is connected with the bending section.

8. The battery of claim 6, wherein the cells are multi-tab cells, and the cell bodies are sequentially stacked along a stacking direction; the positive electrode lug and/or the negative electrode lug are respectively stacked, gathered and fixed at respective first positions, the first positions are located on the positive side of the battery cell main body, and the first positions are far away from the stacking surface of the battery cell main body along the stacking direction.

9. The battery of claim 6, wherein the post connecting portions are arranged side by side with each other, and an orthogonal projection of the post connecting portions along an axial direction of the post coincides with the post.

10. The battery of claim 6, wherein the top cover is provided with a lower plastic part, the lower plastic part is provided with a stop protrusion, and the stop protrusion abuts against the battery core; be provided with the side direction opening between the locking arch, the side direction opening set up in the axial extension section dead side of utmost point post, the side direction opening configuration is for holding the welding the laser beam of utmost point post connecting portion and utmost point post passes.

11. The battery according to claim 6, wherein the width direction of the positive electrode tab and the negative electrode tab is a first direction, and the electrode tab connecting portion is provided to extend laterally of the first direction corresponding to the positive electrode tab and the negative electrode tab.

12. The battery of claim 11, wherein the tab includes a tab connection portion and a post connection portion, and a distance between the tab connection portion and the corresponding tab leading end surface is smaller than a distance between the post connection portion and the corresponding tab leading end surface.

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