CN115954591A

CN115954591A - Battery monomer, battery module and electric device

Info

Publication number: CN115954591A
Application number: CN202211525082.2A
Authority: CN
Inventors: 谢鹏飞; 唐阳
Original assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Current assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-04-11

Abstract

The invention discloses a battery monomer, a battery module and an electric device, wherein the battery monomer comprises: a housing; the battery pack comprises a first core group, a second core group and a plurality of battery packs, wherein the first core group comprises one or at least two battery packs arranged at intervals along a first direction, each first core group comprises a plurality of first battery cells, the plurality of first battery cells are arranged at intervals along a second direction perpendicular to the first direction, and the first battery cells are square battery cells; the second core group comprises at least one second electric core, the second electric core is a cylindrical electric core, a first chamfer is formed at the corner position of the cross section of the first electric core, the second core group is arranged between the first chamfers of the first electric cores in the two adjacent first core groups, and/or the second core group is arranged between the first chamfer of the first electric core in the first core group and the shell. According to the single battery disclosed by the invention, the arrangement density of the battery cells in the shell can be increased, the energy density of the single battery is increased, the lithium precipitation of the first battery cell in the expansion process is prevented, the safety performance of the first battery cell is improved, and the service life of the first battery cell is prolonged.

Description

Battery monomer, battery module and electric device

Technical Field

The invention relates to the technical field of batteries, in particular to a battery monomer, a battery module and an electric device.

Background

In the related art, the battery cell generally includes a top cover, a casing and a battery core, the casing is generally square, the battery core is arranged inside the casing, and the casing and the top cover are assembled and welded to complete the packaging of the battery cell. The forming mode of the battery cell mainly comprises lamination and winding, and the current battery cell packaging mainly comprises a cylindrical battery cell, a square battery cell and a soft package battery cell. Wherein, the square electric core both sides that the coiling formed are circular-arc naturally, when packing into the casing with coiling electric core, the inside great gap that can produce of square battery monomer, on the one hand, be unfavorable for coiling electric core to be fixed in the casing, lead to in the electric core back of packing into, electric core takes place to slide in the casing easily, on the other hand, the gap needs to be filled up with electrolyte, the use amount of electrolyte in monomer battery has been increased, the waste of electrolyte has been caused, in addition, the energy density of battery can be reduced to great gap, influence the promotion of battery energy density.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a single battery, which can increase the arrangement density of battery cells in a shell and increase the energy density of the single battery.

The invention also provides a battery module with the single battery.

The invention also provides an electric device with the battery module.

A battery cell according to a first aspect of the invention includes: a housing; the first core group is arranged in the shell, the number of the first core groups is one or at least two, the first core groups are arranged at intervals along a first direction, each first core group comprises a plurality of first battery cells, the plurality of first battery cells are arranged at intervals along a second direction perpendicular to the first direction, the first battery cells are square battery cells, and the first direction is the length direction of the first battery cells; the second core group is arranged in the shell and comprises at least one second electric core, the second electric core is a cylindrical electric core, a first chamfer is formed at the corner position of the cross section of the first electric core, the second core group is arranged between the first chamfers of the first electric cores in the first core group, and/or the second core group is arranged in the first core group, the first chamfer of the first electric core is arranged between the first chamfers and the shell.

According to the single battery disclosed by the invention, the arrangement density of the battery cells in the shell can be increased, the energy density of the single battery can be increased, the first battery cell is prevented from precipitating lithium in the expansion process, the safety performance of the first battery cell is improved, and the service life of the first battery cell is prolonged; the waste of electrolyte can be further avoided, the utilization rate of the electrolyte is improved, and meanwhile, the second battery cell can play a limiting role in the shell for the first battery cell, so that the stability of the first battery cell in the shell is improved.

According to some embodiments of the invention, the first cell has a first tab formed at one end of the first cell in a third direction, the third direction being a height direction of the first cell; the second battery cell is provided with a second tab, the second tab is formed at two ends of the second battery cell in the third direction, and the axial direction of the second battery cell is parallel to the third direction.

According to some embodiments of the invention, an outer surface of the first cell is coated with a first insulating film, and an outer surface of the second cell is coated with a second insulating film.

According to some embodiments of the invention, the outer surface of the first cell is provided with a first identification layer for identifying the first cell, and the outer surface of the second cell is provided with a second identification layer for identifying the second cell.

According to some embodiments of the invention, the minimum spacing between the second cell and the first cell is between 0.4mm and 1mm.

According to some embodiments of the invention, the first chamfer is a rounded corner, and a ratio of a radius of the second cell to a radius of the first chamfer is 0.45-0.6.

According to some embodiments of the invention, a height of the second cell in a third direction is identical to a height of the first cell in the third direction, the third direction being perpendicular to the first direction and the second direction.

According to some embodiments of the invention, the second cell comprises a plurality of sub-cells, the plurality of sub-cells being arranged in a stack in the third direction.

According to some embodiments of the invention, a plurality of the first cells of the first core pack are connected in series, and a plurality of the second cells of the second core pack are connected in series.

According to some embodiments of the invention, adjacent first and second core groups are connected in series or in parallel.

According to some embodiments of the present invention, a first chamfer is formed at a cross-sectional corner position of the first battery cell, the casing is a square casing, a second chamfer is formed between two adjacent surfaces of the casing in a plane parallel to the first direction and the second direction, and a ratio between a radius of the first chamfer and a radius of the second chamfer is 0.9-1.1.

According to some embodiments of the invention, a distance between the second chamfer and the adjacent first chamfer is d, a thickness of the first cell in the second direction is t, and d and t satisfy: d/t is more than 0 and less than or equal to 6 percent.

A battery module according to a second aspect of the present invention includes a plurality of battery cells according to the first aspect of the present invention.

According to the battery module, the battery cells of the first aspect are arranged, so that the overall performance of the battery module is improved.

The electric device according to the third aspect of the present invention includes the battery module according to the second aspect of the present invention.

According to the electric device of the present invention, the battery module of the second aspect is provided, so that the overall performance of the electric device is improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic view of a battery cell according to some embodiments of the present invention, in which a first core pack is connected in series with a second core pack;

fig. 2 is a schematic view of another angle of the battery cell shown in fig. 1;

fig. 3 is a schematic view of the battery cell shown in fig. 1, in which a first core pack is connected in parallel with a second core pack;

fig. 4 is a schematic view of another angle of the battery cell shown in fig. 3;

FIG. 5 is a schematic view of a battery cell according to further embodiments of the present invention;

fig. 6 is a schematic diagram of a battery cell according to still further embodiments of the invention;

fig. 7 is a schematic diagram of a battery cell according to further embodiments of the invention;

fig. 8 is a schematic view of the first cell shown in fig. 1;

fig. 9 is a schematic diagram of a first cell according to an embodiment of the invention;

fig. 10 is a schematic diagram of a second cell according to an embodiment of the invention.

Reference numerals:

100. a battery cell;

10. a housing; 11. a second chamfer;

20. a first cell; 21. a first chamfer; 22. a first tab;

30. a second cell; 31. a second tab;

40. a connecting member.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.

A battery cell 100 according to an embodiment of the first aspect of the invention is described below with reference to fig. 1 to 10.

As shown in fig. 1, a battery cell 100 according to an embodiment of the first aspect of the present invention includes: the shell 10, the first core group and the second core group.

Specifically, the first core group is disposed in the casing 10, the first core group is one or includes at least two core groups arranged at intervals along a first direction (for example, a front-back direction shown in fig. 1), that is, only one first core group may be disposed in the casing 10, and a plurality of first core groups may be disposed in the casing 10, for example, two, three, four, five or more first core groups may be disposed in the casing 10, and the plurality of first core groups are arranged at intervals in the first direction.

Each first core group includes a plurality of first cells 20, for example, each first core group may include two, three, four, five, six, and more than two first cells 20. The plurality of first cells 20 in each first core group are arranged at intervals along a second direction (e.g., the left-right direction shown in fig. 1) perpendicular to the first direction, and the cross sections of the first cells 20 parallel to the first direction and the second direction are square, that is, the first cells 20 are square cells, where the first cells 20 are square cells formed by winding. The first direction is a length direction of the first battery cell, and the second direction is a width direction of the first battery cell.

The second core group is disposed in the casing 10, and the second core group includes at least one second battery cell 30, for example, the second core group may include only one second battery cell 30, and the second core group may further include two, three, four or more second battery cells 30. The cross section of the second battery cell 30 parallel to the first direction and the second direction is circular, that is, the second battery cell 30 is a cylindrical battery cell.

The second core set is disposed between two adjacent first core sets, and/or the second core set is disposed between the first core set and the shell 10. That is, the second battery cells 30 in the second core group may be only disposed between two adjacent first core groups, may be only disposed between the first core group and the casing 10, and may also be disposed between two adjacent first core groups and between the first core group and the casing 10.

Specifically, as shown in fig. 1, 5 and 6, the first chamfer 21 is formed at the cross-sectional corner position of the first battery cell 20, the second core group is disposed between the first chamfers 21 of the first battery cells 20 in two adjacent first core groups, and/or the second core group is disposed between the first chamfers 21 of the first battery cells 20 in the first core groups and the casing 10. That is to say, a first gap space is defined by cooperation between two adjacent first battery cells 20 and the casing 10, and when the first core group includes a plurality of first core groups, a second gap space is also defined by cooperation between the first chamfers 21 of two adjacent four first battery cells 20 in two adjacent first core groups, and the second battery cell 30 is disposed in the first gap space and/or the second gap space.

Because the first battery cells 20 are square battery cells, the cross sections of the square battery cells are rectangular structures with chamfers, when a plurality of first battery cells 20 are installed in the casing 10, clearance spaces are formed between the first chamfers 21 of two adjacent first battery cells 20 and the casing 10, and between the first chamfers 21 of two adjacent four first battery cells 20 in the first direction and the second direction. With respect to gaps between the first battery cells 20 and the casing 10 at positions other than the first chamfer 21 and gaps between adjacent first battery cells 20 at positions other than the first chamfer 21, the gap size of the gap space is significantly larger than the gap size at the other positions. When only the square first battery cell 20 is disposed in the casing 10, the size of the gap space is large, and the space is wasted.

In this embodiment, in locating the second electric core 30 between the first chamfers 21 of the first electric cores of two adjacent first core groups, the gap space between the adjacent first electric cores 20 can be fully utilized on the premise of not changing the arrangement mode of the first electric cores 20, the arrangement modes of the first electric cores 20 and the second electric cores 30 in the casing 10 are further optimized, the structure is compact, and the energy density of the battery is improved.

The present embodiment enables the first electrical cores 20 of the first core group and the second electrical cores 30 of the second core group to be arranged in a mixed manner in the casing 10 by disposing the second electrical cores 30 with circular cross-sections between the first chamfers 21 of the first electrical cores 20 of the adjacent first core groups, and/or between the adjacent first chamfers 21 and the casing 10, so that the gaps between the first electrical cores 20 and the casing 10 can be filled with the second electrical cores 30, and/or the gaps between the adjacent first electrical cores 20 can be filled with the second electrical cores 30. Therefore, the arrangement density of the battery cells in the casing 10 can be increased, the energy density of the battery cells 100 can be increased, lithium precipitation of the first battery cell 20 in the expansion process can be prevented, and the safety performance and the service life of the first battery cell 20 can be improved. Meanwhile, as the second battery cells 30 are arranged between the shell 10 and the first core group and between the adjacent first core groups, when the electrolyte is filled into the shell 10, the electrolyte is not required to fill all gaps between the shell 10 and the first core group, so that the using amount of the electrolyte can be reduced, the waste of the electrolyte is avoided, and the utilization rate of the electrolyte is improved. In addition, the second battery cell 30 may play a role in limiting the first battery cell 20 in the casing 10, so as to improve the stability of the first battery cell 20 in the casing 10; the gap in the case 10 is filled by using the second cell 30.

According to the single battery 100 provided by the embodiment of the invention, the arrangement density of the battery cells in the casing 10 can be increased, the energy density of the single battery 100 can be increased, lithium precipitation of the first battery cell 20 in the expansion process can be prevented, and the safety performance and the service life of the first battery cell 20 can be improved; electrolyte waste can be avoided, the utilization rate of the electrolyte is improved, and meanwhile, the second battery cell 30 can play a limiting role in the shell 10 for the first battery cell 20, so that the stability of the first battery cell 20 in the shell 10 is improved.

In some embodiments of the present invention, referring to fig. 5, the minimum spacing between the second cell 30 and the first cell 20 is 0.4mm to 1mm. The minimum distance between the second battery cell 30 and the first battery cell 20 is preferably expressed as the shortest distance between a tangent point of the second battery cell 30 toward the first chamfer 21 of the first battery cell and a tangent point of the first chamfer 21 of the first battery cell 20 toward the second battery cell 30. Therefore, on the premise that the second battery cell 30 is used for filling the gap space and the space utilization rate in the casing 10 is improved, the heat diffusion of the first battery cell 20 and the second battery cell 30 is ensured, and the safety performance of the first battery cell 20 and the second battery cell 30 in the casing 10 is improved.

For example, the minimum spacing between the first cell 20 and the second cell 30 may be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, and so on.

In some embodiments of the present invention, referring to fig. 5, the first chamfer 21 is a rounded corner, and the ratio of the radius of the second cell 30 to the radius of the first chamfer 21 is 0.3-0.6. Therefore, it can be ensured that the second battery cell 30 can be placed in a first gap space between the first chamfer 21 and the casing 10, and the second battery cell 30 can be placed in a second gap space between the plurality of first chamfers 21, so that the filling rate of the second battery cell 30 in the gap space can be optimized, the space utilization rate in the casing 10 is improved, and meanwhile, the heat dissipation performance of the first battery cell 20 and the second battery cell 30 is ensured. For example, the ratio of the radius of the second cell 30 to the radius of the first chamfer 21 may be: 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, etc.

It should be noted that, because the size of a first gap space formed by two adjacent first cells 20 and the side wall of the casing 10 is different from the size of a second gap space formed by four adjacent first cells 20, the size of the second cell 30 filled in the first gap space and the second gap space is different.

According to some embodiments of the present disclosure, the height of the second cell 30 in the third direction is identical to the height of the first cell 20 in the third direction, which is perpendicular to the first and second directions. Wherein, when the first direction and the second direction are respectively a front-back direction and a left-right direction, the third direction is a top-bottom direction. In the present embodiment, by keeping the height of the second battery cell 30 consistent with the height of the first battery cell 20, the filling rate of the gap space in the casing 10 can be increased, and the energy density of the battery cell 100 per unit volume can be increased.

In some embodiments, the second cell 30 may include a plurality of sub-cells arranged in a stack in the third direction. Since the cylindrical second battery cell 30 has a smaller cross-sectional size than the square first battery cell 20, when winding and molding sub-battery cells of the second battery cell 30, the height of the sub-battery cells may be smaller than the height of the first battery cell 20, at this time, in order to improve the utilization rate of the space in the casing 10, multiple sub-battery cells may be stacked in the height direction to form the second battery cell 30, so that the height of the second battery cell 30 is consistent with the height of the first battery cell 20, and the energy density of the battery cell 100 is further improved.

According to some embodiments of the present invention, referring to fig. 1, a plurality of first battery cells 20 of the first core pack may be connected in series, and thus, the output voltage of the first core pack may be increased. For example, as shown in fig. 1, for the first battery cell 20 arranged in the middle of the first core group, the positive electrode of the first battery cell 20 is connected to the negative electrode of the right-side adjacent first battery cell 20, and the negative electrode of the first battery cell 20 is connected to the positive electrode of the left-side adjacent first battery cell 20. Alternatively, the connected positive and negative electrodes of the adjacent first battery cells 20 may be connected by the connecting member 40. Wherein, the connecting member 40 may be a metal sheet, for example, the connecting member 40 may be an aluminum sheet.

According to some embodiments of the present invention, referring to fig. 1, a plurality of second battery cells 30 in the second core pack are connected in series. Thereby, the output voltage of the second core pack can be secured. Two adjacent second battery cells 30 may be connected by a connector 40, and optionally, the connector 40 may be an aluminum sheet.

According to some embodiments of the present invention, the adjacent first core groups and second core groups may be connected in series or in parallel. Therefore, the series connection and parallel connection modes between the adjacent first core group and the second core group can be reasonably selected according to the output current or voltage requirement of the battery monomer 100, and the applicability of the battery monomer 100 is improved.

For example, as shown in fig. 1, two first core groups and one second core group are disposed in the casing 10, the two first core groups are arranged at intervals in the front-rear direction, and the second core group is disposed between the first core groups. Wherein a plurality of first cells 20 of the first core pack are connected in series, a plurality of second cells 30 of the second core pack are connected in series, and the second core pack is connected in series between two first core packs.

As shown in fig. 3 and 4, two first core groups and one second core group are disposed in the casing 10, the two first core groups are arranged at intervals in the front-rear direction, and the second core group is disposed between the first core groups. The first electric cores 20 in the first core group are sequentially connected in series, two first core groups are connected in series, the second electric cores 30 in the second core group are connected in series, and the first core group and the second core group are connected in parallel.

According to some embodiments of the present invention, as shown in fig. 1, a first chamfer 21 is formed at a corner position of a cross section of the first cell 20, the casing 10 is a square casing 10, and a second chamfer 11 is formed between two adjacent surfaces of the casing 10 in a plane parallel to the first direction and the second direction. Therefore, the gap between the first battery cell 20 located at the corner of the casing 10 and the casing 10 can be reduced, which is beneficial to preventing the problem of lithium precipitation at the corner during the expansion of the first battery cell 20, improving the safety of the battery cell 100, and increasing the energy density of the unit volume of the battery cell.

In some embodiments, the ratio between the radius of the first chamfer 21 and the radius of the second chamfer 11 is 0.9-1.1. Therefore, the similarity between the first chamfer 21 and the second chamfer 11 can be improved, the gap between the first chamfer 21 and the second chamfer 11 can be further reduced, and the problem of lithium precipitation at the corner position in the expansion process of the first battery cell 20 can be further prevented. For example, the ratio between the radius of the first chamfer 21 and the radius of the second chamfer 11 may be: 0.9, 0.95, 1, 1.05 or 1.1, etc.

Further, the distance between the second chamfer 11 and the adjacent first chamfer 21 is d, the thickness of the first battery cell 20 in the second direction is t, and d and t satisfy: d/t is more than 0 and less than or equal to 6 percent. Therefore, the gap between the first chamfer 21 and the second chamfer 11 can be reduced, the problem of lithium precipitation at the corner position in the expansion process of the first battery cell 20 can be further prevented, the distance between the first chamfer 21 and the second chamfer 11 can meet 95% -98% of group margin, a rebound space is reserved for the expansion of the first battery cell 20, and the pole piece of the first battery cell 20 can be effectively prevented from wrinkling in the expansion process. For example, the ratio of the distance d between the second chamfer 11 and the adjacent first chamfer 21 to the thickness t of the first battery cell 20 in the second direction may be 1%, 2%, 3%, 4%, 5%, or 6%.

In some embodiments of the present invention, as shown in fig. 9 and 10, the first cell 20 has a first tab 22, the first tab 22 is formed at one end of the first cell 20 in a third direction, which is the height direction of the first cell, that is, the first tab 22 is formed at one end of the first cell 20 in the height direction; the second battery cell 30 has second electrode tabs 31, the second electrode tabs 31 are formed at both ends of the second battery cell 30 in the third direction, and the axial direction of the second battery cell 30 is parallel to the third direction, that is, the second electrode tabs 31 are formed at both ends of the second battery cell 30 in the axial direction. From this, simple structure, the equal shaping of first utmost point ear 22 and second utmost point ear 31 is convenient, and can make things convenient for between the first electric core 20 to connect through first utmost point ear 22 electricity, also can make things convenient for between the second electric core 30 to connect through second utmost point ear 31 electricity, can also make things convenient for between first electric core 20 and the second electric core 30 to connect through first utmost point ear 22 and second utmost point ear 31 electricity. For example, the first battery cell has two first tabs, both of which are disposed at one end of the first battery cell in the height direction, and the second battery cell has two second tabs, which are disposed at both ends of the second battery cell in the axial direction, respectively.

In some embodiments of the present disclosure, the outer surface of the first cell 20 is coated with a first insulating film, which may protect and insulate the first cell 20, and the outer surface of the second cell 30 is coated with a second insulating film, which may protect and insulate the second cell 30. Wherein, optionally, the first insulating film may be a mylar tab, and the second insulating film may also be a mylar tab.

In some embodiments of the present invention, the outer surface of the first battery cell 20 is provided with a first identification layer for identifying the first battery cell 20, and the outer surface of the second battery cell 30 is provided with a second identification layer for identifying the second battery cell 30. From this, can discern first electric core 20 through first identification layer, discern second electric core 30 through the second identification layer, be favorable to detecting and managing and controlling first electric core 20 and second electric core 30.

Optionally, the first identification layer may completely cover an outer surface of the first battery cell 20, for example, the first identification layer may cover an outer side of the first insulating film. The second identification layer may completely cover the outer surface of the second battery core 30, for example, the second identification layer may cover the outer side of the second insulating film.

Further, the first identification layer may be a blue glue layer. The second indicia layer may also be a blue gel layer. The blue glue layer can be formed into a blue identification strip, and the sensor can detect the blue identification strip and feed back information associated with the blue identification strip to the controller. In this way, monitoring, management, and control of information of the first battery cell 20 and the second battery cell 30 are facilitated.

The battery module according to the embodiment of the second aspect of the present invention includes a plurality of battery cells 100 according to the embodiment of the first aspect of the present invention.

The number of the battery cells 100 may be two, three, four, five or more. The plurality of battery cells 100 may be connected in series or in parallel, or the plurality of battery cells 100 may be connected in series or in parallel.

According to the battery module provided by the embodiment of the invention, by arranging the single battery 100 of the first aspect, the arrangement density of the battery cells in the shell 10 of the single battery 100 can be increased, the energy density of the single battery 100 can be increased, lithium precipitation of the first battery cell 20 in the expansion process can be prevented, and the safety performance and the service life of the first battery cell 20 can be improved; electrolyte waste can be avoided, the utilization rate of the electrolyte is improved, and meanwhile, the second battery cell 30 can limit the first battery cell 20 in the shell 10, so that the stability of the first battery cell 20 in the shell 10 is improved.

The electric device according to the embodiment of the third aspect of the invention includes the battery module according to the embodiment of the second aspect of the invention. The battery module is used for providing electric energy. The electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft, and the like.

According to the electric device provided by the embodiment of the invention, by arranging the battery module in the embodiment of the second aspect, the arrangement density of the battery cells in the casing 10 of the single battery 100 can be increased, the energy density of the single battery 100 can be increased, lithium precipitation of the first battery cell 20 in the expansion process can be prevented, and the safety performance and the service life of the first battery cell 20 can be improved; electrolyte waste can be avoided, the utilization rate of the electrolyte is improved, and meanwhile, the second battery cell 30 can limit the first battery cell 20 in the shell 10, so that the stability of the first battery cell 20 in the shell 10 is improved.

A battery cell 100 according to an embodiment of the present invention will be described with reference to fig. 1 to 2.

Referring to fig. 1 and fig. 2, the battery cell 100 includes a casing 10, and a first battery cell 20 and a second battery cell 30 that are disposed in the casing 10, where the first battery cell 20 is a square battery cell, and the second battery cell 30 is a cylindrical battery cell.

As shown in fig. 1, the housing 10 is an aluminum shell, and four corners of the aluminum shell are chamfered greatly; the radius and the angle of the chamfer of the aluminum shell are similar to those of the chamfer of the square battery cell, so that the square battery cell and the aluminum shell at the corner can be more tightly attached, the battery cell can be prevented from lithium precipitation at the corner in the battery cell expansion process, the safety is improved, and the energy density of the unit volume of the battery cell is increased; in addition, the shortest distance between the chamfer of the square battery cell and the chamfer of the aluminum shell meets 95% -98% of group margin, so that a rebound space can be reserved for expansion of the battery cell, and wrinkles of pole pieces in the expansion process are effectively prevented.

When the battery cell 100 is assembled, a square battery cell and a cylindrical battery cell are arranged in a mixed manner, specifically, two rows of square battery cells are arranged in the casing 10 along the front-back direction, each row of eight square battery cells are arranged in sequence along the left-right direction, at this time, a larger gap space is formed at the corner position of the adjacent square battery cells, and the cylindrical battery cell can be placed at the central position of the gap space; the height of the cylindrical battery cell is consistent with that of the square battery cell, the overall height of the cylindrical battery cell can be the stacking height of the plurality of cylindrical battery cells, and the energy density of the unit volume of the module is increased.

The positive and negative poles of adjacent square cells in each row are connected through an aluminum bar (connecting piece 40) to realize series connection, the positive and negative poles of the rightmost square cell are connected in series with the positive and negative poles of the nearest cylindrical cell, then the remaining cylindrical cells are connected in series through the aluminum bar, and the positive pole at the bottom of the leftmost cylindrical cell is connected with the negative pole of the square cell through the aluminum bar, so that the energy density of the cell unit volume is increased.

According to the battery monomer 100 provided by the embodiment of the invention, the square battery cell and the shell 10 can be more tightly attached at the chamfer position by making the large chamfer at the four angular positions of the shell 10, so that the square battery cell is beneficial to inhibiting lithium precipitation at the corners in the expansion process of the square battery cell, and the safety is improved; while increasing the energy density per unit volume of the battery cell 100. Meanwhile, when the battery cell 100 is assembled, the square battery cell and the cylindrical battery cell are arranged in a mixed manner, so that the space utilization rate in the whole shell 10 is improved, and the safety is enhanced.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, comprising:

a housing;

the first core groups are arranged in the shell, the number of the first core groups is one or at least two, the first core groups are arranged at intervals along a first direction, each first core group comprises a plurality of first battery cells, the first battery cells are arranged at intervals along a second direction perpendicular to the first direction, the first battery cells are square battery cells, and the first direction is the length direction of the first battery cells;

the second core group is arranged in the shell and comprises at least one second electric core, the second electric core is a cylindrical electric core, a first chamfer is formed at the corner position of the cross section of the first electric core, the second core group is arranged between the first chamfers of the first electric cores in the first core group, and/or the second core group is arranged in the first core group, the first chamfer of the first electric core is arranged between the first chamfers and the shell.

2. The battery cell of claim 1, wherein the first cell has a first tab formed at an end of the first cell in a third direction, the third direction being a height direction of the first cell;

the second battery cell is provided with a second tab, the second tab is formed at two ends of the second battery cell in the third direction, and the axial direction of the second battery cell is parallel to the third direction.

3. The battery cell of claim 1, wherein an outer surface of the first cell is coated with a first insulating film and an outer surface of the second cell is coated with a second insulating film.

4. The battery cell of claim 1, wherein the outer surface of the first cell is provided with a first identification layer for identifying the first cell, and the outer surface of the second cell is provided with a second identification layer for identifying the second cell.

5. The battery cell of any of claims 1-4, wherein the minimum spacing between the second cell and the first cell is 0.4mm-1mm.

6. The battery cell of any of claims 1-4, wherein the first chamfer is a rounded corner, and wherein a ratio of a radius of the second cell to a radius of the first chamfer is 0.45-0.6.

7. The battery cell of any of claims 1-4, wherein a height of the second cell in a third direction is coincident with a height of the first cell in the third direction, the third direction being perpendicular to the first and second directions.

8. The battery cell of claim 7, wherein the second cell comprises a plurality of sub-cells, the plurality of sub-cells being arranged in a stack in the third direction.

9. The battery cell of any of claims 1-4, wherein the first plurality of cells in the first core pack are connected in series and the second plurality of cells in the second core pack are connected in series.

10. The battery cell of any one of claims 1-4, wherein the adjacent first and second core groups are connected in series or in parallel.

11. The battery cell according to any one of claims 1 to 4, wherein a first chamfer is formed at a corner position of the cross section of the first battery cell, the casing is a square casing, a second chamfer is formed between two adjacent surfaces of the casing in a plane parallel to the first direction and the second direction, and a ratio of a radius of the first chamfer to a radius of the second chamfer is 0.9-1.1.

12. The battery cell of claim 11, wherein a distance between the second chamfer and the adjacent first chamfer is d, a thickness of the first cell in the second direction is t, and d and t satisfy: d/t is more than 0 and less than or equal to 6 percent.

13. A battery module comprising a plurality of battery cells according to any one of claims 1 to 10.

14. An electric device, characterized by comprising the battery module according to claim 13.