Patent Description:
Battery cells are widely used in electronic equipment, such as a mobile phone, a notebook computer, a battery car, an electric vehicle, an electric plane, an electric ship, an electric toy vehicle, an electric toy ship, an electric toy plane, and an electric tool, and the like. The battery cells may include a nickel-cadmium battery cell, a nickel-hydrogen battery cell, a lithium ion battery cell, a secondary alkaline zinc-manganese battery cell, and the like. In the development of battery technology, how to improve the ability of allowing current to pass through of battery cells and simplify the structure of battery cells is a research direction in battery technology.

<CIT> discloses a cylindrical battery having improved strength against rotational torque including: an electrode unit configured as a roll of a first electrode plate and a second electrode plate with a separator in between, the first electrode plate being an electrode plate to which one end of a first electrode tab and one end of a second electrode tab are connected, the second electrode plate having opposite polarity from the first electrode plate; a case housing the electrode unit; and a sealing member sealing an opening rim of the case. The first electrode tab and the second electrode tab are disposed to project out from the first electrode plate at opposite ends of a winding axis of the first electrode late. The first electrode tab is in contact with a bottom portion of the case by being welded thereto. The second electrode tab is welded at the opening rim side opposite the bottom portion of the case.

<CIT> discloses a storage battery (<NUM>), which includes a container (<NUM>) containing an electrochemical stack (<NUM>) comprising alternating positive and negative electrodes flanking electrolyte-impregnated separators. A current output terminal (<NUM>) passes through a lid (<NUM>) of the container. A connector (<NUM>), which electrically connects the electrodes of one polarity to the terminal (<NUM>) passing through the lid, includes a flat connection (<NUM>) welded to the electrodes and an elastic connection (<NUM>) which nests into the terminal (<NUM>) passing through the lid. Manufacture of a sealed storage battery is simplified by obviating a manual operation of inserting and bending an elongated connection tab inside the container.

<CIT> is directed to establishing a direct electrical bond between a bonding connector of a contact plate and a battery cell in a battery module. In a first embodiment, an oscillating laser is used to weld the bonding connector to a battery cell terminal over a target area over which the bonding connector makes non-flush contact. In a second embodiment, the bonding connector is flattened to reduce a gap between the bonding connector and the target area on the battery cell terminal, and then laser-welded (e.g., using an oscillating or non-oscillating laser). In a third embodiment, at least one hold-down mechanism is applied over the bonding connector to secure the bonding connector to the battery cell terminal, after which the bonding connector is laser-welded to the battery cell terminal.

The invention is defined by the appended claim set. The present application provides a battery cell, a method and system for manufacturing a battery cell, a battery and an electrical device, which can improve an ability of allowing current to pass through of the battery cell and simplify a structure of the battery cell.

In a first aspect, the embodiments of the present application provide a battery cell for use in a battery, including:.

In the above technical solutions, by using the cover body and the electrode terminal as output poles, the structure of the battery cell can be simplified, and the ability of allowing current to pass through of the battery cell can be ensured. The cover body and the electrode terminal are located at a same end of the battery cell, so that the first connecting member and the second connecting member can be assembled on a same side of the battery cell, which can simplify an assembly process and improve an efficiency of assembling a plurality of battery cells into a group.

The integral structure can save a connection process of the cover body and the cylinder body.

In the above technical solutions, the bending portion may release stress during the process of forming the casing, reduce stress concentration, and reduce a risk of breaking of the casing.

In some embodiments, the connecting portion includes a main body portion and a first concave portion, the main body portion is disposed around an outer periphery of the first concave portion, the main body portion is used for connecting the first connecting member and the first tab, the first concave portion is recessed from an outer surface of the main body portion in a direction facing the electrode assembly, the electrode lead-out hole penetrates a bottom wall of the first concave portion, and communicates the first concave portion with an inner portion of the casing. The battery cell further includes a first insulating member, the first concave portion is configured to accommodate at least a portion of the first insulating member, and a portion of the first insulating member that is accommodated within the first concave portion is attached to a side wall and/or the bottom wall of the first concave portion.

In the above technical solutions, by arranging the first concave portion, the first insulating member can be positioned, thereby simplifying the assembly process. The first concave portion can accommodate at least a portion of the first insulating member, which can reduce a size of the first insulating member protruding from the outer surface of the main body portion, thereby reducing a maximum size of the battery cell and improving an energy density.

In some embodiments, a thickness of the main body portion is greater than a wall thickness of the cylinder body. The main body portion is used for connecting with the first connecting member, so the main body portion needs to have a relatively large thickness to ensure a connection strength between the main body portion and the first connecting member. In addition, the main body portion having a relatively large thickness may support components such as the electrode terminal in a better way. The cylinder body mainly separates the electrode assembly from the outside, and may have a relatively small thickness to reduce an overall weight of the battery cell.

In some embodiments, a difference between the thickness D1 of the main body portion and the wall thickness D2 of the cylinder body satisfies: <NUM>≤D1-D2≤<NUM>.

If D <NUM>-D2 is less than <NUM>, then the thickness of the main body portion is too small or the thickness of the cylinder body is too large. If the thickness of the main body portion is too small, this may cause that a strength of the main body portion is insufficient, and if the thickness of the cylinder body is too large, this may cause that a weight of the cylinder body will be too large, which will affect the energy density. If D <NUM>-D2 is greater than <NUM>, then during the stretching process, a difference between a stretching amount of the main body portion and a stretching amount of the cylinder body is too large, and the cylinder body is easily damaged during the stretching process. Therefore, the embodiments of the present application makes D1 and D2 satisfy: <NUM>≤D1-D2≤<NUM>.

In some embodiments, the cylinder body is cylindrical, the electrode lead-out hole is a circular hole, a central axis of the cylinder body and a central axis of the electrode lead-out hole are arranged to overlap.

In the above technical solutions, the electrode lead-out hole is used to limit a position of the electrode terminal, and the central axis of the electrode lead-out hole and the central axis of the cylinder body are arranged to overlap in the embodiments, so that at least part of the electrode terminal can be located at a central position of the cover body. In this way, under a condition that a plurality of battery cells are assembled into a group, requirements on an accuracy of a position of the electrode terminal can be reduced, the assembly process can be simplified, and an assembly efficiency can be improved.

In some embodiments, an inner radius L <NUM> of the cylinder body and a width L2 of the main body portion satisfy: <NUM> <, L2/L1≤<NUM>, and the width L2 of the main body portion is a difference between an outer radius of the main body portion and an inner radius of the main body portion.

In the above technical solutions, on the premise that the inner radius L1 of the cylinder body is constant, the width L2 of the main body portion is negatively correlated with the radius of the electrode lead-out hole. If the width L2 of the main body portion is too small, this will cause that the ability of allowing current to pass through of the main body portion is insufficient; if the width L2 of the main body portion is too large, this will cause that the radius of the electrode lead-out hole is too small, and the ability of allowing current to pass through of the electrode terminal is insufficient. Through experiments, the inventors found that when the inner radius L1 of the cylinder body and the width L2 of the main body portion satisfy: <NUM>≤L2/L1≤<NUM>, the ability of allowing current to pass through of the main body portion and the ability of allowing current to pass through of the electrode terminal can be balanced in a better way, to meet the requirements for the overcurrent capacity of the battery cell.

In some embodiments, the main body portion is used for welding with the first connecting member and forming a first welding area on the main body portion, the first welding area is disposed to be spaced apart from a first end portion of the bending portion, and the first end portion is used for connecting the main body portion.

In the above technical solutions, the first welding area is disposed to be spaced apart from the first end portion of the bending portion, to reduce a risk of being welded to the bending portion in the welding process due to a process error, thereby reducing a possibility of virtual welding and ensuring a connection strength between the main body portion and the first connection member.

In some embodiments, a welding depth D3 of the first welding area and the thickness D1 of the main body portion satisfy: <NUM>≤D3/D1≤<NUM>.

In the above technical solutions, if a value of D3/D <NUM> is too small, then a volume of the first welding area is too small, which will lead to insufficient connection strength and low ability of allowing current to pass through between the main body portion and the first connecting member. Therefore, in the embodiments, the value of D3/D1 is set to be greater than or equal to <NUM>, so as to ensure the connection strength and the ability of allowing current to pass through between the main body portion and the first connecting member. If the value of D3/D1 is too large, then the power required for welding is also high, and a high temperature generated during welding is likely to burn other components. In addition, if the value of D3/D1 is too large, a risk of the main body portion being melted through will also increase, and after the main body portion is melted through, it is more likely to burn other components in the casing. Therefore, in the embodiments of the present application, the value of D3/D1 is set to be less than or equal to <NUM>, so as to reduce a temperature during welding and reduce a risk of burning other components.

In some embodiments, the battery cell further includes a second insulating member, the second insulating member includes an insulating body and an insulating protrusion protruding from an outer periphery of the insulating body, the insulating body abuts on a side of the main body portion facing the electrode assembly, the insulating protrusion is arranged on a side of the bending portion facing the electrode assembly, a surface of the insulating protrusion away from the electrode assembly is closer to the electrode assembly than a surface of the insulating body away from the electrode assembly, so as to form a second concave portion for avoiding the bending portion.

In the above technical solutions, the insulating body can separate at least a portion of the main body portion from the electrode assembly, and the insulating protrusion can separate at least part of the bending portion from the electrode assembly, so that when the battery cell vibrates, a risk of the electrode assembly coming into contact with the main body portion and a risk of the electrode assembly coming into contact with the bending portion can reduced in the embodiments, thereby improving the safety performance. In the embodiments, the second concave portion is provided to avoid the bending portion to avoid interference between the bending portion and the second insulating member.

In some embodiments, the insulating protrusion protrudes beyond a second end portion of the bending portion in the direction facing the electrode assembly, and the second end portion is used for connecting the cylinder body.

In the above technical solutions, the outer surface of the insulating protrusion is spaced from an inner surface of the bending portion to avoid interference between the insulating protrusion and the bending portion. A size of the insulating protrusion protruding from the insulating body is not affected by the bending portion, so that an isolation effect of the insulating protrusion can be improved.

In some embodiments, an inner surface of the insulating body is formed with a third concave portion recessed in a direction away from the electrode assembly, and at least part of the electrode terminal is accommodated within the third concave portion. By arranging the third concave portion, a space occupied by the second insulating member and the electrode terminal can be reduced, so as to improve the energy density of the battery cell.

In some embodiments, a thickness of the insulating body is greater than a thickness of the main body portion. When the main body portion and the first connecting member are welded, heat will be transferred to the insulating body. In the embodiments, the thickness of the insulating body is larger than the thickness of the main body portion, so as to prolong a heat transfer path and reduce an influence of heat on other components. The insulating body in the embodiments has a relatively large thickness, so that even if a portion of the insulating body close to the first welding area is burned, an insulating effect can be ensured.

In some embodiments, a convex portion is formed at a position on the connecting portion opposite to the first concave portion, and the convex portion protrudes from an inner surface of the main body portion in the direction facing the electrode assembly. The connecting portion further includes a fourth concave portion, the fourth concave portion is recessed from a top end surface of the convex portion to the inner surface of the main body portion in the direction away from the electrode assembly. The battery cell further includes a second insulating member, the fourth concave portion is configured to accommodate at least part of the second insulating member, and the part of the second insulating member that is accommodated within the fourth concave portion is attached to a side wall and/or a bottom wall of the fourth concave portion.

In the above technical solutions, by arranging the convex portion, a thickness of the bottom wall of the first concave portion can be increased, so as to improve a strength of the bottom wall of the first concave portion, so that the bottom wall of the first concave portion can effectively support the electrode terminal. The second insulating member can cover the main body portion from the inside to separate the electrode assembly from the main body portion, thereby reducing a risk of contact and conduction between the electrode assembly and the main body portion when the battery cell vibrates, and improving the safety performance. By arranging the fourth concave portion, the second insulating member can be positioned, thereby simplifying the assembly process. The fourth concave portion can accommodate at least part of the second insulating member, so that an inner space of the casing can be fully utilized and the energy density can be improved.

In the above technical solutions, the thickness of the bending portion is enabled to change gradually, so as to adapt to a thickness difference between the connecting portion and the cylinder body, to smoothly connect the cylinder body and the connecting portion, which reduces a risk that an inner surface and an outer surface of the casing form a step, and reduces stress concentration.

In some embodiments, the second tab is provided at one end of the electrode assembly facing the cover body, and the first tab is provided at the other end of the electrode assembly away from the cover body. The cylinder body is used for connecting the first tab and the cover body to enable the first tab to be electrically connected to the cover body.

In the above technical solutions, the first tab and the second tab are provided at two ends of the electrode assembly, which can reduce a risk of conduction between the first tab and the second tab, and increase a current passing through area of the first tab and a current passing through area of the second tab.

In some embodiments, the first tab is a negative pole tab, and a base material of the casing is steel. The casing is electrically connected to the negative pole tab, that is, the casing is in a low potential state. The casing made of steel is not easily corroded by electrolyte in a low potential state, so as to reduce safety risks.

In some embodiments, the cylinder body has an opening at one end away from the cover body, and the battery cell further includes a cover plate for closing the opening.

In a second aspect, the embodiments of the present application provide a battery, including: the battery cell of any embodiment of the first aspect; the first connecting member connected to the cover body; and the second connecting member connected to the electrode terminal.

In a third aspect, the embodiments of the present application provide an electrical device, including the battery of the second aspect, and the battery is used for providing electrical energy.

In a fourth aspect, the embodiments of the present application provide a method for manufacturing a battery cell, including providing a casing and an electrode terminal, wherein the casing includes a cylinder body and a cover body connected to the cylinder body, the cover body is provided with an electrode lead-out hole, the cylinder body has an opening at one end away from the cover body, and the electrode terminal is disposed at the cover body in an insulating manner and installed at the electrode lead-out hole;providing an electrode assembly including a first tab and a second tab with opposite polarities;installing the electrode assembly into the casing to enable the cylinder body to be disposed around an outer periphery of the electrode assembly and the second tab to be electrically connected to the electrode terminal;providing a cover plate, wherein the cover plate is connected to the cylinder body to close an opening of the cylinder body, and the first tab is electrically connected to the cover plate to enable the first tab to be electrically connected to the cover body through the cover plate and the cylinder body ;wherein, at least part of the cover body is used for electrically connecting the first connecting member of the battery and the first tab, the electrode terminal is used for electrically connecting the second connecting member of the battery and the second tab, one of the cover body and the electrode terminal is a positive output pole of the battery cell, and the other is a negative output pole of the battery cell. In a fifth aspect, the embodiments of the present application provide a system for manufacturing a battery cell, including:a first providing means for providing a casing and an electrode terminal, wherein the casing includes a cylinder body and a cover body connected to the cylinder body, the cover body is provided with an electrode lead-out hole, the cylinder body has an opening at one end away from the cover body, and the electrode terminal is disposed at the cover body in an insulating manner and installed at the electrode lead-out hole;a second providing means for providing an electrode assembly including a first tab and a second tab with opposite polarities;a first assembling means for installing the electrode assembly into the casing to enable the cylinder body to be disposed around an outer periphery of the electrode assembly and the second tab to be electrically connected to the electrode terminal;a second assembling means for providing a cover plate, wherein the cover plate is connected to the cylinder body to close an opening of the cylinder body, and the first tab is electrically connected to the cover plate to enable the first tab to be electrically connected to the cover body through the cover plate and the cylinder body;wherein, at least part of the cover body is used for electrically connecting the first connecting member of the battery and the first tab, the electrode terminal is used for electrically connecting the second connecting member of the battery and the second tab, one of the cover body and the electrode terminal is a positive output pole of the battery cell, and the other is a negative output pole of the battery cell.

In order to more clearly describe technical solutions of the embodiments of the present application, the drawings that need to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative work, other drawings can be obtained based on the drawings. <FIG> is a structural schematic diagram of a vehicle according to some embodiments of the present application;<FIG> is an exploded schematic diagram of a battery according to some embodiments of the present application;<FIG> is an exploded schematic diagram of a battery module shown in <FIG>;<FIG> is a partial cross-sectional schematic diagram of a battery according to some embodiments of the present application;<FIG> is an exploded schematic diagram of a battery cell according to some embodiments of the present application;<FIG> is an enlarged schematic diagram of the battery shown in <FIG> at block A;<FIG> is a partial cross-sectional schematic diagram of a casing of a battery cell according to some embodiments of the present application;<FIG> is an enlarged schematic diagram of the battery shown in <FIG> at circle frame B;<FIG> is a structural schematic diagram of a second insulating member of a battery cell according to some embodiments of the present application;<FIG> is an enlarged schematic diagram of the battery shown in <FIG> at circle frame C;<FIG> is a structural schematic diagram of an electrode terminal of a battery cell according to some embodiments of the present application;<FIG> is a schematic flowchart of a method for manufacturing a battery cell according to some embodiments of the present application;<FIG> is a schematic block diagram of a system for manufacturing a battery cell according to some embodiments of the present application. In the drawings, the drawings are not drawn to actual scale.

In some embodiments, the electrode terminal <NUM> further includes a sealing plate <NUM>, and the sealing plate <NUM> is used for closing an opening of the fifth concave portion 311a. The sealing plate <NUM> may be located entirely outside the fifth concave portion 311a, or may be partially accommodated within the fifth concave portion 311a, as long as the sealing plate <NUM> can close the opening of the fifth concave portion 311a. The sealing plate <NUM> can protect the adapter portion 311b from the outside, reduce external impurities entering the fifth concave portion 311a, reduce a risk of the adapter portion 311b being damaged by external impurities, and improve a sealing performance of the battery cell <NUM>. In some embodiments, the fifth concave portion 311a is a stepped concave portion, and at least part of the sealing plate <NUM> is accommodated within the fifth concave portion 311a and supported by a stepped surface of the fifth concave portion 311a.

In some embodiments, the sealing plate <NUM> is used for welding with the second connecting member <NUM> and a second welding portion W2 is formed. The second welding portion W2 can reduce a contact resistance between the sealing plate <NUM> and the second connecting member <NUM> and improve the ability of allowing current to pass through.

In some embodiments, at least part of the sealing plate <NUM> protrudes from the outer surface <NUM> of the terminal body. Under a condition that the second connecting member <NUM> and the sealing plate <NUM> need to be welded, the second connecting member <NUM> is first attached to an upper surface of the sealing plate <NUM> (that is, an outer surface of the sealing plate <NUM> away from the adapter portion 311b), and then the second connecting member <NUM> and the sealing plate <NUM> are welded.

At least part of the sealing plate <NUM> protrudes from the outer surface <NUM> of the terminal body, so as to prevent the outer surface <NUM> of the terminal body from interfering with the attaching of the sealing plate <NUM> and the second connecting member <NUM>, thereby ensuring that the second connecting member <NUM> and the sealing plate <NUM> are attached closely.

<FIG> is a schematic flowchart of a method for manufacturing a battery cell according to some embodiments of the present application.

As shown in <FIG>, the method for manufacturing a battery cell according to some embodiments of the present application includes:.

It should be noted that, for a related structure of a battery cell manufactured by the above-mentioned method for manufacturing a battery cell, reference may be made to the battery cell provided in the above-mentioned embodiments. When assembling a battery cell based on the above-mentioned method for manufacturing a battery cell, it is not necessary to carry out the above-mentioned steps in sequence, that is, the steps may be carried out in an order mentioned in the embodiments, or in an order different from that mentioned in the embodiments, or several steps may be performed simultaneously. For example, the execution of steps S100 and S200 is in no particular order, and may also be performed simultaneously.

<FIG> is a schematic block diagram of a system for manufacturing a battery cell according to some embodiments of the present application.

As shown in <FIG>, the system <NUM> for manufacturing a battery cell according to some embodiments of the present application includes:.

Claim 1:
A battery cell (<NUM>) suitable to be used in a battery (<NUM>), comprising:
an electrode assembly (<NUM>), comprising a first tab (<NUM>) and a second tab (<NUM>) with opposite polarities;
a casing (<NUM>) for accommodating the electrode assembly (<NUM>), wherein the casing (<NUM>) comprises a cylinder body (<NUM>) and a cover body (<NUM>) connected to the cylinder body (<NUM>), the cylinder body (<NUM>) is disposed around an outer periphery of the electrode assembly (<NUM>), the cover body (<NUM>) is provided with an electrode lead-out hole (<NUM>), and at least part of the cover body (<NUM>) is suitable to be used for electrically connecting a first connecting member (<NUM>) of the battery (<NUM>) and the first tab (<NUM>); and
an electrode terminal (<NUM>) for electrically connecting a second connecting member (<NUM>) of the battery (<NUM>) and the second tab (<NUM>), wherein the electrode terminal (<NUM>) is disposed at the cover body (<NUM>) in an insulating manner and installed at the electrode lead-out hole (<NUM>), one of the cover body (<NUM>) and the electrode terminal (<NUM>) is a positive output pole of the battery cell (<NUM>), and the other is a negative output pole of the battery cell (<NUM>);
wherein the cover body (<NUM>) and the cylinder body (<NUM>) are formed as an integral structure
wherein the cover body (<NUM>) comprises a connecting portion (<NUM>) and a bending portion (<NUM>), the electrode lead-out hole (<NUM>) is provided on the connecting portion (<NUM>), at least a portion of the connecting portion (<NUM>) is suitable to be used for connecting the first connecting member (<NUM>) and the first tab (<NUM>), and the bending portion (<NUM>) is used for connecting the cylinder body (<NUM>) and the connecting portion (<NUM>); and
characterized in that the bending portion (<NUM>) comprises a first end portion (223a) for connecting the connecting portion (<NUM>) and a second end portion (223b) for connecting the cylinder body (<NUM>), and in a direction from the first end portion to the second end portion, a thickness of the bending portion gradually decreases.