The present application claims priority to and the benefit of Korean Patent Application No. 10-2023-0140694, filed on Oct. 19, 2023, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.
This disclosure relates to a rechargeable battery.
Rechargeable batteries have been used for a variety of purposes, including as a power source for small electronic devices, such as mobile phones and laptop computers, and as a power source for driving motors in transportation vehicles, such as electric vehicles and hybrid vehicles. In the latter case, battery modules in which a plurality of rechargeable batteries are combined have been used.
A rechargeable battery includes an electrode assembly, a can that accommodates the electrode assembly with an electrolyte, a cap plate that seals the can, and positive and negative terminals that allow current to flow to an external device. In addition, rechargeable batteries include various components, such as a positive electrode current collecting plate, a negative electrode current collecting plate, and a stopper that seals an electrolyte injection port.
The disclosure relates to various embodiments of a rechargeable battery configured to simplify component configuration and facilitate electrolyte injection and sealing of an electrolyte injection port.
In addition, the disclosure relates to various embodiments of a rechargeable battery configured to increase power and capacity of a battery module by increasing the degree of integration of the rechargeable batteries in a battery module by minimizing the dead space.
A rechargeable battery according to an embodiment includes a can, an electrode assembly, a current collecting plate, a rivet terminal, and a sealing cap. The can has a prismatic shape, and a terminal hole is provided in the can. The electrode assembly is accommodated in an internal space of the can, and electrode tabs are exposed on one side of the electrode assembly. The current collecting plate includes a plate-shaped portion and a tubular portion. The plate-shaped portion is coupled to the electrode tabs, and a liquid injection port is in the plate-shaped portion. The tubular portion surrounds the liquid injection port, is connected to one side of the plate-shaped portion, and extends through the terminal hole. The rivet terminal is coupled to the tubular portion, contacts an outer wall of the tubular portion, and is inserted into the terminal hole through an insulator in the can. The sealing stopper is coupled to the rivet terminal to seal the tubular portion.
The can may be in the shape of a hexagonal pillar. The can may include a top portion with a terminal hole located in the center, and a side portion connected to an edge of the top portion. A hexagonal cap plate may be coupled to an end of the side portion to seal the can. The electrode assembly may have a structure in which the electrodes are arranged in a square sheet shape and are sequentially stacked in a width direction. The width of the electrodes may gradually increase from an outer portion of the electrode assembly toward the center of the electrode assembly.
The can may have a square pillar shape. The can may include a top portion with a terminal hole located in the center and a side portion connected to an edge of the top portion. A square cap plate may be coupled to the end of the side portion to seal the can. The electrode assembly may have a structure in which the electrodes are arranged in a square sheet shape are sequentially stacked in the width direction. The electrodes may have the same width and the same height.
The electrode tabs may be separated into a first region and a second region and located at a distance from each other. The electrode tabs in the first region may be bent in a first direction, and the electrode tabs in the second region may be bent in a direction opposite to the first direction. The plate-shaped portion may include a circular, square, or hexagonal metal plate covering the first region and the second region, and the plate-shaped portion may be fixed to the electrode tabs by welding lines.
The liquid injection port may have an arc shape and may be offset from the electrode tabs. The tubular portion may be cylindrical and may guide injection of an electrolyte. A center hole may be located in the rivet terminal, and the tubular portion may extend into the center hole and be physically and electrically connected to the rivet terminal. A sealing ball may be inside the tubular portion to double-seal the liquid injection port with the sealing stopper.
A rechargeable battery according to another embodiment includes a can, an electrode assembly, a current collecting plate, a rivet terminal, and a cap plate. The can includes a top portion in which the terminal hole is located and a side portion connected to an edge of the top portion. The electrode assembly is accommodated in an internal space of the can and includes first electrode tabs located on one side toward the top and second electrode tabs located on a side opposite to the first electrode tabs. The current collecting plate includes a plate-shaped portion and a tubular portion. The plate-shaped portion is coupled to the first electrode tabs, and a liquid injection port is located on the plate-shaped portion. The tubular portion surrounds the liquid injection port, is connected to one side of the plate-shaped portion, and extends through the terminal hole. The rivet terminal is coupled to the tubular portion, in contact with an outer wall of the tubular portion, and extends into the terminal hole through an insulator in the top portion. The cap plate is coupled to the second electrode tabs and is coupled to an end of the side portion to seal the can.
The electrode assembly may have a structure in which first electrodes and second electrodes are arranged in the form of a square sheet and are alternately stacked one-by-one in the width direction with a separator therebetween. The first electrode tabs may extend from the first electrodes to one side, and the second electrode tabs may extend from the second electrodes to the opposite side of the electrode assembly.
The first electrode tabs may be in the first region and the second region at a distance from each other, and may be bent in opposite directions in the first region and the second region. The second electrode tabs may be located in a third region and in a fourth regions at a distance from each other and may be bent in opposite directions in the third and fourth regions.
The plate-shaped portion may include a circular, square, or hexagonal metal plate covering the first region and the second region, and may be coupled to first electrode tabs by welding lines. The cap plate may be coupled to the second electrode tabs by welding lines.
The liquid injection port may have an arc shape and may be offset from the first electrode tabs. The tubular portion may be cylindrical and may guide injection of an electrolyte. A center hole may be located in the rivet terminal, and the tubular portion may extend into the center hole and be physically and electrically connected to the rivet terminal. The rechargeable battery may further include a sealing ball inside the tubular portion to block the liquid injection port and a sealing stopper coupled to the rivet terminal to cover the tubular portion.
According to embodiments, since the liquid injection port is located in the rivet terminal and the current collecting plate, the component configuration may be simplified and mechanical coupling and electrical connection of the current collecting plate and the rivet terminal may be facilitated. In addition, injection of electrolyte and sealing of the liquid injection port may be facilitated and the degree of integration may be increased when a plurality of rechargeable batteries are arranged together to form a battery module.
Hereinafter, the disclosure is described more fully with reference to the accompanying drawings, in which embodiments of the disclosure are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the disclosure.
Referring to
The can 120 is formed in a prismatic shape, for example, a hexagonal pillar shape. In one or more embodiments, the can 120 includes a top portion 122 and a side portion 123 connected to an edge or edges of the top portion 122. When the rechargeable battery 100 is turned upside down, the top portion 122 may be referred to as a bottom portion.
The top portion 122 may be a hexagonal metal plate, and the side portion 123 may be a hollow hexagonal pillar-shaped metal tube. A terminal hole 121 (see
Hereinafter, a direction parallel to a central axis of the can 120 is referred to as a ‘length direction L’, and a direction in which two surfaces of side portions 123 face each other among the directions perpendicular to the length direction L is referred to as a ‘width direction W’. The six surfaces of the side portion 123 include three pairs of surfaces facing each other, and a direction in which a pair of surfaces face each other is referred to as the width direction W for convenience. In
The electrode assembly 130 may have a structure in which a plurality of electrodes 10 and 20 are sequentially stacked in the width direction W. Each of the plurality of electrodes 10 and 20 may be formed in a square sheet shape. A longer side of each of the electrodes 10 and 20 may be parallel (or substantially parallel) to the length direction L, and a shorter side of each of the electrodes 10 and 20 may be parallel (or substantially parallel) to any two of the six surfaces of the side portion 123 that face each other.
In one or more embodiments, the electrode assembly 130 may include a plurality of first electrodes 10 and a plurality of second electrodes 20 arranged alternately one-by-one in the width direction W and a plurality of separators 30 located between the first electrodes 10 and the second electrodes 20, respectively. Each of the plurality of separators 30 may be formed in a square sheet shape.
The first electrode 10 may include a first substrate 11, a first composite material layer 12 on the first substrate 11, and a first electrode tab 13 extending from one end (e.g., the upper end) of the first substrate 11. The second electrode 20 may include a second substrate 21, a second composite material layer 22 on the second substrate 21, and a second electrode tab 23 extending from the opposite end (e.g., the lower end) of the second substrate 21.
In a lithium-ion rechargeable battery, the first substrate 11 may be formed of aluminum foil, and the first composite material layer 12 may include transition metal oxides, such as LiCoO2, LiNiO2, LiMn2O4, Li(NiCoAl)O2, LiFePO4, Li(NiCoMn)O2, etc, conductive materials, binders, etc. The second substrate 21 may include copper foil or nickel foil, and the second composite material layer 22 may include graphite, a conductive material, a binder, etc. The first electrode 10 may be referred to as a positive electrode, and the second electrode 20 may be referred to as a negative electrode. The separator 30 may include a polymer material, such as polyethylene (PE) or polypropylene (PP), and the separator 30 may insulate the first electrode 10 and the second electrode 20 and allow the movement of lithium ions.
The electrode assembly 130 may include the plurality of electrodes 10 and 20 with different widths to form a hexagon on a plane (when the electrode assembly 130 is viewed from above). Hereinafter, ‘on a plane’ refers to when the electrode assembly 130 is viewed from above.
Among the plurality of electrodes 10 and 20, the two outermost electrodes may have the smallest width, and the electrode located at the center of the electrode assembly 130 may have the largest width. The width of the plurality of electrodes 10 and 20 may gradually (or in a stepwise manner) increase from the outer edge of the electrode assembly 130 toward the center. In one or more embodiments, the plurality of electrodes 10 and 20 may have the same (or substantially the same) height in the length direction L.
In an embodiment in which an electrode assembly wound in a cylindrical shape is located inside the hexagonal pillar-shaped can 120, a dead space may exist between the electrode assembly and the corner of the can 120, thereby reducing battery capacity. In the rechargeable battery 100 of the present embodiment, the electrode assembly 130 may be configured such that there is minimal dead space inside the hexagonal pillar-shaped can 120, and thus, battery power and capacity may be increased compared to an embodiment in which the electrode assembly is cylindrical and the can is hexagonal pillar-shaped.
The plurality of first electrode tabs 13 may be located on one side (e.g., the upper side) of the electrode assembly 130, and the plurality of second electrode tabs 23 may be located on the opposite side (e.g., the lower side) of the electrode assembly 130. The plurality of first electrode tabs 13 may be bent in one direction and overlap neighboring first electrode tabs 13, and the plurality of second electrode tabs 23 may also be bent in one direction to overlap neighboring second electrode tabs 23. Each of the plurality of first electrode tabs 13 and the plurality of second electrode tabs 23 may be bent to overlap and press against each other to form a flat (or generally flat) surface.
Each of the plurality of first electrodes 10 may include two first electrode tabs 13 located at a distance from each other and on the plane of the electrode assembly 130. The plurality of first electrode tabs 13 may be divided or separated into a first region A10 and a second region A20. The plurality of first electrode tabs 13 may be located side-by-side in the width direction W in each of the first region A10 and the second region A20.
In the first region A10, the plurality of first electrode tabs 13 may be bent in the first direction D1, and in the second region A20, the plurality of first electrode tabs 13 may be bent in the second direction D2 different than the first direction D1. The second direction D2 may be a reverse direction (i.e., an opposite direction) of the first direction D1.
Referring to
Referring to
In the third region A30, the plurality of second electrode tabs 23 may be bent in the first direction D1, and in the fourth region A40, the plurality of second electrode tabs 23 may be bent in the second direction D2 different than the first direction D1. The second direction D2 may be a reverse direction (i.e., an opposite direction) of the first direction D1.
The cap plate 160 may be located on one side of the electrode assembly 130 to face the plurality of second electrode tabs 23 and may be coupled to the plurality of second electrode tabs 23 by a method, such as laser welding. A plurality of welding lines 161 resulting from welding the second electrode tabs 23 to the cap plate 160 may be located on the cap plate 160. The plurality of welding lines 161 correspond to the third region A30 and the fourth region A40 and are parallel (or substantially parallel) to the width direction W. The cap plate 160 may be formed of a hexagonal metal plate and may have the same polarity as the plurality of second electrodes 20 to function as a negative current collecting plate.
Referring back to
The rechargeable battery 100 according to one or more embodiments of the present disclosure does not have a separate negative current collecting plate and uses the cap plate 160 for sealing as a negative current collecting plate, thereby simplifying the configuration.
In a configuration in which the plurality of electrode tabs 13 and 23 are bent to overlap each other, the current collection efficiency of the electrodes 10 and 20 may be increased and the quality of welding with the current collecting plate 40 and the cap plate 160 may be improved. In addition, since a height of a portion of the total height of the electrode assembly 130 that is not related to the composite materials 12 and 22 may be minimized (or at least reduced), the capacity of the rechargeable battery 100 may be increased.
In addition, even if an abnormality, such as pressure unevenness, occurs in the current collecting plate 40 during the process of welding the plurality of first electrode tabs 13 to the current collecting plate 40, the first electrode tab 13 in at least one of the first region A10 or the second region A20 may maintain constant (or substantially constant) welding quality with the current collecting plate 40. Similarly, even if an abnormality, such as pressure unevenness, occurs in the cap plate 160 during the process of welding the plurality of second electrode tabs 23 to the cap plate 160, the second electrode tab 23 in at least one of the third region A30 or the fourth region A40 may maintain constant (or substantially constant) welding quality with the cap plate 160.
In this manner, the structure in which the plurality of electrode tabs 13 and 23 are divided or separated into two regions and bent in the opposite directions may be a complementary welding structure with respect to the current collecting plate 40 or the cap plate 160.
Referring to
The plate-shaped portion 43 is located between the electrode assembly 130 and the top portion 122, and may be formed of a metal plate of various shapes, such as a hexagon, a square, or a circle. The plate-shaped portion 43 overlaps the plurality of first electrode tabs 13 and may be coupled to (e.g., integrally fixed with) the plurality of first electrode tabs 13 by the plurality of welding lines 41. In
The liquid injection port 42 is an opening for electrolyte injection and may be located in the center (e.g., or substantially the center) of the plate-shaped portion 43. The liquid injection port 42 may have various shapes, such as circle or a circular arc (e.g., crescent shaped). In
The arc-shaped liquid injection port 42 has a larger length compared to the circular liquid injection port, so when the electrolyte is injected through a portion of the liquid injection port 42, air inside the can 120 may be smoothly discharged through another portion of the liquid injection port 42. The current collecting plate 40 provided with the arc-shaped liquid injection port 42 may facilitate injection of the electrolyte solution.
The liquid injection port 42 may not overlap the plurality of first electrode tabs 13 in the length direction L. In one or more embodiments, the liquid injection port 42 may be located between the first region A10 and the second region A20, and may be offset from the plurality of first electrode tabs 13 in the width direction W. In one or more embodiments, when the electrolyte is injected through the liquid injection port 42, hinderance of the injection and diffusion of the electrolyte by the plurality of first electrode tabs 13 may be prevented, and thus damage to the first electrode tab 13 due to electrolyte injection may be prevented (or at least mitigated).
The tubular portion 44 is a hollow cylindrical metal tube and is coupled to one side (e.g., the upper side) of the plate-shaped portion 43. An outer diameter of the tubular portion 44 is smaller than a diameter of the terminal hole 121, and the tubular portion 44 may protrude to the outside (e.g., the upper side) of the top portion 122 through the terminal hole 121. The rivet terminal 150 may be installed in the terminal hole 121 via the insulator 141. The insulator 141 insulates the rivet terminal 150 and the top portion 122 and may seal the terminal hole 121 around the rivet terminal 150.
A center hole 151 passing through the rivet terminal 150 may be located in the center (or substantially the center) of the rivet terminal 150, and the tubular portion 44 may extend through the center hole 151 of the rivet terminal 150 and be coupled to the rivet terminal 150. The tubular portion 44 and the rivet terminal 150 may be coupled (e.g., integrally fixed) by welding or the like. The rivet terminal 150 may be in contact with an outer surface of the tubular portion 44 and a portion of one surface (e.g., the upper surface) of the plate-shaped portion 43 and may have the same polarity as the first electrode 10 through the current collecting plate 40 to function as a terminal (a positive terminal) of the electrode 10.
The tubular portion 44 of the current collecting plate 40 may be a portion physically and electrically connected to the rivet terminal 150 and may function as a guide tube that guides the injection of the electrolyte. After the current collecting plate 40 and the rivet terminal 150 are coupled together, the electrolyte may be injected into the inside of the can 120 through the tubular portion 44, and after the electrolyte injection is completed, the sealing stopper 155 may be fixed to upper portions of the tubular portion 44 and the rivet terminal 150. The sealing stopper 155 may be coupled (e.g., fixed) to the rivet terminal 150 by welding or the like.
In one or more embodiments, before the sealing stopper 155 is installed, a sealing ball 156 may be positioned inside the tubular portion 44 to double-seal the liquid injection port 42. The sealing ball 156 includes a polymer material and may include, for example, perfluoroalkoxy (PFA), but is not limited to this embodiment.
In the rechargeable battery 100 having the configuration described above, a separate liquid injection port is not provided in the can 120 or the cap plate 160 but the liquid injection port is located in the rivet terminal 150 and the current collecting plate 40, and thus, the configuration may be simplified. In addition, in the rechargeable battery 100 having the configuration described above, mechanical coupling and electrical connection between the current collecting plate 40 and the rivet terminal 150 may be facilitated and injection of electrolyte and sealing of the liquid injection port 42 may be facilitated. Moreover, the rechargeable battery 100 having the configuration described above may increase the degree of integration when forming a battery module.
Referring to
In a related art battery module including a plurality of cylindrical rechargeable batteries, a dead space occurs between neighboring rechargeable batteries, but in the battery module 200 of the present embodiment, a dead space does not occur between neighboring rechargeable batteries 100. Accordingly, the battery module 200 of the present embodiment has a structure that increases space efficiency and is therefore advantageous for increasing power and capacity.
Referring to
The four surfaces of the side portion 126 include two pairs of surfaces facing each other, and a direction in which a pair of surfaces face each other is referred to herein as the ‘width direction W’. An electrode assembly 130A may include a plurality of first electrodes 10 and a plurality of second electrodes 20 alternately stacked one-by-one in the width direction W with a separator 30 therebetween (see
A current collecting plate 40A has the same configuration as the current collecting plate 40 of the first embodiment, except that the plate-shaped portion 45 is square. The current collecting plate 40A may be coupled (e.g., integrally fixed) with the plurality of first electrode tabs 13 by laser welding or the like. The cap plate 160 may be formed of a square metal plate and may be coupled (e.g., integrally fixed) to a plurality of second electrode tabs by laser welding or the like. An edge or edges of the cap plate 160 may be coupled (e.g., fixed) to the side portion 126 of the can 120A.
The rivet terminal 150 is physically and electrically connected to the tubular portion 46 of the current collecting plate 40A and is installed in the terminal hole via the insulator 141. After the electrolyte is injected into the interior of the can 120A through the tubular portion 46, a sealing ball may be positioned within the tubular portion 46, and the sealing stopper 155 may be in upper portions of the tubular portion 46 and the rivet terminal 150 to seal the liquid injection port (see
Since the rechargeable battery 100A of the present embodiment has a square pillar shape, when a plurality of rechargeable batteries 100A are arranged or positioned together to form a battery module, the plurality of rechargeable batteries 100A may be in close contact with each other at the side portions of the can 120A without any dead space therebetween. Accordingly, these battery modules have a structure that increases space efficiency and are thus advantageous for increasing power and capacity.
In the first and second embodiments described above, the can has a hexagonal pillar shape and a square pillar shape, respectively, but the shape of the can is not limited to the illustrated examples, and any one of various shapes of prismatic shapes may be selected and used. In one or more embodiments in which a plurality of rechargeable batteries are arranged or positioned together to form a battery module, any prismatic shape that allows the side portions of the cans to be positioned next to each other without dead space therebetween may be used.
Although the embodiments of the disclosure have been described, the disclosure is not limited thereto and may be implemented to be variously modified within the scope of the claims, the detailed description of the invention, and the accompanying drawings, which also falls within the scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0140694 | Oct 2023 | KR | national |