Rechargeable battery

A rechargeable battery is disclosed. In one embodiment, the battery includes: i) a first current collecting plate, ii) a plurality of electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies and iii) a can configured to accommodate the first current collecting plate and the plurality of electrode assemblies, wherein the can comprises at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly.

BACKGROUND

This disclosure relates to a rechargeable battery. More particularly, this disclosure relates to a rechargeable battery having high-capacity.

2. Description of the Related Technology

A rechargeable battery can be recharged and discharged, unlike a primary battery that cannot be recharged. For example, a large-sized cylindrical battery is required for a high-capacity battery.

SUMMARY

An exemplary embodiment provides a rechargeable battery. Another embodiment provides a rechargeable battery solving the safety problem of high-capacity electrode assembly, decreasing the number of parts connecting cells and circuit devices, and preventing the cell swelling.

Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a plurality of electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies; and a can configured to accommodate the first current collecting plate and the plurality of electrode assemblies. The can may comprise at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly.

In the above battery, each of the electrode assemblies has a cylindrical shape. In the above battery, the non-linear portion comprises at least one curved shape. In the above battery, the curvature of the at least one curved side is substantially similar to that of the outer side of each electrode assembly. In the above battery, the at least one curved side contacts the outer side of at least one electrode assembly.

The above battery further comprises a second current collecting plate electrically connected to the other ends of the electrode assemblies. In the above battery, each of the electrode assemblies comprises a positive electrode, a negative electrode and a separator interposed between the positive and negative electrodes, and wherein the positive and negative electrodes are electrically connected to the first and second current collecting plates, respectively.

In the above battery, each of the positive and negative electrodes comprises a coated region and an uncoated region, and wherein the width of the positive electrode coated region is less than the width of the negative electrode coated region. The above battery further comprises: a cap plate configured to close the can; an electrode terminal formed on the cap plate; and a connection member configured to electrically connect the electrode terminal and the first current collecting plate, wherein the connection member is further configured to support the electrode assemblies so that the electrode assemblies do not move in the can.

In the above battery, the can comprises two opposing ends, wherein the cap plate is located on one end, wherein the electrode terminal is configured to perform as one of the positive and negative terminals of the battery, and wherein the other end of the can is configured to perform as the other terminal of the battery. In the above battery, the electrode assemblies are arranged so as to form a single row inside the can. In the above battery, the electrode assemblies are arranged so as to form a plurality of rows inside the can.

Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a plurality of cylinder-type electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and a cylindrical side, wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies, respectively, and wherein the electrode assemblies are not surrounded by an adhesive medium; and a can configured to accommodate the first current collecting plate and the plurality of cylinder-type electrode assemblies, wherein the can is configured to sufficiently tightly support the electrode assemblies so that the electrode assemblies do not move inside the can.

The above battery further comprises a second current collecting plate electrically connected to the other ends of the electrode assemblies. In the above battery, the can comprises two opposing ends, and wherein the battery further comprises a cap plate configured to close one end of the can, and wherein the second current collecting plate is directly connected to the other end of the can. The above battery further comprises: a cap plate configured to close the can; an electrode terminal formed on the cap plate; and a connection member configured to electrically connect the electrode terminal and the first current collecting plate, wherein the connection member is further configured to support the electrode assemblies so that the electrode assemblies do not move in the can.

In the above battery, the can comprises two curved sides, wherein each curved side has a curvature, and wherein the two curvatures are different. In the above battery, the electrode assemblies are arranged so as to form a plurality of rows. In the above battery, each of the electrode assemblies comprises a positive electrode, a negative electrode and a separator interposed between the positive and negative electrodes, wherein each of the positive and negative electrodes comprises a coated region and an uncoated region, and wherein the width of the positive electrode coated region is less than the width of the negative electrode coated region.

Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a second current collecting plate; a plurality of electrode assemblies electrically connected in parallel with each other via the first and second current collecting plates, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first and second current collecting plates are electrically connected to the two ends of the electrode assemblies; a can, comprising two opposing ends, configured to accommodate the two current collecting plates and the plurality of electrode assemblies, wherein the can comprises at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly; and a cap plate configured to close one end of the can, wherein one of the two current collecting plates is directly connected to the other end of the can.

DETAILED DESCRIPTION

Assuming that they provide the same capacity, one large-sized cylindrical battery may be advantageous over a plurality of a smaller-sized cylindrical batteries which are connected to each other, because the number of parts connecting cells or circuit devices is reduced. How ever, the large-sized cylindrical battery can cause several problems.

For example, when the electrode assembly is spiral-wound in a Jelly Roll shape in order to provide a high-capacity rechargeable battery, the more number of revolutions is needed than that of a low-capacity rechargeable battery.

As the number of spiral-winding revolutions increases, the difference between the area of the positive electrode and that of the negative electrode in the electrode assembly increases and provides a safer cylindrical battery. However, as the large-sized cylindrical battery has a high-capacity electrode assembly, it may increase the explosive power of a cylindrical battery which deteriorates the safety of a rechargeable battery.

FIG. 1is a perspective view of a rechargeable battery according to a first embodiment, andFIG. 2is an exploded perspective view ofFIG. 1. Referring toFIG. 1andFIG. 2, the rechargeable battery100according to one embodiment includes a plurality of electrode assemblies10, a first current collecting plate20(hereinafter, interchangeably used with “lower current collecting plate”), a second current collecting plate30(hereinafter, interchangeably used with “upper current collecting plate”), a can40, a cap plate50, and an electrode terminal60. The rechargeable battery100may be formed by housing a plurality of electrode assemblies10in the can40.

The rechargeable battery100can accomplish high-capacity, and provide safety by connecting a plurality of low-capacity electrode assemblies10in parallel. The rechargeable battery100can also minimize or prevent explosion, as the explosive power of the smaller batteries is significantly less than that of a large sized rechargeable battery.FIG. 3is an exploded perspective view of an electrode assembly, andFIG. 4Ais a cross-sectional view taken along the line IV-IV ofFIG. 1. In one embodiment, as shown inFIGS. 3 and 4A, the electrode assembly10is formed in a Jelly Roll shape by spiral-winding the negative electrode11, the positive electrode12, and an insulator separator13interposed therebetween. In one embodiment, the electrode assembly10may be cylindrical. In one embodiment, a sector pin14is disposed in the center of the cylindrical electrode assembly10to maintain the cylinder shape of the electrode assembly10(SeeFIG. 4A).

In one embodiment, each of the negative electrode11and positive electrode12includes a current collector, for example, formed of thin film metal foil. The electrodes11and12may also include coated regions11aand12awhere the active material is coated on the current collector and uncoated regions11band12bwhere the active material is not coated on the current collector. In one embodiment, as shown inFIG. 3, the uncoated regions11band12bare disposed in the opposite end sides with respect to the coated regions11aand12a, respectively.

A first lead tab11c(hereinafter, interchangeably used with “negative lead tab”) is connected to the uncoated region11bof the negative electrode11; a second lead tab12c(hereinafter, interchangeably used with “positive lead tab”) is connected to the uncoated region12bof the positive electrode12.

Accordingly, in the cylindrical electrode assembly10in which the negative electrode11, the separator13, and the positive electrode12are wound, the negative lead tab11cis protruded toward one direction (e.g., downward) in the exterior surface of the electrode assembly10; the positive lead tab12cis protruded toward the opposite direction (e.g., upward) of the negative lead tab11cin the center of the electrode assembly10(SeeFIG. 2).

In addition, since a plurality of electrode assemblies10are disposed in one can40, it is formed in a cylinder having smaller volume than the entire volume of the cap40.

Accordingly, as the number of winding the electrode assembly10is decreased, it is possible to minimize the width difference (W11-W12) between the negative electrode11and positive electrode12for maintaining the safety of the rechargeable battery100. Thereby, it is possible to prevent the rechargeable battery100from deteriorating the capacity while maintaining a smaller size.

The safety of the rechargeable battery100is ensured by preventing the coated region12aof the positive electrode12and the coated region11aof the negative electrode11from being a short-circuit each other.

For this purpose, the width (W12) of the coated region12aof the positive electrode12is formed to be less (W12<W11) than the width (W11) of the coated region11aof the negative electrode11. As the number of winding the electrode assembly10is decreased, the width difference (W11-W12) required for maintaining the safety of the rechargeable battery100may be minimized. In one embodiment, the can40may include at least one non-linear portion. The non-linear portion may include at least one curved shape. The curvature of the at least one curved side may be substantially similar to or substantially the same as that of the outer side of each electrode assembly10. The at least one curved side may contact the outer side of at least one electrode assembly10. The can may include two curved sides. In one embodiment, each curved side has a curvature, and the two curvatures are substantially the same as or substantially similar to each other, for example, as shown inFIG. 4A. In a rechargeable battery100′ according to a modification of the first embodiment, the two curvatures may be different, for example, as shown inFIG. 4B. The description of this paragraph also applies to FIGS.2and4-7.

FIG. 5is a cross-sectional view taken along the line V-V ofFIG. 1. In one embodiment, as shown inFIG. 5, in each electrode assembly10, the negative lead tabs11care protruded toward the upward of the electrode assembly10and welded and connected to a lower current collecting plate20disposed under the electrode assemblies10.

In one embodiment, the positive lead tabs12care protruded toward the upside of the electrode assembly10and welded and connected to an upper current collecting plate30disposed above the electrode assemblies10. In one embodiment, the electrode assemblies10are connected in parallel by the lower current collecting plate20and the upper current collecting plate30, so as to accomplish a high-capacity battery.

As shown in the first embodiment, the can40may be provided in a modified prismatic shape such that one side is open in order to insert and accommodate a plurality of electrode assemblies10. The corner part of the prismatic shape may be modified into the curved surface corresponding to the exterior shape of the electrode assembly10.

As the can40has space capable of accommodating a plurality of low-capacity cylindrical electrode assemblies10, it is possible to provide a high-capacity rechargeable battery. Accordingly, when a plurality of rechargeable batteries100are connected to each other, it is possible to decrease the number of parts or circuit devices and to prevent the cell swelling.

In one embodiment, the can40having curved both end surfaces in a row direction of electrode assemblies10may contact the exterior shape of the outermost electrode assemblies10(SeeFIGS. 2 and 4), so it is possible to effectively prevent the shaking of the electrode assemblies10in the inserted state of the electrode assemblies10. In the inserted state of the electrode assembly10in the can40, the can40may be welded to the lower current collecting plate20.

In one embodiment, when a negative lead tab11cis connected to the lower current collecting plate20, the can40connected to the lower current collecting plate20may play a role of a negative terminal in the rechargeable battery100. In addition, when a positive lead tab is connected to the lower current collecting plate in the electrode assembly, the can40connected to the lower current collecting plate may play a role of a positive terminal in the rechargeable battery (not shown). The can40may be formed of a conductive metal such as iron or aluminum.

In one embodiment, when the can40is connected to the negative electrode11of the electrode assemblies10to play a role of a negative terminal, the can40may be formed of iron. In addition when the can is connected to the positive electrode of the electrode assemblies10to play a role of a positive terminal, the can40may be formed of aluminum having superior conductivity to iron (not shown).

The cap plate50is connected to the opening of the can40where the electrode assemblies10are inserted. The cap plate50may seal the can40which accommodates the electrode assemblies10and an electrolyte solution.

An electrode terminal60is mounted in the cap plate50to connect the positive electrode12of the electrode assembly10inside the can40. The electrode terminal60is connected to an upper current collecting plate30through a connecting member31. For example, the connection member31is welded and connected to an upper current collecting plate30in one end, and the other end thereof is electrically connected to the electrode terminal60with providing a connecting opening32. In other words, the electrode terminal60may be electrically connected to the positive electrodes12of the electrode assemblies10through the connection member31and the upper current collecting plate30.

In addition, the cap plate50may be electrically connected to the negative electrode11of the electrode assemblies10through the can40. Accordingly, the connecting member31and the electrode terminal60electrically connected to the positive electrode12may provide an electrical insulation structure together with the cap plate50. For example, a lower insulator33is interposed between the cap plate50and the connecting member31to electrically insulate between the connecting member31and the cap plate50.

An upper insulator34is interposed between the upper surface of the cap plate50and the electrode terminal60and between an electrode terminal opening51of the cap plate50and the electrode terminal60to electrically insulate the cap plate50and the electrode terminal60and to electrically insulate the electrode terminal opening51and the electrode terminal60.FIG. 6is a cross-sectional view of a rechargeable battery100″ according to another modification of the first embodiment. Referring to the rechargeable battery100″ shown inFIG. 6, can40″ may be provided in a cuboid prismatic shape such that one side is open in order to insert and accommodate a plurality of electrode assemblies10. The other elements may be provided similar to those of the first embodiment.

FIG. 7is a cross-sectional view of a rechargeable battery according to a second embodiment. Referring toFIG. 7, the rechargeable battery200according to the second embodiment includes the electrode assemblies10which are arranged so as to form a plurality of rows.

The rechargeable battery100according to the first embodiment is provided with electrode assemblies10in one row, and the can40is corresponding to the first row electrode assemblies10(SeeFIG. 4). In the rechargeable battery200according to the second embodiment, a plurality of rows of electrode assemblies10(for example, three rows) are provided, and the can240may be formed to have a structure corresponding to a plurality of rows of electrode assemblies10(SeeFIG. 6).

The rechargeable battery200according to the second embodiment shows the different disposition of the electrode assemblies10in a can240and accommodates more electrode assemblies10compared to the rechargeable battery100according to the first embodiment. Accordingly, the circuit devices and parts connecting to rechargeable batteries200from the outside may be decreased compared to the first embodiment.

FIG. 8is a flow chart showing a manufacturing process of a rechargeable battery according to the first embodiment. For convenience, a method of manufacturing the rechargeable battery100according to the first embodiment is described. Depending on the embodiments, additional processes may be added, others removed, or the order of the processes changes. This applies toFIG. 9.

Referring toFIG. 8, a method of manufacturing a rechargeable battery100includes a first step (ST11) to a sixth step (ST16). The first step (ST11) is to weld each first lead tab11c(negative lead tab) of the electrode assemblies10to a first current collecting plate20(lower current collecting plate).

The second step (ST12) is to insert the electrode assemblies10in the can40in the state of welding the lower current collecting plate20to the negative lead tap11c.

The third step (ST13) is to weld and electrically connect the inserted lower current collecting plate20of the electrode assemblies10with the can40. The second and third steps (ST12and ST13) are to electrically connect the negative lead tabs11cof the electrode assemblies10to the can40with interposing the lower current collecting plate20.

The fourth step (ST14) is to weld a second lead tap12c(positive lead tap) of the electrode assemblies10to a second current collecting plate30(upper current collecting plate) in the state of being inserted in the can40. The fifth step (ST5) is to connect the upper current collecting plate30to an electrode terminal60of the cap plate50using a connection member31. In other words, one end of the connection member31is welded to the upper current collecting plate30and rivet-connects a connecting opening32of the connection member31to the electrode terminal60. The fourth and fifth steps (ST14and ST15) electrically connect the positive lead tabs12cof the electrode assemblies10to the electrode terminal60with interposing the connection member31and the upper current collecting plate30. The sixth step (ST16) is to bind the cap plate50with the can40and to accommodate the electrode assemblies10in the can40and to seal the same.

FIG. 9is a flow chart showing a manufacturing process of a rechargeable battery according to a second embodiment. The manufacturing method according to the first embodiment is to insert the electrode assembly10in which the lower current collecting plate20is connected to the negative lead tap11cin the can40and to connect the positive lead tap12cof the electrode assembly10to the upper current collecting plate30.

The manufacturing method according to the second embodiment is to connect a lower current collecting plate20to a negative lead tap11cand to insert the electrode assembly in which an upper current collecting plate30is connected to the positive lead tap12cin a can40.

Referring toFIG. 9, in the manufacturing method according to the second embodiment, the first step (ST21) is to weld each first lead tap11c(negative lead tap) of the electrode assemblies10to the first current collecting plate20(lower current collecting plate).

The first step (ST21) is to electrically connect the negative lead taps11cof the electrode assemblies10to the can40with interposing the lower current collecting plate20. The second step (ST22) is to weld each second lead tap12c(positive lead tap) of the electrode assemblies10to the second current collecting plate30(upper current collecting plate). The second step (ST22) is also to electrically connect the positive lead tap12cof electrode assemblies10to the electrode terminal60with interposing a connection member31and the upper current collecting plate30.

The third step (ST23) is to weld the negative lead tab11cwith the lower current collecting plate20and to insert the electrode assemblies10in the can40in the state of welding the positive lead tap12cwith the upper current collecting plate30. The fourth step (ST24) is to weld the lower current collecting plate20to the can40.

The fifth step (ST25) is to connect the upper current collecting plate30to an electrode terminal60of cap plate50using a connecting member31. The sixth step (ST26) is to bind the cap plate50to the can240, to accommodate the electrode assembly10in the can40, and to seal the same.

According to at least one embodiment, it is possible to accomplish the high-capacity rechargeable battery having a unit cell by accommodating a plurality of low-capacity cylinder electrode assemblies in one can and coupling the same in parallel to minimize the width difference between positive electrode and negative electrode. Further, it is possible to decrease the number of circuit devices and parts connecting the rechargeable batteries from the outside, to ensure the safety of electrode assemblies even though the rechargeable battery is high-capacity, and to prevent the cell swelling generated in the conventional prismatic rechargeable battery.

While the above description has pointed out novel features of the invention as applied to various embodiments, the skilled person will understand that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made without departing from the scope of the invention. Therefore, the scope of the invention is defined by the appended claims rather than by the foregoing description. All variations coming within the meaning and range of equivalency of the claims are embraced within their scope.