Patent Description:
Secondary batteries capable of being repeatedly chargeable and dischargeable may be classified into a NaS secondary batteries, redox flow batteries, lithium ion secondary batteries, and the like according to types of materials involved in chemical reaction occurring in the charging and discharging. Particularly, such a lithium ion secondary battery is widely used among secondary batteries because the lithium ion secondary battery has high energy density and a few degree of self discharge.

In recent years, various fields requiring secondary batteries have been diversified, and demands for secondary batteries are also increasing. Particularly, demands for lithium ion secondary batteries are increasing in the fields of mobile, automotive and energy storage systems.

Secondary batteries may be classified into circular type secondary batteries, prismatic type secondary batteries, and pouch type secondary batteries according to a manufacturing method or structure. However, in the case of such a secondary battery according to the related art, when manufacture of cells constituting the secondary battery is completed, there is a problem that it is difficult to change a capacity, a voltage, and the like according to the demands of the consumer using the secondary battery.

Also, in the case of the secondary battery according to the related art, the secondary battery and the cells constituting the secondary battery are manufactured in only a regular shape such as a cylindrical shape, a rectangular plate shape, and the like to generate a so-called dead space which does not contribute to generation of an output, resulting in a problem that utilization of a space is deteriorated.

Patent Document <NUM> describes a battery module comprising two or more battery cells or unit modules, in which two or more positive electrode or negative electrode terminals are individually formed at one end unit in the battery cells or the unit modules. The battery cells and the unit modules are connected in series or in parallel in a state in which electrode terminals are stacked or arranged in a side surface to head towards the same direction.

Patent Document <NUM> describes an all-solid-state battery stacked with a positive electrode, a solid electrolyte layer and a negative electrode, having unit cells which are configured to have a collector plate stacked on the positive electrode and the negative electrode arranged in a lateral direction, and having a structure of being connected by the collector plate so that the gap between adjacent unit cells arranged in a lateral direction can be electrically connected in parallel.

Patent Document <NUM> describes a battery cell in which an electrode assembly, which has a structure of a cathode, an anode, and a separation membrane interposed between the cathode and the anode, is embedded in a battery case of a laminate sheet including a resin layer and a metal layer, wherein the battery cell has an irregular structure having at least five outer peripheries on a plane, and a cathode lead and an anode lead of the battery cell respectively protrude, from outer peripheries different from each other, to the outside of the battery case.

Patent Document <NUM> describes an electrode assembly and a secondary battery using the same that are capable of omitting a process to attaching an additional electrode lead by increasing the thickness of an outermost substrate among electrode plates and the size of an electrode tab to use electrodes tabs of internal substrates as an electrode lead while tying the electrode tabs of the internal substrates. The electrode assembly includes: a first electrode plate with a first electrode tab extending to one side; a second electrode plate with a second electrode tab extending to the other side not to be overlapped with the first electrode tab; and a separator interposed between the first electrode plate and the second electrode plate, wherein a first outermost electrode tab of a pair of first outermost electrodes and a second outermost electrode tab of a pair of outermost electrode plates that are positioned at the outermost side between the first electrode plate and the second electrode plate are larger and thicker than a plurality of first intermediate electrode tabs and second intermediate electrode tabs that are positioned in the middle of the first electrode plate and the second electrode plate to cover the plurality of first intermediate electrode tabs and second intermediate electrode tabs.

Patent Document <NUM> describes a secondary battery that includes an electrode assembly and a battery case accommodating the electrode assembly. The battery also includes a plurality of lead terminals comprising a first pair of lead terminals having opposite polarities and outwardly extending from the electrode assembly to protrude from a first side of the battery case and a second pair of lead terminals having opposite polarities and outwardly extending from the electrode assembly to protrude from a second side of the battery case opposing the first side. The battery further includes a plurality of insulation members respectively extending along the first and second pairs of lead terminals to at least partially cover the lead terminals.

Accordingly, an object of the present invention is to provide a secondary battery that is capable of being easily changed in capacity, voltage, and the like according to user's demands.

Also, another object of the present invention is to provide a secondary battery capable of minimizing a dead space that does not contribute to generation of an output to maximize utilization of a space.

According to an aspect of the present invention for achieving the above object, the present invention provides a lithium ion secondary battery including: first and second electrode laminates, each of which has a structure in which a positive electrode, a separator, and a negative electrode, each of which comprises at least one line segment on a circumferential portion thereof, are alternately laminated; and a positive electrode tab and a negative electrode tab, which have shapes protruding from the line segments of the positive electrode and the negative electrode, respectively, wherein the positive electrode, the separator, and the negative electrode are laminated so that the line segments face each other, the positive electrode tabs are laminated to face each other and thereby to provide a positive electrode tab bundle, the negative electrode tabs are laminated to face each other and thereby to provide a negative electrode tab bundle, the second electrode laminate is connected to a side portion of the first electrode laminate, and the first electrode laminate is connected in series to the second electrode laminate, and characterized in that the positive electrode tab bundle of the first electrode laminate is electrically connected to the negative electrode tab bundle of the second electrode laminate, and an insulator is disposed between the negative electrode tab bundle of the first electrode laminate and the positive electrode tab bundle of the second electrode laminate to prevent electrical connection.

Side planes of the first and second electrode laminates, which are formed by alternately laminating the positive electrode, the separator, and the negative electrode, each of which comprise the at least one line segment, may be disposed to face each other.

Each of the first and second electrode laminates may have a polygonal pillar shape because each of the positive electrode, the separator, and the negative electrode has a polygonal shape.

Each of the first and second electrode laminates may have a hexagonal pillar shape because each of the positive electrode, the separator, and the negative electrode has a hexagonal shape.

Each of the first and second electrode laminates may have a regular polygonal pillar shape because each of the positive electrode, the separator, and the negative electrode has a regular polygonal shape of which one internal angle has an aliquot part of <NUM> degrees.

Each of the first and second electrode laminates may have a regular hexagonal pillar shape because each of the positive electrode, the separator, and the negative electrode has a regular hexagonal shape.

The lithium ion secondary battery may further include: a third electrode laminate having a structure in which the positive electrode, the separator, and the negative electrode, each of which comprises at least one line segment on a circumferential portion thereof, are alternately laminated; a positive electrode tab bundle and a negative electrode tab bundle, which respectively have shapes protruding from the second electrode laminate, on an opposite side of the first electrode laminate with respect to the second electrode laminate; and a positive electrode tab and a negative electrode tab, which respectively have shape protruding from the line segments of the positive electrode and the negative electrode of the third electrode laminate, wherein the positive electrode, the separator, the negative electrode of the third electrode laminate are laminated so that the line segments face each other, the positive electrode tabs of the third electrode laminate are laminated to face each other and thereby to provide a positive electrode tab bundle, the negative electrode tabs of the third electrode laminate are laminated to face each other and thereby to provide a negative electrode tab bundle, and the second electrode laminate and the third electrode laminate are connected in series to each other, like the connection between the first electrode laminate and the second electrode laminate such that the positive electrode tab bundle of the second electrode laminate is electrically connected to the negative electrode tab bundle of the third electrode laminate, and an insulator is disposed between the negative electrode tab bundle of the second electrode laminate and the positive electrode tab bundle of the third electrode laminate to prevent electrical connection.

The third electrode laminate may have a hexagonal pillar shape because each of the positive electrode, the separator, and the negative electrode of the third electrode laminate has a hexagonal shape.

The third electrode laminate may have a regular polygonal pillar shape because each of the positive electrode, the separator, and the negative electrode of the third electrode laminate has a regular polygonal shape of which one internal angle has an aliquot part of <NUM> degrees.

The third electrode laminate may have a regular hexagonal pillar shape because each of the positive electrode, the separator, and the negative electrode of the third electrode laminate has a regular hexagonal shape.

According to the present invention, the secondary battery that is capable of being easily changed in capacity, voltage, and the like according to user's demands may be manufactured.

Also, according to the present invention, the dead space that does not contribute to generation of the output may be minimized in the secondary battery to maximize the utilization of the space.

Hereinafter, a structure of a lithium ion secondary battery according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<FIG> is a plan view illustrating a structure of a positive electrode of a lithium ion secondary battery according to an embodiment of the present invention, and <FIG> is a plan view illustrating a structure of a negative electrode of the lithium ion secondary battery according to an embodiment of the present invention.

Referring to <FIG>, a circumferential portion of a positive electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may include at least one line segment. <FIG> illustrates a case in which the circumferential portion of the positive electrode <NUM> includes six line segments. Also, the positive electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may have a polygonal shape. <FIG> illustrates a case in which the positive electrode <NUM> has a hexagonal shape. Also, the positive electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may have a regular polygonal shape (for example, a square shape, an equilateral triangular shape, a regular hexagonal shape, and the like) of which one internal angle has an aliquot part of <NUM> degrees. <FIG> illustrates a case in which the positive electrode <NUM> has a regular hexagonal shape.

Referring to <FIG>, a positive electrode tab 10a having a shape that protrudes from the positive electrode <NUM> may be provided. The positive electrode tab 10a may have a shape protruding from the line segment. Here, the positive electrode tab 10a may be provided in plurality. Here, at least some of the positive electrode tabs 10a may be disposed in directions opposite to each other. <FIG> illustrates a case in which two positive electrode tabs 10a are disposed on the positive electrode <NUM> having the regular hexagonal shape in the directions opposite to each other. However, three or more positive electrode tabs 10a may be disposed on the positive electrode <NUM>.

The above description with respect to the positive electrode of the lithium ion secondary battery according to an embodiment of the present invention may be equally applied to a case of a negative electrode.

That is, referring to <FIG>, a circumferential portion of a negative electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may include at least one line segment. <FIG> illustrates a case in which the circumferential portion of the negative electrode <NUM> includes six line segments. Also, the negative electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may have a polygonal shape. <FIG> illustrates a case in which the negative electrode <NUM> has a hexagonal shape. Also, the negative electrode <NUM> of the lithium ion secondary battery according to an embodiment of the present invention may have a regular polygonal shape (for example, a square shape, an equilateral triangular shape, a regular hexagonal shape, and the like) of which one internal angle has an aliquot part of <NUM> degrees. <FIG> illustrates a case in which the negative electrode <NUM> has a regular hexagonal shape.

Referring to <FIG>, a negative electrode tab 20a having a shape that protrudes from the negative electrode <NUM> may be provided. The negative electrode tab 20a may have a shape protruding from the line segment. Here, the negative electrode tab 20a may be provided in plurality. Here, at least some of the negative electrode tabs 20a may be disposed in directions opposite to each other. <FIG> illustrates a case in which two negative electrode tabs 20a are disposed on the negative electrode <NUM> having the regular hexagonal shape in the directions opposite to each other. However, three or more negative electrode tabs 20a may be disposed on the negative electrode <NUM>.

<FIG> is a side view illustrating a laminated structure of an electrode laminate of the lithium ion secondary battery according to an embodiment of the present invention, and <FIG> is a perspective view illustrating a structure of the electrode laminate of the lithium ion secondary battery according to an embodiment of the present invention.

Referring to <FIG> and <FIG>, an electrode laminate <NUM> may have a structure in which a positive electrode <NUM>, a separator <NUM>, and a negative electrode <NUM> are alternately laminated. Here, the positive electrode <NUM>, the negative electrode <NUM>, and the separator <NUM> may have shapes corresponding to each other. The fact that the positive electrode <NUM>, the negative electrode <NUM>, and the separator <NUM> have the shapes corresponding to each other may mean that the positive electrode <NUM>, the negative electrode <NUM>, and the separator <NUM> are the same or similar to each other. Thus, the fact that the positive electrode <NUM>, the negative electrode <NUM>, and the separator <NUM> have the shapes corresponding to each other may not mean that the positive electrode <NUM>, the negative electrode <NUM>, and the separator <NUM> have the same shape and the same size.

As described above, the positive electrode tab 10a and the negative electrode tab 20a may protrude from the positive electrode <NUM> and the negative electrode <NUM>, respectively. Here, as illustrated in <FIG> and <FIG>, the electrode laminate <NUM> may have a structure in which the positive electrode <NUM> and the negative electrode <NUM> are laminated so that the positive electrode tabs 10a face each other, and the negative electrode tabs 20a face each other. Also, as described above, the positive electrode tab 10a and the negative electrode tab 20a may have shapes protruding from at least one or more line segments constituting the circumferential portions of the positive electrode <NUM> and the negative electrode <NUM>, respectively. Also, since the separator <NUM> has a shape in which the positive electrode <NUM> and the negative electrode <NUM> correspond to each other, the positive electrode <NUM>, the separator <NUM>, and the negative electrode <NUM> may be laminated so that at least one or more line segments face each other. Thus, the electrode laminate of the lithium ion secondary battery according to an embodiment of the present invention may have a pillar shape having the same horizontal cross-section (including a macroscopically pillar shape in which a difference in size between the electrode and the separator is not large). For example, the electrode laminate may have a polygonal pillar shape. <FIG> illustrates a case in which the electrode laminate <NUM> has a regular hexagonal pillar shape.

Since the electrode laminate <NUM> has the structure in which the positive electrode <NUM> and the negative electrode <NUM> are laminated so that the positive electrode tabs 10a face each other and the negative electrode tabs 20a face each other, the electrode laminate <NUM> may include a positive electrode tab bundle 10b in which a plurality of positive electrode tabs 10a are assembled with each other and a negative electrode tab bundle 20b in which a plurality of negative electrode tabs 20a are assembled with each other.

Similar to the cases of the positive electrode tabs and the negative electrode tabs, each of the positive electrode bundle 10b and the negative electrode tab bundle 20b of the electrode laminate <NUM> may also be provided in plurality. At least some of the positive electrode tab bundle 10b may be disposed in directions opposite to each other, and at least some of the negative electrode tab bundle 20b may also be disposed in directions opposite to each other. Three or more positive electrode tab bundle 10b and three or more negative electrode tab bundle 20b may also be provided.

Also, as illustrated in <FIG> and <FIG>, the electrode laminate <NUM> may include a side plane P formed by alternately laminating the positive electrode <NUM>, the separator <NUM>, and the negative electrode <NUM>. <FIG> illustrates a case in which six side planes P are disposed on the electrode laminate <NUM> having the regular hexagonal pillar shape. Here, one or more positive electrode tab bundle 10b and one or more negative electrode tab bundle 20b may be disposed on at least one side plane P. <FIG> illustrates a case in which the positive electrode tab bundle 10b and the negative electrode tab bundle 20b are disposed on each of two side planes, which are disposed in directions opposite to each other, of the side planes of the electrode laminate <NUM>.

The lithium ion secondary battery according to an embodiment of the present invention may be manufactured by connecting the plurality of electrode laminates to each other. According to an embodiment of the present invention, the lithium ion secondary battery may be variously modified by changing the manner, in which the electrode laminates are electrically connected to each other, according to user's demands.

The electrode assembly may be classified into a series connection type and a parallel connection type according to whether the electrodes having the same polarity are connected to each other, or the electrodes having different polarities are connected to each other. That is, the connection of the electrodes having the same polarity to each other between the electrode assemblies is referred to as parallel connection, and the connection of the electrodes having different polarities to each other between the electrode assemblies is referred to as serial connection. According to the present invention, the plurality of electrode assembles are connected to each other in the series connection manner.

In regard of the meaning of the expression to be used below, 'electrically connected between two constituents' may mean a state in which current is capable of flowing between the two constituents. Thus, 'electrically connected' may not mean only that the two constituents come into physical contact with each other.

<FIG> is a plan view illustrating a parallel connection structure between the electrode laminates of the lithium ion secondary battery that is described for reference purposes.

As illustrated in <FIG>, electrode laminates 1a, 1b, and 1c of the lithium ion secondary battery may be electrically connected to each other on the side portion of each of the electrode laminates. For this, the electrode laminates 1a, 1b, and 1c may be disposed so that the side planes P on which the positive electrode tab bundle 10b and the negative electrode tab bundle 20b are disposed are provided to face each other.

As illustrated in <FIG>, the electrode laminates 1a, 1b, and 1c of the lithium ion secondary battery are electrically connected in parallel to each other. For this, the positive electrode tab bundle 10b of the electrode laminate may be electrically connected to the positive electrode tab bundle 10b of the other electrode laminate, and the negative electrode tab bundle 20b of the electrode laminate are electrically connected to the negative electrode tab bundle 20b of the other electrode laminate to form a parallel connection body <NUM>.

This parallel connection may occur not only between two electrode laminates, but also between three or more electrode laminates. For example, in the three electrode laminates illustrated in <FIG>, when the leftmost electrode laminate is referred to as a first electrode laminate 1a, the intermediate electrode laminate is referred to as a second electrode laminate 1b, and the rightmost electrode laminate is referred to as a third electrode laminate 1c, the positive electrode tab bundle 10b and the negative electrode tab bundle 20b, which are disposed at the left side of the second electrode laminate 1b, are electrically connected to the positive electrode tab bundle 10b and the negative electrode tab bundle 20b, which are disposed at the right side of the first electrode laminate 1a, respectively. Thus, the positive electrode tab bundle 10b and the negative electrode tab bundle 20b, which are disposed at the right side of the second electrode laminate 1b, are electrically connected to the positive electrode tab bundle 10b and the negative electrode tab bundle 20b, which are disposed at the left side of the third electrode laminate 1c, respectively.

<FIG> is a plan view illustrating a series connection structure between the electrode laminates of the lithium ion secondary battery according to the present invention.

Similar to the case of <FIG>, electrode laminates 1a, 1b, and 1c of the lithium ion secondary battery according to an embodiment of the present invention may also be electrically connected to each other on the side portion of each of the electrode laminates. For this, the electrode laminates 1a, 1b, and 1c may be disposed so that the side planes P on which the positive electrode tab bundle 10b and the negative electrode tab bundle 20b are disposed are provided to face each other.

As illustrated in <FIG>, the electrode laminates 1a, 1b, and 1c of the lithium ion secondary battery according to the present invention are electrically connected in series to each other. For this, the positive electrode tab bundle 10b of the electrode laminate is electrically connected to the negative electrode tab bundle 20b of the other electrode laminate to form a series connection body <NUM>.

Also, similar to the parallel connection, the series connection may occur not only between two electrode laminates, but also between three or more electrode laminates. For example, in the three electrode laminates illustrated in <FIG>, when the leftmost electrode laminate is referred to as a first electrode laminate 1a, the intermediate electrode laminate is referred to as a second electrode laminate 1b, and the rightmost electrode laminate is referred to as a third electrode laminate 1c, the negative electrode tab bundle 20b disposed at the left side of the second electrode laminate 1b may be electrically connected to the positive electrode tab bundle 10b disposed at the right side of the first electrode laminate 1a, and the positive electrode tab bundle 10b disposed at the right side of the second electrode laminate 1b may be electrically connected to the negative electrode tab bundle 20b disposed at the left side of the third electrode laminate 1c.

However, unlike the parallel connection, the series connection may result in short circuit when both the positive electrode tab bundle and the negative electrode tab bundle are electrically connected between the electrode laminates. That is, referring to <FIG>, when the positive electrode tab bundle 10b and the negative electrode tab bundle 20b, which are disposed at the right side of the first electrode laminate 1a, are electrically connected to the negative electrode tab bundle 20b and the positive electrode tab bundle 20b, which are disposed at the left side of the second electrode laminate 1b, respectively, the short circuit may occur. Thus, in the case of the series connection, only one electrode tab bundle may be electrically connected to each other between the electrode laminates. <FIG> illustrates a case in which the positive electrode tab bundle 10b disposed at the right side of the first electrode laminate 1a is electrically connected to the negative electrode tab bundle 20b disposed at the left side of the second electrode laminate 1b, and the negative electrode tab bundle 20b disposed at the right side of the first electrode laminate 1a is not electrically connected to the positive electrode tab bundle 10b disposed at the left side of the second electrode laminate 1b. Here, an insulator <NUM> for preventing the electrical connection from occurring is disposed between the negative electrode tab bundle 20b disposed at the right side of the first electrode laminate 1a and the positive electrode tab bundle 10b disposed at the left side of the second electrode laminate 2b. Also, <FIG> illustrates a case in which the positive electrode tab bundle 10b disposed at the right side of the second electrode laminate 2b is electrically connected to the negative electrode tab bundle 20b disposed at the left side of the third electrode laminate 1c, and the negative electrode tab bundle 20b disposed at the right side of the second electrode laminate 2b is not electrically connected to the positive electrode tab bundle 10b disposed at the left side of the third electrode laminate 1c. Here, an insulator <NUM> for preventing the electrical connection from occurring is disposed between the negative electrode tab bundle 20b disposed at the right side of the second electrode laminate 1b and the positive electrode tab bundle 10b disposed at the left side of the third electrode laminate 1c.

<FIG> is a plan view illustrating a connection structure between electrode laminates of a lithium ion secondary battery.

A large number of electrode laminates including the first electrode laminate 1a, the second electrode laminate 1b, and the third electrode laminate 1c may be disposed adjacent to each other to form the honeycomb structure.

According to the present invention, as described above, when the side planes of the electrode laminates, each of which has a polygonal pillar structure, are disposed to face and overlap each other, a dead space that does not contribute to generation of an output may be minimized in the secondary battery to maximize utilization of a space of the secondary battery.

Claim 1:
A lithium ion secondary battery comprising:
first and second electrode laminates (1a, 1b), each of which has a structure (<NUM>) in which a positive electrode (<NUM>), a separator (<NUM>), and a negative electrode (<NUM>), each of which comprises at least one line segment on a circumferential portion thereof, are alternately laminated; and
a positive electrode tab (10a) and a negative electrode tab (20a), which have shapes protruding from the line segments of the positive electrode (<NUM>) and the negative electrode (<NUM>), respectively,
wherein the positive electrode (<NUM>), the separator (<NUM>), and the negative electrode (<NUM>) are laminated so that the line segments face each other,
the positive electrode tabs (10a) are laminated to face each other and thereby to provide a positive electrode tab bundle (10b),
the negative electrode tabs (20a) are laminated to face each other and thereby to provide a negative electrode tab bundle (20b),
the second electrode laminate (1b) is connected to a side portion of the first electrode laminate (1a), and
the first electrode laminate (1a) is connected in series (<NUM>) to the second electrode laminate (1b),
characterized in that the positive electrode tab bundle (10b) of the first electrode laminate (1a) is electrically connected to the negative electrode tab bundle (20b) of the second electrode laminate (1b), and
an insulator (<NUM>) is disposed between the negative electrode tab bundle (20b) of the first electrode laminate (1a) and the positive electrode tab bundle (10b) of the second electrode laminate (1b) to prevent electrical connection.