JP2001068076A - Set battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a set battery capable of preventing ruptures or firings, without causing thermal runaway when it is over-charged. SOLUTION: A set battery consists of a series connection of three (Y) assemblies 2A, 2B, 2C, each consisting of a parallel connection of two (X) lithium ion secondary batteries (1A1 and 1A2), two others (1B1 and 1B2) and two others (1C1 and 1C2), respectively. At least one of the assemblies is formed as a combination of the lithium ion secondary battery 1A1 furnished internally with a positive thermal coefficient element 4A1, having a resistance A of 25 mΩ and the lithium ion secondary battery 1A2 furnished internally with a positive thermal coefficient element 4A2 having a resistance B of 50 mΩ. The conditions A≠B, 1<=L<=X-1, 1<=M<=X-1, and L+M<=X are to be made, where X and Y are the numbers of lithium ion secondary batteries and assemblies, respectively, L is the number of these lithium ion secondary batteries in the assembly 2A having different resistance values in its positive thermal coefficient elements which are furnished internally with a positive thermal coefficient element of A mΩ, and M is the number of the lithium ion secondary batteries furnished internally with a positive thermal coefficient element of BmΩ.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack using a lithium ion secondary battery.

[0002]

2. Description of the Related Art In a lithium ion secondary battery, when overcharged, metallic lithium is deposited on the negative electrode in a dendritic manner, causing a short circuit, and a sufficient capacity cannot be obtained for the subsequent discharge. Or, in the worst case due to further overcharging, there is a problem that the internal pressure of the battery rises due to the decomposition reaction of the positive electrode, causing rupture and ignition. In addition, at the time of overdischarge, the current collector copper of the negative electrode elutes into the electrolytic solution, and is deposited on the negative electrode by subsequent charging, so that there is a problem that the capacity cannot be obtained. Therefore, in a battery pack using a lithium ion secondary battery, a protection circuit is provided to prevent overdischarge and overcharge.
However, at the time of failure of the protection circuit and charging circuit,
There is a problem that the above problem occurs.

[0003] To solve this, in the top lid of the battery,
It has been proposed to provide a pressure switch that physically shuts off the current supply to the battery when the internal pressure of the battery increases, to cut off the charging current when overcharging, prevent rupture and ignition, and ensure safety. .

[0004]

However, safety can be ensured by the pressure switch only in the case of a single cell, and in the case of an assembled battery, the heat due to overcharging of other batteries causes the battery to fail. There was a problem of causing a thermal runaway, bursting and firing.

An object of the present invention is to provide an assembled battery that does not cause thermal runaway during overcharge and can prevent bursting and ignition.

[0006]

According to the present invention, X pieces (X ≧
The present invention is to improve an assembled battery in which Y (Y ≧ 1) serially connected lithium ion secondary batteries of 2) are connected in series.

In one assembled battery according to the present invention, at least one of the assemblies has a lithium ion secondary battery incorporating a positive temperature coefficient element having a resistance value of AmΩ and a positive electrode having a resistance value of BmΩ. A combination comprising a lithium ion secondary battery having a built-in temperature coefficient element, wherein the resistance value of this positive temperature coefficient element is different from that of the lithium ion secondary battery having a built-in AmΩ positive temperature coefficient element. Let L be the number, and let M be the number of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ.
B, 1≤L≤X-1, 1≤M≤X-1, and L + M≤X
Is characterized by having the following relationship.

In another battery pack according to the present invention,
A lithium ion secondary battery incorporating a positive temperature coefficient element at which at least one of the assemblies becomes a ° C. when charging the assembled battery, and a lithium ion secondary battery incorporating a positive temperature coefficient element becoming b ° C. L, b are the numbers of lithium ion secondary batteries at a ° C. in one of the above-mentioned assemblies, each of which has a different resistance value of the positive temperature coefficient element.
A, the number of lithium ion secondary batteries that will be at
≠ b, 1≤L≤X-1, 1≤M≤X-1, and L + M≤
X.

In the present invention, the resistance of each of the lithium ion secondary batteries constituting an assembly in which X (X ≧ 2) lithium ion secondary batteries are connected in parallel is made different.
In a battery connected in parallel at the time of charging, current is concentrated on a battery having low resistance and charging is performed. Also, when the battery with a low resistance is overcharged first and the temperature of the battery starts to rise, the trip temperature of the positive temperature coefficient element with a low resistance connected to the battery with a low resistance (the resistance value suddenly rises) Rapidly increases), the resistance value of the positive temperature coefficient element having a low resistance sharply increases, and the difference in resistance increases when the battery temperature rises in the batteries connected in parallel. For this reason, the current is concentrated on the battery with the first high resistance and charging is performed, and this battery is overcharged and the positive temperature coefficient element connected to this battery with the first high resistance is connected. Trip temperature rises rapidly. The timing of the rapid temperature rise of the batteries is shifted between the batteries connected in parallel in this manner, so that the batteries can be prevented from bursting or firing without causing thermal runaway.

On the other hand, when the temperature of the positive temperature coefficient element is changed at the time of charging the battery pack, the resistance is expressed as a function of the temperature, so that the resistance value is different. The battery can be prevented from rupture and fire.

Incidentally, in normal charging, since constant voltage charging is performed, the amount of charge is the same between batteries at the end of charging, and the above-mentioned characteristics do not affect the charging characteristics.

[0012]

Embodiments of the present invention will be described below with reference to examples.

FIG. 1 shows an embodiment 1-1 of an assembled battery according to the present invention.
FIG. 3 is a circuit diagram showing a configuration of a second embodiment and Example 2-1.

The assembled batteries of Examples 1-1 and 2-1 have X = 2, that is, two lithium ion secondary batteries (1).
A1, 1A2), (1B1, 1B2), (1C1,
1C2) are connected in parallel with each other.
B and 2C are connected in series with Y = 3, that is, 3
They are configured in series.

In the assembled battery of the embodiment 1-1, the lithium ion secondary battery 1A1 has a positive temperature coefficient element 4A1 having a resistance value of 25 mΩ in the lithium ion secondary battery main body 3A1.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance of 50 mΩ connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is configured by connecting a positive temperature coefficient element 4B1 having a resistance value of 25 mΩ in series to a lithium ion secondary battery main body 3B1, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B1.
2, a positive temperature coefficient element 4B2 having a resistance value of 50 m.OMEGA. Is connected in series, and these are connected in parallel to form an assembly 2B. Lithium ion secondary battery 1C1
Is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 50 mΩ to the lithium ion secondary battery body 3C1 in series. The lithium ion secondary battery 1C2 has a resistance value of 50 mΩ to the lithium ion secondary battery body 3C2. A positive temperature coefficient element 4C2 is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

In this example, two of the aggregates 2A and 2B are:
A positive temperature coefficient element 4A1 having a resistance value of AmΩ = 25 mΩ
, 4B1 built-in lithium ion secondary battery 1A1,
1B1 and a combination including lithium ion secondary batteries 1A2 and 1B2 incorporating positive temperature coefficient elements 4A2 and 4B2 having a resistance value of BmΩ = 50 mΩ.

The resistance value of the positive temperature coefficient element is different
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2A is L =
1. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1.
That is, 1 = 1 = 1, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 = 2-1, that is, 1 = 1 = 1, and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

In the assembled battery of the embodiment 2-1, the lithium ion secondary battery 1A1 includes a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charge. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is composed of A2 and a positive temperature coefficient element 4A2 whose temperature becomes 120 ° C. at the time of 1 CmA charge, and these elements are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B
1, a positive temperature coefficient element 4B1 whose temperature becomes 100 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
In addition, a positive temperature coefficient element 4B2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 which has a temperature of 120 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 is composed of a lithium ion secondary battery body 3C2.
Further, a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

In this example, two of the aggregates 2A and 2B are:
Lithium ion secondary batteries 1A1 and 1B1 incorporating positive temperature coefficient elements 4A1 and 4B1 whose temperature becomes a.degree. C. = 100.degree. C. at 1 CmA charge, and b.degree. C. = 12 at 1 CmA charge
It is composed of a combination including lithium ion secondary batteries 1A2 and 1B2 having positive temperature coefficient elements 4A2 and 4B2 at 0 ° C.

The positive temperature coefficient element has a different resistance value.
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 1, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1, that is, 1 = 1 = 1, 1 ≦ M ≦ X-1 is 1 = 1 = 2-1, that is, 1 =
1 = 1 and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

FIG. 2 shows an embodiment 1-2 of the battery pack according to the present invention.
FIG. 4 is a circuit diagram illustrating a configuration of a second embodiment.

The assembled batteries of Embodiments 1-2 and 2-2 have X = 2, that is, two lithium ion secondary batteries 1A1,
An assembly 2A in which 1A2 is connected in parallel is provided as Y = 1, that is, one assembly 2A is configured in two parallel.

In the assembled battery of Embodiment 1-2, the lithium ion secondary battery 1A1 is provided with a positive temperature coefficient element 4A1 having a resistance of 25 mΩ in the main body 3A1 of the lithium ion secondary battery.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery body 3A2 and a positive temperature coefficient element 4A2 having a resistance value of 50 mΩ connected in series, and these are connected in parallel to form an assembly 2A.

In this example, the aggregate 2A has an AmΩ = 25 m
From a combination including a lithium ion secondary battery 1A1 containing a positive temperature coefficient element 4A1 having a resistance value of Ω and a lithium ion secondary battery 1A2 containing a positive temperature coefficient element 4A2 having a resistance value of BmΩ = 50 mΩ. Has become.

This positive temperature coefficient element has a different resistance value.
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2A is L =
1. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1.
That is, 1 = 1 = 1, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 = 2-1, that is, 1 = 1 = 1, and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

In the assembled battery of Embodiment 2-2, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 having a temperature of 100 ° C. at 1 CmA charging connected in series. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected in series with a positive temperature coefficient element 4A2 which becomes 120 ° C. at the time of 1 CmA charging.

In this example, the assembly 2A has a positive temperature coefficient element 4A1 at which the temperature is a.degree. C. = 100.degree. C. when charged at 1 CmA.
Lithium-ion rechargeable battery 1A1 and 1CmA
Positive temperature coefficient element 4 whose temperature becomes b ° C = 120 ° C during charging
It is a combination including a lithium ion secondary battery 1A2 containing A2.

This positive temperature coefficient element has a different resistance 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 1, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1, that is, 1 = 1 = 1, 1 ≦ M ≦ X-1 is 1 = 1 = 2-1, that is, 1 =
1 = 1 and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

FIG. 3 shows an embodiment 1-3 of the battery pack according to the present invention.
FIG. 4 is a circuit diagram illustrating a configuration of a second embodiment and a second embodiment.

In the assembled batteries of Examples 1-3 and 2-3, X = 2, that is, two lithium ion secondary batteries (1
A1, 1A2), (1B1, 1B2), (1C1,
1C2) are connected in parallel with each other.
B and 2C are connected in series, that is, Y = 3, that is, three, and are configured in two parallel and three series.

In the assembled battery of the embodiment 1-3, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery main body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 25 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance of 50 mΩ connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is configured by connecting a positive temperature coefficient element 4B1 having a resistance value of 25 mΩ in series to a lithium ion secondary battery main body 3B1, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B1.
2, a positive temperature coefficient element 4B2 having a resistance value of 25 mΩ is connected in series, and these are connected in parallel to form an assembly 2B. Lithium ion secondary battery 1C1
Is composed of a positive temperature coefficient element 4C1 having a resistance value of 25 mΩ connected in series to the lithium ion secondary battery main body 3C1, and a lithium ion secondary battery 1C2 having a resistance value of 25 mΩ to the lithium ion secondary battery main body 3C2. A positive temperature coefficient element 4C2 is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

In this example, the aggregate 2A has an AmΩ = 25 m
From a combination including a lithium ion secondary battery 1A1 containing a positive temperature coefficient element 4A1 having a resistance value of Ω and a lithium ion secondary battery 1A2 containing a positive temperature coefficient element 4A2 having a resistance value of BmΩ = 50 mΩ. Has become.

This positive temperature coefficient element has a different resistance value 1
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2A is L =
1. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1.
That is, 1 = 1 = 1, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 = 2-1, that is, 1 = 1 = 1, and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

In the assembled battery of Embodiment 2-3, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 connected in series with a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charging. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is composed of A2 and a positive temperature coefficient element 4A2 whose temperature becomes 120 ° C. at the time of 1 CmA charge, and these elements are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B
1, a positive temperature coefficient element 4B1 whose temperature becomes 100 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
In addition, a positive temperature coefficient element 4B2 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 having a temperature of 100 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 comprises a lithium ion secondary battery main body 3C2.
In addition, a positive temperature coefficient element 4C2 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2C.

In this example, the assembly 2A has a positive temperature coefficient element 4A1 whose temperature becomes a.degree. C. = 100.degree. C. when charged at 1 CmA.
Lithium-ion rechargeable battery 1A1 and 1CmA
Positive temperature coefficient element 4 whose temperature becomes b ° C = 120 ° C during charging
It is a combination including a lithium ion secondary battery 1A2 containing A2.

The resistance value of this positive temperature coefficient element is different 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 1, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1, that is, 1 = 1 = 1, 1 ≦ M ≦ X-1 is 1 = 1 = 2-1, that is, 1 =
1 = 1 and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

FIG. 4 shows an embodiment 1-4 of the battery pack according to the present invention.
FIG. 4 is a circuit diagram illustrating a configuration of a second embodiment and a second embodiment.

In the assembled batteries of Examples 1-4 and 2-4, X = 2, that is, two lithium ion secondary batteries (1
A1, 1A2), (1B1, 1B2), (1C1,
1C2) are connected in parallel, and Y = 3, that is, three assemblies 2A, 2B, and 2C are connected in series, and are configured in two parallel and three series.

In the assembled battery of Embodiments 1-4, the lithium ion secondary battery 1A1 is provided with a positive temperature coefficient element 4A1 having a resistance of 25 mΩ in the lithium ion secondary battery body 3A1.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance of 50 mΩ connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 comprises a lithium ion secondary battery main body 3B1 and a positive temperature coefficient element 4B1 having a resistance value of 50 mΩ connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B1.
2, a positive temperature coefficient element 4B2 having a resistance value of 50 m.OMEGA. Is connected in series, and these are connected in parallel to form an assembly 2B. Lithium ion secondary battery 1C1
Is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 50 mΩ to the lithium ion secondary battery body 3C1 in series. The lithium ion secondary battery 1C2 has a resistance value of 50 mΩ to the lithium ion secondary battery body 3C2. A positive temperature coefficient element 4C2 is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

In this example, the aggregate 2A has an AmΩ = 25 m
A lithium ion secondary battery 1A1 containing a positive temperature coefficient element 4A1 having a resistance value of Ω, a lithium ion secondary battery 1A2 containing a positive temperature coefficient element 4A2 having a resistance value of BmΩ = 50 mΩ, and CmΩ = It is a combination including a lithium ion secondary battery 1A3 having a built-in positive temperature coefficient element 4A3 having a resistance value of 50 mΩ.

This positive temperature coefficient element has a different resistance value 1
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2A is L =
1. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1.
That is, 1 = 1 = 1, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 = 2-1, that is, 1 = 1 = 1, and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

In the assembled battery of the embodiment 2-4, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charging is connected in series. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is composed of A2 and a positive temperature coefficient element 4A2 whose temperature becomes 120 ° C. at the time of 1 CmA charge, and these elements are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B
1, a positive temperature coefficient element 4B1 whose temperature becomes 120 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
In addition, a positive temperature coefficient element 4B2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 which has a temperature of 120 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 is composed of a lithium ion secondary battery body 3C2.
Further, a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at the time of 1 CmA charging is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2A, 2B,
2C is connected in series.

In this example, the assembly 2A has a positive temperature coefficient element 4A1 whose temperature becomes a.degree. C. = 100.degree. C. when charged at 1 CmA.
Lithium-ion rechargeable battery 1A1 and 1CmA
Positive temperature coefficient element 4 whose temperature becomes b ° C = 120 ° C during charging
It is a combination including a lithium ion secondary battery 1A2 containing A2.

The positive temperature coefficient element has a different resistance 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 1, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 = 2-1, that is, 1 = 1 = 1, 1 ≦ M ≦ X-1 is 1 = 1 = 2-1, that is, 1 =
1 = 1 and L + M ≦ X has a relationship of 1 + 1 = 2, that is, 2 = 2.

FIG. 5 shows an embodiment 1-5 of the battery pack according to the present invention.
FIG. 9 is a circuit diagram illustrating a configuration of a second embodiment and a second embodiment.

The assembled batteries of Examples 1-5 and 2-5 have X = 3, that is, three lithium ion secondary batteries (1).
A1, 1A2, 1A3) and (1B1, 1B2, 1B3).
), (1C1, 1C2, 1C3), (1D1, 1
D2, 1D3) and 2A, 2B,
2C and 2D are Y = 4, that is, four are connected in series, and three parallel
They are configured in series.

In the assembled battery of the embodiment 1-5, the lithium ion secondary battery 1A1 has a positive temperature coefficient element 4A1 having a resistance value of 25 mΩ in the lithium ion secondary battery body 3A1.
Are connected in series, and the lithium ion secondary battery 1
A2 has a positive temperature coefficient element 4A2 having a resistance value of 50 mΩ connected in series to the lithium ion secondary battery body 3A2, and a lithium ion secondary battery 1A3 has a positive temperature coefficient element having a resistance value of 50 mΩ connected to the lithium ion secondary battery body 3A3. Temperature coefficient element 4
A3 is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is connected to the lithium ion secondary battery body 3B1 by 50 mΩ.
And a positive temperature coefficient element 4B2 having a resistance of 50 mΩ is connected in series to the lithium ion secondary battery body 3B2. The lithium ion secondary battery 1B3 has a positive temperature coefficient element 4B3 having a resistance value of 50 mΩ added to the lithium ion secondary battery body 3B3.
Are connected in series, and these are connected in parallel to form an aggregate 2B. Lithium ion secondary battery 1
C1 is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 50 mΩ to the lithium ion secondary battery body 3C1 in series, and a lithium ion secondary battery 1C2 is provided with a 50 mΩ resistance value to the lithium ion secondary battery body 3C2. The positive temperature coefficient element 4C2 is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C.
3, a positive temperature coefficient element 4C3 having a resistance value of 50 mΩ is connected in series, and these are connected in parallel to form an assembly 2C. Lithium ion secondary battery 1D1
Is composed of a positive temperature coefficient element 4D1 having a resistance of 50 mΩ connected in series to the main body 3D1 of the lithium ion secondary battery, and a lithium ion secondary battery 1D2 having a resistance of 50 mΩ to the main body 3D2 of the lithium ion secondary battery. The positive temperature coefficient element 4D2 is connected in series, and the lithium ion secondary battery 1D3 is connected to the lithium ion secondary battery body 3D3.
A positive temperature coefficient element 4D3 having a resistance value of 50 mΩ is connected in series, and these are connected in parallel to form an assembly 2D
Is configured. These aggregates 2A, 2B, 2C, 2
D is connected in series.

In this example, the aggregate 2A has an AmΩ = 25 m
A lithium ion secondary battery 1A1 containing a positive temperature coefficient element 4A1 having a resistance value of Ω, a lithium ion secondary battery 1A2 containing a positive temperature coefficient element 4A2 having a resistance value of BmΩ = 50 mΩ, and BmΩ = It is a combination including a lithium ion secondary battery 1A3 having a built-in positive temperature coefficient element 4A3 having a resistance value of 50 mΩ.

The resistance value of the positive temperature coefficient element is different
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2A is L =
1. The number M of the lithium ion secondary batteries incorporating the positive temperature coefficient element of BmΩ = 50 mΩ is M = 2. Therefore, A ≠ B is 25 ≠ 50, and 1 ≦ L ≦ X−1 is 1 = 1 <3-1.
That is, 1 = 1 <2, 1 ≦ M ≦ X−1 has a relationship of 1 <2 = 3-1, ie, 1 <2 = 2, and L + M ≦ X has a relationship of 1 + 2 = 3, ie, 3 = 3.

In the assembled battery of the embodiment 2-5, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at the time of charging 1 CmA. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected in series with a positive temperature coefficient element 4A2 whose temperature becomes 120 ° C. at the time of 1 CmA charging. The lithium ion secondary battery 1A3 is composed of a lithium ion secondary battery body 3A
3, a positive temperature coefficient element 4A3 whose temperature becomes 120 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B1.
And a positive temperature coefficient element 4B1 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
And a positive temperature coefficient element 4B2, whose temperature becomes 120 ° C. at the time of 1 CmA charge, is connected in series. The lithium ion secondary battery 1B3 is composed of a lithium ion secondary battery body 3B3
In addition, a positive temperature coefficient element 4B3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 which has a temperature of 120 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 is composed of a lithium ion secondary battery body 3C2.
And a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C3.
In addition, a positive temperature coefficient element 4C3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is configured to be connected in series, and these are connected in parallel to form an assembly 2C. The lithium ion secondary battery 1D1 is a lithium ion secondary battery body 3D1.
A positive temperature coefficient element 4D1 whose temperature becomes 120 ° C. at the time of 1 CmA charging is connected in series, and the lithium ion secondary battery 1D2 is a lithium ion secondary battery main body 3D2.
And a positive temperature coefficient element 4D2, whose temperature becomes 120 ° C. at the time of 1 CmA charging, is connected in series. The lithium ion secondary battery 1D3 is a lithium ion secondary battery main body 3D3.
Further, a positive temperature coefficient element 4D3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2D. These aggregates 2
A, 2B, 2C, and 2D are connected in series.

In this example, the assembly 2A has a positive temperature coefficient element 4A1 whose temperature becomes a ° C. = 100 ° C. when charged at 1 CmA.
Lithium-ion rechargeable battery 1A1 and 1CmA
Positive temperature coefficient element 4 whose temperature becomes b ° C = 120 ° C during charging
Lithium-ion secondary battery 1A2 with built-in A2 and 1C
It is a combination including a lithium ion secondary battery 1A3 having a built-in positive temperature coefficient element 4A3 whose temperature becomes b.degree.

The resistance value of this positive temperature coefficient element is different 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. during the charge of 1,1 CmA is M = 2. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 = 1 <3-1, ie, 1 = 1 <2, and 1 ≦ M ≦ X−1 is 1 <2 = 3-1, 1 <
2 = 2 and L + M ≦ X have a relationship of 1 + 2 = 3, that is, 3 = 3.

FIG. 6 shows an embodiment 1-6 of the assembled battery according to the present invention.
FIG. 9 is a circuit diagram illustrating a configuration of a second embodiment and a second embodiment.

The assembled batteries of Examples 1-6 and 2-6 are lithium ion secondary batteries (1A1, 1A2, 1A3).
), (1B1, 1B2, 1B3), (1C1, 1
C2, 1C3) and (1D1, 1D2, 1D3) are connected in parallel to form a set 2A, 2B, 2C, 2D of Y = 4, that is, four sets are connected in series to form three parallels and four series.

In the assembled battery of the embodiment 1-6, the lithium ion secondary battery 1A1 has a positive temperature coefficient element 4A1 having a resistance value of 25 mΩ added to the lithium ion secondary battery body 3A1.
Are connected in series, and the lithium ion secondary battery 1
A2 has a positive temperature coefficient element 4A2 having a resistance value of 25 mΩ connected in series to the lithium ion secondary battery main body 3A2, and a lithium ion secondary battery 1A3 has a positive resistance having a resistance value of 25 mΩ connected to the lithium ion secondary battery main body 3A3. Temperature coefficient element 4
A3 is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is connected to the lithium ion secondary battery body 3B1 by 25 mΩ.
The positive temperature coefficient element 4B2 having a resistance value of 25 mΩ is connected in series to the lithium ion secondary battery body 3B2 in the lithium ion secondary battery 1B2. The lithium ion secondary battery 1B3 has a positive temperature coefficient element 4B3 having a resistance value of 50 mΩ added to the lithium ion secondary battery body 3B3.
Are connected in series, and these are connected in parallel to form an aggregate 2B. Lithium ion secondary battery 1
C1 is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 25 mΩ in series to the lithium ion secondary battery main body 3C1. Lithium ion secondary battery 1C2 is provided with a 50 mΩ resistance value to the lithium ion secondary battery main body 3C2. The positive temperature coefficient element 4C2 is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C.
3, a positive temperature coefficient element 4C3 having a resistance value of 50 mΩ is connected in series, and these are connected in parallel to form an assembly 2C. Lithium ion secondary battery 1D1
Is composed of a positive temperature coefficient element 4D1 having a resistance of 50 mΩ connected in series to the main body 3D1 of the lithium ion secondary battery, and a lithium ion secondary battery 1D2 having a resistance of 50 mΩ to the main body 3D2 of the lithium ion secondary battery. The positive temperature coefficient element 4D2 is connected in series, and the lithium ion secondary battery 1D3 is connected to the lithium ion secondary battery body 3D3.
A positive temperature coefficient element 4D3 having a resistance value of 50 mΩ is connected in series, and these are connected in parallel to form an assembly 2D
Is configured. These aggregates 2A, 2B, 2C, 2
D is connected in series.

In this example, the aggregates 2B and 2C
= Positive temperature coefficient elements 4B1, 4C having a resistance value of 25 mΩ
Lithium ion secondary battery 1B1 with built-in 1,4B2
1C1 and 1B2 and a combination including lithium ion secondary batteries 1C2, 1B3 and 1C3 containing positive temperature coefficient elements 4C2, 4B3 and 4C3 having a resistance value of BmΩ = 50 mΩ.

This positive temperature coefficient element has a different resistance value.
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one assembly 2B is L =
2. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, and 1 ≦ L ≦ X−1 is 1 <2 = 3-1.
That is, 1 <2 = 2, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 <3-1, ie, 1 = 1 <2, and L + M ≦ X has a relationship of 2 + 1 = 3, ie, 3 = 3.

In the assembled battery of Example 2-6, the lithium ion secondary battery 1A1 is composed of a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charge. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected to a positive temperature coefficient element 4A2 which becomes 100 ° C. at the time of 1 CmA charge. The lithium ion secondary battery 1A3 is composed of a lithium ion secondary battery main body 3A.
3, a positive temperature coefficient element 4A3 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B1.
And a positive temperature coefficient element 4B1 having a temperature of 100 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B2.
And a positive temperature coefficient element 4B2, whose temperature rises to 100 ° C. at the time of 1 CmA charge, is connected in series. The lithium ion secondary battery 1B3 comprises a lithium ion secondary battery body 3B3.
In addition, a positive temperature coefficient element 4B3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 having a temperature of 100 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 comprises a lithium ion secondary battery main body 3C2.
And a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C3.
Further, a positive temperature coefficient element 4C3 whose temperature becomes 120 ° C. at the time of 1 CmA charging is configured to be connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1D1 is a lithium ion secondary battery body 3D1.
A positive temperature coefficient element 4D1 whose temperature becomes 120 ° C. at the time of 1 CmA charging is connected in series, and the lithium ion secondary battery 1D2 is a lithium ion secondary battery main body 3D2.
And a positive temperature coefficient element 4D2, whose temperature becomes 120 ° C. at the time of 1 CmA charging, is connected in series. The lithium ion secondary battery 1D3 is a lithium ion secondary battery main body 3D3.
Further, a positive temperature coefficient element 4D3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2D. These aggregates 2
A, 2B, 2C, and 2D are connected in series.

In this example, the aggregates 2B and 2C are 1 Cm
During charging A, the temperature rises to a.degree. C. = 100.degree. C. The positive temperature coefficient elements 4B1, 4C.sub.1, and 4B.sub.2 have built-in positive temperature coefficient elements 4B1, 1C1, and 1B2. Temperature coefficient elements 4C2, 4B3
, 4C3 built-in lithium ion secondary battery 1C2,
1B3 and 1C3.

The positive temperature coefficient element has a different resistance value 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2A =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 2, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 <2 = 3-1, that is, 1 <2 = 2, 1 ≦ M ≦ X-1 is 1 = 1 = 2-1, that is, 1 =
1 = 1 and L + M ≦ X has a relationship of 2 + 1 = 3, that is, 3 = 3.

FIG. 7 shows an embodiment 1-7 of the assembled battery according to the present invention.
FIG. 9 is a circuit diagram illustrating a configuration of a second embodiment and a second embodiment.

The battery packs of Examples 1-7 and 2-7 have X = 3, that is, three lithium ion secondary batteries (1).
A1, 1A2, 1A3) and (1B1, 1B2, 1B3).
), (1C1, 1C2, 1C3), (1D1, 1
D2, 1D3) and 2A, 2B,
2C and 2D are Y = 4, that is, four are connected in series, and three parallel
They are configured in series.

In the assembled battery of Embodiment 1-7, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery main body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 25 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 has a positive temperature coefficient element 4A2 having a resistance value of 25 mΩ connected in series to the lithium ion secondary battery main body 3A2, and a lithium ion secondary battery 1A3 has a positive resistance having a resistance value of 25 mΩ connected to the lithium ion secondary battery main body 3A3. Temperature coefficient element 4
A3 is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is connected to the lithium ion secondary battery body 3B1 by 25 mΩ.
The positive temperature coefficient element 4B2 having a resistance value of 25 mΩ is connected in series to the lithium ion secondary battery body 3B2 in the lithium ion secondary battery 1B2. The lithium ion secondary battery 1B3 has a positive temperature coefficient element 4B3 having a resistance value of 25 m.OMEGA.
Are connected in series, and these are connected in parallel to form an aggregate 2B. Lithium ion secondary battery 1
C1 is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 25 mΩ to the lithium ion secondary battery body 3C1 in series, and the lithium ion secondary battery 1C2 is provided with a resistance value of 25 mΩ to the lithium ion secondary battery body 3C2. The positive temperature coefficient element 4C2 is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C.
3, a positive temperature coefficient element 4C3 having a resistance value of 25 mΩ is connected in series, and these are connected in parallel to form an assembly 2C. Lithium ion secondary battery 1D1
Is constituted by connecting a positive temperature coefficient element 4D1 having a resistance value of 25 mΩ to the lithium ion secondary battery main body 3D1 in series. The lithium ion secondary battery 1D2 has a resistance value of 25 mΩ to the lithium ion secondary battery main body 3D2. The positive temperature coefficient element 4D2 is connected in series, and the lithium ion secondary battery 1D3 is connected to the lithium ion secondary battery body 3D3.
A positive temperature coefficient element 4D3 having a resistance value of 50 mΩ is connected in series, and these are connected in parallel to form an assembly 2D
Is configured. These aggregates 2A, 2B, 2C, 2
D is connected in series.

In this example, the aggregate 2D is expressed as AmΩ = 25 m
Lithium ion secondary batteries 1D1 and 1D2 incorporating positive temperature coefficient elements 4D1 and 4D2 having a resistance of Ω, and Bm
It is a combination including a lithium ion secondary battery 1D3 having a built-in positive temperature coefficient element 4D3 having a resistance value of Ω = 50 mΩ.

This positive temperature coefficient element has a different resistance value 1
The number L of lithium ion secondary batteries having a built-in positive temperature coefficient element of AmΩ = 25 mΩ in one set 2D is L =
2. The number M of lithium ion secondary batteries incorporating a positive temperature coefficient element of BmΩ = 50 mΩ is M = 1. Therefore, A ≠ B is 25 ≠ 50, and 1 ≦ L ≦ X−1 is 1 <2 = 3-1.
That is, 1 <2 = 2, 1 ≦ M ≦ X−1 has a relationship of 1 = 1 <3-1, ie, 1 = 1 <2, and L + M ≦ X has a relationship of 2 + 1 = 3, ie, 3 = 3.

In the assembled battery of Example 2-7, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 connected in series with a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charge. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected to a positive temperature coefficient element 4A2 which becomes 100 ° C. at the time of 1 CmA charge. The lithium ion secondary battery 1A3 is composed of a lithium ion secondary battery main body 3A.
3, a positive temperature coefficient element 4A3 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B1.
And a positive temperature coefficient element 4B1 having a temperature of 100 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B2.
And a positive temperature coefficient element 4B2, whose temperature rises to 100 ° C. at the time of 1 CmA charge, is connected in series. The lithium ion secondary battery 1B3 comprises a lithium ion secondary battery body 3B3
In addition, a positive temperature coefficient element 4B3 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 having a temperature of 100 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 comprises a lithium ion secondary battery main body 3C2.
And a positive temperature coefficient element 4C2, whose temperature becomes 100 ° C. at the time of 1 CmA charging, is connected in series. The lithium ion secondary battery 1C3 is a lithium ion secondary battery body 3C3.
Further, a positive temperature coefficient element 4C3 whose temperature becomes 100 ° C. at the time of 1 CmA charging is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1D1 is a lithium ion secondary battery body 3D1.
And a positive temperature coefficient element 4D1 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and the lithium ion secondary battery 1D2 is a lithium ion secondary battery main body 3D2.
And a positive temperature coefficient element 4D2 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and the lithium ion secondary battery 1D3 is a lithium ion secondary battery body 3D3.
In addition, a positive temperature coefficient element 4D3 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B.

In this example, the assembly 2D has a positive temperature coefficient element 4D1 at a temperature of a.degree. C. = 100.degree. C. when charged at 1 CmA.
, 4D2 built-in lithium ion secondary battery 1D1,
1D2 and a combination including a lithium-ion secondary battery 1D3 having a built-in positive temperature coefficient element 4D3 at a temperature of b ° C. = 120 ° C. when charged at 1 CmA.

The resistance value of this positive temperature coefficient element is different 1
The temperature is a ° C. at the time of charging 1 CmA in the two assemblies 2D =
The number L of the lithium ion secondary batteries at 100 ° C. is L =
The number M of the lithium ion secondary batteries whose temperature becomes b ° C. = 120 ° C. at the time of 2, 1 CmA charging is M = 1. For this reason,
A ≠ B is 25 ≠ 50, 1 ≦ L ≦ X-1 is 1 <2 = 3-1, that is, 1 <2 = 2, 1 ≦ M ≦ X-1 is 1 = 1 <3-1, that is, 1 =
1 <2 and L + M ≦ X has a relationship of 2 + 1 = 3, that is, 3 = 3.

FIG. 8 is a circuit diagram showing the configuration of Comparative Example 1-1 and Comparative Example 2-1 of the battery pack of the comparative example.

The battery packs of Comparative Example 1-1 and Comparative Example 2-1 have X = 2, that is, two lithium ion secondary batteries (1).
A1, 1A2), (1B1, 1B2), (1C1,
1C2) are connected in parallel with each other.
B and 2C are connected in series with Y = 3, that is, 3
They are configured in series.

In the battery pack of Comparative Example 1-1, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 25 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance of 25 mΩ connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 comprises a lithium ion secondary battery main body 3B1 and a positive temperature coefficient element 4B1 having a resistance value of 50 mΩ connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B1.
2, a positive temperature coefficient element 4B2 having a resistance value of 50 m.OMEGA. Is connected in series, and these are connected in parallel to form an assembly 2B. Lithium ion secondary battery 1C1
Is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 50 mΩ to the lithium ion secondary battery body 3C1 in series. The lithium ion secondary battery 1C2 has a resistance value of 50 mΩ to the lithium ion secondary battery body 3C2. A positive temperature coefficient element 4C2 is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

In this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

In the battery pack of Comparative Example 2-1, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is composed of a positive temperature coefficient element 4A2 whose temperature becomes 100 DEG C. at the time of 1 CmA charging, and these elements are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B
1, a positive temperature coefficient element 4B1 whose temperature becomes 120 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
In addition, a positive temperature coefficient element 4B2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 which has a temperature of 120 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 is composed of a lithium ion secondary battery body 3C2.
Further, a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

FIG. 9 is a circuit diagram showing the configuration of Comparative Example 1-2 and Comparative Example 2-2 of the battery pack of the comparative example.

The assembled batteries of Comparative Example 1-2 and Comparative Example 2-2 have X = 2, that is, two lithium ion secondary batteries 1A 1,
An assembly 2A in which 1A2 is connected in parallel is provided as Y = 1, that is, one assembly 2A is configured in two parallel.

In the battery pack of Comparative Example 1-2, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery main body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 25 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance value of 25 mΩ connected in series, and these are connected in parallel to form an assembly 2A.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

In the battery pack of Comparative Example 2-2, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected in series with a positive temperature coefficient element 4A2 which becomes 100 ° C. at the time of 1 CmA charging.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

FIG. 10 is a circuit diagram showing the configuration of Comparative Example 1-3 and Comparative Example 2-3 of the battery pack of the comparative example.

The assembled batteries of Comparative Example 1-3 and Comparative Example 2-3 have X = 2, that is, two lithium ion secondary batteries (1).
A1, 1A2), (1B1, 1B2), (1C1,
1C2) are connected in parallel with each other.
B and 2C are connected in series, that is, Y = 3, that is, three, and are configured in two parallel and three series.

In the assembled battery of Comparative Example 1-3, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery main body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 50 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 is composed of a lithium ion secondary battery main body 3A2 and a positive temperature coefficient element 4A2 having a resistance of 50 mΩ connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 comprises a lithium ion secondary battery main body 3B1 and a positive temperature coefficient element 4B1 having a resistance value of 50 mΩ connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B1.
2, a positive temperature coefficient element 4B2 having a resistance value of 50 m.OMEGA. Is connected in series, and these are connected in parallel to form an assembly 2B. Lithium ion secondary battery 1C1
Is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 50 mΩ to the lithium ion secondary battery body 3C1 in series. The lithium ion secondary battery 1C2 has a resistance value of 50 mΩ to the lithium ion secondary battery body 3C2. A positive temperature coefficient element 4C2 is connected in series, and these are connected in parallel to form an assembly 2C. These aggregates 2
A, 2B and 2C are connected in series.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

In the battery pack of Comparative Example 2-3, the lithium ion secondary battery 1A1 has a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature becomes 120 ° C. at the time of charging 1 CmA. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is composed of A2 and a positive temperature coefficient element 4A2 whose temperature becomes 120 ° C. at the time of 1 CmA charge, and these elements are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B
1, a positive temperature coefficient element 4B1 whose temperature becomes 120 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1B2 is a lithium ion secondary battery main body 3B2.
In addition, a positive temperature coefficient element 4B2 whose temperature becomes 120 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 which has a temperature of 120 ° C. when charged at 1 CmA is connected in series, and the lithium ion secondary battery 1C2 is composed of a lithium ion secondary battery main body 3C2.
Further, a positive temperature coefficient element 4C2 whose temperature becomes 120 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2C.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

FIG. 11 is a circuit diagram showing the configuration of Comparative Examples 1-4 and 2-4 of the assembled battery of the comparative example.

The battery packs of Comparative Examples 1-4 and 2-4 have X = 3, that is, three lithium ion secondary batteries (1).
A1, 1A2, 1A3) and (1B1, 1B2, 1B3).
), (1C1, 1C2, 1C3), (1D1, 1
D2, 1D3) and 2A, 2B,
2C and 2D are Y = 4, that is, four are connected in series, and three parallel
They are configured in series.

In the battery pack of Comparative Examples 1-4, the lithium ion secondary battery 1A1 is connected to the lithium ion secondary battery main body 3A1 by a positive temperature coefficient element 4A1 having a resistance of 25 mΩ.
Are connected in series, and the lithium ion secondary battery 1
A2 has a positive temperature coefficient element 4A2 having a resistance value of 25 mΩ connected in series to the lithium ion secondary battery main body 3A2, and a lithium ion secondary battery 1A3 has a positive resistance having a resistance value of 25 mΩ connected to the lithium ion secondary battery main body 3A3. Temperature coefficient element 4
A3 is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is connected to the lithium ion secondary battery body 3B1 by 25 mΩ.
The positive temperature coefficient element 4B2 having a resistance value of 25 mΩ is connected in series to the lithium ion secondary battery body 3B2 in the lithium ion secondary battery 1B2. The lithium ion secondary battery 1B3 has a positive temperature coefficient element 4B3 having a resistance value of 25 m.OMEGA.
Are connected in series, and these are connected in parallel to form an aggregate 2B. Lithium ion secondary battery 1
C1 is constituted by connecting a positive temperature coefficient element 4C1 having a resistance value of 25 mΩ to the lithium ion secondary battery body 3C1 in series, and the lithium ion secondary battery 1C2 is provided with a resistance value of 25 mΩ to the lithium ion secondary battery body 3C2. The positive temperature coefficient element 4C2 is connected in series, and the lithium ion secondary battery 1C3 is a lithium ion secondary battery main body 3C.
3, a positive temperature coefficient element 4C3 having a resistance value of 25 mΩ is connected in series, and these are connected in parallel to form an assembly 2C. Lithium ion secondary battery 1D1
Is constituted by connecting a positive temperature coefficient element 4D1 having a resistance value of 25 mΩ to the lithium ion secondary battery main body 3D1 in series. The lithium ion secondary battery 1D2 has a resistance value of 25 mΩ to the lithium ion secondary battery main body 3D2. The positive temperature coefficient element 4D2 is connected in series, and the lithium ion secondary battery 1D3 is connected to the lithium ion secondary battery body 3D3.
A positive temperature coefficient element 4D3 having a resistance of 25 mΩ is connected in series, and these elements are connected in parallel to form an assembly 2D
Is configured. These aggregates 2A, 2B, 2C, 2
D is connected in series.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

In the assembled battery of Comparative Example 2-4, the lithium ion secondary battery 1A1 was connected in series with a lithium ion secondary battery main body 3A1 and a positive temperature coefficient element 4A1 whose temperature became 100 ° C. at 1 CmA charge. The lithium ion secondary battery 1A2 is composed of a lithium ion secondary battery body 3
A2 is connected to a positive temperature coefficient element 4A2 which becomes 100 ° C. at the time of 1 CmA charge. The lithium ion secondary battery 1A3 is composed of a lithium ion secondary battery main body 3A.
3, a positive temperature coefficient element 4A3 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2A. The lithium ion secondary battery 1B1 is a lithium ion secondary battery body 3B1.
And a positive temperature coefficient element 4B1 having a temperature of 100 ° C. at the time of 1 CmA charge is connected in series, and the lithium ion secondary battery 1B2 comprises a lithium ion secondary battery main body 3B2
And a positive temperature coefficient element 4B2, whose temperature rises to 100 ° C. at the time of 1 CmA charge, is connected in series. The lithium ion secondary battery 1B3 comprises a lithium ion secondary battery
In addition, a positive temperature coefficient element 4B3 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2B. The lithium ion secondary battery 1C1 is a lithium ion secondary battery body 3C1.
And a positive temperature coefficient element 4C1 having a temperature of 100 ° C. when charged at 1 CmA is connected in series. The lithium ion secondary battery 1C2 comprises a lithium ion secondary battery main body 3C2.
And a positive temperature coefficient element 4C2, whose temperature becomes 100 ° C. at the time of 1 CmA charging, is connected in series. The lithium ion secondary battery 1C3 is a lithium ion secondary battery body 3C3.
In addition, a positive temperature coefficient element 4C3 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2C. The lithium ion secondary battery 1D1 is a lithium ion secondary battery body 3D1.
And a positive temperature coefficient element 4D1 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and the lithium ion secondary battery 1D2 is a lithium ion secondary battery main body 3D2.
And a positive temperature coefficient element 4D2 whose temperature becomes 100 ° C. at 1 CmA charge is connected in series, and the lithium ion secondary battery 1D3 is a lithium ion secondary battery body 3D3.
In addition, a positive temperature coefficient element 4D3 whose temperature becomes 100 ° C. at the time of 1 CmA charge is connected in series, and these are connected in parallel to form an assembly 2D. These aggregates 2
A, 2B, 2C, and 2D are connected in series.

Also in this example, there is no assembly of lithium ion secondary batteries having positive temperature coefficient elements having different resistance values. Therefore, there is no relation of the inequality described above.

Tables 1 and 2 show the results of an overcharge test performed using the assembled batteries of the above Examples and Comparative Examples. That is, Table 1 shows that Examples 1-1 to 1-7 and Comparative Example 1
1 shows overcharge tests according to Comparative Examples 1-4. Table 2
The overcharge test by Example 2-1 to Example 2-7 and Comparative Example 2-1 to Comparative Example 2-4 is shown. The lithium ion secondary battery used this time has a nominal capacity of 1300 m, where the positive electrode active material is lithium cobalt oxide and the negative electrode active material is amorphous carbon.
For the Ah battery, the overcharge test method was performed at a current value of 2 CmA and an ambient temperature of 30 ° C.

[0094]

[Table 1]

[Table 2] From these Tables 1 and 2, the battery pack of the present embodiment was found to be burst,
No ignition occurred, indicating that the battery was superior to the battery pack of the comparative example. Further, as for the comparative example, as the number of batteries constituting the assembled battery increases, the number of bursts and ignition increases, so that the more the number of batteries constituting the assembled battery,
It was found that the number of firings was large.

In this case, the resistance of the positive temperature coefficient element and the temperature of the positive temperature coefficient element when the battery pack is charged are described in two types. However, up to five types of experiments were performed, and similar effects were obtained. . It goes without saying that similar effects can be obtained for more than that.

Similarly, in a battery pack using a lithium ion secondary battery in which the positive electrode and the negative electrode are made of another material, the battery pack is composed of a lithium ion secondary battery having a function of physically interrupting an electric current in the battery. Needless to say, the same effect can be obtained when a battery is used.

[0097]

In the battery pack according to the present invention, the resistance of each of the lithium ion secondary batteries constituting an assembly in which X (X ≧ 2) lithium ion secondary batteries are connected in parallel is made different. In the battery connected in parallel at the time of charging, current is concentrated on a battery having low resistance, and charging is performed. Also, when the battery with a low resistance becomes overcharged first and the temperature of the battery starts to rise, the trip temperature of the low-resistance positive temperature coefficient element connected to the battery with a low resistance sharply rises, The resistance value of the positive temperature coefficient element having a small resistance sharply increases, and the difference in resistance increases when the battery temperature rises in the batteries connected in parallel. For this reason, the current is concentrated on the battery with the first high resistance and charging is performed, and this battery is overcharged and the positive temperature coefficient element connected to this battery with the first high resistance is connected. Trip temperature rises rapidly. The timing of the rapid temperature rise of the batteries is shifted between the batteries connected in parallel in this manner, and the battery pack according to the present invention can prevent bursting and ignition without causing thermal runaway.

On the other hand, when the temperature of the positive temperature coefficient element is changed at the time of charging the battery pack, the resistance is expressed as a function of the temperature, so that the resistance value differs. The battery can be prevented from rupture and fire.

[Brief description of the drawings]

FIG. 1 shows an embodiment 1-1 and an embodiment 2 of a battery pack according to the present invention.
FIG. 2 is a circuit diagram illustrating a configuration of -1.

FIG. 2 shows Embodiments 1-2 and 2 of the battery pack according to the present invention.
FIG. 2 is a circuit diagram showing a configuration of -2.

FIG. 3 is an assembled battery according to Embodiments 1-3 and 2 of the present invention;
FIG. 4 is a circuit diagram illustrating a configuration of a -3.

FIG. 4 is an assembled battery according to Embodiments 1-4 and 2 of the present invention;
FIG. 4 is a circuit diagram illustrating a configuration of a -4.

FIG. 5 is an assembled battery according to embodiments 1-5 and 2 of the present invention;
It is a circuit diagram which shows the structure of -5.

FIG. 6 is an assembled battery according to Embodiments 1-6 and 2 of the present invention;
It is a circuit diagram which shows the structure of -6.

FIG. 7 is an assembled battery according to Embodiments 1-7 and 2 of the present invention.
It is a circuit diagram which shows the structure of -7.

FIG. 8 shows a comparative example 1-1 and a comparative example 2-1 of the assembled battery of the comparative example.
FIG. 3 is a circuit diagram showing the configuration of FIG.

FIG. 9 shows comparative examples 1-2 and 2-2 of the battery pack of the comparative example.
FIG. 3 is a circuit diagram showing the configuration of FIG.

FIG. 10 shows Comparative Examples 1-3 and Comparative Example 2- of the assembled batteries of Comparative Examples.
3 is a circuit diagram illustrating a configuration of FIG.

FIG. 11 shows Comparative Examples 1-4 and Comparative Example 2- of the battery packs of Comparative Examples.
4 is a circuit diagram showing a configuration of FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H020 AA01 AS06 CC41 DD13 KK08 5H022 AA09 AA19 CC08 KK01 5H029 AJ12 AK03 AL06 BJ06 BJ27 DJ01 DJ18 HJ20

Claims (2)

[Claims] 1. An assembled battery in which X (X ≧ 2) lithium-ion secondary batteries are connected in series and Y (Y ≧ 1) are connected in series, wherein at least one of the assemblies is AmΩ And a lithium ion secondary battery having a positive temperature coefficient element having a resistance value of BmΩ and a lithium ion secondary battery having a positive temperature coefficient element having a resistance value of BmΩ. The number of lithium ion secondary batteries incorporating the AmΩ positive temperature coefficient element in one of the assemblies having different resistance values is L, and the number of lithium ion secondary batteries incorporating the BmΩ positive temperature coefficient element. Where M is AＭB, 1 ≦ L ≦ X−1, 1 ≦ M ≦ X−1, and L + M ≦ X. 2. An assembled battery in which X (X ≧ 2) lithium ion secondary batteries are connected in parallel, and Y (Y ≧ 1) in an assembled battery, wherein the assembled battery is charged when the assembled battery is charged. A combination comprising a lithium ion secondary battery having a positive temperature coefficient element having at least one of which is a ° C. and a lithium ion secondary battery having a positive temperature coefficient element having a temperature of b ° C. Let L be the number of the lithium ion secondary batteries at which the a value is equal to a ° C. and M be the number of the lithium ion secondary batteries that are at b ° C.
A ≠ b, 1 ≦ L ≦ X−1, 1 ≦ M ≦ X−1, and L + M ≦ X.