阅读说明：本技术 二次电池和具有该二次电池的电池模块 (Secondary battery and battery module having the same ) 是由 李在璨 于 2019-12-10 设计创作，主要内容包括：公开了一种二次电池和包括该二次电池的电池模块。根据本发明的一个方面,一种二次电池,包括：电极组件；配置成容纳电极组件的片型外壳；和多个温度感测部,该多个温度感测部与外壳相邻设置,以感测外壳的一个区域的温度,其中温度感测部中的至少一个包括：正温度系数(PTC)元件；和负温度系数(NTC)元件。(Disclosed are a secondary battery and a battery module including the same. According to an aspect of the present invention, a secondary battery includes: an electrode assembly; a sheet type case configured to accommodate the electrode assembly; and a plurality of temperature sensing parts disposed adjacent to the case to sense a temperature of one region of the case, wherein at least one of the temperature sensing parts includes: a Positive Temperature Coefficient (PTC) element; and a Negative Temperature Coefficient (NTC) element.)

1. A secondary battery comprising:

an electrode assembly;

a sheet type case configured to accommodate the electrode assembly; and

a plurality of temperature sensing parts disposed adjacent to the case to sense a temperature of one region of the case,

wherein at least one of the temperature sensing parts includes:

a Positive Temperature Coefficient (PTC) element; and

a Negative Temperature Coefficient (NTC) element.

2. The secondary battery according to claim 1, further comprising an electrode lead having an outwardly protruding shape,

wherein the NTC element is disposed in a temperature sensing part adjacent to the electrode lead among the plurality of temperature sensing parts.

3. The secondary battery according to claim 2, wherein the electrode lead comprises a positive electrode lead and a negative electrode lead, and

the NTC element is disposed in a temperature sensing part adjacent to the negative lead among the plurality of temperature sensing parts.

4. The secondary battery according to claim 1, wherein the plurality of temperature sensing parts are attached to a top surface or a bottom surface of the case as a main plane (main plane).

5. The secondary battery according to claim 1, wherein the plurality of temperature sensing parts are attached to a side surface of the case.

6. The secondary battery according to claim 1, wherein the case comprises:

a main body part having an inner space in which the electrode assembly is accommodated; and

a sealing portion configured to seal an internal space of the main body portion from outside,

wherein the plurality of temperature sensing parts are attached to the sealing part, and

the sealing part is bent to be in close contact with a side surface of the housing.

7. The secondary battery according to claim 1, further comprising an adhesive portion adhered to a portion of a surface of the case,

wherein the plurality of temperature sensing parts are attached to the adhesive part.

8. The secondary battery according to claim 7, wherein the case comprises:

a main body portion having an inner space accommodating the housing; and

a sealing portion configured to seal an internal space of the main body portion from outside,

wherein the adhesive part adheres to the sealing part and the main body part together such that the sealing part is bent to be in close contact with a side surface of the case.

9. The secondary battery according to claim 7, wherein the adhesive part is attached only to the entire top or bottom surface of the case as a main plane (main plane).

10. The secondary battery according to claim 1, wherein the circuit configured to connect the plurality of temperature sensing parts to each other connects the plurality of temperature sensing parts to each other in a zigzag shape.

11. A battery module, comprising:

the secondary battery according to claim 1; and

a controller configured to receive temperature information of a case on a region to which the temperature sensing part of the secondary battery is attached,

wherein the controller (i) blocks a current of the secondary battery or (ii) transmits a warning signal to the outside when a temperature on a portion of the region to which the temperature sensing part is attached exceeds a predetermined value.

12. The battery module according to claim 11, wherein the controller receives temperature information from each temperature sensing part provided with both the PTC element and the NTC element, and

the controller transmits the warning signal to the outside when the temperature supplied from the NTC element exceeds a first reference temperature.

13. The battery module according to claim 12, wherein the controller blocks the current of the secondary battery when the temperature supplied from the NTC element exceeds a second reference temperature and the temperature supplied from the PTC element exceeds a third reference temperature.

14. The battery module of claim 13, wherein the second reference temperature is greater than the first reference temperature.

15. The battery module according to claim 13, wherein the second reference temperature is the same as the third reference temperature.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of priority from korean patent application No. 10-2019-0044991, filed on 17.4.2019, which is hereby incorporated by reference in its entirety.

Technical Field

The present invention relates to a secondary battery and a battery module including the same, and more particularly, to a secondary battery having a structure capable of blocking current when the temperature of the secondary battery exceeds a predetermined value, and a battery module including the same.

Background

A secondary battery capable of repeated charging and discharging needs to ensure safety so that fire or explosion does not occur when abnormal operation occurs.

For example, when the temperature within the secondary battery exceeds a predetermined value due to a short circuit or the like of the secondary battery, it is necessary to block the current from flowing through the secondary battery.

The secondary battery may be classified into a cylinder type secondary battery, a prismatic type secondary battery, a pouch type secondary battery, and the like according to its structure or manufacturing method.

Among these secondary batteries, the pouch-type secondary battery has a structure in which an electrode assembly having a structure in which electrodes and separators are alternately disposed is received in a sheet-shaped pouch case.

In particular, pouch-type secondary batteries are widely used due to their relatively simple processes and low manufacturing costs.

However, according to the related art, there is a problem in ensuring safety because the pouch type secondary battery is not provided with a member capable of blocking current when the temperature within the secondary battery abnormally increases.

Disclosure of Invention

Technical problem

Therefore, in order to solve the above-mentioned problems, it is an object of the present invention to provide a pouch type secondary battery in which current is blocked when the temperature inside the secondary battery abnormally increases, thereby ensuring safety.

Technical scheme

In order to achieve the above object, according to one aspect of the present invention, a secondary battery includes: an electrode assembly; a sheet type case configured to accommodate the electrode assembly; and a plurality of temperature sensing parts disposed adjacent to the housing to sense a temperature of one region of the housing, wherein at least one of the temperature sensing parts includes: a Positive Temperature Coefficient (PTC) element; and a Negative Temperature Coefficient (NTC) element.

The secondary battery may further include an electrode lead having an outwardly protruding shape, wherein the NTC element may be disposed in a temperature sensing part adjacent to the electrode lead among the plurality of temperature sensing parts.

The electrode lead may include a positive lead and a negative lead, and the NTC element may be disposed in a temperature sensing part adjacent to the negative lead among the plurality of temperature sensing parts.

The plurality of temperature sensing parts may be attached to a top surface or a bottom surface of the housing as a main plane (main plane).

The plurality of temperature sensing parts may be attached to a side surface of the housing.

The housing may include: a main body part having an inner space in which the electrode assembly is accommodated; and a sealing part configured to externally seal the inner space of the main body part, wherein the plurality of temperature sensing parts are attachable to the sealing part, and the sealing part is bendable to be in close contact with a side surface of the housing.

The secondary battery may further include an adhesive part adhered to a portion of a surface of the case, wherein the plurality of temperature sensing parts may be attached to the adhesive part.

The housing may include: a main body part having an inner space in which the electrode assembly is accommodated; and a sealing part configured to externally seal an inner space of the main body part, wherein the adhesive part may be adhered to the sealing part and the main body part together such that the sealing part is bent to be in close contact with a side surface of the housing.

The adhesive part may be attached only to the entire top or bottom surface of the housing as a main plane (main plane).

The circuit configured to connect the plurality of temperature sensing parts to each other may connect the plurality of temperature sensing parts to each other in a zigzag shape.

In order to achieve the above object, according to another aspect of the present invention, a battery module includes: the secondary battery; and a controller configured to receive temperature information of the case on a region of the temperature sensing part to which the secondary battery is attached, wherein when a temperature on a portion of the region to which the temperature sensing part is attached exceeds a predetermined value, the controller (i) blocks a current of the secondary battery, or (ii) transmits a warning signal to the outside.

The controller may receive temperature information from each temperature sensing part provided with both the PTC element and the NTC element, and may transmit the warning signal to the outside when the temperature provided from the NTC element exceeds a first reference temperature.

The controller may block the current of the secondary battery when the temperature supplied from the NTC element exceeds a second reference temperature and the temperature supplied from the PTC element exceeds a third reference temperature.

The second reference temperature may be greater than the first reference temperature.

The second reference temperature may be the same as the third reference temperature.

Advantageous effects

According to the present invention, current can be blocked when the temperature in the pouch type secondary battery abnormally increases, thereby improving safety.

Drawings

Fig. 1 is a plan view illustrating the structure of a secondary battery according to a first embodiment of the present invention.

Fig. 2 is a plan view illustrating the structure of a secondary battery according to a second embodiment of the present invention.

Fig. 3 is a side view illustrating the structure of a secondary battery according to a third embodiment of the present invention.

Fig. 4 is a plan view illustrating the structure of a secondary battery according to a fourth embodiment of the present invention.

Fig. 5 is a plan view illustrating the structure of a secondary battery according to a fifth embodiment of the present invention.

Fig. 6 is a side view illustrating the structure of a secondary battery according to a sixth embodiment of the present invention.

Fig. 7 is a side sectional view illustrating the structure of a secondary battery taken along line a-a of fig. 4.

Fig. 8 is a side sectional view illustrating the structure of a secondary battery taken along line B-B of fig. 5.

Fig. 9 is a side sectional view illustrating the structure of a secondary battery taken along line C-C of fig. 6.

Fig. 10 is a plan view illustrating the structure of a battery module according to the present invention.

Detailed Description

Hereinafter, the structures of the secondary battery and the battery module according to the present invention will be described with reference to the accompanying drawings.

Secondary battery

Fig. 1 is a plan view illustrating the structure of a secondary battery according to a first embodiment of the present invention, and fig. 2 is a plan view illustrating the structure of a secondary battery according to a second embodiment of the present invention.

Further, fig. 3 is a side view illustrating the structure of a secondary battery according to a third embodiment of the present invention.

The secondary battery 10 according to the present invention may include an electrode assembly and a sheet type case 200 (hereinafter, referred to as "case") housing the electrode assembly.

The electrode assembly may have a structure in which electrodes and separators are alternately arranged.

As shown in fig. 1 and 2, the case 200 may include a body part 210 in which an inner space accommodating the electrode assembly is defined, and a sealing part 220 sealing the inner space of the body part 210 from the outside. The sealing part 220 may have a structure in which two sheets are bonded to each other.

In the present application, a surface having the largest area among surfaces of main body portion 210 of housing 200 is referred to as a "main plane", and a surface formed around the main plane is referred to as a "side surface". Referring to fig. 1 to 3, the region of the main body portion 210 of the housing shown in fig. 1 and 2 is a main plane of the housing 200, and the region of the main body portion 210 of the housing shown in fig. 3 is a side surface of the housing 200. The major plane of the housing 200 may be understood as a top surface or a bottom surface of the housing 200.

In addition, the secondary battery 10 according to the present invention may include an electrode lead 100 having a shape protruding to the outside. The electrode lead 100 may include a positive electrode lead 100a and a negative electrode lead 100 b.

As shown in fig. 1, according to the first embodiment of the present invention, the cathode lead 100a and the anode lead 100b may be disposed at one side of the case 200 so as to protrude in the same direction.

However, as shown in fig. 2, according to the second embodiment of the present invention, the cathode lead 100a and the anode lead 100b may be disposed at one side of the case 200 and the other side opposite to the one side, respectively, so as to protrude in opposite directions.

The secondary battery 10 according to the present invention may include a plurality of temperature sensing parts 300 disposed adjacent to the case 200. The temperature sensing part 300 according to the present invention may be configured to sense a temperature in one region of the case 200. As described below, information about the temperature in one region of the housing 200 sensed by the temperature sensing part 300 may be provided to the controller 20 (see fig. 10). In fig. 1 and 2, the temperature sensing parts 300 are disposed on the main plane of the housing in the form of a 3 × 3 matrix. Here, the circuit connecting the temperature sensing parts 300 to each other has a shape in which the temperature sensing parts 300 are connected to each other in a zigzag shape. Fig. 3 illustrates a state in which three temperature sensing parts 300 are arranged side by side on the housing 200.

The plurality of temperature sensing parts 300 may be directly attached to one surface of the case 200. Here, as shown in fig. 1 and 2, the temperature sensing part 300 may be attached to a top surface or a bottom surface of the case 200 as a main plane, and as shown in fig. 3, the temperature sensing part 300 may be attached to a side surface of the case 200.

As shown in fig. 1 to 3, the secondary battery 10 according to the present invention may further include a terminal part 400, the terminal part 400 being disposed on the surface of the case 200 and connected to any one of the plurality of temperature sensing parts 300 through the circuit. Fig. 1 to 3 illustrate a case in which a terminal portion 400 is provided at a side of a case 200 where an electrode lead 100 is provided.

According to the present invention, each of the plurality of temperature sensing parts 300 provided in the secondary battery 10 may include a Positive Temperature Coefficient (PTC) element. In addition, at least one of the plurality of temperature sensing parts 300 may include a Negative Temperature Coefficient (NTC) element. At least one of the plurality of temperature sensing parts 300 may include a PTC element and an NTC element.

The PTC element denotes an element in which resistance rapidly increases when temperature increases, and the NTC element denotes an element in which resistance increases when temperature decreases.

According to the present invention, since at least one of the plurality of temperature sensing parts includes both the PTC element and the NTC element, more reliable information about the temperature in a specific region of the housing can be obtained.

That is, when only one kind of temperature sensing element is provided in the temperature sensing part, the temperature information in a specific region of the housing is limited to information obtained from only one kind of temperature sensing element. Thus, even if temperature information obtained from one kind of temperature sensing element is erroneous, the information is not known to be erroneous, thereby deteriorating the reliability of the temperature information in a specific region of the case.

However, according to the present invention, since at least one temperature sensing part includes two kinds of temperature sensing elements, temperature information in a specific region of the housing can also be obtained through two channels. If the temperature information obtained from one type of temperature sensing element is erroneous, the error of the temperature information can be revealed by cross-checking with temperature information obtained from different types of temperature sensing elements. Thus, according to the present invention, the reliability of information relating to the temperature in a specific region of the housing can be improved.

It is considered that each of the plurality of temperature sensing parts includes an NTC element and at least one of the plurality of temperature sensing parts includes a PTC element. However, in the case of the NTC element, since the NTC element is generally more expensive than the PTC element, it is not desirable in terms of economy when the temperature sensing part is configured in the above-described structure.

In view of the safety of the temperature of the secondary battery, it may be preferable that the temperature sensing part provided with two kinds of temperature sensing elements among the plurality of temperature sensing parts is provided at a position where the temperature is higher in the secondary battery. This is because, at a position where the heat quantity is large, the possibility of an abnormal temperature rise is also high.

In the secondary battery, a region where the electrode assembly and the electrode leads are connected to each other generally has a relatively high temperature. In order to connect the electrode assembly to the electrode leads, a welding process is performed. Since the current flowing through the electrode assembly having a relatively large width is concentrated in the electrode lead having a relatively narrow width, large heat generation is generated on the welding region.

Thus, the NTC element may be disposed in a temperature sensing part adjacent to the electrode lead among the plurality of temperature sensing parts 300. Referring to fig. 1 and 2, an NTC element may be disposed in at least one of the temperature sensing parts 300 of the upper part closest to the electrode lead 100 among the plurality of temperature sensing parts 300.

In general, since the thermal conductivity of a material (e.g., copper) for the anode lead is larger than that of a material (e.g., aluminum) for the cathode lead, it is known that large heat generation occurs in the anode lead. Further, when the secondary battery is discharged, since a current flows from the anode lead to the cathode lead, it is known that a relatively high temperature is generated on a region where the anode lead and the electrode assembly are electrically connected to each other.

Thus, an NTC element may be disposed in a temperature sensing part adjacent to the negative lead 100b among the plurality of temperature sensing parts 300. Referring to fig. 2, the NTC element may be disposed in a temperature sensing part disposed at a central portion among the temperature sensing parts 300 of the upper part closest to the negative lead 100b among the plurality of temperature sensing parts 300.

Fig. 4 is a plan view illustrating the structure of a secondary battery according to a fourth embodiment of the present invention, and fig. 5 is a plan view illustrating the structure of a secondary battery according to a fifth embodiment of the present invention. Further, fig. 6 is a side view illustrating the structure of a secondary battery according to a sixth embodiment of the present invention.

As shown in fig. 4 to 6, the secondary battery 10 according to the fourth embodiment of the present invention may further include an adhesive part 500 adhered to a portion of the surface of the case 200, and the plurality of temperature-sensing parts 300 may be attached to the adhesive part 500. According to the fourth and fifth embodiments of the present invention, since the adhesive part 500 to which the plurality of temperature sensing parts 300 are attached is adhered to the surface of the case, the plurality of temperature sensing parts 300 can be brought into close contact with the surface of the case 200 by the adhesive part 500.

Here, the adhesive part 500 may be provided in the secondary battery 10 in various ways. As shown in fig. 4, 5, 7 and 8, the adhesive part 500 may be adhered to the sealing part 220 and the body part 210 together such that the sealing part 220 is bent to be in close contact with the side surface of the case 200. Here, as shown in fig. 4, according to the fourth embodiment of the present invention, the adhesive part 500 may extend in the width direction of the main plane of the case 200 to be adhered together to the surface of the main body part 210 and each surface of the two sealing parts 220 respectively disposed at both sides of the main body part 210. Alternatively, as shown in fig. 5, according to a fifth embodiment of the present invention, the adhesive part 500 may be adhered to the main plane of the main body part 210 and the surface of one sealing part 220 provided at one side of the case 200 together. In fig. 4, three bonding portions 500 are provided. Here, three temperature sensing parts 300 are respectively disposed on regions adhered to the main plane of the case 200 in the respective adhesive parts 500. In fig. 5, six bonding portions 500 are provided. Here, one temperature sensing part 300 is disposed on each region of the respective adhesive parts 500 adhered to the main plane of the case 200. However, in contrast, the temperature sensing part 300 may be disposed on an area of the adhesive part 500 adhered to the side surface of the case 200. That is, as shown in fig. 6 and 9, according to the sixth embodiment of the present invention, the adhesive part 500 may be adhered to the sealing part 220 and the body part 210 together such that the sealing part 220 is bent to be in close contact with the side surface of the case 200. Here, one temperature sensing part 300 may be disposed on each region of the surface adhered to the sealing part 220 in each adhesive part 500. Thus, according to the sixth embodiment of the present invention, the sealing part 200 may be bent to be in close contact with the side surface of the case 200 due to the adhesive parts 500, and since the plurality of temperature sensing parts 300 attached to each adhesive part 500 are attached to the sealing part 200, the temperature sensing parts 300 may be disposed adjacent to the side surface of the case 200.

Or, conversely, the adhesive part to which the plurality of temperature sensing parts are attached may be attached only to the entire top or bottom surface of the housing as the main plane. In this case, the structure of the secondary battery provided with the plurality of temperature sensing parts may be substantially the same as that of each of fig. 1 and 2.

Battery module

Fig. 10 is a plan view illustrating the structure of a battery module according to the present invention. As shown in fig. 10, the battery module 1 according to the present invention may include a plurality of secondary batteries 10. The description of the structure of the secondary battery 10 will be replaced with the above description.

Further, the battery module 1 according to the present invention includes the controller 20, and the controller 20 receives information on the temperature of the case from the region to which the temperature sensing part 300 (see fig. 1 to 9) of the secondary battery 10 is attached.

According to the present invention, the temperature sensing parts mounted on the plurality of secondary batteries 10 sense the temperature of the case on the region to which the temperature sensing parts are attached to transmit sensed temperature information to the controller 20. Thereafter, when the temperature on a part of the region to which the temperature sensing parts attached with the plurality of secondary batteries 10 are attached exceeds a predetermined value, the controller 20 may (i) block the current of the secondary battery to which the temperature sensing part transmitting information on the temperature exceeding the predetermined value is attached, or (ii) transmit a warning signal to the outside. A control method of the controller in the battery module according to the present invention will be described in more detail as follows.

The controller 20 of the battery module 1 receives information related to temperature from each of the PTC element and the NTC element provided in the temperature sensing part of the secondary battery 10.

According to the present invention, the controller may determine whether the temperature provided from the NTC element is (i) equal to or less than a first reference temperature, (ii) equal to or less than a second reference temperature that exceeds the first reference temperature and is greater than the first reference temperature, or (iii) exceeds the second reference temperature.

Further, according to the present invention, the controller determines whether the temperature supplied from the PTC element is (i) equal to or less than the third reference temperature or (ii) exceeds the third reference temperature.

Here, the controller transmits a first warning signal to the outside when it is determined that the temperature supplied from the NTC element exceeds a first reference temperature. Thereafter, when it is determined that the temperature supplied from the NTC element exceeds the second reference temperature, the controller operates as follows according to the temperature supplied from the PTC element of the temperature sensing part provided with the NTC element.

The controller blocks a current of the secondary battery provided with the temperature sensing part including the NTC element and the PTC element when the temperature supplied from the NTC element exceeds the second reference temperature, and also when the temperature supplied from the PTC element exceeds the third reference temperature.

On the other hand, when the temperature supplied from the NTC element exceeds the second reference temperature, and when the temperature supplied from the PTC element is equal to or less than the third reference temperature, the controller transmits a second warning signal to the outside. The second reference temperature and the third reference temperature may be identical to each other. When the second reference temperature and the third reference temperature are the same as each other, since the temperature serving as a reference for interrupting the current of the secondary battery is set to one, it is possible to enable the controller to perform stable control and simplified control. Here, the second reference temperature and the third reference temperature being "identical" to each other means not only that the second reference temperature is numerically identical to the third reference temperature but also that the difference between the second reference temperature and the third reference temperature is insignificant. Thus, it should be construed to include situations where one skilled in the art can determine that the two temperatures are about the same. Alternatively, conversely, the second reference temperature may be greater than the third reference temperature.

In the battery module according to the present invention, the operation of the above-described controller is related to a case in which information related to temperature is provided from the temperature sensing part including the PTC element and the NTC element. Thus, when temperature information is provided from the temperature sensing part provided with only the PTC element, the controller may perform the following operation.

The controller may block a current of the secondary battery provided with the temperature sensing part including the PTC element when the temperature supplied from the PTC element exceeds a third reference temperature. The controller may transmit a warning signal to the outside.

When the current of the secondary battery is blocked by the above algorithm in the battery module according to the present invention, the blocking may be permanently or temporarily performed. The permanent interruption of the current of the secondary battery may mean that the current is interrupted even when the temperature of the secondary battery returns to a normal temperature. Further, when the interruption of the current of the secondary battery is temporarily performed, it may mean that the current of the secondary battery flows again when the temperature of the secondary battery returns to a normal temperature.

According to the present invention, since each of a plurality of secondary batteries constituting a battery module is provided with at least one temperature sensing part including a PTC element and an NTC element, it is possible to improve the reliability of control of the secondary batteries based on information on temperatures supplied from the PTC element and the NTC element.

Although the embodiments of the present invention have been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.