Temperature sensor, secondary battery including the same, and method for manufacturing secondary battery

Abstract

The secondary battery of the present invention includes an electrode assembly, a pouch that houses the electrode assembly, an electrode lead that is coupled to an electrode tab provided in the electrode assembly, has a tip drawn out of the pouch, and has an insertion hole formed therein so as to extend from the inside to the outside of the pouch, a temperature measurement unit having a thermistor chip that is inserted into the insertion hole and is located inside the pouch to measure the temperature inside the pouch, and a temperature sensor including a connector located outside the pouch.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0088571, filed on July 18, 2022, and all of the contents disclosed in the Korean Patent Application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a temperature sensor, a secondary battery including the same, and a method for manufacturing a secondary battery. In particular, the present invention relates to a temperature sensor capable of measuring the temperature inside a pouch, a secondary battery including the same, and a method for manufacturing a secondary battery.

Background Art

[0003] Generally, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in the field of advanced electronic devices such as mobile phones, notebook computers, and camcorders.

[0004] The secondary battery is classified into a can-type secondary battery in which an electrode assembly is built into a metal can and a pouch-type secondary battery in which an electrode assembly is built into a pouch. The can-type secondary battery includes an electrode assembly, a can that houses the electrode assembly, and a cap assembly mounted on an opening of the can. The pouch-type secondary battery includes an electrode assembly and a pouch that houses the electrode assembly. The electrode assembly is classified into a jelly roll type (winding type) electrode assembly, a stack type (laminated type) electrode assembly, and a stack / folding type electrode assembly.

[0005] On the other hand, when measuring the temperature of a pouch-type secondary battery, a method of measuring the temperature outside the pouch is used.

[0006] However, since there is a temperature difference between the inside and outside of the pouch in the pouch-type secondary battery, there is a problem in that it is difficult to accurately measure the temperature unless the internal temperature of the pouch is measured.

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a temperature sensor capable of accurately measuring the temperature inside a pouch, a secondary battery including the same, and a method for manufacturing the secondary battery.

Means for Solving the Problems

[0008] The secondary battery of the present invention includes an electrode assembly, a pouch that houses the electrode assembly, an electrode lead that is coupled to an electrode tab provided on the electrode assembly, has a tip drawn out of the pouch, and has an insertion hole formed so as to extend from the inside to the outside of the pouch, a temperature measurement unit having a thermistor chip that is inserted into the insertion hole and is located inside the pouch to measure the temperature inside the pouch, and a temperature sensor including a connector located outside the pouch.

[0009] The temperature sensor can have a thickness smaller than or the same as that of the electrode lead in which the insertion hole is formed.

[0010] The temperature measurement unit can be coated with an antioxidant protective layer.

[0011] The antioxidant protective layer is a polymer coating layer, and the polymer coating layer can be made of a parylene material.

[0012] A lead film is provided on the electrode lead located at the seal portion of the pouch, and the temperature sensor is provided with a connecting portion provided between the temperature measurement unit and the connector and in contact with the lead film, and the connecting portion can be provided with a reinforcing layer for enhancing the adhesive force with the lead film.

[0013] The reinforcing layer can be made of a metal material plated on the connecting portion.

[0014] It can further include a sealing material provided between the temperature sensor and the inner wall of the insertion hole and sealing the space between the temperature sensor and the inner wall of the insertion hole.

[0015] The sealing material can be made of the same material as the lead film.

[0016] On the other hand, the method for manufacturing a secondary battery of the present invention can include: (a) a step of preparing a temperature sensor; (b) a step of cutting one side surface of an electrode lead to process an insertion hole; (c) a step of connecting the rear end of the electrode lead to an electrode tab provided on an electrode assembly and inserting the temperature sensor into the insertion hole of the electrode lead; (d) a step of accommodating the electrode assembly in a pouch, and at this time, disposing the temperature measurement part of the temperature sensor inside the pouch and disposing the connector of the temperature sensor outside the pouch.

[0017] In the step (b), the temperature sensor can be smaller than or have the same thickness as the electrode lead in which the insertion hole is formed.

[0018] The step (a) can further include a step of coating an antioxidant protective layer on the surface of the temperature measurement part, and the antioxidant protective layer can be formed by vapor-depositing parylene coating on the temperature measurement part.

[0019] The step (a) can further include a step of forming a reinforcing layer for enhancing adhesion on a connecting part provided between the temperature measurement part and the connector. The reinforcing layer is made of a metal material and can be formed by plating on the surface of the connecting part.

[0020] The step (c) can further include a step of inserting and sealing a sealing material into the gap between the inner wall of the insertion hole and the temperature sensor after inserting the temperature sensor into the insertion hole of the electrode lead.

[0021] After the step (d), (e) a step of arranging a lead film so as to surround the electrode lead so as to pass between the temperature measurement unit and the connector; and after sealing a part of the seal portion of the pouch in the step (f), the electrolyte is injected through the unsealed portion of the pouch to impregnate the electrode assembly, and the secondary battery can be further manufactured by sealing the unsealed portion of the pouch.

[0022] On the other hand, the temperature sensor of the present invention includes a temperature measurement unit having a thermistor chip provided at one end for measuring temperature, a connector provided at the other end, and a connecting unit for connecting the temperature measurement unit and the connector, and a reinforcing layer for increasing the adhesive force can be provided in the connecting unit.

Effect of the Invention

[0023] The secondary battery of the present invention includes a temperature sensor for measuring the internal temperature of the pouch, and the temperature sensor is provided so as to be inserted into an insertion hole formed in the electrode lead. With such a feature, it is possible to minimize an increase in the thickness of the seal portion of the pouch where the electrode lead is located, and in particular, the temperature sensor can be fixed more stably.

[0024] Further, in the secondary battery of the present invention, the temperature sensor is characterized in that it has a thickness smaller than or the same as that of the electrode lead in which the insertion hole is formed. With such a feature, it is possible to prevent an increase in the thickness of the seal portion of the pouch.

[0025] Further, in the secondary battery of the present invention, the temperature measurement unit of the temperature sensor is coated with an antioxidant protective layer, and the antioxidant protective layer is made of a parylene material. With such a feature, it is possible to significantly prevent the temperature measurement unit from being oxidized by the electrolyte.

[0026] Also, in the secondary battery of the present invention, a connecting portion is provided between the temperature measuring portion and the connector of the temperature sensor, and a reinforcing layer made of a metal material for enhancing the adhesive force with the lead film is plated on the connecting portion. With such a feature, the sealing force between the temperature sensor and the lead film can be enhanced.

[0027] Also, in the secondary battery of the present invention, a sealing substance is included between the temperature sensor and the inner wall of the insertion hole of the electrode lead. With such a feature, the space between the temperature sensor and the inner wall of the insertion hole can be stably sealed.

Brief Description of the Drawings

[0028]

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Figure 10

Modes for Carrying Out the Invention

[0029] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be realized in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clearly explain the present invention, parts not related to the explanation are omitted, and similar reference numerals are given to similar parts throughout the specification.

[0030] [Secondary battery according to the first embodiment of the present invention] FIG. 1 is a perspective view showing a secondary battery according to the first embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a left side view of FIG. 1.

[0031] As shown in FIGS. 1 to 3, the secondary battery 1 according to the first embodiment of the present invention has a structure including a temperature sensor 15 that measures the temperature inside the pouch 12.

[0032] That is, the secondary battery 1 according to the first embodiment of the present invention includes an electrode assembly 11, a pouch 12 that houses the electrode assembly 11, an electrode lead 13 coupled to the electrode assembly 11, a lead film 14 provided on the electrode lead 13, and a temperature sensor 15 that measures the temperature inside the pouch 12.

[0033] Electrode assembly The electrode assembly 11 has a structure in which separators and electrodes are alternately laminated, and the electrodes include electrode tabs 111.

[0034] On the other hand, the electrodes can be a positive electrode and a negative electrode, and the electrode tabs 111 include a positive electrode tab provided on the positive electrode and a negative electrode tab provided on the negative electrode.

[0035] Pouch The pouch 12 includes a housing portion 121 that houses the electrode assembly 11, and a seal portion 122 that is formed along the edge surface of the housing portion 121 and seals the housing portion 121.

[0036] Electrode lead The electrode lead 13 has the form of a long rectangular plate, and its rear end (the end facing the electrode assembly in FIG. 2) is coupled to the electrode tab 111, and its front end is drawn out to the outside of the pouch 12.

[0037] FIG. 4 is a perspective view showing a temperature sensor and an electrode lead of a secondary battery according to a first embodiment of the present invention.

[0038] In particular, as shown in FIG. 4, an insertion hole 131 is formed in the electrode lead 13 so as to extend from the inside to the outside of the pouch 12. The insertion hole 131 is formed so as to penetrate in the vertical direction (the vertical direction in FIG. 4). That is, the insertion hole 131 is formed long in the entire length direction of the electrode lead 13.

[0039] On the other hand, a temperature sensor 15 is inserted into the insertion hole 131.

[0040] Lead film The lead film 14 is for enhancing the sealing force between the seal portion 122 of the pouch 12 and the electrode lead 13. That is, the lead film 14 is provided in a form surrounding the peripheral surface of the electrode lead 13 located at the seal portion 122 of the pouch 12.

[0041] FIG. 5 is a plan view of the temperature sensor 15 shown in FIG. 4, and FIG. 6 is a cross-sectional view taken along line A-A shown in FIG. 4.

[0042] Temperature sensor The temperature sensor 15 has a structure inserted into the insertion hole 131 as shown in FIGS. 5 and 6.

[0043] In particular, the temperature sensor 15 includes a temperature measurement unit 151 having a thermistor chip 1511 located inside the pouch 12 and measuring the temperature inside the pouch 12, and a connector 152 having a terminal 1521 located outside the pouch 12.

[0044] Here, the connector 152 includes a terminal 1521 that is connected to a temperature measuring device (not shown). The temperature measuring device compares the internal temperature of the pouch 12 transmitted from the connector 152 with a set temperature in real time and inspects for defects. In particular, the temperature measuring device displays the internal temperature of the pouch 12 transmitted from the connector 152 on an external display window in real time.

[0045] That is, the temperature sensor 15 measures the internal temperature of the pouch 12 with the thermistor chip 1511 of the temperature measuring unit 151, and the connector 152 transmits the measured temperature measured by the thermistor chip 1511 to the temperature measuring device, inspects and displays the internal temperature of the pouch 12.

[0046] In this way, by inserting the temperature sensor 15 into the insertion hole 131 formed in the electrode lead 13, the fixing force of the temperature sensor 15 can be increased, the internal temperature of the pouch 12 can be accurately measured, and it can be quickly transmitted to the outside. In particular, the temperature sensor 15 can minimize an increase in the thickness of the electrode lead 13 and prevent weakening of the sealing force between the seal portion 122 of the pouch 12 and the lead film 14.

[0047] On the other hand, the temperature sensor 15 can be smaller than or have the same thickness as the electrode lead 13 in which the insertion hole 131 is formed. Preferably, the temperature sensor 15 can have the same thickness as the electrode lead 13. Thereby, it is possible to minimize the occurrence of a step between the temperature sensor 15 and the electrode lead 13, and as a result, the adhesion and adhesive force between the temperature sensor 15 and the lead film 14 can be increased.

[0048] On the other hand, since the temperature measuring unit 151 is located inside the pouch 12, oxidation can occur due to the electrolytic solution. To prevent this, an antioxidant protective layer 154 can be coated on the surface of the temperature measuring unit 151, thereby preventing oxidation of the temperature measuring unit 151 by the electrolytic solution.

[0049] Here, the antioxidant protective layer 154 can be composed of a polymer coating layer. More specifically, the antioxidant protective layer 154 can be made of a parylene material.

[0050] Here, parylene coating means a polymer coating that is vapor-deposited on a subject in a gaseous form in a vacuum state in micro-thickness units regardless of the shape. The parylene coating is used for parts that require protection of the LED surface, protection of the PCB surface, corrosion resistance, chemical resistance, chemical resistance, lubricity, etc.

[0051] On the other hand, a connecting portion 153 is provided between the temperature measuring portion 151 and the connector 152 of the temperature sensor 15 and is in contact with the lead film 14. Here, the connecting portion 153 can be provided with a reinforcing layer 155 for enhancing the adhesive force with the lead film 14.

[0052] The reinforcing layer 155 can be made of a metal material plated on the surface of the connecting portion 153, and the metal material can be gold or nickel (Ni). Thereby, the reinforcing layer 155 is plated on the surface of the connecting portion 153, so that the adhesive force and the sealing force between the connecting portion 153 and the lead film 14 can be enhanced.

[0053] FIG. 7 is a plan view showing a state in which a temperature sensor and an electrode lead are coupled in the present invention.

[0054] On the other hand, a sealing substance 156 is provided between the temperature sensor 15 and the inner wall of the insertion hole 131 and further includes a sealing substance 156 for sealing between the temperature sensor 15 and the inner wall of the insertion hole 131. That is, as shown in FIG. 7, the sealing substance 156 serves to finish the gap between the temperature sensor 15 and the insertion hole 131. Thereby, the gap between the insertion hole 131 and the temperature sensor 15 can be stably sealed.

[0055] On the one hand, the sealing material 156 can be made of the same material as the lead film 14. Preferably, the sealing material 156 can be polypropylene.

[0056] By inserting the temperature sensor 15 having such a structure into the insertion hole 131 formed in the electrode lead 13, it can be stably fixed to the secondary battery, and the temperature inside the pouch 12 can be accurately measured.

[0057] Therefore, the secondary battery 1 according to the first embodiment of the present invention can accurately measure the temperature inside the pouch 12 by including the temperature sensor 15 that measures the temperature inside the pouch 12.

[0058] Hereinafter, a method for manufacturing the secondary battery 1 according to the first embodiment of the present invention will be described.

[0059] FIG. 8 is a flowchart showing a method for manufacturing a secondary battery according to the first embodiment of the present invention.

[0060] As shown in FIG. 8, the method for manufacturing a secondary battery according to the first embodiment of the present invention includes: (a) a step of preparing the temperature sensor 15; (b) a step of processing the electrode lead 13; (c) a step of inserting the temperature sensor 15 into the electrode lead 13; (d) a step of arranging the electrode assembly 11 into which the temperature sensor 15 is inserted in the pouch 12; (e) a step of arranging the lead film 14; and (f) a step of sealing the pouch 12.

[0061] In step (a), the temperature sensor 15 is prepared. The temperature sensor 15 includes a temperature measurement unit 151 having a thermistor chip 1511 that measures temperature, a connector 152 to which the temperature of the temperature measurement unit 151 is transmitted, and a connection unit 153 that connects the temperature measurement unit 151 and the connector 152.

[0062] On the one hand, step (a) may further include a step of coating a surface of the temperature measurement unit 151 with an anti-oxidation protective layer 154 to prevent the temperature measurement unit 151 from being oxidized by the electrolytic solution. That is, the anti-oxidation protective layer 154 is formed by vapor-depositing a parylene coating on the temperature measurement unit 151.

[0063] On the one hand, step (a) may further include a step of forming a reinforcing layer 155 on the surface of the connecting portion 153 to enhance the adhesive force between the connecting portion 153 and the lead film 14. That is, the reinforcing layer 155 is made of a metal material and is formed by plating on the surface of the connecting portion 153.

[0064] On the other hand, the metal material can be nickel (Ni) or gold.

[0065] In step (b), a surface on one side of the electrode lead 13 is cut or punched to process an insertion hole 131. Here, the insertion hole 131 has a length with one end located inside the pouch 12 and the other end located outside the pouch 12. And the insertion hole 131 has a width corresponding to the length in the entire width direction of the temperature sensor 15, whereby the gap between the insertion hole 131 and the temperature sensor 15 can be minimized to prevent the temperature sensor 15 from moving within the insertion hole 131.

[0066] Also, in step (b), the temperature sensor 15 can be made of a thickness smaller than or the same as that of the electrode lead 13 in which the insertion hole 131 is formed. Preferably, the temperature sensor 15 has the same thickness as the electrode lead 13. This can prevent a step from occurring between the temperature sensor 15 and the electrode lead 13, and as a result, enhance the adhesive force and sealing force between the temperature sensor 15 and the lead film 14.

[0067] In step (c), the rear end of the electrode lead 13 is coupled to the electrode tab 111 provided on the electrode assembly 11, and the temperature sensor 15 is inserted into the insertion hole 131 of the electrode lead 13. At this time, the temperature measurement unit 151 of the temperature sensor 15 is positioned inside the pouch 12, and the connector 152 of the temperature sensor 15 is inserted so as to be positioned outside the pouch 12.

[0068] On the other hand, step (c) further includes a step of inserting and sealing a sealing material 156 into the gap between the inner wall of the insertion hole 131 and the temperature sensor 15 after the temperature sensor 15 is inserted into the insertion hole 131 of the electrode lead 13. Thereby, the gap between the insertion hole 131 and the temperature sensor 15 can be stably sealed. Here, the sealing material 156 can be made of the same material as the lead film 14. Thereby, the adhesive force between the sealing material 156 and the lead film 14 can be increased.

[0069] In step (d), the electrode assembly 11 is housed in the pouch 12. At this time, the temperature measurement unit 151 of the temperature sensor 15 is disposed inside the pouch 12, and the connector 152 of the temperature sensor 15 is disposed outside the pouch 12.

[0070] In step (e), the lead film 14 is coupled so as to pass between the temperature measurement unit 151 and the connector 152 and to surround the electrode lead 13.

[0071] In step (f), after a part of the seal portion 122 of the pouch 12 is sealed, an electrolytic solution is injected through the unsealed portion of the pouch 12 to impregnate the electrode assembly 11, and the unsealed portion of the pouch 12 is sealed.

[0072] When the above steps are completed, the secondary battery 1 of the final product can be manufactured.

[0073] Hereinafter, when describing other embodiments of the present invention, the same constituent elements having the same functions as those in the foregoing embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0074] [Temperature Sensor According to the Second Embodiment of the Present Invention] FIG. 9 is a perspective view showing a temperature sensor according to the second embodiment of the present invention, and FIG. 10 is a plan view of FIG. 9.

[0075] The temperature sensor 15 according to the second embodiment of the present invention is a separately commercialized product of only the temperature sensor 15 in the secondary battery 1 according to the above-described first embodiment.

[0076] That is, as shown in FIGS. 9 and 10, the temperature sensor 15 according to the second embodiment of the present invention includes a temperature measurement unit 151 provided at one end and having a thermistor chip 1511 for measuring temperature, a connector 152 provided at the other end, and a connection unit 153 that connects the temperature measurement unit 151 and the connector 152.

[0077] Here, the connection unit 153 can be provided with a reinforcing layer 155 for enhancing the adhesive force, and the reinforcing layer 155 can be made of a metal material plated on the connection unit 153. On the other hand, since the reinforcing layer 155 has been described in detail in the first embodiment, a detailed description thereof will be omitted.

[0078] On the other hand, the temperature measurement unit 151 can be coated with an antioxidant protective layer 154. On the other hand, since the antioxidant protective layer 154 has been described in detail in the first embodiment, a detailed description thereof will be omitted.

[0079] Therefore, the temperature sensor 15 according to the second embodiment of the present invention can enhance the marketability by separately commercializing only the temperature sensor 15 in the secondary battery 1 according to the first embodiment.

[0080] The scope of the present invention is shown by the appended claims rather than the above detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts are possible.

Explanation of Reference Numerals

[0081] 1 Secondary battery 11 Electrode assembly 111 Electrode tab 12 Pouch 121 Accommodation part 122 Seal part 13 Electrode lead 131 Insertion hole 14 Lead film 15 Temperature sensor 151 Temperature measurement part 1511 Thermistor chip 152 Connector 153 Connection part 154 Antioxidant protective layer 155 Reinforcing layer 156 Sealing substance

Claims

1. An electrode assembly, a pouch for housing the electrode assembly, an electrode lead coupled to an electrode tab provided on the electrode assembly, with a tip drawn out of the pouch and an insertion hole formed so as to extend from the inside to the outside of the pouch, a temperature sensor including a thermistor chip inserted into the insertion hole and located inside the pouch for measuring the temperature inside the pouch, and a connector located outside the pouch. A secondary battery comprising:

2. The temperature sensor has a thickness smaller than or the same as that of the electrode lead in which the insertion hole is formed. The secondary battery according to Claim 1.

3. The temperature measurement unit is coated with an antioxidant protective layer. The secondary battery according to Claim 1.

4. The antioxidant protective layer is a polymer coating layer, The polymer coating layer is made of a parylene material. The secondary battery according to Claim 3.

5. The electrode lead located at the seal portion of the pouch is provided with a lead film, The temperature sensor is provided with a connecting portion provided between the temperature measurement unit and the connector and in contact with the lead film, The connecting portion is provided with a reinforcing layer for enhancing the adhesive force with the lead film. The secondary battery according to Claim 1.

6. The reinforcing layer is made of a metal material plated on the connecting portion. The secondary battery according to Claim 5.

7. The secondary battery according to Claim 5, further comprising a sealing material provided between the temperature sensor and the inner wall of the insertion hole for sealing between the temperature sensor and the inner wall of the insertion hole.

8. The sealing material is made of the same material as the lead film. The secondary battery according to Claim 7.

9. (a) preparing a temperature sensor; (b) cutting the surface of one side of the electrode lead to process an insertion hole; (c) coupling the rear end of the electrode lead to an electrode tab provided on the electrode assembly and inserting the temperature sensor into the insertion hole of the electrode lead; (d) housing the electrode assembly in a pouch, and at this time, arranging the temperature measurement unit of the temperature sensor inside the pouch and arranging the connector of the temperature sensor outside the pouch. A method for manufacturing a secondary battery comprising:

10. In the step (b), the temperature sensor has a thickness smaller than or the same as that of the electrode lead in which the insertion hole is formed, according to the method for manufacturing a secondary battery as claimed in claim 9.

11. The step (a) further includes a step of coating a protective layer for preventing oxidation on the surface of the temperature measurement part, The protective layer for preventing oxidation is formed by vapor-depositing parylene coating on the temperature measurement part, according to the method for manufacturing a secondary battery as claimed in claim 9.

12. The step (a) further includes a step of forming a reinforcing layer for enhancing the adhesive force on a connecting part provided between the temperature measurement part and the connector, The reinforcing layer is made of a metal material and is formed by plating on the surface of the connecting part, according to the method for manufacturing a secondary battery as claimed in claim 9.

13. The step (c) further includes a step of inserting a temperature sensor into the insertion hole of the electrode lead and then inserting a sealing substance into the gap between the inner wall of the insertion hole and the temperature sensor to seal it, according to the method for manufacturing a secondary battery as claimed in claim 9.

14. After the step (d), (e) a step of arranging a lead film so as to surround the electrode lead so as to pass between the temperature measurement part and the connector, (f) After sealing a part of the seal part of the pouch, injecting an electrolytic solution through the unsealed part of the pouch to impregnate the electrode assembly, and further including a step of manufacturing a secondary battery by sealing the unsealed part of the pouch, according to the method for manufacturing a secondary battery as claimed in claim 9.

15. A temperature measurement part having a thermistor chip provided at one end for measuring temperature, A connector provided at the other end, A connecting part connecting the temperature measurement part and the connector, and including, A temperature sensor, wherein the connecting part is provided with a reinforcing layer for enhancing the adhesive force.

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