Battery module having fixing structure for temperature sensing element

Abstract

The present invention relates to a battery module, and the battery module includes at least one battery cell, a protection circuit module that includes a rigid printed circuit board, and is electrically connected with the battery cell, at least one temperature sensing element provided at a surface of the battery cell, and a flexible printed circuit board that electrically connects the protection circuit module and the temperature sensing element.

Claims

1. A battery module comprising: at least one battery cell; a protection circuit module that includes a rigid printed circuit board, and is electrically connected with the battery cell; at least one temperature sensing element provided at a surface of the battery cell; and a flexible printed circuit board that electrically connects the protection circuit module and the temperature sensing element, wherein the rigid printed circuit board comprises a slit, and the flexible printed circuit board extends to a top surface of the rigid printed circuit board from the temperature sensing element through the slit and is combined with the protection circuit module at the top surface of the rigid printed circuit board.

2. The battery module of claim 1, comprising a foam member disposed between a bottom surface of the rigid printed circuit board and the temperature sensing element.

3. The battery module of claim 2, wherein the foam member is formed of an electrically insulating material.

4. The battery module of claim 2, wherein the foam member is configured to press the temperature sensing element at the top surface of the battery cell.

5. The battery module of claim 1, wherein a heat conductive adhesive layer is provided between the temperature sensing element and a surface of the battery cell.

6. A vehicle comprising the battery module of claim 1.

Description

DESCRIPTION OF THE DRAWINGS

(1) In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration.

(2) FIG. 1 is a perspective view of a battery module.

(3) FIG. 2 is a partial cross-sectional view of a battery cell according to the present invention.

(4) FIG. 3 is a partially enlarged cross-sectional perspective view of the battery cell of FIG. 2.

(5) FIG. 4 is a partial perspective view of a battery module that includes a temperature sensing element combined with a rigid printed circuit board through a flexible printed circuit.

(6) FIG. 5 is a partial perspective view of a battery module that includes a temperature sensing element combined with a rigid printed circuit board through a flexible printed circuit including a foam member.

MODE FOR INVENTION

(7) Hereinafter, basic features of the present invention and a method for achieving the present invention can be more easily understood by referring to the detailed description of exemplary embodiments and accompanying drawings. Parts duplicated with descriptions are omitted for clear description of the present invention, and like reference numerals designate like elements throughout the specification. The present invention can be implemented in various other forms, and thus the present invention is not necessarily limited to the embodiments shown in the drawings. These embodiments are means for thoroughly and completely describing the features and various aspects of the present invention, and are provided as examples for helping full understanding by those skilled in the art. Thus, for a thorough understanding of the features of the present invention, unnecessary explanations, that is, of processes, components, and techniques, will be omitted to those skilled in the art. Throughout the specification, like reference numerals designate like elements, and duplicated description with the same constituent elements will be omitted. In the drawings, several constituent elements, layers, and regions are exaggerated for clarity.

(8) A spatial representation, such as below, under, at a lower portion, on, above, or at an upper portion, is intended to compare features of one component relative to other components as shown in the figures. On the other hand, since the components may have different directions or may be arranged in various spaces depending on the use or operation of the device, the spatial representation is not necessarily limited by the illustrated aspects of the present invention. For example, if the direction of the device shown in the drawing is inverted, one component described below, under, or at a lower portion will be oriented on, above, or an upper portion relative to the other component. Thus, the expressions below and above may include both upward and downward directions. Also, the device may be interpreted as being disposed in various directions, such as being able to rotate by 90 degrees or another direction.

(9) When a component or layer is referred to as being connected or coupled on another component or layer, it may be directly connected to another component or layer, or at least one another component or layer may exist between the components. In addition, a component or layer may solely exist between two different components or layers, and at least one intermediate component or layer may be disposed between the components.

(10) Although not specifically defined, all of the terms including technical and scientific terms used herein have meanings understood by persons ordinarily skilled in the art. The terms have specific meanings coinciding with related technical references and the present specification, as well as lexical meanings. That is, the terms are not to be construed as having idealized or formal meanings.

(11) Referring to FIG. 1, a battery module 100 according to an exemplary embodiment includes a plurality of battery cells 10 arranged in one direction, and a heat exchange member 110 that is disposed to be adjacent to bottom sides of the plurality of battery cells 10. A pair of end plates 18 are provided to face a side surface of the battery cell 10 at the outside of the battery cell 10, and a connection plate 19 connects the pair of end plates 18 to fix the plurality of battery cells 10 together. Fastening portions 18a formed at opposite sides of the battery module 100 are fixed to a support plate 31 through bolts 40. The support plate 31 is a part of a housing 30. In addition, an elastic member 120 formed of rubber or another elastic material may be disposed between the support plate 31 and the heat exchange member 110.

(12) Here, each battery cell 10 is a prism-shaped (or quadrangular-shaped) cell, and a wide plane of each cell is layered such that a battery module is formed. In addition, each battery cell 10 includes an electrode assembly and a battery case receiving an electrolyte solution. The battery case is sealed by a cap assembly 14. The cap assembly 14 is provided with a positive terminal 11, a negative terminal 12, and a vent 13. The positive terminal 11 and the negative terminal 12 have different polarities. The vent 13, which is a safety means of the battery cell 10, functions as a path through which a gas generated by the battery cells 10 is discharged to the outside. Positive terminals 11 and negative terminals 12 of neighboring battery cells 10 are electrically connected through a bus bar 15, and the bus bar 15 may be fixed by a fastening means such as a nut 16 and the like. Thus, the battery module 100 may be used as a power device by electrically connecting the plurality of battery cells 10 as a bundle. As the battery cell 10, a rechargeable battery such as a lithium secondary battery may be used. The battery module 100 may be a 48 V battery used in a vehicle-related application. In general, the battery cell 10 generates a large amount of heat while performing charging and discharging. The generated heat is accumulated in the battery cell 10, and accelerates deterioration of the battery cell 10. Thus, the battery module 100 includes the heat exchange member 110 that is provided to be adjacent to the bottom side of the battery cell 10 to cool the battery cell 10. Further, a means for detecting a temperature of the battery cell 10 is included for safe operation of the battery module 100. Such a temperature detection means includes a protection circuit module and a temperature sensor (not shown in FIG. 1).

(13) FIG. 2 is a partial cross-sectional view of a single battery call 10 of the battery module 100 in FIG. 1. FIG. 3 is a partially enlarged cross-sectional view of one area of the battery cell shown in FIG. 2, in which temperature measurement with respect to the battery cell 10 is carried out. Referring to FIG. 2 and FIG. 3, the battery module 100 includes a protection circuit module 130 electrically connected to the battery cell 10. In addition, the protection circuit module 130 is electrically connected with a temperature sensing element 150 through a flexible printed circuit board 140.

(14) In general, each battery cell 10 of the battery module 100 is electrically connected to the protection circuit module 130. According to the present exemplary embodiment, only one protection circuit module 130 is connected to all the battery cells 10 of the battery module 100. However, two or more individual protection circuit modules may be connected to one battery cell or a set of battery cells.

(15) The protection circuit module 130 is placed at a side surface of the battery cell 10 such that a gap is formed between a surface of the battery cell 10 and a surface of the protection circuit module 130 which faces the battery cell 10. In the present exemplary embodiment, the protection circuit module 130 is disposed on an upper surface of the battery cell 10, in which the electrode terminals 11 and 12 are disposed. In particular, the protection circuit module 130 is electrically connected with the battery cell 10 to control charging and discharging, and prevents excessive charging/discharging of the battery call 10.

(16) The protection circuit module 130 includes a rigid printed circuit board 131 having connection terminals 132a and 132b for connection of the terminals 11 and 12 of the battery cell 10, and at least one semiconductor element 133 disposed at an upper surface of the rigid printed circuit board 131. The semiconductor element 133 may include an integrated circuit formed to compare a measurement temperature of the battery cell 10 with a threshold value for an allowable battery cell temperature. The circuit board 131 includes a wiring pattern (not shown) formed on a surface thereof. A body of the circuit board 131 may be made of a rigid electrically insulating material such as a polyimide (PI) or polyethylene (PET). The wiring pattern may be formed of an electrically conductive material such as copper (Cu), titanium (Ti), nickel (Ni), or palladium (Pd).

(17) The connection terminals 132a and 132b may be formed by partially exposing the wiring pattern, or as implemented in the present exemplary embodiment, may be formed by further providing a conductive material such as gold (Au) and the like to the exposed portion of the wiring pattern.

(18) The semiconductor element 133 applies a signal for controlling operation of the battery cell 10. In particular, the semiconductor element 133 controls charging and discharging through a high-current line of the battery cell 10. Further, the semiconductor element 133 applies a signal that indicates a voltage, a current, and a temperature of the battery cell 10 to prevent, for example, over-charging or over-discharging.

(19) For this, the semiconductor element 133 applies temperature information of the battery cell 20 from the temperature sensing element 150 through the flexible printed circuit board 140, and controls operation of the battery cell 10. Here, information on the voltage, the current, and the temperature may be transmitted to the semiconductor element 133 through the wiring pattern of the circuit board 131.

(20) The flexible printed circuit board 140 connects the temperature sensing element 150 and the protection circuit module 130 that are provided on the surface of the battery cell 10. According to an exemplary embodiment of the present invention, each of the battery cells 10 of the battery module 100 includes at least one temperature sensing element 150 to individually measure a temperature of each battery cell 10. However, in some applications, a minimum of two temperature sensing elements 150 is sufficient in the battery module 100.

(21) The flexible printed circuit board 140 includes a sense line (not shown) for transmitting a signal from the temperature sensing element 150 connected thereto to the protection circuit module 130. Accordingly, the protection circuit module 130 can check a temperature value of the corresponding battery cell 10.

(22) In addition, the flexible printed circuit board 140 extends between the protection circuit module 130 and the temperature sensing element 150. Since the flexible printed circuit board 140 can be easily bent, connection between parts can be stably maintained even if the battery cell 10 or the protection circuit module 130 moves in the housing 30. In more detail, the flexible printed circuit board 140 extends while penetrating a slit 135 in the circuit board 131, and one end of the flexible printed circuit board 140 is electrically connected with the wiring pattern of the protection circuit module 130 at the top surface of the circuit board 131. Accordingly, a connector (not shown) that can contact the sense line of the flexible printed circuit board 140 can be provided with general soldering and the like on the top surface of the circuit board 131.

(23) The temperature sensing element 150 is provided at one side of the battery cell 10. The temperature sensing element 150 may be a temperature sensor, and when the temperature sensing element 150 is, for example, a negative characteristic (NTC) thermistor, an electrical resistance value may be reduced to a negative temperature coefficient as a temperature of the battery cell 10 is increased, but when the temperature sensing element 150 is provided as a positive characteristic (PTC) thermistor, the electrical resistance value is increased as the temperature of the battery cell 10 is increased. Since the temperature sensing element 150 sensitively reacts to a temperature and thus resistance of the temperature sensing element 150 is changed depending on a temperature, the protection circuit module 130 can control charging and discharging of the battery cell 10.

(24) Specifically, the temperature sensing element 150 is provided as a chip thermistor. The chip thermistor can be simply connected to the circuit board 131 of the protection circuit module 130 through the flexible printed circuit board 140 by a solder mounting process, and accordingly, the number of processes can be reduced. Moreover, such a solder mounting process can be automated.

(25) In order to fix the temperature sensing element 150 to the top surface of the battery cell 10, a foam member 160 is provided between the protection circuit module 130 and a part of the flexible printed circuit board 140 that supports the temperature sensing element 150. Thus, the temperature sensing element 150 is pressurized to the top surface of the battery cell 10 by the foam member 160 inserted between the flexible printed circuit board 140 and the protection circuit module 130. Selectively, the temperature sensing element 150 may be fixed to the top surface of the battery cell 10 that includes a conductive adhesive layer 170.

(26) The foam member 160 may be formed of an electrically insulating material. The foam member 160 is preferably formed of a polymer material such as an elastomer so as to attenuate the relative movement between the battery cell 10 and the protection circuit module 130. Materials useful as the foam member include polyurethane and the like.

(27) FIG. 4 is a partial perspective view of the battery module 100 including the temperature sensing element 150 that is combined with a rigid printed circuit board 131 through the flexible printed circuit board 140. For convenience in description, the battery cell 10 and the foam member 160 are not illustrated in FIG. 4, and the rigid printed circuit board 131 is semi-transparently illustrated by dotted lines. As shown in the drawing, the flexible printed circuit board 140 extends to a surface that opposes the battery cell from a surface that faces the battery cell through the slit 135 of the rigid printed circuit substrate 131. The flexible printed circuit board 140 is combined with a wiring pattern (not shown) at the top surface of the rigid printed circuit board 131.

(28) FIG. 5 is a partial perspective view of the battery module 100 to which the foam member 160 of FIG. 4 is additionally illustrated.

(29) While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

DESCRIPTION OF SYMBOLS

(30) TABLE-US-00001 10: battery cell 133: semiconductor element 100: battery module 135: slit 11, 12: electrode terminal 140: flexible printed circuit board 130: protection circuit module 150: temperature sensing element 131: right printed circuit board 160: foam member 132a, 132b: connection terminal 170: heat conductive adhesive layer