Safety apparatus and protection method of secondary battery for electric vehicle using switch

Abstract

The present invention relates to a safety apparatus and a protection method of a secondary battery, which can prevent explosion and fire of the secondary battery using a switch or a rupture switch attached on the outside of the secondary battery if a swelling degree of the secondary battery reaches a predetermined value when the secondary battery is swelled due to abnormal usage such as overcharge, short-circuit, reverse-connection and heat-exposure of large-capacity lithium polymer battery.

Claims

1. A rupture switch comprising: a first holding unit attached to the outside of a secondary battery for use in the electric vehicle and having holding holes provided on one side of a folded metal piece for attaching and holding to the secondary battery for use in the electric vehicle, a second holding unit having a holding hole provided on one end in another side of the folded metal piece for attaching and holding to the secondary battery for use in the electric vehicle, a third holding unit having a holding hole equipped on another end in the other side of the folded metal piece for attaching and holding to the secondary battery for use in the electric vehicle, a destruction unit equipped in a center portion between one side and the other side of the folded metal piece, and a fifth switch lead and a sixth switch lead attached to the second holding unit and the third holding unit, wherein the rupture switch is destroyed and controls a relay connecting the secondary battery with a drive motor generating a power of the electric vehicle when the secondary battery undergoes a displacement greater than a prescribed value.

2. The rupture switch according to claim 1, wherein the destruction unit comprises a first destruction unit and a second destruction unit, which are destroyed if the secondary battery for use in the electric vehicle undergoes a displacement greater than a prescribed value.

3. The rupture switch according to claim 1, wherein the rupture switch is applied with a flame-resistant insulating material having plasticity on its overall surface in order to prevent diffusion of electric flame generated when the destruction unit is destroyed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

(2) FIG. 1(a) is a cross-sectional view showing a safety apparatus of a secondary battery according to prior art.

(3) FIG. 1(b) is a cross-sectional view showing a safety apparatus of a rupture disc-type secondary battery according to prior art.

(4) FIG. 2 is a conception view showing a pouch-type lithium polymer secondary battery.

(5) FIG. 3 is a conception view showing a switch apparatus according to the present invention.

(6) FIG. 4(a) is a conception view showing an adjacent switch.

(7) FIG. 4(b) is a state view showing on-state of the adjacent switch according to the present invention.

(8) FIG. 4(c) is a state view showing off-state of the adjacent switch according to the present invention.

(9) FIG. 5(a) is a conception view showing a micro switch.

(10) FIG. 5(b) is a state view showing on-state of the micro switch according to the present invention.

(11) FIG. 5(c) is a state view showing off-state of the micro switch according to the present invention.

(12) FIG. 6(a) is a conception view showing a rupture switch according to the present invention.

(13) FIG. 6(b) is a conception view showing the rupture switch attached to the pouch-type lithium polymer secondary battery according to the present invention.

(14) FIG. 7 is a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the rupture switch is applied according to the present invention.

(15) FIG. 8 is a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the adjacent switch is applied according to the present invention.

(16) FIG. 9 is a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the micro switch is applied according to the present invention.

(17) FIG. 10 is a sequential view showing a method of protecting destruction of the secondary battery for use in electric vehicle according to the present invention.

DETAILED DESCRIPTION

(18) TABLE-US-00001 Table of Reference Numbers 1: secondary battery pack 2: case 3: electrode assembly 4: secondary battery 5: projecting portion 6: cap cover 7: gas exhaust hole 8: cap 9: rupture disc 20: pouch-type lithium polymer secondary battery 21: first secondary battery 10: insulating gasket 22: second secondary battery 23: switch unit 24: operation inducing unit 31: first coupling body 32: second coupling body 33: first switch lead 34: second switch lead 35: sealing case 36: magnet 41: first stationary contact 42: second stationary contact 43: movable contact 44: third switch lead 45: fourth switch lead 46: spring 47: press button 48: housing 50: first holding unit 50-1: first holding hole 50-2: second holding hole 51-1: third holding hole 52-1: fourth holding hole 51: second holing unit 52: third holding unit 60: destruction unit 61: first destruction unit 62: second destruction unit 70: fifth switch lead 75: sixth switch lead 80: battery controller 81: output unit 90-1 to 90-n: rupture switches 100: battery relay coil unit 105: battery relay contact 106: first battery relay contact 107: second battery relay contact 110: secondary battery for use in electric vehicle 120: charging unit 130: inverter unit 140: drive motor 150-1 to 150-n: adjacent switches 160-1 to 160-n: micro switches

Best Mode

(19) Hereinafter, a safety apparatus and a protection method of a secondary battery for use in electric vehicle using a switch according to the present invention will be described in detail with reference to accompanying drawings. The accompanying drawings are provided as an example sufficiently to deliver an idea of the present invention to the person skilled in the art. Therefore, the present invention is not bounded by the drawings presented hereinafter but can be specified in another form. Further, like reference numerals denote like element throughout the following detailed description of the invention.

(20) At this time, if the technological terms and science terms used herein do not have any other definition, they have meanings that can be typically understood by the person skilled in the art. Further, known functions and structures which can unnecessary make obscure the subject matter of the present invention in the following description and accompanying drawings will be omitted.

(21) First, it will be described on a pouch-type secondary battery applied to the large capacity secondary battery according to the present invention, referring to FIG. 2.

(22) FIG. 2(a) is a front view of the pouch-type secondary battery, FIG. 2(b) is side view of the pouch-type secondary battery, and FIG. 2(c) is a side view illustrating that the pouch-type secondary battery is swollen due to abnormal operation such as overcharge, short-circuit and reverse connection.

(23) The pouch-type lithium polymer secondary battery 20 has an air-tight structure. If the pouch-type lithium polymer secondary battery 20 is exposed to excessive state such as overcharge, short-circuit, reverse-connection and heat exposure, the pouch-type lithium polymer secondary battery 20 generates gas therein. The pouch-type lithium polymer secondary battery 20 is swollen due to the gas. If the pouch-type lithium polymer secondary battery 20 continues to be swollen, a chemical material such as an electrolyte can be discharged from inside of the pouch-type lithium polymer secondary battery 20 and fire and explosion can be happened if the chemical material is severely discharged.

(24) Referring to FIG. 3, it will be described on a switch apparatus of the secondary battery for use in electric vehicle according to the present invention.

(25) First, the switch apparatus of the secondary battery for use in electric vehicle is provided between the secondary batteries for use in electric vehicle in which at least one secondary battery is stacked.

(26) As shown in FIG. 3, a first secondary battery 21 and a second secondary battery 22 are equipped with the switch apparatus. The switch unit 23 is provided one surface of the first secondary battery 21 and the operation inducing unit 24 is provided to operate the switch unit 24 on one surface of the second secondary battery 22 opposite to the switch unit 23.

(27) At this time, if the first secondary battery 21 and the second secondary battery 22 are swollen, the switch unit 23 comes close to the operation inducing unit 24 to make the first secondary battery 21 and the second secondary battery 22 no longer swollen.

(28) Then, the switch unit 23 can be equipped with an adjacent switch 150-1, a micro switch 160-1 and a rupture switch 90-1.

(29) Hereinafter, operations of the adjacent switch 150-1, the micro switch 160-1 and the rupture switch 90-1 will be described through embodiments, respectively.

Embodiment 1

(30) A first embodiment is directed to a safety apparatus and a protection method of the secondary battery for use in electric vehicle using the adjacent switch 150-1.

(31) FIG. 4(a) is a conception view of the adjacent switch; FIG. 4(b) is a state view showing on-state of the adjacent switch according to the present invention; FIG. 4(c) is a state view showing off-state of the adjacent switch according to the present invention; and FIG. 8 is a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the adjacent switch is applied according to the present invention.

(32) As shown in FIG. 4(a), a first coupling body 31 and a second coupling body 32 are provided within a sealing case 35 of the adjacent switch 150-1.

(33) At this time, the first coupling body 31 is connected to a first switch lead 33 and the second coupling body 32 is connected to a second switch lead 34. In addition, a magnet for controlling the first coupling body 31 and the second coupling body 32 is provided together with the adjacent switch 150-1.

(34) Meanwhile, an operation of the adjacent switch 150-1 will be briefly described as follows:

(35) The adjacent switch 150-1 becomes off-state if the magnet 36 is close to the adjacent switch 150-1, and it becomes on-state again if the magnet 36 is far away from the adjacent switch 150-1.

(36) Referring to FIG. 4(b) and FIG. 4(c), the on and off operation of the adjacent switch 150-1 will be described hereinafter.

(37) As shown in FIG. 4(b), the adjacent switch 150-1 of on-state is provided on one surface of the first secondary battery 21 and the magnet 36 is provided on one surface of the second secondary battery 22.

(38) As shown in FIG. 4(c), if the first secondary battery 21 and the second secondary battery 22 are swollen, the adjacent switch 150-1 is allowed to be close to the magnet 36. The first coupling body 31 and the second coupling body 32 which has been connected are separated by a prescribed distance due to a magnetic field of the magnet 36 so that the adjacent switch 150-1 is converted from on-state to off-state.

(39) The adjacent switch 150-1 having such operational state is provided in the secondary battery for use in electric vehicle 110 to protect the destruction of the secondary battery for use in electric vehicle.

(40) Referring to FIG. 8, it will be described on a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the adjacent switch is applied according to the present invention.

(41) As shown in FIG. 8, the protection circuit is structured such that at least one adjacent switch 150-1 is provided on an output unit 81 of a battery controller 80 and a battery relay coil unit 100 is connected to the adjacent switch 150-1.

(42) The power systematic view of the electric vehicle drive motor has a battery relay point of contact 105 provided between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140 to connect the secondary battery for use in electric vehicle 110 with the electric vehicle drive motor 140

(43) Further, a charging unit 120 for charging power generated from the secondary battery for use in electric vehicle 110 and an inverter unit 130 for controlling velocity and direction of the drive motor 140 are provided on the side of the drive motor 140.

(44) Herein, the relay is consisted of the battery relay coil unit 100 and the battery relay contact of point 105 to control a connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

(45) The battery relay coil unit 100 controls a first battery relay contact 106 and a second battery relay contact 107 of the battery relay contact 105 under the control of the battery controller 80.

(46) Further, a plurality of control signals outputted from the battery relay coil unit 100 in accordance with an output type of the battery controller 80 is sent to the first battery relay contact 106 and the second battery relay contact 107 to control the connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

Second Embodiment

(47) A second embodiment is directed to a safety apparatus and a protection method of the secondary battery for use in electric vehicle using the micro switch 160-1.

(48) FIG. 5(a) is a conception view showing a micro switch; FIG. 5(b) is a state view showing on-state of the micro switch according to the present invention; FIG. 5(c) is a state view showing off-state of the micro switch according to the present invention; and FIG. 9 is a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the micro switch is applied according to the present invention.

(49) As shown in FIG. 5(a), the micro switch 160-1 has a first stationary contact 41, a second contact 42 and a movable contact 43 provided within a housing 48.

(50) At this time, a third switch lead 44 is connected to the movable contact 43 and a fourth lead 45 is connected to the first stationary contact 41.

(51) Further, a press button 47 provided on one side of the movable contact 43 is projected to the outside of the housing 48 and a spring 46 is provided on the other side of the movable contact 43.

(52) Hereinafter, an operation of the micro switch 160-1 will be briefly described.

(53) The operation of the micro switch 160-1 becomes off-state if the press button 47 is pressed and becomes on-state again due to a force of the spring 46 if the press button 47 returns to an original state.

(54) Referring to FIGS. 5(b) and (c), the on and off operation-state of the micro switch 160-1 will be described.

(55) As shown in FIG. 5(b), the micro switch 160-1 of on-state in that the first stationary contact 41 is connected to the movable contact 43 is provided on one side of the first secondary battery 21.

(56) As shown in FIG. 5(c), if the first secondary battery 21 and the second secondary battery 22 are swollen, the second secondary battery 22 presses the press button 47 so that the movable contact 43 is separated from the first stationary contact 41 and connected to the second stationary contact 42 to cause the micro switch to be converted from on-state to off-state.

(57) The above-mentioned micro switch 160-1 is included in the secondary battery for use in electric vehicle 110 to protect the destruction of the secondary battery for use in electric vehicle 110.

(58) Referring to FIG. 9, it will be described on a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the micro switch is applied according to the present invention.

(59) As shown in FIG. 9, the protection circuit is structured such that at least one micro switch 160-1 is provided on the side of an output unit 81 of a battery controller 80 and a battery relay coil unit 100 is connected to the micro switch 160-1.

(60) The power systematic view of the electric vehicle drive motor has a battery relay contact 105 provided between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140 to connect the secondary battery for use in electric vehicle 110 with the electric vehicle drive motor 140

(61) Further, a charging unit 120 for charging power generated in the secondary battery for use in electric vehicle 110 and an inverter unit 130 for controlling velocity and direction of the drive motor 140 are provided on the side of the drive motor 140.

(62) Herein, the relay is consisted of the battery relay coil unit 100 and the battery relay contact 105 to control a connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

(63) The battery relay coil unit 100 controls a first battery relay contact 106 and a second battery relay contact 107 of the battery relay contact 105 under the control of the battery controller 80.

(64) Further, a plurality of independent control signals outputted from the battery relay coil unit 100 in accordance with an output type from the battery controller 80 is sent to the first battery relay contact 106 and the second battery relay contact 107 to control the connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

Third Embodiment

(65) A third embodiment is directed to a safety apparatus and a protection method of the secondary battery for use in electric vehicle using a rupture switch 90-1.

(66) FIG. 6(a) is a conception view of a rupture switch according to the present invention, and FIG. 6(b) is a conception view of the rupture switch attached to the pouch-type lithium polymer secondary battery.

(67) As shown in FIG. 6(a), the rupture switch 90-1 is consisted of a U type metal piece.

(68) The rupture switch 90-1 is attached on one surface of the pouch-type lithium polymer secondary battery 20 using a first holding unit 50 provided on one side of the U type metal piece and a second holding unit 51 and a third holding unit 52 provided on both end of the other side of the U type metal piece.

(69) The rupture switch 90-1 is held in the pouch-type lithium polymer secondary battery 20 using a first holding hole 50-1, a second holding hole 50-2, a third holding hole 51-1 and a fourth holding hole 52-1 provided in the first holding unit 50, the second holding unit 51 and the third holding unit 52 respectively.

(70) The rupture switch 90-1 is attached and held on one side of the pouch type lithium polymer secondary battery 20 and equipped with a destruction unit 60 consisted of a first destruction unit 61 and a second destruction unit 62 on a center portion of it.

(71) At this time, if the pouch type lithium polymer secondary battery 20 is exposed to overcharge, short-circuit, reverse connection or high temperature and thus undergoes displacement greater than a prescribed value, the destruction unit 60 is destroyed by sensing the displacement.

(72) Destroying the destruction unit 60 safely protects the pouch type lithium polymer secondary battery 20 by stopping the operation of the pouch type lithium polymer secondary battery 20 through a fifth switch lead 70 connected to the second holding unit 51 and a sixth switch lead 75 connected to the third holding unit 52 of the rupture switch 90-1.

(73) At this time, it is preferable to apply flame-resistant insulating material having plasticity to overall surface of the rupture switch 90-1, in order to prevent the diffusion of an electric fire generated when the destruction unit 60 of the rupture switch unit 90-1 is destroyed.

(74) Though the pouch-type lithium polymer secondary battery 20 can be taken as an example for the purpose of understanding the present invention, the rupture switch 901 can be attached to a typical secondary battery in various manners.

(75) Referring to FIG. 7, a battery control systematic view and a power systematic view of the electric vehicle drive motor, including a protection circuit to which the rupture switch is applied according to the present invention will be described.

(76) As shown in FIG. 7, the protection circuit has at least one rupture switch 90-1 provided on an output unit 81 of a battery controller 80 and a battery relay coil unit 100 connected to the rupture switch 90-1.

(77) The power systematic view of the electric vehicle drive motor has a battery relay contact 105 provided between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140 to connect the secondary battery for use in electric vehicle 110 with the electric vehicle drive motor 140

(78) Further, a charging unit 120 for charging power generated in the secondary battery for use in electric vehicle 110 and an inverter unit 130 for controlling velocity and direction of the drive motor 140 are provided on the side of the drive motor 140.

(79) Herein, the relay is consisted of the battery relay coil unit 100 and the battery relay contact of point 105 to control a connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

(80) The battery relay coil unit 100 controls a first battery relay contact 106 and a second battery relay contact 107 of the battery relay contact 105 under the control of the battery controller 80.

(81) Further, a plurality of independent control signals outputted from the battery relay coil unit 100 in accordance with an output type from the battery controller 80 is sent to the first battery relay contact 106 and the second battery relay contact 107 to control the connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

(82) Hereinafter, it will be described on the protection method of the secondary battery for use in electric vehicle using the adjacent switch 150-1, the micro switch 160-1 and rupture switch 90-1 according to the first embodiment, the second embodiment and the third embodiment respectively.

(83) Referring to FIG. 10, the protection method of the secondary battery for use in electric vehicle according to the present invention will be described below.

(84) The protection method of the secondary battery for use in electric vehicle 110 will be described taking as an example a case of using one rupture switch 90-1 for the purpose of understanding the present invention.

(85) First, the battery controller 80 of the electric vehicle outputs a control signal to operate the secondary battery for use in electric vehicle 110 and monitor a state of the electric vehicle (S10).

(86) If the secondary battery for use in electric vehicle 110 undergoes a displacement greater than a prescribed value, a physical displacement such as high temperature and internal pressure is occurred in the secondary battery for use in electric vehicle 110.

(87) The rupture switch 90-1 attached on one surface of the secondary battery for use in electric vehicle 110 senses the physical displacement of the secondary battery for use in electric vehicle 110.

(88) Then, the destruction unit 60 of the rupture switch 90-1 is destroyed if the physical displacement of the secondary battery for use in electric vehicle 110 is sensed (S20).

(89) Comparing with the rupture switch 901-, the adjacent switch 150-1 and the micro switch 160-1 become off-operation-state if the physical displacement of the secondary battery for use in electric vehicle 110 is sensed.

(90) The destruction of the rupture switch 90-1 is delivered to the battery controller 80 through the switch lead of the rupture switch 90-1.

(91) The battery controller 80 senses the destruction of the rupture switch 90-1 through the switch lead and controls the battery relay coil unit 100 to interrupt the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140.

(92) The battery relay coil unit 100 generates an interrupt control signal to interrupt the electric vehicle drive motor (S30).

(93) The interrupt control signal is delivered to the battery relay contact 105 via a magnetic signal system of the battery relay coil unit 100 to control the battery relay contact (S40).

(94) The battery relay contact 105 controls the first battery relay contact 106 and the second battery relay contact 107 in accordance with the interrupt control signal.

(95) The secondary battery for use in electric vehicle 110 can be safely protected by interrupting the connection between the secondary battery for use in electric vehicle 110 and the electric vehicle drive motor 140 under the control of the battery relay contact 105 (S50).

(96) Meanwhile, though only one battery relay coil unit 100 is shown for the purpose of understanding the present invention, the battery relay can control the first battery relay contact 106 and the second battery relay contact 107 independently through at least one relay coil in accordance with an output type of the battery controller 80.

(97) Further, though the protection method of the secondary battery for use in electric vehicle 110 using one rupture switch 90-1 is described for the purpose of understanding the present invention, it is possible to obtain the same effect as that of the protection method even when using the adjacent switch 150-1 and the micro switch 160-1.

(98) Further, the number of the adjacent switch 150-1, the micro switch 160-1 and the rupture switch 90-1 can be preferably a plural in accordance with the number of the secondary batteries used in the electric vehicle.

(99) Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.