JP2004063397A - Battery, battery pack, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery the temperature of which is quickly raised, a battery pack composed of connected batteries, and to provide a vehicle having a good start performance at low temperatures. <P>SOLUTION: The battery 10 has a positive electrode terminal 111 and a negative electrode terminal 112 to lead out electricity. A temperature sensor 220 measures the temperature of a battery main body 100. Base on a measured result from the temperature sensor 220, a control element 230 controls a relay 240 and switches from the short circuit state to the open state, or vice versa between the positive and negative electrode terminals 111 and 112. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery and a battery pack having a temperature raising function, and a vehicle equipped with the same.
[0002]
[Prior art]
In recent years, reduction of carbon dioxide emission has been urgently required for environmental protection. The automobile industry is expected to reduce carbon dioxide emissions through the introduction of electric vehicles (EVs) and hybrid electric vehicles (HEVs), and is keen to develop secondary batteries for motor drives, which are key to their practical use. Is being done. As a secondary battery, attention has been focused on a lithium ion secondary battery that can achieve high energy density and high output density.
[0003]
Various proposals have also been made regarding the structure of the battery. For example, a battery using a solid polymer electrolyte instead of a liquid electrolyte has been proposed. A battery using a solid polymer electrolyte is less likely to release gas from the electrolyte and separate components of the electrolyte, even when a high current is applied and the temperature rises, as compared to a battery using a liquid electrolyte. Therefore, the solid polymer electrolyte type battery has an advantage of high tolerance to a large current and a high temperature.
[0004]
Further, as disclosed in JP-A-2000-100471, a battery called a bipolar battery has been proposed. A bipolar battery has a plurality of bipolar electrodes in which a positive electrode active material is arranged on one surface of a plate-shaped conductor called a current collector and a negative electrode active material is arranged on the other surface. It has an electrolyte layer sandwiched between.
[0005]
As described above, various batteries have been proposed. However, in order to use these batteries as a power source for an electric vehicle (EV) or a hybrid electric vehicle (HEV), it is necessary to cope with cold regions where vehicles can be used. It needs to be considered. Since the battery uses a chemical reaction, there is a possibility that at low temperatures, the internal resistance increases and the output decreases. In particular, a battery using a solid polymer electrolyte as an electrolyte has a lower ion mobility in the electrolyte than a battery using a liquid electrolyte, and thus is strongly affected by a decrease in output at low temperatures. In order to solve this problem, conventionally, a technique has been proposed in which a heater is provided outside the battery, and when the temperature is low, current is supplied from an external power supply (for example, a generator) to the heater to heat the battery.
[0006]
However, according to this technique, since the battery is heated by a heater placed outside the battery, there is a problem that it takes time to raise the temperature of the battery to an appropriate temperature. Further, since an external power supply is required, there is a problem that the method cannot be applied in a situation without an external power supply such as a generator. Further, there is a problem that a space for installing an external power supply is required and a relatively complicated circuit for connecting the external power supply and the battery is required.
[0007]
The above problem is not limited to the case of a car, but is a problem common to all batteries used in equipment used at low temperatures.
[0008]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems. Therefore, an object of the present invention is to provide a battery capable of rapidly raising the battery temperature, an assembled battery in which a plurality of batteries are connected, and a vehicle with high startability at low temperatures. Another object of the present invention is to provide a battery and an assembled battery that can maintain the battery temperature at an appropriate temperature without requiring an external power supply.
[0009]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following means.
(1) The battery of the present invention is a battery having a positive electrode terminal and a negative electrode terminal, and includes a measuring unit for measuring the temperature of the battery, and a battery between the positive electrode terminal and the negative electrode terminal based on a measurement result by the measuring unit. And a switch unit for switching between a short-circuit state in which the terminals are short-circuited and an open state in which the terminals are opened.
(2) The battery of the present invention is a battery having a positive electrode terminal and a negative electrode terminal, and includes a heater provided inside the battery, a measuring unit for measuring the temperature of the battery, and a measurement result by the measuring unit. And a switch unit for switching between a state in which the heater is electrically connected and a state in which the heater is not connected between the positive electrode terminal and the negative electrode terminal.
(3) The assembled battery of the present invention is configured by connecting a plurality of the batteries described in any of the above.
(4) The vehicle of the present invention includes any one of the batteries or the assembled battery described above as a power source.
[0010]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the battery of this invention, since it can heat quickly from the inside of the unit cell layer of a battery, the battery temperature can be quickly raised to an appropriate temperature.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a perspective view schematically showing a battery according to one embodiment of the present invention. The battery 10 includes a battery body 100 from which a positive external terminal (positive terminal) 111 and a negative external terminal (negative terminal) 112 protrude, and a short circuit 200 for short-circuiting these two terminals 111 and 112. The short circuit 200 is preferably attached to the battery body 100 and is covered by a protective cover 210. The protective cover 210 protects the short circuit 200 from external impact. Here, a short circuit is a state in which two lines having a potential difference are directly connected by a conductor having a relatively small resistance or impedance, and does not include a state in which they are connected through a load such as an electric motor.
[0012]
The short circuit 200 includes a temperature sensor 220, a control element 230, a relay section 240, and a resistance element 250. Temperature sensor (measuring unit) 220 is, for example, a thermocouple, and is a sensor that measures the temperature of battery main body 100. The control element 230 is a circuit that drives the relay unit 240 based on the measurement result by the temperature sensor 220. The relay unit 240 is a relay for switching between a state in which the terminals 111 and 112 are short-circuited and a state in which the terminals are opened. The control element 230 and the relay element 240 are in a state in which the terminals 111 and 112 are short-circuited (hereinafter referred to as a “short-circuit state”) and a state in which the terminals 111 and 112 are open (hereinafter referred to as “open”). State)).
[0013]
The resistance element 250 is connected in series with the relay section 240. Therefore, in the above-described short-circuit state, the terminals 111 and 112 are short-circuited via the resistance element 250. That is, the resistance element 250 is used for adjusting the value of the current flowing between the terminals 111 and 112 (hereinafter referred to as “short-circuit current”) when the terminals 111 and 112 are short-circuited by the relay unit 240. Functions as a resistor.
[0014]
Next, the configuration of the battery body will be described. FIG. 2 is a cross-sectional view showing a state of the battery 10 of FIG. 1 viewed from the direction of arrow A. In FIG. 2, a short circuit 200 attached to the battery main body 100 is schematically shown. The surface of the battery body 100 is covered with a film sheet 130. As the film sheet 130, for example, a laminated film in which a metal layer such as aluminum, stainless steel, nickel, or copper and an insulating layer such as a polypropylene film are laminated is used.
The battery main body 100 includes a positive electrode active material layer 121, an electrolyte layer 122, and a negative electrode active material layer 123 therein in this order. In the present embodiment, the electrolyte layer 122 is composed of a solid polymer electrolyte substantially containing no solution. In other words, the battery 10 of the present embodiment is a solid electrolyte type battery. Note that a battery in which the electrolyte layer 122 is formed of a solid electrolyte has high tolerance to large currents and high temperatures. Therefore, there is a high tolerance for flowing a relatively large current between the terminals 111 and 112 by the short circuit 200.
[0015]
One set of the positive electrode active material layer 121, the electrolyte layer 122, and the negative electrode active material layer 123 forms one unit cell layer 140. Here, the unit cell layer refers to a minimum structural unit necessary for generating an electromotive force. In the battery main body shown in FIG. 2, five unit cell layers 140a to 140e are arranged in series.
[0016]
More specifically, the battery 10 shown in FIG. 2 is a so-called bipolar battery. Therefore, as shown in FIG. 3, the battery body 100 includes a plurality of bipolar electrodes 150 in which the positive electrode active material layer 121, the current collector 124, and the negative electrode active material layer 123 are stacked in this order, and the adjacent bipolar electrodes 150. It has an electrolyte layer 122 sandwiched between the electrodes 150. By alternately arranging the plurality of bipolar electrodes 150 and the electrolyte layers 122 in this manner, the plurality of unit cell layers 140a to 140e connected in series are formed as described above.
[0017]
The structure shown in FIG. 2 can be produced, for example, by applying an electrolyte film on both surfaces of bipolar electrode 150 and then laminating a plurality of bipolar electrodes to which the electrolyte film is applied. In particular, the plurality of bipolar electrodes are stacked such that the positive electrode active material layer 121 and the negative electrode active material layer 123 face each other with the electrolyte film interposed therebetween. In this case, the bonded electrolyte film corresponds to the electrolyte layer 122.
[0018]
The current collector 124 shown in FIG. 3 is a metal plate, for example, a stainless steel foil. Of course, another substance such as aluminum, copper, titanium, nickel, or an alloy thereof may be used as the pyroelectric body 124. Further, the surface of current collector 124 may be covered with aluminum or the like.
[0019]
The positive electrode active material layer 121 is formed on one surface of the current collector 124. More specifically, the positive electrode active material layer 121 is a positive electrode slurry prepared by mixing a positive electrode active material, a conductive auxiliary, a solid polymer electrolyte, a supporting salt, a viscosity adjusting solvent, and a polymerization initiator in a predetermined ratio. Is applied to one surface of the current collector 124 and cured by thermal polymerization or photopolymerization.
[0020]
Here, the positive electrode active material is LiMn. ₂ O ₄ And the like. However, different from this embodiment, a composite oxide of another transition metal and lithium may be used. For example, as a positive electrode active material, LiCoO ₂ Li-Co based composite oxides such as LiNiO ₂ Li-Ni-based composite oxides such as LiFeO ₂ Li.Fe-based composite oxides such as these may be used. In addition, the conductive additive works to enhance the electron conductivity between the active material particles. The conductive assistant is, for example, acetylene black. Note that carbon black or graphite may be used instead of acetylene black as the conductive additive. The solid polymer electrolyte contained in the positive electrode active material layer 121 works to increase ion conductivity and ion diffusion in the active material layer. The solid polymer electrolyte may be any polymer having ion conductivity, and is not particularly limited. Examples of the polymer having ion conductivity include polyethylene oxide (PEO), polypropylene oxide (PPO), and a copolymer thereof.
[0021]
As a supporting salt (lithium salt), LiN (SO ₂ C ₂ F ₅ ) ₂ Can be used. However, LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ Or a mixture thereof. The viscosity adjuster is a solvent for adjusting the viscosity when forming the slurry, and in the present embodiment, N-methyl-2-pyrrolidone (hereinafter, referred to as “NMP”) is used. However, other viscosity modifiers may be used. As the polymerization initiator, azobisisobutyronitrile, which is a thermal polymerization initiator, is used. However, when the positive electrode active material layer 121 is cured by photopolymerization, a photopolymerization initiator such as benzyl dimethyl ketal is used.
[0022]
On the other hand, the negative electrode active material layer 123 is formed by mixing a negative electrode slurry prepared by mixing the negative electrode active material, the conductive auxiliary agent, the solid polymer electrolyte, the supporting salt, the clay adjusting solvent, and the polymerization initiator in a predetermined ratio, into a current collector. 124 is formed on the other surface (the surface opposite to the surface on which the positive electrode slurry is applied) and cured by thermal polymerization or photopolymerization.
[0023]
The configuration of the negative electrode active material layer 123 is basically the same as the above-described positive electrode active material layer except for the type of the negative electrode active material to be used, and thus a detailed description is omitted. Preferably, the negative electrode active material is Li ₄ Ti ₅ O ₁₂ And a composite oxide of titanium and lithium. However, a composite oxide of another transition metal and lithium may be used as the negative electrode active material.
[0024]
Next, the electrolyte layer 122 will be described. The electrolyte layer 122 is formed on both surfaces of the bipolar electrode 150 and is a layer made of a polymer having ion conductivity. In the present embodiment, a known solid polymer electrolyte such as polyethylene oxide (PEO), polypropylene oxide (PPO), or a copolymer thereof is used for the electrolyte layer 122. The electrolyte layer 122 contains a lithium salt in order to secure ion conductivity. Further, a polymerization initiator is added to cure the electrolyte layer 122 by polymerization. For example, a thermal polymerization initiator such as azobisisobutyronitrile and a photopolymerization initiator such as benzyldimethyl ketal are used as the polymerization initiator.
[0025]
Next, an equivalent electric circuit of the battery 10 configured as described above will be described. FIG. 4 is a diagram showing an equivalent electric circuit of the battery 10 shown in FIG. Each of the unit cell layers 140a to 140e described above is an element that generates an electromotive force, and includes an internal resistance. Therefore, each cell layer 140 corresponds to a pair of DC power supply 141 and electric resistance 142. For example, the battery 10 shown in FIG. 2 includes five unit cell layers 140a to 140e connected in series. The five unit cell layers 140a to 140e correspond to a configuration in which five sets of a DC power supply 141 and an electric resistor 142 are connected in series. Both ends of this configuration are extended as a positive external terminal 111 and a negative external terminal 112, and a relay 240 and an electric resistor 142 are connected in series between the positive external terminal 111 and the negative external terminal 112. .
[0026]
More specifically, one end of the relay unit 240 is connected to one terminal (the terminal 112 in the figure) of the positive external terminal 111 or the negative external terminal 112. The other end of relay section 240 is connected to one end of resistance element 250. The other end of the resistance element 250 is connected to the remaining terminal (the terminal 111 in the figure) of the positive external terminal 111 or the negative external terminal 112. As a result, a circuit loop is formed by the terminal 112, the relay unit 240, the electric resistor 142, and the other terminal 111.
[0027]
The control element 230 is connected to both terminals 111 and 112 and receives power from the battery body 111. A temperature sensor 220 is connected to the control element 230, and the control element 230 receives a temperature measurement result of the temperature of the battery body 100 by the temperature sensor 220. When the temperature sensor 220 is a thermocouple, the control element 230 receives a temperature measurement result as a voltage. Further, the control element 230 is connected to the control terminal of the relay section 240 described above. The control element 230 supplies a predetermined signal to the control terminal of the relay section 240 based on the temperature measurement result from the temperature sensor 220. Relay section 240 switches between a short-circuit state and an open state.
[0028]
The battery 10 according to the present embodiment configured as described above operates as follows. FIG. 5 is a flowchart showing the operation of the battery according to the present embodiment.
[0029]
First, the temperature sensor 220 starts measuring the temperature of a predetermined portion of the battery body 100 (step S100). For example, the temperature measurement may be started in conjunction with an instruction to start a device (for example, an automobile) using battery 10 as a power supply. The measurement result of the battery temperature is transmitted to the control element 230. When the temperature sensor 220 is a thermocouple, the measurement result of the battery temperature is obtained as a voltage.
[0030]
The control element 230 determines whether the battery temperature measured by the temperature sensor 220 is lower than a predetermined first temperature (first threshold) (Step S101). When the temperature sensor 220 is a thermocouple, a voltage corresponding to the measured battery temperature is compared with a reference voltage corresponding to the first threshold. As a result of the comparison, when the battery temperature measured by the temperature sensor 220 is equal to or higher than a predetermined first temperature (first threshold value) (Step S101: NO), the battery 10 is heated because the battery temperature is sufficiently high. No need to do. Therefore, the process ends. On the other hand, if the battery temperature measured by the temperature sensor 220 is lower than the predetermined first temperature (first threshold) (step S101: YES), it is necessary to increase the battery temperature, so step S102. Move to the processing of. For example, the reference first temperature is any temperature within a range of about -40 to -10C, and more preferably about -30C. However, the first temperature is not limited to this value and is appropriately determined according to the performance and specifications of the battery 10.
[0031]
Next, in step S102, the control element 230 outputs a signal to the relay unit 240 as a process for raising the battery temperature. As a result, relay section 240 short-circuits between positive external terminal 111 and negative external terminal 112. As described above, the functions in step S101 and step S102 correspond to a switch unit that switches between a state in which the terminals 111 and 112 are short-circuited and a state in which the terminals are opened based on the temperature measurement result. As described above, a short-circuit current flows between the terminals 111 and 112 and the inside of the battery 100. As shown in FIG. 4, since internal resistance (corresponding to the electric resistance 142 in FIG. 4) exists inside the battery 100, Joule heat is generated and the battery 100 is heated from the inside. In the short-circuit state, the terminals 111 and 112 are short-circuited via the resistance element 250. The short-circuit current differs depending on the resistance value of the resistance element 250. Here, the short-circuit current differs depending on the specifications and requirements of the battery and is set in advance. The short-circuit current also depends on the internal resistance of the battery 10. In particular, as described above, the value of the internal resistance of the battery 10 increases as the temperature of the battery 10 decreases.
[0032]
As described above, the value of the short-circuit current is different depending on various conditions. Large current can flow. In addition, as described with reference to FIGS. 2 and 3, when the electrolyte layer of the battery 10 is a solid electrolyte layer, the value of the short-circuit current should be set relatively large as compared with a battery using a liquid electrolyte. Can be. Therefore, the temperature of the battery 10 can be suitably raised.
[0033]
Next, the control element 230 determines whether or not the battery temperature measured by the temperature sensor 220 has become equal to or higher than a predetermined second temperature (second threshold) (step S103). When the temperature sensor 220 is a thermocouple, a voltage corresponding to the measured battery temperature is compared with a reference voltage corresponding to the second threshold value. As a result of the comparison, when the battery temperature measured by the temperature sensor 220 is lower than the second predetermined temperature (first threshold) (step S103: NO), the temperature increasing process in step S102 is continued, If the battery temperature measured by the temperature sensor 220 is equal to or higher than a predetermined second temperature (first threshold value) (step S103: YES), the process proceeds to step S104. Note that the reference second temperature is, for example, about 0 to 50 ° C. However, the second temperature is not limited to this value, and is appropriately determined according to the performance and specifications of the battery 10. In addition, as described with reference to FIGS. 2 and 3, when the electrolyte layer of the battery 10 is a solid electrolyte layer, the second temperature can be set higher than that of a battery using a liquid electrolyte. Also, unlike the present embodiment, it is possible to automatically open the terminals 111 and 112 when a predetermined time elapses without comparing with the second temperature.
[0034]
In step S104, as a process when the battery temperature has sufficiently risen, control unit 230 stops outputting a signal to relay unit 240, and as a result, relay unit 240 returns to the open state. As a result, the relay unit 240 ends the short circuit between the positive external terminal 111 and the negative external terminal 112, and switches between the two terminals 111 and 112 to the open state.
[0035]
As described above, according to the battery of the present embodiment, the following effects can be obtained.
(A) The temperature is raised by using the energy of the battery body 100 itself without requiring an external power supply such as a generator or a separately provided battery. Therefore, even in an environment where an external power supply cannot be used, the temperature of the battery body 100 is raised to an appropriate temperature, and the performance of the battery is exhibited.
(B) Since an external power supply is not required, an installation place for the external power supply is unnecessary.
(C) The battery body 100 can be heated from the inside by the Joule heat caused by the internal resistance of the battery body 100 itself. Therefore, compared to the case where heating is performed from the outside of the battery main body 100, the temperature raising efficiency is higher, and the temperature reaches the appropriate temperature in a short time.
(2) In addition, by exchanging current with an external power supply or an external battery, the temperature of the battery main body 100 can be increased more efficiently than when heating is performed from the inside of the battery.
(E) Further, in the case of a battery in which the electrolyte layer 122 is made of a solid polymer electrolyte, there is little gas ejection and separation of the electrolyte, and high tolerance to a large current and a high temperature is obtained. It is highly adaptable to battery temperature rising technology using a short circuit current.
(F) In particular, a bipolar battery has a configuration in which a plurality of unit cell layers 140 are connected in series, so that the energy output is high, and this energy can be used for raising the battery temperature. Further, many bipolar batteries use a solid polymer electrolyte, and thus have the same effect as (e).
(G) When the external terminal 111 and the external terminal 112 are short-circuited, the electric resistance 142 for adjustment electrically connected between the terminals 111 and 112 is provided. Can be set.
(Second embodiment)
In the first embodiment, the case where the battery temperature is raised by using the energy of the battery and utilizing the Joule heat caused by the internal resistance of the battery has been described. The battery of the second embodiment uses the same energy as the battery itself, but is similar to the battery of the first embodiment except that the battery temperature is increased by a heater embedded inside the battery. This is different from the battery of the first embodiment. In the following description, the same members as those of the first embodiment are denoted by the same reference numerals.
[0036]
FIG. 6 is a cross-sectional view of the battery of the present embodiment. As shown in FIG. 6, the basic configuration of the battery 10 is substantially the same as that of the first embodiment. That is, the battery 10 has the unit cell layer 140 including the positive electrode active material layer 121, the electrolyte layer 122, and the negative electrode active material layer 123 in this order. More specifically, the battery 10 includes a plurality of bipolar electrodes 150 in which the positive electrode active material layer 121, the current collector 124, and the negative electrode material layer 123 are stacked in this order, and the battery 10 between adjacent bipolar electrodes 150 This is a bipolar battery having an electrolyte layer 122 sandwiched between them. The electrolyte layer 122 is a solid polymer electrolyte layer.
[0037]
A feature of the present embodiment is that the heater unit 300 is provided inside the battery main body 100, that is, any one of the positive electrode active material layer 121, the electrolyte layer 122, and the negative electrode active material. More preferably, as shown in FIG. 6, the heater unit 300 is characterized in that it is embedded inside the electrolyte layer 122.
[0038]
FIG. 7 is a diagram schematically illustrating the heater section 300 in one electrolyte layer 122. FIG. In the case of the battery 10 provided with a plurality of electrolyte layers 122, the heater section 300 is embedded in each electrolyte layer 122. The heater section 300 is, for example, a linear or foil-shaped electric resistance made of a metal such as a nickel-chromium alloy. For example, as shown in FIG. 7, the metal wire is processed into a shape that heats the entire inside of the electrolyte layer 122. Then, after disposing the metal wire inside the electrolyte layer 122 before curing, the electrolyte layer 122 is cured by polymerization. As a result, the electrolyte layer 122 in which the heater section 300 is embedded is formed. In addition, as described above, a multilayer structure of the bipolar electrode and the electrolyte layer 122 can be manufactured by overlapping a plurality of bipolar electrodes 130 each having a surface coated with an electrolyte film, but in this case, By sandwiching the metal wire when the bipolar electrodes 130 are overlapped with each other, the electrolyte layer 122 in which the heater unit 300 is embedded can be formed.
[0039]
Each heater unit 300 and relay unit 240 configured as described above are connected in series between the positive external terminal 111 and the negative external terminal 112. More specifically, one end of the relay unit 240 is connected to one terminal (the terminal 112 in the figure) of the positive external terminal 111 or the negative external terminal 112, and the other end of the relay unit 240 is connected to each heater unit. 300 is connected to one end. The other end of each heater section 300 is connected to the remaining terminal (terminal 111 in the figure). As a result, a circuit loop is formed by the terminal 112, the relay unit 240, the respective heater units 300, and the other terminals 111.
[0040]
Further, control element 230 outputs a signal to relay section 240 based on the temperature detection result of the battery temperature from temperature sensor 220. As a result, based on the detected battery temperature, relay section 240 switches between a state in which heater section 300 is electrically connected between both terminals 111 and 112 and a state in which heater section 300 is not connected. If necessary, another electric resistance element for adjusting the current may be connected in series to the heater unit 300.
[0041]
The operation of battery 10 in the present embodiment is the same as the operation shown in FIG. 5 described in the first embodiment. Therefore, detailed description is omitted. In brief, when the battery temperature measured by the temperature sensor 220 is lower than the first temperature, the relay unit 240 connects the heater unit 300 between the terminals 111 and 112 until the battery temperature reaches the second temperature. Make an electrical connection. Therefore, current flows from the positive external terminal 111 to the negative external terminal 112 through the heater unit 300. As a result, the heater 300 generates Joule heat, and the battery 100 is heated by Joule heat generated inside. Then, when the battery temperature measured by the temperature sensor 220 becomes equal to or higher than the second temperature, the relay unit 240 is opened, and the terminals 111 and 112 are opened.
[0042]
As described above, the second embodiment has been described, but the present invention is not limited to this case. For example, the heater 300 can be coated so as not to contact the positive electrode active material layer 121 and the negative electrode active material layer 123.
[0043]
As described above, the battery according to the present embodiment has the following effects.
(H) Since the heater section 300 (heater resistance) is provided inside the battery 10, that is, any one of the positive electrode active material layer 121, the electrolyte layer 122, and the negative electrode active material layer 123, Can be heated from above, and the effect of raising the temperature is high.
(Re) It is not necessary to attach the heater section 300 to the outside of the battery body 100, and the size can be reduced.
(V) By connecting the heater section 300 between the positive electrode external terminal 111 and the negative electrode external terminal 112, the battery 10 can be heated from the inside by the Joule heat by the heater section 300 together with the Joule heat by the internal resistance of the battery body 100. it can.
(V) When the heater section 300 is embedded in the solid polymer electrolyte layer 122, the heater section 300 is embedded before the solid polymer electrolyte is cured, and the heater section 300 is fixed by polymerizing the solid polymer electrolyte. Can be fixed at the position. Therefore, the configuration of the fixing means is simplified.
(Third embodiment)
Next, an assembled battery in which a plurality of the batteries 10 described in the first or second embodiment are electrically connected will be described.
[0044]
FIG. 8 is a diagram showing the battery pack of the present embodiment. The battery pack 400 is configured by connecting a plurality of the electricity 10. The plurality of batteries 10 are connected in series and / or in parallel. As a result, a battery pack 400 that can achieve a desired output voltage and capacity can be configured. When the battery pack 400 is configured, the temperature sensor 220 and / or the control element 230 described above need not be separately provided for each battery 10, but may be provided in any part of the battery pack 400. Is enough.
[0045]
FIG. 9 is a diagram illustrating an external shape of an electric vehicle (EV) using the battery 10 described in the first or second embodiment or the battery pack 400 as a power source. In the example shown in FIG. 9, the battery pack 400 is mounted below the driver's seat of the electric vehicle 500. The electric vehicle 500 runs using the assembled battery 400 as a power source while rotating an electric motor (not shown). The operation of the electric vehicle 500 in a cold region needs to be guaranteed. For example, the electric vehicle 500 is required to start in a low temperature environment of about −30 ° C.
[0046]
Before the electric motor is rotated, the battery pack 400 is cooled in accordance with the temperature, and in a low-temperature environment, the internal resistance is high, so that sufficient startability may not be obtained. Therefore, when the user operates the switch inside the driver's seat to start the car, first, the temperature of the battery pack 400 is measured, and if the temperature is lower than the first temperature, the relay unit 240 is opened. To short-circuit state. As a result, Joule heat due to the internal resistance of the battery 100 and / or Joule heat due to the heater unit 300 provided in the electrolyte layer 122 of the battery 100 are generated, and the assembled battery 400 is heated from the inside. . Then, after waiting for the temperature of the battery pack 400 to reach the second temperature, the relay unit 240 switches the terminals of the battery 100 to the open state. For example, by passing a current of about several tens of degrees C for several seconds, the batteries 100 constituting the battery pack 400 are evenly heated, and the temperature of the battery pack 400 is quickly raised. As a result, even in a low temperature environment, the electric vehicle 500 can be started in a short time, and the startability is improved. It is needless to say that the present invention is applied to other types of vehicles such as hybrid electric vehicles instead of electric vehicles 500.
[0047]
As described above, according to the electric vehicle 500 of the present invention, even in the case where the electric vehicle 500 is placed in a low-temperature environment, a state where a sufficient output is possible is promptly achieved.
[0048]
Although the preferred embodiments of the present invention have been described above, the present invention is not limited to this case, and various modifications, additions, and omissions are possible within the scope of the technical idea of the present invention.
[0049]
For example, in the above description, the case where the present invention is applied to a solid polymer electrolyte type battery has been described, but the present invention is not limited to this case. Certainly, it is preferable to use a solid polymer electrolyte type battery from the viewpoint of acceptability to a large current and a high temperature. However, the set value of the second temperature and the value of the resistance element 250 for adjustment are appropriately adjusted. By setting, the present invention can be applied to a liquid electrolyte type battery or a gel electrolyte type battery. In addition, in order to prevent an overcurrent from flowing more than expected due to a rise in the temperature of the battery body and a decrease in the internal resistance value, a shutoff circuit that appropriately cuts off the circuit when an overcurrent flows is provided. It may be added.
[0050]
Further, in the above description, the case where the present invention is applied to the bipolar battery in which the plurality of unit cell layers 140 are connected in series inside the battery main body 100 has been described. However, the present invention is applicable to other types of batteries. Of course.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a battery according to a first embodiment.
FIG. 2 is a cross-sectional view schematically showing the battery of FIG.
FIG. 3 is a view showing a structure of a bipolar electrode provided in the battery of FIG. 1;
FIG. 4 is an equivalent electric circuit diagram of the battery of FIG.
FIG. 5 is a flowchart showing the operation of the battery of FIG.
FIG. 6 is a cross-sectional view schematically showing a battery according to a second embodiment.
FIG. 7 is a diagram showing a structure of an electrolyte layer provided in the battery of FIG.
FIG. 8 is a diagram showing an assembled battery composed of the batteries of FIG. 1 or FIG.
FIG. 9 is a diagram showing a vehicle including the battery pack of FIG. 8;
[Explanation of symbols]
100 ... battery body,
111 ... Positive electrode external terminal,
112 ... negative electrode external terminal
121 ... Positive electrode active material layer,
122 ... electrolyte layer,
123 ... negative electrode active material layer,
124 ... current collector,
140 ... cell layer,
150 ... Bipolar electrode
200 ... short circuit,
220 ... temperature sensor,
230 ... control element,
240 ... relay part,
250 ... resistance element,
300: heater part,
400 ... battery pack,
500 ... Electric vehicle.

Claims (11)

A battery having a positive terminal and a negative terminal,
A measuring unit for measuring the temperature of the battery,
A battery comprising: a switch unit that switches between a short-circuit state in which the positive electrode terminal and the negative electrode terminal are short-circuited and an open state in which the terminals are opened based on a measurement result by the measurement unit. An electrical resistance unit connected in series with the switch unit between the positive terminal and the negative terminal,
2. The battery according to claim 1, wherein in the short-circuit state, the positive terminal and the negative terminal are short-circuited via the electric resistance unit. 3. When the battery temperature measured by the measuring unit is lower than a predetermined first temperature, the switch unit short-circuits the positive terminal and the negative terminal until the battery temperature reaches a predetermined second temperature. The battery according to claim 1, wherein: A battery having a positive terminal and a negative terminal,
A heater provided inside the battery;
A measuring unit for measuring the temperature of the battery,
A battery comprising: a switch unit that switches between a state in which the heater is electrically connected and a state in which the heater is not connected between the positive electrode terminal and the negative electrode terminal based on a measurement result by the measurement unit. The switch section, when the temperature of the battery measured by the measuring section is lower than a predetermined first temperature, the voltage between the positive terminal and the negative terminal until the temperature of the battery reaches a predetermined second temperature. The battery according to claim 4, wherein the heater is electrically connected. The battery according to claim 4, wherein the heater is provided inside an electrolyte. The battery according to any one of claims 1 to 6, wherein the battery is a battery using a solid polymer as an electrolyte. The battery has a plurality of bipolar electrodes in which a positive electrode active material layer including a positive electrode active material, a current collector, and a negative electrode active material layer including a negative electrode active material are stacked in this order, and between adjacent bipolar electrodes. The battery according to any one of claims 1 to 7, wherein the battery is a bipolar battery having a structure in which an electrolyte is sandwiched between the batteries. The battery according to claim 1, wherein the battery is a lithium ion secondary battery including a composite oxide of lithium and a transition metal as a positive electrode active material and a composite oxide of lithium and a transition metal or carbon as a negative electrode active material. 9. The battery according to any one of items 1 to 8. A battery pack comprising a plurality of the batteries according to claim 1 connected to each other. A vehicle comprising the battery according to any one of claims 1 to 9 or the battery pack according to claim 10 as a power supply.

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