JP4075487B2 - Power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power supply device configured by connecting different types of batteries in parallel.
[0002]
[Prior art]
As a power supply device configured by connecting different types of batteries in parallel, one disclosed in JP-A-11-332023 is known.
[0003]
In this power supply device, a high output density type battery and a high energy type battery are connected in parallel, and high output characteristics can be maintained for a long time.
[0004]
[Problems to be solved by the invention]
By the way, in general, the output characteristics of a high power density type battery are good at a relatively low temperature side, and the high energy type battery has a particularly bad output characteristic at a low temperature side. In addition, high power density batteries often have poorer life characteristics than high energy batteries.
[0005]
However, in the above prior art, the batteries are combined by paying attention only to the power density characteristics and the energy characteristics, and the temperature characteristics and life characteristics of the batteries are not considered.
[0006]
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply device capable of increasing battery life.
[0007]
[Means for Solving the Problems]
The present invention connects in parallel a low temperature type lithium battery capable of obtaining good output characteristics from a relatively low temperature side and a high temperature type lithium battery capable of obtaining good output characteristics on a relatively high temperature side. The high temperature type lithium battery was heated using a current flowing through the lithium battery .
[0008]
【The invention's effect】
Therefore, in the present invention, the low temperature type lithium battery and the high temperature type lithium battery are connected in parallel, and the high temperature type lithium battery is heated using the current flowing in the low temperature type lithium battery. The output characteristics of the high temperature type lithium battery can be improved.
[0009]
Moreover, by heating the high-temperature type lithium battery, by suppressing the operation of the lithium battery life characteristics is relatively low low temperature to expand the operating range of the high temperature type lithium battery that has excellent cycle life characteristics, power supply The life characteristics of the entire device can be improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a power supply device according to the present invention will be described below with reference to the accompanying drawings.
[0011]
1 and 2 show a first embodiment of a power supply apparatus according to the present invention, FIG. 1 is a schematic configuration diagram of the power supply apparatus, and FIG. 2 is a perspective view showing a specific configuration of the power supply apparatus.
[0012]
The power supply device 1 is configured by connecting an all-solid-state lithium battery SB as a high-temperature battery and an electrolyte lithium battery LB as a low-temperature battery in parallel.
[0013]
The all solid lithium battery SB is a battery using only a polymer solid electrolyte obtained by dissolving a lithium salt in PEO (polyethylene oxide), for example. This all-solid-state lithium battery SB is a high-temperature battery that does not provide sufficient output characteristics at low temperatures but can provide sufficient output characteristics at high temperatures, and has excellent life characteristics.
[0014]
The electrolyte lithium battery LB is, for example, a battery using an electrolyte obtained by dissolving a lithium salt in PC (propylene carbonate). The electrolyte lithium battery LB is a low-temperature battery that cannot obtain sufficient output characteristics at a high temperature, but can obtain sufficient output characteristics at a low temperature, and has inferior life characteristics as compared with the all-solid-state lithium battery SB.
[0015]
The two types of batteries SB and LB are both sheet-type batteries, which are stacked in the thickness direction and are in close contact with each other. That is, two all solid lithium batteries SB are sandwiched between two electrolyte lithium batteries LB.
[0016]
As shown in FIG. 2, the sheet type battery is also referred to as a laminate type, in which a plate-shaped battery element (battery body) is sandwiched between two laminate films 10 and 11, and the periphery is welded and sealed. The positive and negative terminals 12 and 13 are drawn out from between the laminate films 10 and 11. Such sheet-type batteries are stacked in the thickness direction to greatly increase the contact area between the batteries.
[0017]
In the power supply device having the above configuration, when used under a low temperature condition such as when the vehicle is started, the load sharing of the low-temperature electrolyte lithium battery LB increases, and a large current flows through the electrolyte lithium battery LB. The temperature of the electrolyte lithium battery LB rises due to internal heat generation due to this current, and this heat is transferred to the all solid lithium batteries SB that are in contact with each other, thereby raising the temperature of the all solid lithium batteries SB. For this reason, when compared with a power supply device in which two types of batteries are simply connected in parallel and does not transfer heat, the power supply device 1 has good discharge capacity characteristics at low temperatures. In particular, since two types of batteries are brought into contact with each other by stacking sheet-type batteries in the thickness direction, the heat transfer area is increased, and heat can be efficiently transferred from the electrolyte lithium battery LB to the all-solid-state lithium battery SB. .
[0018]
Further, in the power supply device 1, at a high temperature, instead of the low-temperature electrolyte lithium battery LB, the high-temperature all-solid lithium battery SB having excellent life characteristics makes the discharge capacity characteristics of the power supply device good.
[0019]
In the present embodiment described above, the following effects can be obtained.
[0020]
(A) An electrolyte lithium battery LB as a low temperature type battery and an all solid lithium battery SB as a high temperature type battery are connected in parallel, and a high temperature type battery is used by using the current flowing in the low temperature type electrolyte lithium battery LB. Since the all solid lithium battery SB is heated, the output characteristics of the high temperature all solid lithium battery SB can be improved in a short time.
[0021]
(A) Moreover, the operating range of the high-temperature type all-solid lithium battery SB, which has excellent life characteristics, is expanded by heating the high-temperature type all-solid-state lithium battery SB, and the low-temperature type electrolyte solution having relatively low life characteristics The operation of the lithium battery LB can be suppressed and the life characteristics of the entire power supply device 1 can be improved.
[0022]
(C) Since the high-temperature all-solid lithium battery SB and the low-temperature electrolyte lithium battery LB are adjacent to each other by stacking or the like, the heat of the electrolyte lithium battery LB is completely reduced particularly at low temperatures. Moving to the solid lithium battery SB, it is possible to raise the temperature of the all solid lithium battery SB in a short time.
[0023]
(D) Since the high-temperature all-solid lithium battery SB is placed inside the batteries stacked as the power supply device 1, the all-solid lithium battery SB can be easily heated, and the output of the battery can be output in a shorter time. Improved characteristics.
[0024]
(E) The high-temperature type all-solid lithium battery SB and the low-temperature type electrolyte lithium battery LB are made of laminated films 10 and 11 so that the heat exchange with the outside becomes easy. It becomes possible to heat early.
[0025]
(F) Since the high-temperature battery and the low-temperature battery are the lithium batteries SB and LB using all solids and an electrolyte, the effectiveness of the above-described effect is improved.
[0026]
FIG. 3 is a schematic configuration diagram showing a second embodiment of the power supply device of the present invention. When the all-solid lithium battery SB is heated at a low temperature, the heating means is used instead of the internal heat generation of the electrolyte lithium battery LB. It is made to heat by.
[0027]
In FIG. 3, the all solid lithium battery SB and the electrolyte lithium battery LB are connected in parallel as in the first embodiment. The electrolyte lithium battery LB includes a power control unit 2 and a heater 5 connected in series. The power control unit 2 and the heater 5 are positioned in parallel to the all solid lithium battery SB. The heater 5 is disposed in contact with the all solid lithium battery SB.
[0028]
The power control means 2 includes a relay that turns on / off the input / output power of the electrolyte lithium battery LB or a variable resistor that adjusts the input / output power. The power control unit 2 controls the input / output power of the electrolyte lithium battery LB in accordance with a control signal from the controller 3 that controls the power supply device 1. The heater 5 is heated according to the input / output power of the electrolyte lithium battery LB controlled by the power control means 2 connected in series.
[0029]
The controller 3 generates a control signal for the power control means 2 based on the output signal of the temperature sensor 4 disposed in the vicinity of the all solid lithium battery SB. Specifically, when the temperature of the all-solid-state lithium battery SB is low, a control signal for connecting the relay is sent or a control signal for reducing the resistance value of the variable resistor is sent, so that the electrolyte lithium battery LB The power control means 2 is controlled to use or increase the input / output power. The temperature sensor 4 measures the temperature of the all solid lithium battery SB and inputs it to the controller 3. The temperature sensor 4 only needs to output a signal having a correlation with the temperature of the all-solid lithium battery SB, and is not necessarily arranged in close contact with the all-solid lithium battery SB.
[0030]
In the power supply device 1 having the above configuration, when used under a low temperature condition such as when the vehicle is started, the controller 3 determines that the temperature of the all-solid lithium battery SB is low by the temperature sensor 4, and the electrolyte lithium The power control means 2 is controlled to use the battery LB. That is, the controller 3 sends a control signal for connecting the relay and sends a control signal for reducing the resistance value of the variable resistor. Thereby, even when the temperature is below a temperature at which sufficient output characteristics cannot be obtained with only the all-solid-state lithium battery SB, the output characteristics of the power supply device 1 can be sufficiently ensured.
[0031]
With the above operation, the input / output power of the electrolyte lithium battery LB is also energized and heated by the heater 5 to raise the temperature of the all-solid lithium battery SB. If this operation is continued, even when the ambient temperature is low, the temperature of the all-solid lithium battery SB reaches a temperature condition that provides sufficient output characteristics, is detected by the temperature sensor 4, and is input to the controller 3. The controller 3 controls the power control means 2 to restrict the use of the electrolyte lithium battery LB, and supplies the input / output power of the all solid lithium battery SB to the load.
[0032]
Further, under the temperature conditions where sufficient output characteristics can be obtained only with the all solid lithium battery SB, similarly to the above, the use of the electrolyte lithium battery LB is limited, and the electrolyte lithium having inferior life characteristics than the all solid lithium battery SB. The usage time of the battery LB is suppressed as much as possible.
[0033]
Since the electrolyte lithium battery LB and the heater 5 should be used when the all-solid lithium battery SB is below the operating temperature, a single power control means 2 can be used in common.
[0034]
FIG. 4 shows a modification of the power supply device of the second embodiment, which is a power supply device using a PTC element as a heating means.
[0035]
The PTC element P is a semiconductor ceramic mainly composed of barium titanate (BaTiO ₃ ), and the Curie temperature (temperature at which the electrical resistance changes suddenly) can be arbitrarily set by adjusting the material composition.
[0036]
The PTC element P is connected in series to the electrolyte lithium battery LB and is disposed adjacent to the all solid lithium battery SB. The Curie temperature of the PTC element is set to a temperature at which sufficient output characteristics cannot be obtained with the all solid lithium battery SB alone. It is matched.
[0037]
Therefore, the resistance of the PTC element P becomes small at low temperatures when the all-solid lithium battery SB alone cannot provide sufficient output characteristics, and the input / output power of the electrolyte lithium battery LB is used, and the resistance of the PTC element P at high temperatures. Increases and the use of the electrolyte lithium battery LB is restricted.
[0038]
Further, when the electrolyte lithium battery LB is used at a low temperature, the PTC element P itself generates heat due to the resistance of the PTC element P, and the all solid lithium battery SB is heated by this heat.
[0039]
As described above, the PTC element P has the functions of the power control unit 2, the temperature sensor 4, the controller 3, and the heater 5 of the power supply device 1 shown in FIG.
[0040]
In the present embodiment, in addition to the effects (a), (b), (e), and (f) in the first embodiment, the following effects can be achieved.
[0041]
(G) The low-temperature electrolyte lithium battery LB includes the heater 5 or the semiconductor ceramic PTC element P connected in series as a heating means for heating the high-temperature all-solid lithium battery SB. The all-solid lithium battery SB can be heated while using the battery LB, and the output characteristics can be improved in a short time.
[0042]
(H) In the power supply device 1 of FIG. 3, the low-temperature electrolyte lithium battery LB includes power control means 2 for controlling its input / output power in series, so that when the all-solid lithium battery SB is warmed, the electrolyte solution The power of the lithium battery LB can be limited, and the life of the electrolyte lithium battery LB can be increased.
[0043]
(K) In the power supply device 1 of FIG. 3, since the low temperature type battery includes the power control means 2 for controlling the input / output power in series with the heating means, the electrolyte lithium is used when the all solid lithium battery SB is warmed. The power of the battery LB can be limited, and the life of the electrolyte lithium battery LB can be increased. In addition, useless heating can be prevented and energy efficiency can be improved.
[0044]
(G) In the power supply device 1 of FIG. 4, since the heating means is formed of an element whose resistance increases as the temperature increases, for example, the PTC element P, the power control of the electrolyte lithium battery LB and the heating of the all solid lithium battery SB Combined with each function, the structure can be simplified.
[0045]
(S) Since the PTC element P of the power supply device 1 in FIG. 4 is a ceramic PTC element, the PTC element P generates a large amount of heat, and the all-solid lithium battery SB can be easily heated.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a power supply device according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a specific configuration of the power supply device.
FIG. 3 is a schematic configuration diagram of a power supply device showing a second embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of a power supply device according to a modification of the second embodiment.
[Explanation of symbols]
SB All solid-state lithium battery LB as a high-temperature type battery LB Electrolyte lithium battery P as a low-temperature type battery Ceramic PTC element as a PTC element 1 Power supply device 2 Power control means 3 Controller 4 Temperature sensor 5 Heaters 10 and 11 as heating means Laminate the film

Claims (9)

With connecting the relatively low comparatively high temperature that good output characteristics at high temperature side is obtained with a lithium battery low temperature that good output characteristics can be obtained from the side lithium battery in parallel, the lithium battery of the low temperature A power supply device characterized in that the high-temperature lithium battery is heated using a flowing current.   The power supply device according to claim 1, wherein the high-temperature battery and the low-temperature battery are disposed adjacent to each other.   The power supply device according to claim 1, wherein the high-temperature battery is disposed on the inner side between batteries stacked as a power supply device.   The power supply apparatus according to any one of claims 1 to 3, wherein the low-temperature battery includes power control means for controlling input / output power in series.   The power supply apparatus according to claim 1, wherein the low-temperature battery includes heating means for heating the high-temperature battery connected in series. A low temperature battery that provides good output characteristics from a relatively low temperature side and a high temperature battery that provides good output characteristics from a relatively high temperature side are connected in parallel,
The low-temperature battery, the high temperature type battery is heated heating means and power control means and wherein the to that power supplies to be provided by connecting in series a to control the input and output power. A low temperature battery that provides good output characteristics from a relatively low temperature side and a high temperature battery that provides good output characteristics from a relatively high temperature side are connected in parallel,
The low-temperature batteries, power supplies you, comprising connected in series a device resistance at higher temperatures increases as a heating means for heating the high-temperature battery.   The power supply device according to claim 7, wherein the element whose resistance increases as the temperature increases is a ceramic PTC element.   The power supply apparatus according to any one of claims 1 to 8, wherein the high-temperature battery and the low-temperature battery have a cell enveloped by a laminate film.

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