JP2023030371A - System for charging lithium ion secondary battery and method for charging lithium ion secondary battery - Google Patents

Abstract

To enable extraction of a larger volume from a lithium ion secondary battery which is used as a power source of a device when the device requires the volume.SOLUTION: An embodiment is a charging system of a lithium ion secondary battery (battery) which is used as a power source of a device. The system includes: a selection unit which selects either charge mode of a first charge mode for charging the battery when operating the device and a second charge mode for charging the battery when operating the device in such a manner that the battery volume becomes larger than in the first charge mode; a set unit which sets a target volume when charging by the second charge mode; and a temperature control unit which, when charging by the second charge mode, controls the battery to a higher set temperature than in the first charge mode. The temperature control unit determines the set temperature based on the target volume set by the set unit and the relationship between the temperature and the volume of the battery.SELECTED DRAWING: Figure 6

Description

The present invention relates to technology for charge control of a lithium ion secondary battery.

2. Description of the Related Art In recent years, mobile cordless products such as mobile phones, notebook personal computers, and video cameras are becoming more and more compact and portable. In addition, from the viewpoint of environmental problems such as air pollution and increased carbon dioxide, the development of electric vehicles such as hybrid vehicles, electric vehicles, electric ships, and small aircraft such as drones is progressing, and it is at the stage of practical use. It has become. Electric vehicles such as these electronic devices and electric vehicles require excellent secondary batteries having characteristics such as high efficiency, high output, high energy density, and light weight. Furthermore, as a means for efficiently storing electricity generated by nighttime power or natural energy such as sunlight, the effective use of secondary batteries is attracting attention. Development and research on secondary batteries having such characteristics have been actively carried out, and various secondary batteries such as lithium batteries and lithium ion batteries have been put to practical use.
Among them, composite oxides such as nickel, cobalt, and manganese, which have a layered crystal structure, are positive electrode active materials for high-energy-density lithium-ion batteries by intercalating and deinserting electrically active lithium ions between the layers. It is preferably used as (for example, Patent Document 1).

JP 2016-184528 A

By the way, for example, when the above-described secondary battery is used as a storage battery, it is required to supply a larger amount of power than during normal use when the power supply infrastructure is cut off due to a disaster or the like. In addition, the above-mentioned drones are also required to have functions such as supplying supplies to areas where transportation networks are cut off in the event of a disaster. It is also required to supply a large amount of power.

The present invention was made to solve the above-mentioned problems, and its object is to extract more capacity from the lithium-ion secondary battery used as the power source of the device when the device needs it. It is to make it possible.

A first aspect of the present invention is a charging system for a lithium ion secondary battery used as a power source for a device, comprising: a first charging mode for charging the lithium ion secondary battery when operating the device; Alternatively, a second charging mode for charging the lithium-ion secondary battery when operating the device, wherein the lithium-ion secondary battery has a larger capacity than the first charging mode. a second charging mode for charging an ion secondary battery; a selecting unit for selecting one charging mode; a storage unit for storing a relationship between temperature and capacity of the lithium ion secondary battery; A setting unit that sets a target capacity when charging in the charging mode, and controls the lithium ion secondary battery to a higher set temperature than in the first charging mode when charging in the second charging mode. a temperature control unit, wherein the temperature control unit is based on the target capacity set by the setting unit and the relationship between the temperature and capacity of the lithium ion secondary battery stored in the storage unit, A lithium-ion secondary battery charging system that determines the set temperature.

A second aspect of the present invention is a charging system for a lithium-ion secondary battery used as a power source for an apparatus, comprising a processor, wherein the processor controls a target capacity when charging the lithium-ion secondary battery. is controlled to charge the lithium ion secondary battery based on, and when the lithium ion secondary battery is charged, if the target capacity is less than a predetermined value, the temperature of the lithium ion secondary battery is While controlling the temperature below a predetermined first upper limit temperature, when the target capacity is equal to or higher than the predetermined value, the temperature of the lithium ion secondary battery is set to a temperature equal to or higher than the first upper limit temperature and a predetermined second temperature. It is a charging system for a lithium-ion secondary battery that controls the temperature below the upper limit temperature.

A third aspect of the present invention is a charging system for a lithium ion secondary battery used as a power source of an apparatus, comprising a processor, wherein the processor controls a target capacity when charging the lithium ion secondary battery. is controlled to charge the lithium ion secondary battery based on, and when the lithium ion secondary battery is charged, if the target capacity is less than a predetermined value, the temperature of the lithium ion secondary battery is While prohibiting control to a predetermined upper limit temperature or higher, permitting control of the temperature of the lithium ion secondary battery to a temperature equal to or higher than the upper limit temperature when the target capacity is equal to or higher than the predetermined value, lithium This is an ion secondary battery charging system.

A fourth aspect of the present invention is a method for charging a lithium ion secondary battery used as a power source of a device, comprising: a first charging mode for charging the lithium ion secondary battery when operating the device; Alternatively, a second charging mode for charging the lithium-ion secondary battery when operating the device, wherein the lithium-ion secondary battery has a larger capacity than the first charging mode. A step (A) of selecting one of a second charging mode for charging an ion secondary battery; a step (B) of setting a target capacity for charging in the second charging mode; As the set temperature for charging in the second charging mode, based on the target capacity set in step (B) and the pre-stored relationship between the temperature and capacity of the lithium ion secondary battery. , a step (C) of setting a temperature higher than that in the first charging mode, and a step (D) of controlling to the set temperature during charging in the second charging mode. This is the charging method for the next battery.

According to one aspect of the present invention, it is possible to extract more capacity from the lithium-ion secondary battery used as the power source of the device when the device requires it.

FIG. 4 is a diagram illustrating the relationship between temperature and positive electrode capacity when different positive electrode active materials are used in a lithium ion secondary battery. 1 is a block diagram showing the system configuration of a charging system for a lithium ion secondary battery according to one embodiment; FIG. 4 is a flow chart showing charging control of a lithium ion secondary battery of one embodiment. 4 is a detailed flowchart of the temperature control process of FIG. 3; 4 is a flow chart showing charging control of a lithium ion secondary battery of one embodiment. 4 is a flow chart showing charging control of a lithium ion secondary battery of one embodiment.

Embodiments of the present invention will be described below.
In a lithium ion secondary battery including a positive electrode having a positive electrode active material layer formed on a current collector, a negative electrode having a negative electrode active material layer formed on a current collector, and an electrolyte, the positive electrode active material includes: A lithium-transition metal composite oxide having a layered crystal structure, which is a layered crystal structure, is preferably used as a positive electrode active material for high energy density lithium ion batteries. Such a lithium ion secondary battery is characterized in that as the temperature rises, part of the positive electrode active material undergoes a phase transition reaction, causing a slight change in the layer structure, thereby increasing the charge capacity. On the other hand, it is generally preferable to use a lithium ion battery in a high temperature environment because the lithium ion deinsertion reaction in the layer tends to be difficult to proceed, and the service life of the battery tends to decrease. It is said that there is not.

However, as a result of intensive research by the inventors of the present application, the above phase transition phenomenon can be appropriately controlled by appropriately controlling the temperature during charging of the lithium ion secondary battery. The inventors have found that the capacity of the positive electrode active material can be temporarily increased while suppressing the decrease in service life. If a lithium-ion secondary battery (hereinafter simply referred to as a "battery" or "battery cell" as appropriate) is used as the power source of the device and the capacity required for the operation of the device is known in advance, the capacity (target By controlling the set temperature when charging the battery cells so that the battery cells are charged to the maximum capacity, the battery cell capacity can be set to an optimum value for the operation of the device.

FIG. 1 illustrates the relationship between temperature and positive electrode capacity when different positive electrode active materials are used in battery cells. In FIG. 1, Li(Ni, Co, Al) O ₂ (indicated by ◯) and Li(Ni, Co, Mn) O ₂ (indicated by ◇) are used as ternary positive electrode active materials, and positive electrodes that are not ternary LiMn ₂ O ₄ (lithium manganate) (indicated by Δ) is illustrated as an active material.
As shown in FIG. 1, particularly in a battery cell using a ternary positive electrode active material, the change in capacity with respect to temperature changes is large. is generally linear, and it can be seen that it is easy to estimate the battery cell capacity with respect to temperature.
Therefore, by referring to the map data describing the relationship between temperature and battery cell capacity shown in FIG. 1 when charging the battery cell, the battery cell can be charged to the target capacity.

Next, with reference to FIG. 2, a charging system for a lithium ion secondary battery (hereinafter simply referred to as "charging system") according to one embodiment will be described.
As shown in FIG. 2 , the charging system of one embodiment includes a battery module 2 composed of a plurality of battery cells, a battery control device 1 and a charging device 5 for charging the battery module 2 . The battery control device 1 may be configured integrally with the battery module 2 . In the following description, it is assumed that the battery module 2 is used as a power source for mobile objects such as electric vehicles and small aircraft. The battery module 2 is charged in advance before operating the moving body.

When charging the battery module 2 , the battery module 2 and the charging device 5 are connected by a connector (not shown) to form a closed circuit for charging the battery module 2 . When a closed circuit is formed, the battery module 2 is ready to be charged by the charging current supplied from the power supply circuit section 52 of the charging device 5 .

As shown in FIG. 2 , the battery control device 1 includes a processor 11 , a storage device 12 , a cell monitoring section 13 and a communication section 14 .
The processor 11 is mainly composed of a microprocessor, and the microprocessor executes a predetermined program to control the operation of the battery control device 1 .
The storage device 12 (an example of a storage unit) is a non-volatile memory and contains map data and charging history information.
The map data is data describing the relationship between temperature and battery cell capacity illustrated in FIG. The charging history information is information relating to the charging history of the battery module 2 up to the present, and includes, for example, the number of past charging times in the second charging mode and the set temperature.

The processor 11 executes programs to function as a charge mode selection unit 111 , a capacity setting unit 112 , and a temperature control unit 113 .

The charging mode selection unit 111 selects, for example, a first charging mode in which the battery modules 2 are charged when the mobile body is operated, or a second charging mode in which the battery modules 2 are charged when the mobile body is operated. , a second charging mode in which the battery module 2 is charged so that the capacity of the battery module 2 is larger than that in the first charging mode.
Here, the first charging mode is, for example, a charging mode when operating the moving object normally. The second charge mode is a charge mode when a larger battery capacity than usual is required, such as when the mobile object is used for a longer time than usual.

In one embodiment, the charging mode selection unit 111 selects the first charging mode or the second charging mode based on data input to an input device (not shown) or data received from an external host computer via the communication unit 14. You can choose one of the charging modes. Since the operator of the mobile unit knows information such as the operating speed and travel distance of the mobile unit from the operation plan of the mobile unit, based on that information, one of the charging modes is determined, and one of the charging modes is selected. Data indicating the mode can be input to the input device or transmitted from the host computer to the battery control device 1 . Note that the battery control device 1 may receive data indicating the charging mode from an operation control device (not shown) of a moving body.

In another embodiment, the charging mode selector 111 may autonomously select either the first charging mode or the second charging mode. For example, the charging mode selection unit 111 acquires data on the current location of the mobile object and the destination of the mobile object from the operation control device of the mobile object, and based on the data, the capacity required to reach the destination (required operation capacity ) and select either the first charging mode or the second charging mode based on the required operating capacity.

When the second charging mode is selected by the charging mode selection unit 111, the capacity setting unit 112 sets the target capacity for charging in the second charging mode. The purpose of setting the target capacity is to prevent the service life of the battery from being shortened by overheating the battery module 2 .
In one embodiment, the capacity setting unit 112 can set the requested value as the target capacity when receiving the requested value of the capacity from the operation control device of the mobile body. In another embodiment, the capacity setting unit 112 may calculate the required operating capacity by itself and use the calculated required operating capacity as the target capacity.

During charging in the second charging mode, the temperature control unit 113 controls the temperature of the battery module 2 to be higher than that in the first charging mode. At this time, the temperature control section 113 determines the set temperature based on the target capacity set by the capacity setting section 112 and the map data stored in the storage device 12 .
As described above, the map data describes the relationship between temperature and battery cell capacity. Therefore, the temperature control unit 113 can determine the temperature corresponding to the target capacity as the set temperature by referring to the map data. In order to control the battery module 2 to the set temperature, the temperature control unit 113 is provided near the battery module 2 while monitoring the temperature value detected by the temperature sensor 133 arranged near the battery module 2 . A control signal is sent to the heater 3 (see FIG. 2).

As shown in FIG. 2 , the charging device 5 includes a control section 51 , a power supply circuit section 52 , a communication section 53 and a current sensor 54 .
The control unit 51 is mainly composed of a microprocessor, and controls charging of the battery module 2 connected to the charging device 5 . A current sensor 54 is arranged on a closed circuit including the battery module 2 . The control unit 51 controls the power supply circuit unit 52 to perform CCCV charging based on the current value detected by the current sensor 54 and/or the voltage value of the battery module 2 supplied from the battery control device 1. .
The power supply circuit unit 52 supplies charging current to the battery module 2 connected to the charging device 5 under the control of the control unit 51 .
The communication unit 53 performs data communication with the communication unit 14 of the battery control device 1 using a communication protocol according to the charging method.

Next, the operation of charging the battery module 2 by the charging system of one embodiment will be described with reference to the flowcharts of FIGS. 3 and 4. FIG. The flowcharts of FIGS. 3 and 4 are executed by the processor 11 of the battery control device 1. FIG.
Referring to FIG. 3, processor 11 first selects a charging mode (step S2). As described above, the selection of the charging mode is determined based on, for example, data input to the input device or data received from the external host computer via the communication unit 14 .
When the first charging mode is selected, the processor 11 immediately executes the charging process because it is not necessary to perform temperature control before charging (step S8). That is, the processor 11 starts communication with the charging device 5 for charging the battery module 2 .

The selection of the second charging mode in step S2 means that the capacity needs to be increased more than usual. Therefore, the processor 11 sets the target capacity of the battery module 2 (step S4). The setting of the target capacity is performed, for example, as described above, based on the requested capacity value from the operation control device of the moving object or the required operation capacity calculated by itself.

Processor 11 then executes a temperature control process (step S6). The temperature control process is performed for the purpose of temporarily increasing the capacity of the battery module 2 while suppressing the decrease in battery service life. That is, the temperature is controlled so as to obtain the required capacity while controlling the thermal energy given to the battery module 2 so as not to heat the battery module 2 more than necessary.

A temperature control process of one embodiment is illustrated in FIG.
Referring to FIG. 4, processor 11 refers to map data describing the relationship between temperature and battery cell capacity to determine the temperature corresponding to the target capacity set in step S4 as the set temperature ( step S10).

Next, the processor 11 reads out the charging history information from the storage device 12 (step S12), and determines whether or not to execute limited temperature control based on the charging history information (step S14). The limited temperature control is, for example, temperature control that is performed while limiting the heat energy given to the battery module 2 via the heater 3 . That is, when temperature control with a limit is executed, the set temperature of the battery module 2 is limited (step S16). When the set temperature of the battery module 2 is restricted, the set temperature determined in step S10 may be lowered.

It should be noted that the determination of whether or not to execute the limited temperature control in step S14 and the degree of limitation when the limited temperature control is executed include various embodiments based on the charging history information. obtain.
In one embodiment, if the charging history information includes information on the number of past charging times in the second charging mode, it is determined to execute the limited temperature control when the past charging number is equal to or greater than a predetermined threshold. do. When the limited temperature control is executed, the set temperature determined in step S10 is limited so that the set temperature is kept lower as the number of times of charging in the past increases.
In another embodiment, if the charging history information includes past temperature setting information in the second charging mode, when the maximum or average past temperature setting value is equal to or greater than a predetermined threshold, the limited temperature Decide to take control. When the limited temperature control is executed, the set temperature determined in step S10 is limited so that the larger the maximum or average value of the past set temperatures, the lower the set temperature.

Processor 11 then performs temperature control based on the set temperature determined in step S10 or the set temperature limited in step S16 (step S18). In temperature control, the processor 11 sends a control signal to the heater 3 to heat the battery module 2 . The processor 11 monitors whether the temperature value detected by the temperature sensor 133 has reached the set temperature (step S20), and when the set temperature has been reached, controls the heater 3 to maintain the set temperature. .

Returning to the flow chart of FIG.
When the second charging mode is selected, the processor 11 performs the charging process (step S8) after the temperature of the battery module 2 is raised to the set temperature by the temperature control process (step S6). This charging process may be general charging such as CCCV charging, for example, and is performed while the battery module 2 is maintained at the set temperature. Thereby, in the second charging mode, the capacity of the battery module 2 can be made higher than in the case of the first charging mode at the completion of charging.
After the battery module 2 is attached to the moving body after charging is completed, the temperature of the battery module 2 decreases, but the capacity once increased due to heating is not lost.

As described above, the charging system of one embodiment is applied when a device uses a lithium-ion secondary battery as a power source, which can temporarily increase the capacity of the positive electrode active material by heating. In this charging system, when the second charging mode is selected as the charging mode before operating the device, the battery in the device is operated at a higher capacity than usual by charging while heating the battery. be able to.
When charging the battery, the temperature is controlled so that the battery does not become hotter than necessary. That is, based on the target capacity required for the operation of the device, the set temperature is determined with reference to map data describing the relationship between battery temperature and capacity. Since the battery is not heated more than necessary, it is possible to suppress the shortening of the service life of the battery.
Preferably, the set temperature for the battery is limited based on information on the number of past charging times in the second charging mode and/or the set temperature included in the charge history information. As a result, it is possible to further suppress the decrease in the service life of the battery.

In one embodiment, it is preferable to determine the set temperature in consideration of cycle deterioration of the battery cells. That is, since the full charge capacity decreases with cycle deterioration of the battery cells, it is preferable to determine the set temperature so as to compensate for the decrease in the full charge capacity.
In that case, processor 11 functions as an estimator that estimates the current full charge capacity of battery module 2 . The temperature control unit 113 determines the set temperature based on the current full charge capacity of the battery module 2 estimated by the estimation unit. For example, assume that the initial full charge capacity is 100% and the estimated full charge capacity after 1000 cycles is 80% (20% decrease). In that case, if the set temperature determined during initial charging for a given target capacity is _T0 , then the set temperature _T1000 determined during charging for 1000 cycles for the same target capacity is It is set to a value higher than the temperature _T0 so as to compensate for the full charge capacity, which has decreased by 20% in comparison. Thereby, the same capacity can be obtained in spite of the decrease in the full charge capacity.

Such processing according to the current cycle number is performed, for example, in step S10 of FIG.
For example, the storage device 12 stores the value of the initial full charge capacity. When determining the set temperature, the processor 11 first estimates the current full charge capacity and compares it with the initial full charge capacity to determine the correction coefficient. For example, if the initial full charge capacity is FCC ₀ and the current full charge capacity is FCC _C , the correction coefficient P=FCC _C /FCC ₀ (where 0<P<1).
Since the map data stored in the storage device 12 is data for battery cells in the initial state, the processor 11 corrects the map data based on the correction coefficient. For example, the map data is corrected by multiplying the capacity corresponding to the predetermined temperature by a correction coefficient. The processor 11 then determines the set temperature corresponding to the target capacity based on the corrected map data.

In one embodiment, when the processor 11 of the battery control device 1 functions as a detection unit that detects an overcharged state of the battery by comparing the voltage of the battery module 2 or the voltage of each battery cell with a threshold, the second In the second charge mode, it is preferable to increase the threshold as compared to the first charge mode. That is, in the second charging mode, the capacity of the battery module 2 is larger than in the first charging mode, and the voltage of the battery module 2 or each battery cell immediately after charging is higher than in the first charging mode. Rise. At that time, it is preferable to increase the threshold so as not to erroneously detect that the battery is in an overcharged state based on the increased voltage.

Next, the operation of charging the battery module 2 by the charging system of another embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 5 is executed by the processor 11 of the battery control device 1. FIG. In the charging operation of this embodiment, there is no charge mode selection, and temperature control is performed according to the target capacity.

Referring to FIG. 5, the processor 11 first sets the target capacity of the battery module 2 (step S20). This target volume setting process is the same as step S4 in FIG.
Processor 11 then compares the target capacity set in step S20 with a predetermined value (step S32), and determines the set temperature according to the comparison result. That is, when the target capacity is less than the predetermined value (step S32: NO), the processor 11 sets the set temperature of the battery module 2 to less than the predetermined first upper limit temperature LMT1 (step S34). That is, when the target capacity is relatively low, it is not necessary to increase the capacity of the battery module 2 more than necessary, so the set temperature is suppressed.
For example, if the temperature corresponding to the target capacity set in step S30 is 30.degree. C. and the first upper limit temperature LMT1 is 35.degree.

When the target capacity is equal to or higher than the predetermined value (step S32: YES), the processor 11 sets the temperature of the battery module 2 to be equal to or higher than the first upper limit temperature LMT1 and lower than the predetermined second upper limit temperature LMT2 ( step S36). That is, when the target capacity is relatively high, the set temperature is set relatively high in order to extract more capacity from the battery module 2 . Even in that case, the set temperature is limited to the second upper limit temperature LMT2 at the highest in order to suppress the decrease in battery service life.
For example, if the temperature corresponding to the target capacity set in step S30 is 60°C, the first upper limit temperature LMT1 is 35°C, and the second upper limit temperature LMT2 is 50°C, the set temperature is 50°C. .

Next, the processor 11 performs temperature control on the heater 3 based on the set temperature determined in step S34 or S36 (step S38). Then, when the value of the temperature detected by the temperature sensor 133 reaches the set temperature (step S40: YES), the charging process is executed (step S42). The charging process is performed while the battery module 2 is maintained at the set temperature, as in step S8 of FIG. Thereby, the capacity of the battery module 2 can be temporarily increased to the set target capacity or a value close to the target capacity.

Next, the operation of charging the battery module 2 by the charging system of still another embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 6 is executed by the processor 11 of the battery control device 1. FIG. In the charging operation of this embodiment, there is no charge mode selection, and temperature control is performed according to the target capacity.

Referring to FIG. 6, the processor 11 first sets the target capacity of the battery module 2 (step S30). This target volume setting process is the same as step S4 in FIG.
Next, the processor 11 compares the target volume set in step S30 with a predetermined value (step S32), and determines the set temperature condition according to the comparison result. Specifically, when the target capacity is less than the predetermined value (step S32: NO), the processor 11 prohibits setting the temperature of the battery module 2 to a predetermined upper limit temperature LMT or higher (step S35). . That is, when the target capacity is relatively low, it is not necessary to increase the capacity of the battery module 2 more than necessary, so the set temperature is suppressed below the upper limit temperature LMT.
For example, if the temperature corresponding to the target capacity set in step S30 is 35°C and the upper limit temperature LMT is 50°C, setting the temperature to 50°C is prohibited. Note that in this example, the set temperature can be a value between 35 and 50.degree.

If the target capacity is equal to or higher than the predetermined value (step S32: YES), the processor 11 allows the set temperature of the battery module 2 to be equal to or higher than the upper limit temperature LMT (step S37). That is, when the target capacity is relatively high, it is possible to set the set temperature to the upper limit temperature LMT or higher in order to extract more capacity from the battery module 2 .
For example, if the temperature corresponding to the target capacity set in step S30 is 60.degree. C. and the upper limit temperature LMT is 50.degree.

Next, the processor 11 performs temperature control for the heater 3 based on the set temperature that satisfies the conditions determined in step S35 or S37 (step S39). Then, when the value of the temperature detected by the temperature sensor 133 reaches the set temperature (step S40: YES), the charging process is executed (step S42). The charging process is performed while the battery module 2 is maintained at the set temperature, as in step S8 of FIG. Thereby, the capacity of the battery module 2 can be temporarily increased to the set target capacity or a value close to the target capacity.

Although the embodiments of the lithium ion secondary battery charging system and the lithium ion secondary battery charging method of the present invention have been described above, the present invention is not limited to the above embodiments. Also, the above embodiments can be modified and modified in various ways without departing from the gist of the present invention. For example, individual technical features described in each of the embodiments described above can be appropriately combined as long as there is no technical contradiction.
For example, when determining the set temperature for temperature control, it is not necessary to refer to map data describing the relationship between target capacity and temperature. The temperature corresponding to the target capacity may be calculated and obtained based on a function that approximates the relationship between the target capacity and temperature.
In addition, the lithium ion secondary battery charging system and the lithium ion secondary battery charging method of the present invention are not limited to lithium ion secondary batteries mounted on moving bodies, and can be applied to stationary energy storage systems. System: ESS) and the like.

DESCRIPTION OF SYMBOLS 1... Battery control apparatus 11... Processor 111... Charge mode selection part 112... Capacity setting part 113... Temperature control part 12... Storage device 13... Cell monitoring part 131... Voltage sensor 132... Current sensor 133... Temperature sensor 14... Communication part 2 ... Battery module 3 ... Heater 5 ... Charging device 51 ... Control section 52 ... Power supply circuit section 53 ... Communication section 54 ... Current sensor

Claims (10)

A charging system for a lithium ion secondary battery used as a power source for a device,
A first charging mode for charging the lithium ion secondary battery when operating the device, or a second charging mode for charging the lithium ion secondary battery when operating the device, wherein a second charging mode for charging the lithium ion secondary battery so that the capacity of the lithium ion secondary battery is larger than that in the first charging mode;
a storage unit that stores the relationship between temperature and capacity of the lithium ion secondary battery;
a setting unit that sets a target capacity for charging in the second charging mode;
a temperature control unit that controls the lithium-ion secondary battery to a set temperature higher than that in the first charging mode during charging in the second charging mode;
with
The temperature control unit determines the set temperature based on the target capacity set by the setting unit and the relationship between the temperature and capacity of the lithium ion secondary battery stored in the storage unit.
Lithium-ion secondary battery charging system. further comprising a second storage unit that stores charging history information including the number of past charging times in the second charging mode and the set temperature;
When determining the set temperature, the temperature control unit limits the set temperature based on charging history information stored in the second storage unit.
The charging system for a lithium ion secondary battery according to claim 1. Further comprising an estimation unit for estimating the current full charge capacity of the lithium ion secondary battery,
The temperature control unit further determines the set temperature based on the current full charge capacity of the lithium ion secondary battery estimated by the estimation unit.
3. A charging system for a lithium ion secondary battery according to claim 1 or 2. Further comprising a detection unit that detects an overcharged state of the lithium ion secondary battery based on a threshold,
The detection unit makes the threshold after charging in the second charging mode higher than the threshold after charging in the first charging mode.
The charging system for a lithium ion secondary battery according to any one of claims 1 to 3. The lithium ion secondary battery is
A positive electrode having a positive electrode active material layer formed on a current collector, a negative electrode having a negative electrode active material layer formed on a current collector, and an electrolytic solution,
The positive electrode contains a lithium-transition metal composite oxide having a layered structure as a positive electrode active material,
The charging system for a lithium ion secondary battery according to any one of claims 1 to 4. A charging system for a lithium ion secondary battery used as a power source for a device,
having a processor;
The processor
Control to charge the lithium ion secondary battery based on a target capacity when charging the lithium ion secondary battery,
When charging the lithium ion secondary battery,
When the target capacity is less than a predetermined value, while controlling the temperature of the lithium ion secondary battery to be less than a predetermined first upper limit temperature,
When the target capacity is equal to or higher than the predetermined value, controlling the temperature of the lithium ion secondary battery to be equal to or higher than the first upper limit temperature and lower than a predetermined second upper limit temperature,
Lithium-ion secondary battery charging system. A charging system for a lithium ion secondary battery used as a power source for a device,
having a processor;
The processor
Control to charge the lithium ion secondary battery based on a target capacity when charging the lithium ion secondary battery,
When charging the lithium ion secondary battery,
When the target capacity is less than a predetermined value, while prohibiting control of the temperature of the lithium ion secondary battery to a predetermined upper limit temperature or higher,
If the target capacity is equal to or higher than the predetermined value, allowing the temperature of the lithium ion secondary battery to be controlled to the upper limit temperature or higher.
Lithium-ion secondary battery charging system. A method for charging a lithium ion secondary battery used as a power source for a device, comprising:
A first charging mode for charging the lithium ion secondary battery when operating the device, or a second charging mode for charging the lithium ion secondary battery when operating the device, wherein a step (A) of selecting a charging mode from a second charging mode in which the lithium ion secondary battery is charged so that the capacity of the lithium ion secondary battery is greater than that in the first charging mode;
step (B) of setting a target capacity for charging in the second charging mode;
As the set temperature for charging in the second charging mode, based on the target capacity set in step (B) and the pre-stored relationship between the temperature and capacity of the lithium ion secondary battery. , step (C) of setting the temperature to a higher temperature than in the first charging mode;
a step (D) of controlling to the set temperature during charging in the second charging mode;
A method of charging a lithium ion secondary battery, comprising: In the step (C), when determining the set temperature, the set temperature is limited based on charging history information including the number of past charging times in the second charging mode and the set temperature.
The charging method of the lithium ion secondary battery according to claim 8. further comprising a step (E) of estimating the current full charge capacity of the lithium ion secondary battery;
In the step (C), the set temperature is further determined based on the current full charge capacity of the lithium ion secondary battery estimated in the step (E).
The charging method of the lithium ion secondary battery according to claim 8 or 9.

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