KR102611395B1 - Apparatus and method for charging battery - Google Patents

Abstract

A battery charging device according to an embodiment of the present invention includes a power source configured to supply a charging current to a battery, a battery voltage controller configured to increase the voltage of the battery at a preset rate within a reference voltage range before charging the battery, and a voltage A voltage region classifier configured to classify the reference voltage range into a plurality of voltage regions based on the current generated from the battery as the voltage increases, and when charging the battery, determines the current density corresponding to each of the plurality of voltage regions to generate a charging current and a charging current controller configured to control the density.

Description

Battery charging device and charging method {APPARATUS AND METHOD FOR CHARGING BATTERY}

The present invention relates to a battery charging device and charging method, and more specifically, to a battery charging device and method for efficiently charging a lithium secondary battery.

Batteries such as lithium secondary batteries are a key component in energy storage and conversion technology and may include an anode, a cathode, and an electrolyte. These lithium secondary batteries can be used in various fields such as energy storage systems (ESS), hybrid electric vehicles (HEVs)/electric vehicles (EVs), and portable IT devices. In addition, due to the advancement of IoT (Internet of Things) technology, autonomous driving technology, and artificial intelligence technology, high-specification sensor networks and portable devices are required, and for this, high-performance and high-safety energy storage devices are essential.

Currently manufactured lithium secondary batteries have different charge/discharge characteristics and cycle characteristics depending on the manufacturer, and the lithium secondary batteries can be operated or their performance evaluated based on the charge/discharge current and capacity provided by the manufacturer. However, while actually using a lithium secondary battery, it is difficult to satisfy the current conditions specified by the manufacturer, and accordingly, battery characteristics such as capacity and cycle characteristics may also differ from those provided by the manufacturer. This difference is a problem that becomes even greater in electric vehicles and ESS that use large-capacity lithium secondary batteries.

The present invention is intended to solve the above-described technical problem, and the purpose of the present invention is to provide a battery charging device and charging method that can supply efficient charging current when charging a battery, taking into account the charging and discharging characteristics of batteries that vary by manufacturer. There is.

A battery charging device according to an embodiment of the present invention includes a power source configured to supply charging current to a battery, and a battery voltage controller configured to increase the voltage of the battery at a preset rate within a reference voltage range before charging the battery. , a voltage region classifier configured to classify the reference voltage range into a plurality of voltage regions based on the current generated from the battery as the voltage increases, and when charging the battery, corresponding to each of the plurality of voltage regions. and a charging current controller configured to control the density of the charging current by determining the current density.

In one embodiment, the voltage region classifier includes a slope calculator configured to calculate a slope of the current with respect to the voltage, and a slope calculator configured to compare the slope with at least one reference value to divide the reference voltage range into the plurality of voltage regions. It may include a slope comparator configured to classify.

In one embodiment, the slope comparator may be configured to classify a voltage range in which the slope is less than a specific reference value as a first voltage region, and classify a voltage range in which the slope is greater than the specific reference value as a second voltage region. You can.

In one embodiment, the charging current controller determines the density of the charging current as the first current density when the voltage of the battery is the first voltage region, and the charging current controller determines the density of the charging current as the first current density when the voltage of the battery is the second voltage region. In this case, it may be configured to determine the density of the charging current as a second current density higher than the first current density.

The battery charging device according to an embodiment of the present invention further includes a charging time and discharging capacity detector configured to detect the charging time and discharging capacity of the battery, and the charging current controller detects the charging time and discharging capacity of the battery. and may be further configured to determine a charging mode of the battery based on at least one of capacity.

In one embodiment, when the charging mode is a first mode that gives priority to the charging time and the discharging capacity, the charging current controller sets the ratio of the detected discharging capacity to the detected charging time to a preset ratio. If it is smaller than that, it may be further configured to adjust the current density corresponding to each of the plurality of voltage regions.

In one embodiment, when the charging mode is a second mode that prioritizes the charging time, the charging current controller controls the charging current controller corresponding to each of the plurality of voltage regions when the detected charging time is greater than a preset time. It can be further configured to increase current density.

In one embodiment, when the charging mode is a third mode that gives priority to the discharge capacity, the charging current controller controls each of the plurality of voltage regions when the detected discharge capacity is less than a preset capacity. It may be further configured to reduce the current density.

The battery charging device according to one embodiment of the present invention may further include a communication module configured to receive information about the reference voltage range, the preset speed, and the corresponding current density from outside the battery charging device. .

In the method of charging a battery of a battery charging device according to an embodiment of the present invention, the step of increasing the voltage of the battery at a preset rate within a reference voltage range, the current generated from the battery according to the increase in voltage It includes classifying the reference voltage range into a plurality of voltage regions based on and charging the battery based on a density of charging current corresponding to each of the plurality of voltage regions.

In one embodiment, classifying the reference voltage range into a plurality of voltage regions includes calculating a slope of the current with respect to the voltage and classifying a voltage range in which the slope is less than or equal to a reference value into a first voltage region. and classifying a voltage range in which the slope is greater than the reference value as a second voltage region.

In one embodiment, charging the battery includes charging the battery at a first current density when the voltage of the battery is in the first voltage region, and charging the battery at a first current density when the voltage of the battery is in the second voltage region. In this case, it may include charging the battery at a second current density higher than the first current density.

A battery charging method according to an embodiment of the present invention includes determining a charging mode of the battery based on at least one of the charging time of the battery and the discharging capacity of the battery, and detecting the charging time and the discharging capacity. It may further include.

In one embodiment, when the charging mode is a first mode that gives priority to the charging time and the discharging capacity, the step of charging the battery is performed by determining in advance the ratio of the detected discharging capacity to the detected charging time. If it is less than the set ratio, it may include adjusting the density of the charging current corresponding to each of the plurality of voltage regions and charging the battery with the adjusted density of the charging current.

In one embodiment, when the charging mode is a second mode that prioritizes the charging time, charging the battery may include charging the battery in each of the plurality of voltage regions when the detected charging time is greater than a preset time. It may include increasing the density of the charging current corresponding to and charging the battery with the increased density of the charging current.

In one embodiment, when the charging mode is a third mode that gives priority to the discharge capacity, charging the battery may include charging the battery in each of the plurality of voltage regions when the detected discharge capacity is less than a preset capacity. It may include reducing the density of the charging current corresponding to and charging the battery with the reduced density of the charging current.

The battery charging device according to an embodiment of the present invention can shorten the charging time of the battery and achieve high discharge capacity of the battery by supplying efficient charging current.

1 is a block diagram showing a battery charging device according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the voltage domain classifier of FIG. 1.
FIG. 3 is a diagram showing an example of voltage regions classified by the voltage region classifier of FIG. 2.
Figure 4 is a table showing examples of charge and discharge characteristics of a battery according to a plurality of current densities according to an embodiment of the present invention.
Figure 5 is a table showing the density of charging current determined according to one embodiment of the present invention.
FIG. 6 is a flowchart showing an example of a charging operation of the battery charging device of FIG. 1.
Figure 7 is a block diagram showing a battery charging device according to another embodiment of the present invention.
FIG. 8 is a flowchart showing an example of a charging operation of the battery charging device of FIG. 7.
Figure 9 is a block diagram showing a battery charging device according to another embodiment of the present invention.
Figure 10 is a graph showing the discharge capacity according to the cycle of a battery charged by applying the pattern current method (PCC) according to an embodiment of the present invention and the conventional constant current method (CCC; Constant Current Condition).
Figure 11 is a table showing the charging time and discharge capacity of a battery using the pattern current method (PCC) according to an embodiment of the present invention and the conventional constant current method (CCC).

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the following description, details such as detailed configurations and structures are provided simply to facilitate an overall understanding of embodiments of the present invention. Therefore, modifications to the embodiments described in the text can be made by those skilled in the art without departing from the technical spirit and scope of the present invention. Furthermore, descriptions of well-known functions and structures are omitted for clarity and conciseness. The terms used in this specification are terms defined in consideration of the functions of the present invention, and are not limited to specific functions. Definitions of terms may be determined based on the details described in the detailed description.

Components in the following drawings or detailed description may be connected to elements other than those shown in the drawings or described in the detailed description. Connections between components may be direct or non-direct, respectively. The connection between components may be a communication connection or a physical connection.

Components such as modules used in the detailed description may be implemented in the form of software, hardware, or a combination thereof. By way of example, software may be machine code, firmware, embedded code, and application software. For example, hardware may include an electrical circuit, an electronic circuit, a processor, a computer, an integrated circuit, integrated circuit cores, a pressure sensor, an inertial sensor, a Micro Electro Mechanical System (MEMS), a passive component, or a combination thereof. You can.

Unless otherwise defined, all terms including technical or scientific meanings used in the text have meanings that can be understood by those skilled in the art to which the present invention pertains. In general, terms defined in dictionaries are interpreted to have a meaning equivalent to the contextual meaning in the relevant technical field, and are not interpreted to have an ideal or excessively formal meaning unless clearly defined in the text.

1 is a block diagram showing a battery charging device according to an embodiment of the present invention. Referring to FIG. 1 , the battery charging device 100 may charge the battery 10 by supplying charging current to the battery 10 . For example, the battery 10 may be a lithium secondary battery. When charging the battery 10, the battery charging device 100 may vary the density of charging current supplied to the battery 10 depending on the voltage of the battery 10. Accordingly, the charge/discharge characteristics of the battery 10 may be improved. The charge/discharge characteristics of the battery 10 may refer to values for the charging time and discharge capacity of the battery 10. When charge/discharge characteristics are improved, charging time may be shortened and discharge capacity may be increased.

Before charging the battery 10, the battery charging device 100 may detect a change in current while changing the voltage of the battery 10. Although not shown in FIG. 1, the battery charging device 100 may detect a current change according to a voltage change of the battery 10 through a voltage and current detector. When charging the battery 10, the battery charging device 100 may adjust the density of the charging current supplied to the battery 10 based on the current change according to the voltage change of the battery 10.

The battery charging device 100 may include a power source 110, a battery voltage controller 120, a voltage region classifier 130, and a charging current controller 140. The power source 110 may supply charging current to the battery 10 . For example, the power source 110 may supply charging current with a specific current density to the battery 10 .

The battery voltage controller 120 may control the voltage of the battery 10 before charging the battery 10. As an example, the battery voltage controller 120 may increase the voltage of the battery 10 at a preset rate within a reference voltage range. The reference voltage range may be a range of the voltage of the battery 10 that varies depending on charging and discharging of the battery 10. Information about the reference voltage range may be provided from outside the battery charging device 100 or may be stored in advance within the battery charging device 100. The battery voltage controller 120 may increase the voltage of the battery 10 from the minimum voltage to the maximum voltage in the reference voltage range.

The battery voltage controller 120 transmits a control signal to the battery 10 to control the voltage of the battery 10, or adjusts the current supplied to the battery 10 through the power source 110 to control the voltage of the battery 10. can be controlled.

Before charging the battery 10, the voltage region classifier 130 determines a plurality of reference voltage ranges based on the current generated from the battery 10 as the voltage of the battery 10 increases by the battery voltage controller 120. It can be classified into voltage areas. For example, the battery voltage controller 120 may divide the reference voltage range into first to fifth voltage ranges based on a change in current according to an increase in voltage. The battery voltage controller 120 may classify the first and third voltage ranges into a first voltage region and the second, fourth, and fifth voltage ranges into a second voltage region. That is, the classified voltage region may include at least one voltage range within the reference voltage range.

When charging the battery 10, the charging current controller 140 may control the density of charging current supplied to the battery 10 based on the voltage regions classified by the voltage region classifier 130. The charging current controller 140 can control the density of charging current through the power source 110. By way of example, the charging current controller 140 may control the density of the charging current according to the density of the current corresponding to each of the voltage regions. Accordingly, when the voltage of the battery 10 is in the same voltage region, the same density of charging current can be supplied to the battery 10.

The density of current corresponding to each of the voltage regions may be determined in advance based on the charge/discharge characteristics of the battery 10. For example, the corresponding current density may be predetermined based on at least one of the charging time and discharging capacity of the battery 10. That is, the corresponding current density can be determined to reduce the charging time or increase the discharging capacity of the battery 10. Accordingly, for each voltage region, a charging current that can reduce the charging time or increase the discharge capacity of the battery 10 can be supplied.

As described above, the battery charging device 100 according to an embodiment of the present invention can supply charging current that can improve the charging and discharging characteristics of the battery 10 according to the voltage of the battery 10. Accordingly, the charging time of the battery 10 may be reduced or the discharge capacity may be increased.

FIG. 2 is a block diagram showing the voltage domain classifier of FIG. 1. Referring to FIG. 2, the voltage domain classifier 130 may receive information about the current generated according to the voltage change of the battery 10. The voltage region classifier 130 may classify the reference voltage range into a plurality of voltage regions based on voltage and current information.

The voltage domain classifier 130 may include a slope operator 131, a register 132, and a slope comparator 133. The slope calculator 131 can calculate the slope of the current according to the change in voltage of the battery 10. The slope calculator 131 may calculate the slope based on information on the current corresponding to each voltage as the voltage of the battery 10 increases from the minimum voltage to the maximum voltage in the reference voltage range.

The register 132 may store slope information calculated by the slope calculator 131. The register 132 can store various slope information calculated within the reference voltage range.

The slope comparator 133 may classify the reference voltage range into a plurality of voltage regions based on the slope information stored in the register 132. Exemplarily, the slope comparator 133 may compare each slope with at least one reference value. For example, when the first slope of the first voltage range among the reference voltage ranges is less than or equal to a specific reference value, the slope comparator 133 may classify the first voltage range as the first voltage region. When the second slope of the second voltage range among the reference voltage ranges is greater than a specific reference value, the slope comparator 133 may classify the second voltage range as the second voltage region.

FIG. 3 is a diagram showing an example of voltage regions classified by the voltage region classifier of FIG. 2. Referring to FIG. 3, a curve of current according to the voltage of the battery 10 within the reference voltage range is shown. The horizontal axis represents the voltage of the battery 10, and the vertical axis represents the current of the battery 10.

As shown in FIG. 3, the battery voltage controller 120 of FIG. 1 can increase the voltage of the battery 10 from 3V to 4.25V at a preset rate of 0.1 mV/s. That is, the reference voltage range in FIG. 3 may be 3V to 4.25V, and the preset speed may be 0.1 mV/s. The size of the current generated by the battery 10 may vary depending on the voltage change.

The voltage domain classifier 130 of FIG. 2 can calculate a slope through the slope calculator 131 from information about the current generated according to the voltage of the battery 10. The voltage region classifier 130 may classify the reference voltage range into a first voltage region and a second voltage region based on the magnitude of the calculated slope. The first voltage area includes the first voltage range (C1) and the third voltage range (C3) of the reference voltage range, and the second voltage area includes the second voltage range (C2) and the fourth voltage range (C2) of the reference voltage range ( C4) and a fifth voltage range (C5). The first voltage area may be a voltage area with a relatively gentle slope, and the second voltage area may be a voltage area with a relatively steep slope. The voltage region classifier 130 compares the slope calculated through the slope comparator 133 with a reference value to determine a first voltage region (i.e., a voltage region with a gentle slope) and a second voltage region (i.e., a voltage region with a sharp slope). ) can be classified.

For example, the voltage region classifier 130 may pre-store '1' as a reference value and determine whether the slope is gentle or steep based on '1'. The first voltage range (C1) from 3V to 3.73V may have a slope of 0.013A/V (=0.05A / 3.73V). Since the slope of the first voltage range C1, '0.013', is less than or equal to '1', the voltage region classifier 130 divides the first voltage range C1 into a voltage region with a gentle slope (i.e., a first voltage region). Can be classified. The second voltage range (C2) within 3.73V to 3.83V may have a slope of 1.8A/V (=(0.23-0.05)A/(3.83-3.73)V). Since the slope of the second voltage range C2, '1.8', is greater than '1', the voltage region classifier 130 divides the second voltage range C2 into a voltage region with a steep slope (i.e., a second voltage region). Can be classified. In this way, the voltage region classifier 130 classifies the third voltage range C3 into a voltage region with a gentle slope (i.e., a first voltage region) and the fourth and fifth voltage ranges C4 and C5. can be classified into a voltage region with a steep slope (i.e., a second voltage region).

When the battery 10 is charged with a high current density in a first voltage region with a gentle slope, the physical or chemical state of the battery 10 may be greatly modified, which may adversely affect cycle characteristics. Cycle characteristics are one of the charging and discharging characteristics, and may refer to the battery capacity maintenance rate that changes as the charging and discharging cycle progresses. When the battery 10 is charged with a high current density in a second voltage region with a sharp slope, high-speed charging is possible with relatively little structural change within the positive and negative electrodes of the battery 10, and the high current density allows A lot of lithium accumulated in the cathode can contribute to discharge capacity, so high capacity can be realized.

Accordingly, the charging current controller 140 of FIG. 1 can control the density of charging current to be supplied to the battery 10 by considering the characteristics of voltage regions according to slope. For example, the charging current controller 140 controls the power source 110 so that a charging current with a relatively low current density is supplied to the battery 10 in a first voltage region with a gentle slope, and in a second voltage region with a steep slope. The power source 110 can be controlled so that a charging current with a relatively high current density in the voltage range is supplied to the battery 10.

Figure 4 is a table showing examples of charge and discharge characteristics of a battery according to a plurality of current densities according to an embodiment of the present invention. Referring to FIG. 4, the charging time, discharging time, ratio of charging capacity to design capacity (charging capacity/design capacity), and design capacity of the battery 10 corresponding to each of the six current densities (C-rate). The values of the ratio of discharge capacity to discharge capacity (discharge capacity/design capacity) and the ratio of discharge capacity to charge time (discharge capacity/charge time) may be different. For example, as the current density increases, the values of charge time, discharge time, charge capacity, and discharge capacity may decrease.

By way of example, the charge/discharge characteristic values corresponding to the current density in FIG. 4 may vary depending on the voltage range of the battery 10. Figure 4 may show charge/discharge characteristic values in a voltage region with a gentle slope. The charging current controller 140 may determine the current density in the first voltage region of FIG. 3 based on the values of FIG. 4 . For example, when determining the current density based on the ratio of discharge capacity to charge time (discharge capacity/charge time), the charge current controller 140 sets the value of discharge capacity/charge time to the largest value (2C). The current density can be determined.

As explained in FIG. 3, in a voltage region with a steep slope, the battery 10 can be charged with a higher current density than in a voltage region with a gentle slope, so the charging current controller 140 controls the current density in the first voltage region ( The current density of the second voltage region can be determined with a current density higher than 2C). Although not shown in FIG. 4 , the charging current controller 140 may determine the current density of the second voltage region based on the charging/discharging characteristic values in the voltage region with a steep slope.

By way of example, the charge/discharge characteristic values corresponding to the current density in FIG. 4 may be information provided by the battery 10 manufacturer. The battery charging device 100 may pre-store information on different charge/discharge characteristics for each battery 10 and determine the density of charging current based on the stored information.

Alternatively, charge/discharge characteristic values corresponding to the current density in FIG. 4 may be calculated inside the battery charging device 100 during the initial charge/discharge cycle (eg, 1 to 5 cycles) of the battery charging device 100. Since the charge/discharge characteristics of the battery 10 may vary as the charge/discharge cycle is repeated, the battery charging device 100 uses the charge/discharge characteristic values of FIG. 4 after a predetermined cycle (e.g., 50 cycles). It can be updated.

As described above, the battery charging device 100 stores the charge/discharge characteristic values of the battery 10 according to the current density, and determines the value of the current density corresponding to each of the voltage regions based on the charge/discharge characteristic values. there is.

Figure 5 is a table showing the density of charging current determined according to one embodiment of the present invention. Referring to FIG. 5, the battery charging device 100 can classify the reference voltage range into first voltage regions (C1, C3, C5) and second voltage regions (C2, C4) through the voltage region classifier 130. there is. The first voltage region includes a first voltage range (C1) of OCV (Open Circuit Voltage) of more than 3.73V, a third voltage range (C3) of more than 3.83V and less than 3.91V, and a fifth voltage range of more than 4.04V and less than 4.2V. (C5), and the second voltage region may include a second voltage range (C2) of 3.73V or more and less than 3.83V and a fourth voltage range (C4) of 3.91V or more and less than 4.04V.

The battery charging device 100 provides 1080 mA (2C) for the first voltage range (C1), 1620 mA (3C) for the second voltage range (C2), and a third voltage range (C2) through the charging current controller 140. The battery 10 can be charged using 1080 mA (2C) for C3), 1620 mA (3C) for the fourth voltage range (C4), and 1080 mA (2C) for the fifth voltage range (C5). . For the fifth voltage range C5, constant current (CC) charging and constant voltage (CV) charging at a cut-off voltage may be performed continuously. When the battery 10 is discharged, the battery charging device 100 can supply a current of 1080 mA (2C). In this way, a method of charging a battery using a different current density for each voltage region may be referred to as a pattern current condition (PCC).

The charging/discharging characteristic values and charging current density in FIGS. 4 and 5 are merely examples for explaining the operation of the battery charging device 100, and the present invention is not limited thereto.

FIG. 6 is a flowchart showing an example of a charging operation of the battery charging device of FIG. 1. Referring to FIG. 6, in step S101, the battery charging device 100 may increase the voltage of the battery 10 at a preset rate within the reference voltage range. For example, the reference voltage range and preset speed may vary depending on the battery 10.

In step S102, the battery charging device 100 may classify the reference voltage range into a plurality of voltage regions based on the current generated from the battery 10 as the voltage increases. The battery charging device 100 may calculate the slope of current with respect to voltage and classify the reference voltage range according to the size of the calculated slope. For example, a voltage range whose slope is less than a reference value may be classified as a first voltage region, and a voltage range whose slope is greater than the reference value may be classified as a second voltage region.

In step S103, the battery charging device 100 may charge the battery 10 based on the density of charging current corresponding to each of the plurality of voltage regions. For example, when the voltage of the battery 10 belongs to a first voltage region where the slope is relatively gentle, the battery charging device 100 may charge the battery 10 at a first current density. When the voltage of the battery 10 is in a second voltage region where the slope is relatively steep, the battery charging device 100 may charge the battery 10 with a second current density that is higher than the first current density.

Figure 7 is a block diagram showing a battery charging device according to another embodiment of the present invention. Referring to FIG. 7, the battery charging device 200 can control the charging current to be supplied to the battery 10 according to various charging modes. That is, the battery charging device 200 can adjust the density of charging current depending on the charging mode. The charging mode may be provided from outside the battery charging device 200 or may be determined inside the battery charging device 200.

The battery charging device 200 may include a power source 210, a battery voltage controller 220, a voltage region classifier 230, a charging current controller 240, and a charging time and discharging capacity detector 250. The operation of the power source 210, the battery voltage controller 220, the voltage region shunt 230, and the charging current controller 240 are similar to those of the power source 110, the battery voltage controller 120, the voltage region shunt 130, and Since it is similar to the operation of the charging current controller 140, detailed description may be omitted.

The battery charging device 200 may classify the reference voltage range into a plurality of voltage regions through the battery voltage controller 220 and the voltage region classifier 230. When charging the battery 10, the charging current controller 240 may determine the charging mode of the battery 10. The charging current controller 240 may determine the current density so that at least one characteristic of the charging time and discharging capacity of the battery 10 is improved according to the charging mode. For example, the charging current controller 240 may determine the current density based on pre-stored charging/discharging characteristic values, as shown in FIG. 4 .

For example, when the charging mode is a mode that gives priority to charging time and discharging capacity, the charging current controller 240 may determine the current density so that the ratio of discharging capacity to charging time is higher than a preset ratio. The preset ratio may be a ratio of discharge capacity to charge time when the charge time and discharge capacity characteristics of the battery 10 satisfy standard conditions. That is, when charging the battery 10, if the ratio of discharge capacity to charging time detected is higher than a preset ratio, the charging current controller 240 may determine that the charging time and discharge capacity satisfy the standard conditions. there is.

When charging the battery 10, if the ratio of the discharge capacity to the detected charging time is smaller than a preset ratio, the charging current controller 240 may adjust the density of the charging current corresponding to each of the plurality of voltage regions. . When the ratio of discharge capacity to charging time detected by adjusting the current density is greater than or equal to a preset ratio, the charging current controller 240 may control the output of the power source 210 based on the adjusted current density value. .

For example, when the charging mode is a mode that prioritizes charging time, the charging current controller 240 may determine the current density so that the charging time is smaller than a preset time. The preset time may be the charging time when the charging time of the battery 10 satisfies the standard time. That is, when charging the battery 10, if the detected charging time is less than the preset time, the charging current controller 240 may determine that the charging time satisfies the reference time.

When charging the battery 10, if the detected charging time is greater than a preset time, the charging current controller 240 may increase the density of charging current corresponding to each of the plurality of voltage regions. If the charging time detected as the current density increases is smaller than the preset time, the charging current controller 240 may control the output of the power source 210 based on the increased current density.

For example, when the charging mode is a mode that prioritizes discharging capacity, the charging current controller 240 may determine the current density so that the discharging capacity is greater than a preset capacity. The preset capacity may be the discharge capacity when the discharge capacity of the battery 10 satisfies the standard capacity. That is, when charging the battery 10, if the detected discharge capacity is greater than the preset capacity, the charging current controller 240 may determine that the discharge capacity satisfies the reference capacity.

When charging the battery 10, if the detected discharge capacity is smaller than the preset capacity, the charging current controller 240 may reduce the density of the charging current corresponding to each of the plurality of voltage regions. When the charging time detected as the current density decreases becomes greater than the preset capacity, the charging current controller 240 may control the output of the power source 210 based on the reduced current density value.

The charging time and discharge capacity detector 250 can detect the charging time and discharge capacity of the battery 10. The charging current controller 240 may determine whether the standard conditions according to the charging mode are satisfied based on the charging time and discharging capacity provided from the charging time and discharging capacity detector 250. As described above, when the charging time and discharge capacity do not meet the standard conditions according to the mode, the charging current controller 240 may adjust the density of the charging current.

The battery charging device 100 of FIG. 1 controls the current density to improve the ratio of discharge capacity to charging time, but the battery charging device 200 of FIG. 7 has a ratio of discharge capacity to charging time depending on the charging mode. The current density can be controlled to improve, and the current density can be controlled to reduce charging time or increase discharge capacity. Accordingly, the battery charging device 200 can charge the battery 10 so that various charging and discharging conditions are satisfied.

FIG. 8 is a flowchart showing an example of a charging operation of the battery charging device of FIG. 7. Referring to FIG. 8, the operation of the battery charging device 200 according to the charging mode of the battery 10 is shown. The charging mode of the battery 10 may include a first mode that gives priority to charging time and discharge capacity, a second mode that gives priority to charging time, and a third mode that gives priority to discharge capacity.

In step S201, the battery charging device 200 may classify the reference voltage range into a plurality of voltage regions based on the current resulting from an increase in the voltage of the battery 10. Since the operation of step S201 is similar to the operation of steps S101 and S102 of FIG. 6, detailed description may be omitted.

In step S202, the battery charging device 200 may determine whether the charging mode of the battery 10 is the first mode. When the charging mode is the first mode, in step S203, when the ratio of discharge capacity to the detected charging time is less than a preset ratio, the battery charging device 200 determines the charging current corresponding to each of the plurality of voltage regions. Density can be adjusted. When charging, the charging time and discharge capacity of the battery 10 according to the charging current provided from the battery charging device 200 may be detected. The battery charging device 200 may maintain the density of the charging current when the ratio of the discharge capacity to the detected charging time is greater than or equal to a preset ratio.

If the charging mode is not the first mode, the battery charging device 200 may determine whether the charging mode of the battery 10 is the second mode in step S204. When the charging mode is the second mode, in step S205, the battery charging device 200 may increase the density of the charging current corresponding to each of the plurality of voltage regions when the detected charging time is greater than the preset time. . The battery charging device 200 may maintain the density of charging current when the detected charging time is less than or equal to a preset time.

If the charging mode is not the second mode, the battery charging device 200 may determine that the charging mode of the battery 10 is the third mode. In step S206, the battery charging device 200 may reduce the density of charging current corresponding to each of the plurality of voltage regions when the detected discharge capacity is smaller than the preset capacity. The battery charging device 200 may maintain the density of charging current when the detected discharge capacity is greater than or equal to a preset capacity.

In step S207, the battery charging device 200 may charge the battery 10 with the adjusted charging current density in each mode.

As described above, the battery charging device 200 according to an embodiment of the present invention can determine whether the standard condition according to the charging mode is satisfied and adjust the density of the charging current based on the determination result. The battery charging device 200 may adjust the density of charging current based on pre-stored charge/discharge characteristic values of the battery 10 as shown in FIG. 4 .

Figure 9 is a block diagram showing a battery charging device according to another embodiment of the present invention. Referring to FIG. 9 , the battery charging device 300 may include a power source 310, a battery voltage controller 320, a voltage region classifier 330, a charging current controller 340, and a communication module 350. The operation of the power source 310, the battery voltage controller 320, the voltage region shunt 330, and the charging current controller 340 are similar to those of the power source 110, the battery voltage controller 120, the voltage region shunt 130, and Since it is similar to the operation of the charging current controller 140, detailed description may be omitted.

The battery charging device 300 can transmit and receive information with an external system or device through the communication module 350. The battery charging device 300 may receive information for the operation of the battery voltage controller 320 from the outside through the communication module 350. The communication module 350 may receive information about the reference voltage range and preset speed and transmit it to the battery voltage controller 320. Before charging the battery 10, the battery voltage controller 320 may control the voltage of the battery 10 based on a received reference voltage range and a preset speed.

The battery charging device 300 may receive information for the operation of the voltage region classifier 330 from the outside through the communication module 350. The communication module 350 may receive at least one reference value for classifying the reference voltage range into a plurality of voltage regions and transmit it to the voltage region classifier 330. The voltage region classifier 330 may classify the reference voltage range into a plurality of voltage regions based on a comparison result between the slope of the current with respect to voltage and the reference value.

The battery charging device 300 may receive information for the operation of the charging current controller 340 from the outside through the communication module 350. The communication module 350 may receive charge/discharge characteristic values of the battery 10 as shown in FIG. 4 and transmit them to the charge current controller 340. The charging current controller 340 may determine the density of current corresponding to each of the voltage regions based on the charging and discharging characteristic values. The charging current controller 340 may control the density of the charging current according to the determined current density. Additionally, the battery charging device 300 may receive the charging mode from the outside through the communication module 350 and transmit it to the charging current controller 340. The charging current controller 340 may determine the density of charging current according to the charging mode.

Figure 10 is a graph showing the discharge capacity according to the cycle of a battery charged by applying the pattern current method (PCC) according to an embodiment of the present invention and the conventional constant current method (CCC; Constant Current Condition). The constant current method (CCC) is a method of supplying charging current with the same current density for all voltage regions.

Referring to FIG. 10, in any cycle, the discharge capacity when the pattern current method (PCC) is applied may be higher than the discharge capacity when the constant current method (CCC) is applied. That is, the battery 10 charged using the pattern current method (PCC) may have superior cycle characteristics compared to the battery 10 charged using the constant current method (CCC).

Figure 11 is a table showing the charging time and discharge capacity of a battery using the pattern current method (PCC) according to an embodiment of the present invention and the conventional constant current method (CCC). Specifically, Figure 11 shows the charging time and discharge capacity detected in the 10th cycle. Referring to FIG. 11, the discharge capacity/charge time (1.296) of the battery 10 using the pattern current method (PCC) is greater than the discharge capacity/charge time (1.262) of the battery 10 using the constant current method (CCC). You can. In other words, the charge/discharge characteristics of the battery 10 using the pattern current method (PCC) may be better than the charge/discharge characteristics of the battery 10 using the constant current method (CCC).

As described above, the battery charging device according to embodiments of the present invention can improve the charging and discharging characteristics of the battery 10 by varying the density of the charging current supplied according to the voltage range of the battery 10. Therefore, according to embodiments of the present invention, the battery 10 can be charged efficiently.

The above-described details are specific embodiments for carrying out the present invention. The present invention will include not only the above-described embodiments, but also embodiments that can be simply changed or easily changed in design. In addition, the present invention will also include technologies that can be easily modified and implemented using the embodiments. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the claims and equivalents of the present invention as well as the claims described later.

100, 200, 300: Battery charging device
110, 210, 310: Power
120, 220, 320: Battery voltage controller
130, 230, 330: Voltage domain classifier
140, 240, 340: Charging current controller
131: Gradient calculator
132: register
133: slope comparator
250: Charge time and discharge capacity detector
350: Communication module

Claims (16)

A power source configured to supply charging current to a battery;
a battery voltage controller configured to increase the voltage of the battery at a preset rate within a reference voltage range before charging the battery;
a voltage region classifier configured to classify the reference voltage range into a plurality of voltage regions based on a current generated from the battery as the voltage increases; and
When charging the battery, a charging current controller configured to control the density of the charging current by determining a current density corresponding to each of the plurality of voltage regions,
The voltage region classifier is,
a slope calculator configured to calculate a slope of the current with respect to the voltage; and
A battery charging device comprising a slope comparator configured to classify the reference voltage range into the plurality of voltage regions by comparing the slope with at least one reference value. delete According to claim 1,
The slope comparator is configured to classify a voltage range in which the slope is less than a specific reference value as a first voltage region, and classifies a voltage range in which the slope is greater than the specific reference value as a second voltage region. According to claim 3,
When the voltage of the battery is in the first voltage region, the charging current controller determines the density of the charging current as the first current density, and when the voltage of the battery is in the second voltage region, the density of the charging current is determined. A battery charging device configured to determine a second current density higher than the first current density. According to claim 1,
further comprising a charging time and discharging capacity detector configured to detect the charging time of the battery and the discharging capacity of the battery,
the charging current controller is further configured to identify a charging mode of the battery based on at least one of the charging time and the discharging capacity,
The above charging modes are:
a first mode that prioritizes the charging time and the discharging capacity;
a second mode that prioritizes the charging time; and
A battery charging device comprising at least one of a third mode that gives priority to the discharge capacity. According to claim 5,
When the charging mode is the first mode, the charging current controller determines the current density corresponding to each of the plurality of voltage regions if the ratio of the detected discharge capacity to the detected charging time is less than a preset ratio. A battery charging device further configured to regulate. According to claim 5,
When the charging mode is the second mode, the charging current controller is further configured to increase the current density corresponding to each of the plurality of voltage regions when the detected charging time is greater than a preset time. According to claim 5,
When the charging mode is the third mode, the charging current controller is further configured to reduce the current density corresponding to each of the plurality of voltage regions when the detected discharge capacity is less than a preset capacity. . According to claim 1,
A battery charging device further comprising a communication module configured to receive information about the reference voltage range, the preset speed, and the corresponding current density from outside the battery charging device. In a method of charging a battery of a battery charging device,
increasing the voltage of the battery at a preset rate within a reference voltage range;
classifying the reference voltage range into a plurality of voltage regions based on a current generated from the battery as the voltage increases; and
Comprising charging the battery based on a density of charging current corresponding to each of the plurality of voltage regions,
The step of classifying into the plurality of voltage regions is,
calculating a slope of the current with respect to the voltage; and
Comparing the slope with at least one reference value to classify the reference voltage range into the plurality of voltage regions. delete delete delete delete delete delete

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