KR102585720B1 - Shunt register, charging device and the operation method - Google Patents

Abstract

The present invention includes first and second shunt blocks and a plurality of plate-shaped shunts electrically connected between the first and second shunt blocks, and both ends of each of the plurality of plate-shaped shunts are connected to the first and second shunt blocks. It is fixedly joined to the slit formed in the horizontal direction on each inner surface with silver solder, and provides a shunt resistance made of manganese or manganese alloy material.

Description

Shunt resistor, charging device and the operation method {Shunt register, charging device and the operation method}

The present invention relates to a shunt resistor, a charging device, and a method of operating the same, and more specifically, to a shunt resistor, a charging device, and the same that facilitate preventing heat generation between a jig and a secondary battery during formation. It's about how it works.

In producing electrical energy based on renewable energy sources, especially solar power or wind power, there is a growing demand for efficient storage of the generated energy so that the stored electrical energy can be used when and as needed. This is changing.

Generally, lithium-ion batteries, known as secondary batteries, have a high number of charging cycles, long lifespan, and high storage capacity.

Depending on the design, lithium-ion batteries discharge up to 30% of their capacity. In other words, if the battery is discharged below the critical value of 30%, the lithium-ion battery is irreparably damaged, so 30% of the inherent energy stored in the battery cannot be utilized by the user. If the battery discharges below this threshold, ions can separate from the electrode material (copper, A1), which can destroy the electrode.

In order to produce and ship batteries such as lithium-ion batteries, several processes are required, including aging, formation, OCV (Open Circuit Voltage) inspection, IR (internal resistance) inspection, and grading.

Among these processes, the Formation process repeats the process of charging the produced O Volt battery to a cell voltage of 4.2 V and discharging it again to 2.7 V, repeating the process several times before shipping with a final voltage of 3.7 V. Therefore, since the characteristics and quality of the battery are determined in this process, formation is a very important process that determines the quality of the battery.

However, during the conversion process, lithium-ion batteries are only charged to 80% of their capacity, because the current is normally limited when the end-of-charge voltage is reached, so the remaining 20% of the capacity % is charged at less amperage, so in terms of time, less energy is stored or built into the battery, so it takes exponentially more time for the battery to charge to 100%.

Recently, there is a trend to improve the characteristics and quality of batteries by charging and discharging with high current during the chemical conversion process, and when charging and discharging with high current, the generated in the contact area between the jig and the secondary battery is reduced. Since ignition may occur due to heat generation, research is being conducted to control charging and discharging according to the contact resistance between the jig that responds to heat generation and the secondary battery.

The purpose of the present invention is to provide a shunt resistor, a charging device, and a method of operating the same that facilitate the formation of a solid electrolyte interphase (SEI) layer in a secondary battery in a discharged state.

Additionally, the purpose of the present invention is to provide a shunt resistor, a charging device, and a method of operating the same that can easily prevent heat generation between a jig and a secondary battery during the formation process.

Additionally, the purpose of the present invention is to provide a shunt resistor, a charging device, and a method of operating the same that are integrally connected to the output terminal of a charging/discharging module and facilitate measuring the charging current and discharging current output.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention that are not mentioned can be understood by the following description and will be more clearly understood by the examples of the present invention. Additionally, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the patent claims.

The shunt resistor according to the present invention includes first and second shunt blocks and a plurality of plate-shaped shunts electrically connected between the first and second shunt blocks, and both ends of each of the plurality of plate-shaped shunts are connected to the first and second shunt blocks. , 2 It is fixedly coupled with silver solder to a slit formed in the horizontal direction on the inner surface of each shunt block, and may be made of manganese or manganese alloy material.

The charging device according to the present invention is a charging and discharging module that charges and discharges a secondary battery that is contact-coupled with a jig, and when charging and discharging the secondary battery, measures the charging current and discharging current output from the output terminal of the charging and discharging module. and a resistance measurement module that measures the contact resistance occurring at the contact surface between the jig and the secondary battery based on the charging current and the discharging current, and based on the contact resistance during charging and discharging of the secondary battery and a set reference contact resistance. It may include a control module that controls the operation of the charging and discharging module according to whether charging and discharging of the secondary battery is determined.

The charge/discharge module may output the charge current of charge pulses when charging the secondary battery, and output the discharge current of discharge pulses when the secondary battery is discharged.

The resistance measurement module includes a first amplifier that amplifies the output terminal voltage of the charging and discharging module to a first differential voltage when charging and discharging the secondary battery, and converts the voltage at both ends of the secondary battery to a second differential voltage when charging and discharging the secondary battery. A second amplifier that amplifies, is integrally connected to the output terminal of the charge and discharge module, and measures the charge current and the discharge current based on a shunt resistor and the charge current, the discharge current and the first and second differential voltages. , may include a resistance meter that measures the contact resistance.

The first and second amplifiers may include at least one of a differential amplifier and an instrumentation amplifier.

When the secondary battery is being charged, the resistance meter is, The charging contact resistance (R ₁ ) is measured by , where V ₁ may be the first differential voltage, V ₂ may be the second differential voltage, and I ₁ may be the charging current.

When the secondary battery is discharging, the resistance meter is, The discharge contact resistance (R ₂ ) is measured by , where V ₁ may be a first differential voltage, V ₂ may be a second differential voltage, and I ₂ may be a discharge current.

The resistance meter may measure the contact resistance as an average value of the charging contact resistance and the discharging contact resistance.

The control module controls the charging and discharging module to continue charging and discharging of the secondary battery when the contact resistance is lower than the reference contact resistance, and when the contact resistance is higher than the reference contact resistance, charging and discharging of the secondary battery continues. The charging/discharging module can be controlled to be blocked.

The shunt resistor, charging device, and method of operation according to the present invention provide charging at up to 3 times higher than the rated current of the secondary battery to initiate the formation of a solid electrolyte interphase (SEI) layer in the discharged state of the secondary battery. There is an advantage in that the lifespan and capacity of the secondary battery can be increased by alternately supplying pulses and discharge pulses for a very short period of time.

In addition, the shunt resistor, charging device, and method of operation according to the present invention can prevent damage to the secondary battery due to heat generation by temporarily stopping charging and discharging according to the contact resistance of the secondary battery in the charging and discharging state of the secondary battery. There is an advantage.

In addition, the shunt resistance, charging device, and method of operation according to the present invention are a shunt resistor integrally connected to the output terminal of the charging/discharging module to measure the contact resistance of the secondary battery in the charging/discharging state of the secondary battery, and measure the charging current and discharging current. There is an advantage in that the contact resistance can be accurately measured.

Meanwhile, the effects of the present invention are not limited to the effects mentioned above, and various effects may be included within the range apparent to those skilled in the art from the contents described below.

1 is a diagram showing the formation process of a lithium secondary battery according to the present invention.
Figure 2 is a perspective view showing a shunt resistance according to the present invention.
FIG. 3 is a diagram showing an embodiment of the combination of the shunt resistors shown in FIG. 2.
Figure 4 is a control block diagram showing the control configuration of the charging device according to the first embodiment of the present invention.
FIG. 5 is a timing diagram showing charge pulses and discharge pulses output from the charge/discharge module shown in FIG. 4.
FIG. 6 is a circuit diagram showing the charging device shown in FIG. 4 in detail.
Figure 7 is a flowchart showing a method of operating a charging device according to the first embodiment of the present invention.
Figure 8 is a control block diagram showing the control configuration of the charging device according to the second embodiment of the present invention.
FIG. 9 is a circuit diagram showing the charging device shown in FIG. 8 in detail.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

1 is a diagram showing the formation process of a lithium secondary battery according to the present invention.

Figure 1(a) is a state in which a lithium secondary battery has no electrical properties after being manufactured, and Figure 1(b) is a formation process, in which a solid electrolyte intermediate (SEI) is formed to have electrical properties in a lithium secondary battery. , Solid Electrolyte Interphase (Solid Electrolyte Interphase) layer formation is starting, and Figure 1(c) shows a lithium secondary battery with electrical characteristics after the chemical conversion process is completed.

Here, the solid electrolyte intermediate layer (SEI) is an important factor that determines the electric capacity, performance, and lifespan of lithium secondary batteries.

That is, in Figure 1(b), in order to activate the lithium secondary battery, charge pulses and discharge pulses are alternately supplied to the cathode and anode to create a solid electrolyte intermediate layer (SEI) on the anode side.

Here, the electrolyte intermediate layer (SEI) can prevent lithium ions (Li+) from reacting with other substances at the anode when charging the lithium secondary battery in the future.

Additionally, the electrolyte intermediate layer (SEI) performs a type of ion tunnel function and can only allow lithium ions (Li+) to pass through.

In other words, the solid electrolyte intermediate layer (SEI) can be created through the formation process, that is, the process of activating a cell in a discharged state as the first charging process of a lithium secondary battery.

First, when charging a lithium secondary battery, when a charging pulse is supplied to the lithium secondary battery, lithium ions (Li+) pass from the cathode of the lithium secondary battery to the anode and react with additives in the cathode electrolyte solution, forming a charge at the front of the anode interface. A thin solid electrolyte intermediate (SEI) layer can be created.

In other words, the solid electrolyte intermediate layer (SEI) is an insulator that is formed when the amount of ion movement in the battery increases, and once formed, it can prevent lithium ions (Li+) from reacting with other substances at the anode during subsequent battery charging.

Figure 2 is a perspective view showing a shunt resistor according to the present invention, and Figure 3 is a diagram showing an embodiment of the combination of the shunt resistor shown in Figure 2.

Referring to FIGS. 2 and 3 , the shunt resistor 10 may include first and second shunt blocks 1 and 2 and a plurality of plate-shaped shunts 7 .

The first shunt block 1 is a connection block electrically connected to a plurality of plate-shaped shunts 7 and may be made of a metal material, for example, copper.

Here, the first shunt block 1 may include a first input unit 3 through which current is input and a first output unit 4 electrically connected to the first input unit 3.

The first input unit 3 receives a current output from a charge/discharge module, which will be described later, and the first output unit 4 can output the current to a resistance measurement module, which will be described later.

The second shunt block 2 includes a second input unit 5 and a second input unit ( It may include a second output unit 6 electrically connected to 5).

The second input unit 5 outputs the current output from the plurality of plate-shaped shunts 7 to the secondary battery, and the second output unit 6 is electrically connected to the second input unit 5, and the resistance measurement module Current can be output as .

Here, the first and second input units 3 and 5 may be electrically connected to the copper film pattern of the charge/discharge module and the resistance measurement module.

In the embodiment, the first and second input units 3 and 5 are described as inputting and outputting current through a screw connection with a current line electrically connected to the copper film pattern, but the present invention is not limited thereto.

The first and second output units 4 and 6 may branch the current input to the first and second input units 3 and 5 and output the current to the resistance measurement module.

In the embodiment, the first and second output units 4 and 6 are described as inputting and outputting current through a screw connection with a current line electrically connected to the copper film pattern, but the present invention is not limited thereto.

The plurality of plate-shaped shunts 7 may be fixed with silver soldering with one end coupled to each slit (not shown) formed in a horizontal direction on the inner surface of the first shunt block 1.

In an embodiment, three slits in the form of straight holes extending in the horizontal direction are formed on the inner surface of the first shunt block 1 along the vertical direction of the first shunt block 1, so that three plate-shaped shunts 7 ) can be fixedly joined to the first shunt block 1 with silver soldering while one end is inserted into each slit.

Additionally, the plurality of plate-shaped shunts 7 may be fixed with silver soldering while the other end is coupled to each slit (not shown) formed in the horizontal direction on the inner surface of the second shunt block 2.

The plurality of plate-shaped shunts 7 may be configured so that the width of the side portion is relatively small compared to the width of the orthogonal plane portion. Accordingly, the plurality of plate-shaped shunts 7 may be configured in a flat-convex shape with wide surfaces in both side directions when viewed from above.

In an embodiment, the plurality of plate-shaped shunts 7 may be made of manganese or a manganese alloy (for example, a mixed alloy of manganese and copper, etc.).

In addition, the plurality of plate-shaped shunts (7) are arranged at regular intervals in the vertical direction with respect to the first and second shunt blocks (1, 2), creating a structure in which a heat dissipation space is secured between each of the plurality of plate-shaped shunts (7). You can have it.

Here, FIG. 3 is a diagram showing the process of coupling the shunt resistor 10 to a printed circuit board (PCB).

That is, Figure 3(a) shows the side of the shunt resistor 10, Figure 3(b) shows a printed circuit board (PCB) implemented in a 'ㄷ' shape, and Figure 3(c) shows the shunt resistor ( This is a diagram showing the combination of 10) and a printed circuit board (PCB).

The charge/discharge module and the resistance measurement module may be mounted on a printed circuit board (PCB), and a copper foil pattern (h) electrically connected to the first and second output units 4 and 6 is formed, and the copper foil pattern ( A hole h is formed in the center of h), and the first and second output units 4 and 6 can be screwed together.

FIG. 4 is a control block diagram showing the control configuration of the charging device according to the first embodiment of the present invention, and FIG. 5 is a timing diagram showing charging pulses and discharge pulses output from the charging and discharging module shown in FIG. 4.

Referring to FIGS. 4 and 5 , the charging device 100 may include an input module 110, a charging/discharging module 120, a resistance measurement module 130, and a control module 140.

In the embodiment, the charging device 100 is described as being applied to a formation process for activating a secondary battery, for example, a lithium secondary battery, but the present invention is not limited thereto.

The input module 110 may input rated capacity information of a secondary battery without electrical characteristics and a command to start activating the secondary battery.

First, the rated capacity information of the secondary battery may include at least one of the maximum charging capacity and the rated current of the secondary battery, but is not limited thereto.

Here, the activation start command may be a command to start the initial charging and discharging of the secondary battery.

As a result, the input module 110 may input the activation start command to start the formation of a solid electrolyte interphase (SEI) layer in a discharged state of the secondary battery.

The charge/discharge module 120 supplies charge pulses (cp) for charging and discharge pulses (dp) for discharge to the secondary battery contact-coupled to a jig under the control of the control module 130. You can.

The resistance measurement module 130 can measure contact resistance (R) generated at the contact surface between the jig and the secondary battery when charging and discharging the secondary battery.

Here, the resistance measurement module 130 may include first and second amplifiers 132 and 134, a shunt resistor 137, and a resistance meter 138. Here, the shunt resistor 137 is described as the shunt resistor 10 shown in FIG. 2, but is not limited thereto.

The first amplifier 132 may amplify the output terminal voltage (Vcc) of the charge/discharge module 120 to a first differential voltage (V ₁ ) when charging and discharging the secondary battery.

The second amplifier 134 may amplify the voltage (Vbat) at both ends of the secondary battery to a second differential voltage (V ₂ ) when the secondary battery is charged and discharged.

Here, the first and second amplifiers 132 and 134 are Op-Amp amplifiers and may be at least one of a differential amplifier and an instrumentation amplifier, but are not limited thereto.

That is, the first and second amplifiers 132 and 134 each measure the output terminal voltage of the charge/discharge module 120 and the voltage between both ends of the secondary battery to measure the contact resistance (R) at the contact surface between the secondary battery and the jig. Each can be differentially amplified.

The shunt resistor 137 can measure a large current and is integrally connected to the output terminal of the charge/discharge module 120 to measure the charge current and discharge current output from the output terminal of the charge/discharge module 120.

The resistance meter 138 can calculate and measure the contact resistance (R) using the charging current of the charging pulses (cp), the discharge current of the discharge pulses (dp), and the first and second differential voltages (V ₁ and V ₂ ). there is.

First, the resistance meter 138 can measure the charging contact resistance (R ₁ ) using the following [Equation 1] during charging of the secondary battery.

Here, V ₁ may be the first differential voltage, V ₂ may be the second differential voltage, and I ₁ may be the charging current measured at the shunt resistor 137 .

Additionally, the resistance meter 138 can measure the discharge contact resistance (R ₂ ) using the following [Equation 2] during charging of the secondary battery.

Here, V ₁ may be the first differential voltage, V ₂ may be the second differential voltage, and I ₂ may be the discharge current measured at the shunt resistor 137 .

The resistance meter 138 may measure the contact resistance (R) as the average value of the charging contact resistance (R ₁ ) and the discharging contact resistance (R ₂ ).

Here, the resistance meter 138 is an analog-to-digital converter (Analog Digital) that converts the first and second differential voltages (V ₁ , V ₂ ) of the analog type output from the first and second amplifiers 132 and 134, respectively, into digital types. Converter, ADC), but is not limited thereto.

The control module 140 may set the charging current (Ic) of the charging pulses (cp) and the discharging current (Id) of the discharging pulses (dp) according to the energetic capacity information.

Thereafter, when the activation start command is input, the control module 140 charges and discharges high-current charging pulses (cp) and discharge pulses (dp) alternately to the secondary battery from the activation start point (TP). The module 120 can be controlled.

Here, the control module 140 may set and determine the charging current (I ₁ ) and the discharging current (I ₂ ) based on the rated current.

First, the charging current (I ₁ ) may be 1 to 3 times the rated current. If it is less than 1 times the rated current, the charging time of the secondary battery becomes longer, and if it is greater than 3 times the rated current, the secondary battery The charging time of the battery may be shortened, but salt reaction may occur due to overcharging.

In addition, the discharge current (I ₂ ) may be 0.2 to 0.5 times the rated current. If it is less than 0.2 times the rated current, the discharge time of the secondary battery becomes longer, and if it is greater than 0.5 times the rated current, the secondary battery The discharge time of the battery may be shortened, but overcharging may cause salting.

At this time, the control module 140 may determine the charging maintenance time (ct) according to the charging current (I ₁ ).

For example, when the charging current (I ₁ ) is 3 times greater than the rated current, the charge maintenance time (ct) of the charging current (I ₁ ) can be maintained for a longer time than when the charging current (I 1 ) is 1 times greater than the rated current.

The charging maintenance time (ct) of the charging current (I ₁ ) may be 20 ms to 100 ms, and if it is faster than 20 ms, the charging current (I ₁ ) may be greater than 3 times the rated current, resulting in overcharging. If it is longer than 100 ms, the charging time may be longer because the charging current (I ₁ ) is less than 1 times the rated current.

Additionally, the control module 140 may determine the discharge maintenance time (dt) according to the discharge current (I ₂ ).

For example, when the discharge current (I ₂ ) is 0.5 times greater than the rated current, the discharge maintenance time (dt) of the discharge current (I ₂ ) may be maintained for a shorter time than when the discharge current (I 2 ) is 0.2 times greater than the rated current.

The discharge maintenance time (dt) of the discharge current (I ₂ ) may be 5 ms to 30 ms. If it is faster than 5 ms, the discharge effect by the discharge current (I ₂ ) is lowered, and if it is longer than 30 ms, the discharge effect of the discharge current (I ₂ ) is lowered. Discharge time may become longer.

Additionally, the charge maintenance time (ct) of the charge pulses (cp) may be 1.5 to 5 times the discharge maintenance time (dt) of the discharge pulses (dp), but is not limited thereto.

Additionally, the discharge amount of each of the discharge pulses (dp) may be 0.04 to 0.16 times the charge amount of each of the charge pulses (cp).

Here, the charge amount and the discharge amount may be determined by current and maintenance time, and may be adjusted according to the rated capacity of the secondary battery, but are not limited thereto.

In this way, the charging device 100 sequentially supplies charge pulses (cp) and discharge pulses (dp) to the secondary battery that does not have electrical characteristics, thereby forming a solid electrolyte intermediate (SEI, solid) in the secondary battery. Electrolyte Interphase) layer can be formed to have the electrical characteristics of the secondary battery.

In addition, the charging device 100 supplies high current charging pulses (cp) and discharge pulses (dp) within a very short time, thereby lowering endothermic and exothermic reactions, lowering salt generation due to overcharging, and lowering the negative electrode. The solid electrolyte intermediate formed on the surface becomes thicker, which can increase its lifespan.

In the charging and discharging state of the secondary battery, the control module 140 determines whether charging and discharging of the secondary battery continues based on the contact resistance (R) measured by the resistance measurement module 130 and the set reference contact resistance, and charges. The operation of the discharge module 120 can be controlled.

That is, the control module 140 operates the charge/discharge module 120 to prevent heat generation due to contact resistance (R) generated at the contact surface between the jig and the secondary battery during charging and discharging of the secondary battery in order to activate the secondary battery. ) operation can be controlled.

The control module 140 controls the charge/discharge module 120 to continue charging and discharging of the secondary battery when the contact resistance (R) is lower than the reference contact resistance, and when the contact resistance (R) is higher than the reference contact resistance. The charging and discharging module 120 can be controlled to block charging and discharging of the secondary battery.

That is, as described above, the control module 140 operates the charge and discharge module 120 to prevent heat generation when the contact resistance (R) increases due to the high current charge pulses (cp) and discharge pulses (dp). By controlling, it is possible to prevent accidents due to heat generation.

FIG. 6 is a circuit diagram showing the charging device shown in FIG. 4 in detail.

Here, FIG. 6 is an example diagram for explaining the operation of the resistance measurement module 130 shown in FIG. 4.

Referring to FIG. 6, the resistance measurement module 130 may include first and second amplifiers 132 and 134, a shunt resistor 137, and a resistance meter 138.

The first amplifier 132 differentially amplifies the output voltage (Vcc) between the output terminal (not shown) that outputs the charging current (I ₁ ) and the discharging current (I ₂ ) in the charging and discharging module 120 and the ground (GND). A first differential voltage (V ₁ ) can be output.

That is, the first amplifier 132 is connected to the first coupling terminal (not shown) of the jig that is contact-coupled with the charge/discharge module 120 and the anode of the secondary battery (BAT). ) and the output terminal voltage (Vcc) on the second line (line2) connecting the second coupling terminal (not shown) of the jig coupled to the cathode of the secondary battery (BAT) and the ground (GND). The first differential voltage (V ₁ ) can be output by differential amplification.

The second amplifier 134 may output a second differential voltage (V ₂ ) obtained by differentially amplifying the voltage (Vbat) between both ends of the secondary battery (BAT) between the anode and the cathode.

Here, the first and second amplifiers 132 and 134 are the line resistance of the first and second lines (line1), the anode and cathode of the secondary battery (BAT), and the first and second amplifiers of the jig. In order to measure the contact resistance (R) including the resistance of the contact surface (S) of each coupling terminal, the output voltage (Vcc) of the charge/discharge module 120 and the voltage (Vbat) of both ends of the secondary battery (BAT) are amplified. can do.

The shunt resistor 137 is connected to the output terminal of the charge/discharge module 120 and can measure the charge current (I ₁ ) and discharge current (I ₂ ) output to the output terminal.

Here, the shunt resistor 137 may be directly connected to the copper foil pattern formed as the output terminal of the charging and discharging module 120 on the printed circuit board on which the charging device 100 is formed, but is not limited thereto.

The resistance meter 138 measures the first and second differential voltages (V ₁ , V ₂ ) output from the first and second amplifiers 132 and 134 and the charge current (I ₁ ) and discharge current measured at the shunt resistor 137. The contact resistance (R) can be calculated and measured based on (I ₂ ).

For example, when the charging current (I ₁ ) is supplied to the secondary battery (BAT), the resistance meter 138 measures the first and second differential voltages (V ₁ , V ₂ ) and charging current (I ₁ ) can be measured according to Ohm's law shown in [Equation 1] described above.

In addition, when the discharge current (I ₂ ) is supplied to the secondary battery (BAT), the resistance meter 138 measures the first and second differential voltages (V ₁ and V ₂ ) input from the first and second amplifiers 132 and 134. ) and discharge current (I ₂ ) can be measured according to Ohm's law shown in [Equation 2] described above.

The control module 140 may compare the contact resistance (R) measured from the resistance meter 138 with a set reference contact resistance.

If the contact resistance (R) is less than the reference contact resistance, the control module 140 controls the charging current (I ₁ ) and discharging current (I ₂ ) to be continuously output from the charging and discharging module 120 to the secondary battery (BAT). can do.

In addition, when the contact resistance (R) is greater than the reference contact resistance, the control module 140 determines that the charging current (I ₁ ) and discharging current (I ₂ ) output from the charging and discharging module 120 to the secondary battery (BAT) are The charging/discharging module 120 can be controlled to be blocked.

As such, the charging device 100 according to the present invention has the advantage of preventing heat generated at the contact surface (S) due to the contact resistance (R) during charging and discharging of the secondary battery (BAT).

Figure 7 is a flowchart showing a method of operating a charging device according to the first embodiment of the present invention.

Referring to FIG. 7 , rated capacity information of the secondary battery and an activation start command may be input to the charging device 100 (S110).

The charging device 100 may set the charging current (I ₁ ) of the charging pulses (cp) and the discharging current (Id) of the discharging pulses (dp) according to the rated capacity information (S120).

That is, the control module 140 of the charging device 100 may set the charging current (Ic) of the charging pulses (cp) and the discharging current (I ₂ ) of the discharging pulses (dp) according to the energetic capacity information. .

The rated capacity information of the secondary battery may include at least one of the maximum charging capacity and the rated current of the secondary battery, but is not limited thereto.

The control module 140 may set and determine the charging current (I ₁ ) and the discharging current (I ₂ ) based on the rated current. Additionally, the control module 140 may determine a charge maintenance time (ct) based on the charging current (I ₁ ) and a discharge maintenance time (dt) based on the discharge current (I ₂ ).

The charging device 100 may perform charging and discharging by alternately supplying charging pulses (cp) and discharging pulses (dp) according to the activation start command (S130).

That is, the control module 140 supplies charging pulses (cp) for charging and discharge pulses (dp) for discharging to the secondary battery contact-coupled to a jig, thereby forming a solid state in the secondary battery. The electrical characteristics of the secondary battery can be obtained by forming an electrolyte intermediate (SEI, Solid Electrolyte Interphase) layer.

The charging device 100 may measure the contact resistance (R) generated at the contact surface between the jig and the secondary battery when charging and discharging the secondary battery (S140).

That is, the resistance measurement module 130 included in the charging device 100 is a first differential voltage (V ₁ ) that amplifies the output terminal voltage (Vcc) of the charging and discharging module 120 when charging and discharging the secondary battery and the secondary battery. When charging and discharging a battery, the contact resistance (R) can be measured based on the second differential voltage (V ₂ ) amplified by the voltage (Vbat) at both ends of the secondary battery.

The resistance measurement module 130 uses the charging current of the charging pulses (cp), the discharge current of the discharging pulses (dp), and the first and second differential voltages (V ₁ and V ₂ ) measured by the charging and discharging module 120. Contact resistance (R) can be calculated and measured.

The charging device 100 determines whether the contact resistance (R) is less than the set reference contact resistance (S150), and if the contact resistance (R) is less than the reference contact resistance, charge pulses (cp) and discharge pulses are sent to the secondary battery. (dp) can be continuously supplied according to step (S130).

After step (S150), when the contact resistance (R) is greater than the reference contact resistance, the charging device 100 may block the charging pulses (cp) and discharge pulses (dp) supplied to the secondary battery (S160) ).

The charging device (S160) may perform step (S130) after a predetermined time has elapsed while the charging pulses (cp) and discharge pulses (dp) are blocked.

That is, in the charging and discharging state of the secondary battery, the control module 140 determines whether to continue charging and discharging the secondary battery based on the contact resistance (R) measured by the resistance measurement module 130 and the set reference contact resistance. , the operation of the charging/discharging module 120 can be controlled.

In order to activate the secondary battery, the control module 140 controls the charging and discharging module 120 to prevent heat generation due to contact resistance (R) generated at the contact surface between the jig and the secondary battery during charging and discharging of the secondary battery. Movement can be controlled.

First, the control module 140 controls the charging and discharging module 120 so that charging and discharging of the secondary battery continues when the contact resistance (R) is lower than the reference contact resistance, and the contact resistance (R) is lower than the reference contact resistance. If it is higher, the charging and discharging module 120 can be controlled to block charging and discharging of the secondary battery.

After step (S150), when charging of the secondary battery is completed, the charging device 100 may block the supply of charge pulses (cp) and discharge pulses (dp) (S170).

FIG. 8 is a control block diagram showing the control configuration of the charging device according to the second embodiment of the present invention, and FIG. 9 is a circuit diagram showing the charging device shown in FIG. 8 in detail.

Referring to FIGS. 8 and 9 , the charging device 200 may include an input module 210, a charging/discharging module 220, a resistance measurement module 230, and a control module 240.

Since the input module 210 and the charging/discharging module 220 are the same as the input module 110 and the charging/discharging module 120 shown in FIG. 2, detailed descriptions are omitted.

Here, the resistance measurement module 230 can measure the contact resistance (R) generated at the contact surface between the jig and the secondary battery when charging and discharging the secondary battery.

Here, the resistance measurement module 230 may include first, second, and third amplifiers 232, 234, and 236, a shunt resistor 237, and a resistance meter 238.

The first amplifier 132 is connected to the cathode of the secondary battery (BAT) and the second coupling terminal of the jig (not shown) coupled to the cathode of the secondary battery (BAT) when charging and discharging the secondary battery. A first differential voltage (V ₁ ) obtained by differentially amplifying the negative voltage (V-) can be output between the second line (line2) connecting C) and ground (GND).

The second amplifier 234 may output a second differential voltage (V ₂ ) obtained by differentially amplifying the voltage (Vbat) between both ends of the anode and the cathode of the secondary battery (BAT).

The third amplifier 236 is a first line (line1) connected to the first coupling terminal (not shown) of a jig that is contact-coupled with the charge/discharge module 120 and the anode of the secondary battery (BAT). A third differential voltage (V ₃ ) can be output by differentially amplifying the positive voltage (V+) between the anodes of the secondary battery (BAT).

The shunt resistor 237 can measure a large current and is integrally connected to the output terminal of the charge/discharge module 220 to measure the charge current and discharge current output from the output terminal of the charge/discharge module 220.

The resistance meter 238 measures the first to third differential voltages (V ₁ to V 3 ) output from the first to third amplifiers 232, 234, and ₂₃₆ and the charging current (I ₁ ) measured at the shunt resistor 237. ) and discharge current (I ₂ ), the contact resistance (R) can be calculated and measured.

That is, the resistance meter 238 calculates the average value for the negative voltage based on the first differential voltage (V ₁ ) and the second differential voltage (V ₂ ), and the second differential voltage (V ₂ ) and the third differential voltage After calculating the average value for the positive voltage based on (V ₃ ), the contact resistance (R) can be calculated and measured based on the calculated average values and the charging current (I ₁ ) and discharging current (I ₂ ).

The control module 240 may compare the contact resistance (R) measured from the resistance meter 238 with a set reference contact resistance.

If the contact resistance (R) is less than the reference contact resistance, the control module 240 controls the charging current (I ₁ ) and discharging current (I ₂ ) to be continuously output from the charging and discharging module 220 to the secondary battery (BAT). can do.

In addition, when the contact resistance (R) is greater than the reference contact resistance, the control module 240 determines that the charging current (I ₁ ) and discharging current (I ₂ ) output from the charging and discharging module 220 to the secondary battery (BAT) are The charging/discharging module 220 can be controlled to be blocked.

The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, although the above description focuses on the embodiments, this is only an example and does not limit the present invention, and those skilled in the art will understand the above examples without departing from the essential characteristics of the present embodiments. You will see that various modifications and applications are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (9)

delete An input module for inputting an activation start command to start the formation of a solid electrolyte interphase (SEI) layer in a discharged state of the secondary battery;
A charging/discharging module that charges and discharges a secondary battery contact-coupled to a jig;
It is integrally connected to the output terminal of the charging and discharging module, and includes a shunt resistor that measures the charging current and discharging current output from the output terminal of the charging and discharging module when charging and discharging the secondary battery, and the shunt resistance measured by the shunt resistance. a resistance measurement module that measures contact resistance occurring at a contact surface between the jig and the secondary battery based on the charging current and the discharging current; and
Comprising a control module that controls the operation of the charging and discharging module according to whether charging and discharging of the secondary battery continues, which is determined based on the contact resistance and a set reference contact resistance during charging and discharging of the secondary battery,
Charging device. According to claim 2,
The charging/discharging module is,
Outputting the charging current of charging pulses when charging the secondary battery, and outputting the discharge current of discharge pulses when discharging the secondary battery,
Charging device. According to claim 2,
The resistance measurement module is,
A first amplifier that amplifies the output terminal voltage of the charging and discharging module to a first differential voltage when charging and discharging the secondary battery;
a second amplifier that amplifies the voltage at both ends of the secondary battery to a second differential voltage when the secondary battery is charged and discharged; and
Comprising a resistance meter that measures the contact resistance based on the charging current, the discharging current, and the first and second differential voltages,
Charging device. According to claim 4,
The first and second amplifiers are:
Comprising at least one of a differential amplifier and an instrumentation amplifier,
Charging device. According to claim 5,
When the secondary battery is being charged,
The resistance meter is,
The charging contact resistance (R ₁ ) is measured by , where V ₁ is the first differential voltage, V ₂ is the second differential voltage, and I ₁ is the charging current,
Charging device. According to claim 6,
If the secondary battery is discharging,
The resistance meter is,
The discharge contact resistance (R ₂ ) is measured by, where V ₁ is the first differential voltage, V ₂ is the second differential voltage, and I ₂ is the discharge current,
Charging device. According to claim 7,
The resistance meter is,
Measuring the contact resistance as an average value of the charging contact resistance and the discharging contact resistance,
Charging device. According to claim 2,
The control module is,
If the contact resistance is lower than the reference contact resistance, control the charging and discharging module to continue charging and discharging of the secondary battery,
Controlling the charging and discharging module to block charging and discharging of the secondary battery when the contact resistance is higher than the reference contact resistance,
Charging device.