KR101580823B1 - Method of reducing charge and discharge measurement time in rechargeable battery manufacturing process and apparatus thereof - Google Patents

Abstract

Disclosed herein is a method for shortening a charge / discharge measurement time in a secondary battery production process, and a device thereof. After performing electrical connection between a battery cell and a charge / discharge device for performing charging and discharging operations, Discharging operation is performed through the charge / discharge unit based on the preset C value after the charging operation is performed, and when the charging operation is performed, When the internal voltage of the battery cell inputted from the means becomes less than the preset discharge end voltage, the first stage discharge work is terminated and the two stage discharge work is performed through the charge / discharge device based on the preset C value, When the internal voltage of the battery cell inputted from the means becomes less than the preset discharge end voltage, the second stage discharge operation is terminated.
Accordingly, the present invention can significantly shorten the measurement time while maintaining the capacity measurement value equivalent to that of the conventional method, thereby reducing the time required for the production of the secondary battery.

Description

TECHNICAL FIELD The present invention relates to a rechargeable battery manufacturing process and apparatus, and more particularly,

The present invention relates to a method for shortening a charging / discharging measurement time in a secondary battery producing process and a device for shortening a measuring time through a two-stage discharging operation in a charging / discharging operation of a battery cell produced.

Generally, a rechargeable battery refers to a battery that can be used semi-permanently by charging electric current generated by an electric current supplied from an external power source to an anode and a cathode in a process of oxidizing or reducing a material. The primary battery has a disadvantage of being incapable of being re-used and costly to recycle or recharge the battery, while the rechargeable battery has the advantage that it can be charged several times. In addition, secondary batteries are the core materials of electric vehicles as well as electronic devices carrying notebook computers, mobile phones, camcorders, etc., and are considered to be 'three major electronic components' in the 21st century along with semiconductors and displays due to their high added value. In particular, rechargeable batteries have surpassed the $ 20 billion global market by 2011, and the size of the rechargeable battery market is expected to expand in the future as the market for electric vehicles grows and the market for rechargeable batteries for medium and large-sized energy storage grows.

The rechargeable battery is divided into a nickel battery, an ion battery, a lithium ion battery, a polymer battery, a lithium polymer battery, and a lithium sulfide battery depending on what is used as a charging material. Since the introduction of nickel-cadmium batteries and nickel-metal hydride batteries in the 1980s, lithium-based secondary batteries have emerged in the 1990s, and lithium-polymer batteries have been introduced since the 2000s.

Lithium-ion batteries have recently become the mainstream of the rechargeable battery market because of the miniaturization and weight reduction of electronic equipment and the generalization of use of portable electronic devices. As a result, materials capable of inserting and removing lithium ions are used as cathode and anode And an organic electrolytic solution or a polymer electrolytic solution is charged between the anode part and the cathode part, and electrical energy is generated by oxidation and reduction reaction when lithium ions are inserted and removed from the anode part and the cathode part. It is light in weight and has a wide range of uses, from low-capacity cell phone batteries to large-capacity electric vehicle batteries, which is advantageous in making high capacity batteries.

In addition, the lithium polymer battery is a step-up battery in a lithium ion battery, and generates electricity by using an electrolyte made of a polymer material of a solid or gel form between the anode and the cathode. It has the advantage of being able to make various shapes and to make the thinnest battery among the secondary batteries developed so far.

Meanwhile, the secondary battery is manufactured through a process of assembling the battery cell and a process of activating the battery. In the battery activation step, the battery cell to be inspected is charged and discharged under the conditions necessary for activation. Conventional secondary batteries, such as nickel-cadmium batteries and lead-acid batteries, can be used immediately after production, so charging and discharging devices are needed only for performance evaluation. However, recently, in the case of a lithium secondary battery such as a lithium ion battery and a lithium polymer battery widely used in recent years, the performance as a battery is completed only after a predetermined charging / discharging process, that is, It became an essential equipment for the production line of the battery.

The charging and discharging device repeats charging and discharging processes several times in order to store the electric energy in the first battery, which is assembled during the production process of the secondary battery, to perform the function of imparting the characteristics of the secondary battery. In addition, as the supply of the secondary battery is increased due to the surge in demand, a large number of charge / discharge units performing charge / discharge function in the production stage of the secondary battery are required. In order to evaluate the performance of the secondary battery, I needed a discharge machine.

When charging / discharging each battery cell produced in the production process by using the charge / discharge device, it is conventionally charged at 0.5 C (C-rate, charge / discharge current divided by the battery rated capacity) Discharge method was applied. On the average, the time required for charge / discharge operation of one cycle was approximately 289 minutes.

However, in the battery cell charge / discharge operation of the related art as described above, it takes a long time to perform the charging / discharging operation, which causes a problem that the throughput rate of the battery cell greatly decreases.

Accordingly, many methods have been introduced to shorten the measurement time by changing the conventional discharge method. However, when the high rate discharge is applied (that is, when the C-rate value is raised), the measurement time is greatly shortened, The measurement value is inaccurate and a sufficient discharge operation is not performed. That is, in order to shorten the measurement time, the current value must be increased, but when the current value is increased, a difference occurs in the measurement capacity.

Korean Patent Publication No. 10-2011-24707 March 9, 2011

Disclosure of Invention Technical Problem [8] The present invention provides a method for shortening a charge / discharge measurement time in a secondary battery production process in which the discharge time is shortened by adjusting the discharge in two steps when charging / discharging a battery cell in a secondary battery production process .

The method for shortening the charge / discharge measurement time in the secondary battery manufacturing process according to an embodiment of the present invention includes the steps of: (1) controlling the electrical connection between the battery cell and the charge / discharge device for performing charging and discharging operations; And (2) the control means performs a charging operation of the battery cell until a full charge is achieved based on the preset C value through the charge / discharge device; and (3) Discharging operation through a charge / discharge unit based on the preset C value after performing the operation, (4) the control means determines that the internal voltage of the battery cell inputted from the measuring means is preset Performing a two-step discharge operation through the charge / discharge unit based on the preset C value, and (5) when the control unit determines that the discharge Means When the internal voltage of the battery cell becomes less than the predetermined discharge end voltage, the step (2) may include terminating the two-step discharge operation in step (4).

At this time, it is preferable that the C value set in the first stage discharge operation in step (3) is set to be larger than the C value set in the second stage discharge operation in step (4).

It is preferable that the C values set in the charging operation in the step (2), the discharging operation in the step 1 in the step 3, and the discharging operation in the step 2 in the step 4 are respectively set to 0.5C, 0.77C and 0.5C .

The discharge end voltage which is a condition for terminating the first stage discharge operation in the step (3) and the second stage discharge operation in the step (4) is preferably set to 3V.

The waiting time is set between the first stage discharging operation performed in step (3) and the second stage discharging operation performed in step (4), and the battery cell internal voltage rises above the predetermined discharge end voltage for the waiting time (4) discharge operation until the internal voltage of the battery cell becomes less than a predetermined discharge end voltage when the waiting time has elapsed.

In addition, an apparatus for shortening a charge / discharge measurement time in a secondary battery manufacturing process according to an embodiment of the present invention includes a battery cell, a charge / discharge unit for performing charging and discharging operations by performing electrical connection with the battery cell, And a charging / discharging operation of the battery cell is controlled through a charging / discharging unit, and the charging / discharging operation of the battery cell is controlled by controlling the charging / discharging operation of the battery cell And a control means for controlling the charging operation, the first stage discharging operation, and the second stage discharging operation to be sequentially performed in accordance with the preset C value based on the voltage.

At this time, it is preferable that the control means sets the C value set in the first stage discharge operation to be larger than the C value set in the second stage discharge operation.

The C values set for the charging operation, the first stage discharging operation and the second stage discharging operation are preferably 0.5C, 0.77C, and 0.5C, respectively.

When the internal voltage of the battery cell inputted from the measuring means becomes less than the preset discharge end voltage in the course of performing the first stage discharge operation, the control means terminates the first stage discharge operation, It is preferable to start the second stage discharge operation.

The control means preferably terminates the two-step discharge operation when the internal voltage of the battery cell inputted from the measuring means becomes less than the predetermined discharge end voltage in the course of performing the two-stage discharge operation.

The discharge end voltage set as the termination condition of the first stage discharge operation and the second stage discharge operation is preferably set to 3V.

As described above, according to the method of reducing the charging / discharging measurement time in the secondary battery producing process of the present invention and the apparatus thereof, when performing the charging / discharging operation of the produced battery cell, the discharging method is changed into two steps, It is possible to greatly reduce the measurement time while maintaining the capacity measurement value equivalent to that of the conventional method using the discharge method of the secondary battery, thereby reducing the time required for the production of the secondary battery.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating a configuration of a charge / discharge measurement time reduction device in a secondary cell production process according to an embodiment of the present invention;
FIG. 2 and FIG. 3 are views for comparing and comparing the charge / discharge time and the capacity measurement value according to the conventional system and the system of the present invention,
FIG. 4 is a flowchart illustrating an operation of a method for reducing a charge / discharge measurement time in a secondary battery manufacturing process according to an embodiment of the present invention.

Hereinafter, a method for shortening the charge / discharge measurement time in the secondary battery production process of the present invention and its apparatus will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view illustrating a configuration of a charge / discharge measurement time reduction device in a secondary cell production process according to an embodiment of the present invention. Referring to FIG.

As shown in the figure, the apparatus of the present invention comprises a battery cell 10, a charge / discharge unit 20, a measuring unit 30, a control unit 40, and the like.

The battery cell 10 is produced in the production process and is electrically connected to the charge / discharge unit 20 based on the control of the control means 40 to perform a charge / discharge operation.

The charge / discharge unit 20 performs the charging and discharging operations of the electrically connected battery cell 10 based on the control of the control means 40.

The measuring means 30 measures the internal voltage and the capacity measurement value of the battery cell 10 in which charging and discharging operations are performed through the charge and discharge unit 20 and outputs measurement data to the control means 40.

The control means 40 controls the electrical connection between the battery cell 10 and the charging and discharging device 20 and controls the charging and discharging operations of the battery cell 10 through the charging and discharging device 20, The charging operation, the first stage discharging operation, and the second stage discharging operation are sequentially performed in accordance with the preset C value based on the internal voltage of the battery cell inputted from the measuring means 30. [

At this time, the control means 40 generally sets the C value set in the first stage discharge operation to be larger than the C value set in the second stage discharge operation.

For example, the control means 40 sets 0.5C, 0.77C, and 0.5C for the charging operation, the first stage discharging operation, and the second stage discharging operation, respectively. That is, the control means 40 controls to sequentially perform a charging operation of 0.5C, a first stage discharging operation of 0.77C, and a second stage discharging operation of 0.5C.

When the internal voltage of the battery cell 10 inputted from the measuring means 30 becomes lower than the preset discharge end voltage in the course of performing the first stage discharge operation, the control means 40 performs the first stage discharge operation And when the preset waiting time has elapsed, the second stage discharge operation is started.

When the internal voltage of the battery cell 10 inputted from the measuring means 30 becomes less than the previously set discharge end voltage in the course of performing the two-step discharge operation, the control means 40 performs the two- And terminates.

The control means 40 preferably sets the discharge end voltage set as the end condition of the first stage discharge operation and the second stage discharge operation to 3 V, but it can be arbitrarily changed depending on the use environment or the battery cell to be inspected Of course.

FIGS. 2 and 3 are diagrams for comparing charging and discharging times and capacity measurement values according to the conventional system and the method of the present invention.

As shown in the figure, it can be seen that the introduction of the two-stage discharge method of the present invention enables the maintenance of the capacity measurement value equivalent to that of the conventional system even if the secondary additional discharge is performed after the primary discharge.

In addition, since the time required for charging and discharging of one cycle is about 248 minutes on average, it is confirmed that the time required for measurement per one cycle is reduced by about 41 minutes as compared with the conventional method, Can be predicted to be greatly shortened.

The following table is for comparing discharge conditions and measurement capacities according to the conventional method and the method of the present invention as described above. In the conventional method of performing only one discharge operation, the discharge current is set to 1960 mA (i.e., 0.5 C) 121 minutes, and the measured discharge capacity was 3996 mAh. In the method of the present invention for performing the discharging operation of two stages, it takes 80 minutes when the discharging current is set to 3000 mA (i.e., 0.77C) in the first stage discharging operation and 1960 mA (i.e., 0.5C) And the measured discharge capacity was 3996 mAh.

That is, when the two-stage discharge method is employed as in the present invention, even if the secondary additional discharge is performed after the first discharge, the capacity measurement value equivalent to that of the conventional method can be maintained and the measurement time can be greatly shortened.

division Discharge condition
(Stage 1) Discharge condition
(Step 2) Discharge time Measured discharge capacity
(mAh) Conventional method
(Stage 1) Discharge current: 1960mA (0.5C)
Discharge end voltage: 3V - 121 minutes 3996mAh According to the present invention
(Step 2) Discharge current: 3000mA (0.77C)
Discharge end voltage: 3V Discharge current: 1960mA (0.5C)
Discharge end voltage: 3V 80 minutes 3996mAh

The reason why the termination conditions of the first stage discharging operation and the second stage discharging operation are the same is that after the internal voltage of the battery cell 10 becomes less than the predetermined discharge end voltage and the first stage discharging operation is completed, This is because the internal voltage of the battery cell 10 rises above a predetermined discharge end voltage during the waiting time before starting.

Next, an embodiment of the method for shortening the charge / discharge measurement time in the secondary battery manufacturing process according to the present invention will be described in detail with reference to FIG.

FIG. 4 is a flowchart illustrating an operation of a method for reducing a charge / discharge measurement time in a secondary battery manufacturing process according to an embodiment of the present invention.

First, the control means 40 controls the electrical connection between the battery cell 10 and the charge / discharge device 20 for performing charging and discharging operations (S10).

After performing the electrical connection between the battery cell 10 and the charge / discharge device 20, the control means 40 controls the charge / discharge device 20 to charge the battery cell 10 ) (S20). That is, the charging operation is performed at 0.5C, which is preset in the charging operation.

After performing the charging operation of the battery cell 10, the control unit 40 performs a first stage discharge operation through the charge / discharge unit 20 based on the preset C value (S30). That is, the first stage discharging operation is performed at 0.77C which is already set in the first stage discharging operation. At this time, the C value set in the first stage discharge operation in step S30 is generally set to be larger than the C value set in the second stage discharge operation in step S60 described later.

In step S30, the control unit 40 determines whether the internal voltage of the battery cell 10 input from the measuring unit 30 is less than the preset discharge end voltage 3V (S40).

If it is determined in step S40 that the internal voltage of the battery cell 10 is less than the preset discharge end voltage 3V, the control unit 40 ends the one-step discharge operation in step S30 (S50).

The control unit 40 performs a two-stage discharge operation through the charge / discharge unit 20 based on the preset C value (S60). That is, the second stage discharging operation is performed at 0.5C, which is already set in the second stage discharging operation.

At this time, a predetermined waiting time for condition resetting or the like is set between the discharging operation at the step S60 and the discharging operation at the step S60 after the discharging operation of the discharging operation of the step S50 is completed, and the internal voltage of the battery cell 10 The discharge end voltage is increased to 3V or more. Accordingly, the control means 40 performs the discharging operation in two stages until the internal voltage of the battery cell 10 raised to 3V or more becomes less than 3V. That is, the control means 40 waits until the predetermined waiting time elapses after the completion of the discharging operation of the first stage in operation S50, and performs the discharging operation for the two stages of operation S60.

The control means 40 judges whether or not the internal voltage of the battery cell 10 inputted from the measuring means 30 is less than the previously set discharge end voltage 3V (S70).

If it is determined in step S70 that the internal voltage of the battery cell 10 is less than the preset discharge end voltage 3V, the control unit 40 ends the two-step discharge operation in step S60 (S80).

As described above, the present invention applying the two-stage discharge method can greatly shorten the measurement time while maintaining the capacity measurement value equivalent to the discharge method of the first stage used in the past.

In other words, in order to shorten the measurement time, the current must be increased. However, when the current is increased, there is a difference in the measurement capacity. Therefore, as in the method of the present invention, And the current is again lowered to maintain the same measurement capacity as the conventional one.

It will be apparent to those skilled in the art that various modifications may be made to the invention without departing from the spirit and scope of the invention as defined in the following claims And changes may be made without departing from the spirit and scope of the invention.

10: Battery cell
20: Charger / discharger
30: Measuring means
40: control means

Claims (11)

(1) The control means controls the electrical connection between the battery cell and the charge / discharge device for performing charging and discharging operations,
(2) The control means performs a charging operation of the battery cell until a full charge is obtained based on a first C (C-rate) value previously set through the charge / discharge device,
(3) The control means performs a first stage discharge operation through the charge / discharge device based on the second C value that has been set after performing the charging operation in the step (2)
(4) When the internal voltage of the battery cell inputted from the measuring means becomes less than the preset discharge end voltage, the control means ends the one-step discharge operation of the step (3) Performing a two-stage discharge operation through the charge / discharge unit on the basis of the value of C, and
(5) The control means includes a step of terminating the two-stage discharging operation of the step (4) when the internal voltage of the battery cell inputted from the measuring means becomes less than the discharging end voltage,
A waiting time is set between the discharging operation of the first stage performed in the step (3) and the discharging operation of the second stage performed in the step (4)
During the standby time, the battery cell internal voltage rises above the discharge end voltage, and when the standby time elapses, the two-stage discharge operation of the step (4) is repeated until the internal voltage of the battery cell becomes less than the discharge end voltage A method for shortening the charging / discharging measurement time in the secondary cell production process. The method according to claim 1,
Wherein the second C value set in the one-step discharge operation in the step (3) is set to be larger than the third C value set in the two-step discharge operation in the step (4) Way. The method according to claim 1,
The first C value set in the charging operation in the step (2), the second C value set in the one-stage discharging operation in the step (3), the third C value set in the two- A method of shortening the charge / discharge measurement time in the secondary battery production process wherein the values are 0.5C, 0.77C and 0.5C, respectively. The method according to claim 1,
Wherein the discharge end voltage which is a condition for terminating the one-step discharge operation of the step (3) and the two-step discharge operation of the step (4) is set to 3 V (volt) Shortening method. delete Battery cell,
A charging / discharging unit for performing charging and discharging operations by performing an electrical connection with the battery cell,
Measurement means for measuring an internal voltage and a capacity measurement value of the battery cell, and
A control unit for controlling electrical connection between the battery cell and the charging / discharging unit, controlling charging and discharging operations of the battery cell through the charging / discharging unit, 1 control to control the charge operation according to the value of C (C-rate), the discharge operation for the first stage according to the set second C value, and the discharge operation for the second stage according to the predetermined third C value sequentially Means,
The control means
Wherein when the internal voltage of the battery cell input from the measurement means becomes less than a preset discharge end voltage in the course of performing the first stage discharge operation, the first stage discharge operation is terminated, Discharging operation of the secondary battery is started. The method according to claim 6,
The control means
Wherein the second C value set in the first stage discharge operation is set to be larger than the third C value set in the second stage discharge operation. The method according to claim 6,
Wherein the first C value set for the charging operation, the second C value set for the first stage discharge operation, and the third C value set for the second stage discharge operation are 0.5C, 0.77C, 0.5C respectively A device for shortening the measurement time of charge and discharge in a process. delete The method according to claim 6,
The control means
Wherein the step of discharging the secondary battery discharges the secondary battery when the internal voltage of the battery cell inputted from the measuring means is less than the discharge end voltage in the course of performing the secondary discharging operation, Device. 11. The method of claim 10,
Wherein the discharge end voltage set as the end condition of the first stage discharge operation and the second stage discharge operation is 3V (volt).

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