KR20210059935A - Device for Charge and Discharge of Secondary Battery - Google Patents

Abstract

The present invention provides an apparatus for charging and discharging a secondary battery for charging and discharging battery cells during an activation process of a battery cell, comprising: an activation tray accommodating a plurality of battery cells side by side; A charge/discharge operation unit provided to be electrically connected to the positive electrode and the negative electrode of the battery cells accommodated in the activation tray; A cooling unit including a blower fan for cooling the battery cells in which charging and discharging are performed to control the temperature of the battery cells; A plurality of temperature sensors disposed around the battery cells in which charging and discharging are performed; And a controller configured to receive a temperature signal sensed by the temperature sensor, analyze it, and control an operation of the cooling unit.
In the charging/discharging apparatus of the present invention, the control unit controls the on-off state or the flow rate of the blowing fan according to the temperature condition of the individual battery cells, so that the temperature of the battery cell becomes uniform, thereby improving the reliability of the manufacturing process. Can be improved.

Description

Device for Charge and Discharge of Secondary Battery

The present invention relates to an apparatus for charging and discharging a secondary battery.

Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative energy or clean energy is increasing, and as part of that, the fields that are most actively studied are the fields of power generation and storage using electrochemistry.

Currently, a secondary battery is a representative example of an electrochemical device that uses such electrochemical energy, and its use area is gradually expanding.

Secondary batteries are classified according to the structure of the anode/separator/cathode electrode assembly. Typically, a jelly-roll structure in which long sheet-shaped anodes and cathodes are wound with a separator interposed therebetween. (Wound type) electrode assembly, a stacked (stacked) electrode assembly in which a plurality of anodes and cathodes cut in units of a predetermined size are sequentially stacked with a separator interposed therebetween, a state of a predetermined unit of anodes and cathodes with a separator interposed And a stack/folding type electrode assembly having a structure in which bi-cells stacked with each other or full cells are wound.

In recent years, a pouch-type battery having a structure in which a stack-type or stack/folding-type electrode assembly is embedded in a pouch-type battery case of an aluminum laminate sheet is attracting a lot of attention due to low manufacturing cost, low weight, and easy shape transformation. Also, its usage is gradually increasing.

Such a secondary battery undergoes an activation process after a battery cell packaging process. Here, the "activation process of a battery cell" refers to a process of performing a predetermined charge/discharge after manufacturing a lithium secondary battery such as a lithium ion battery and a lithium polymer battery, which are widely used recently, that is, a chemical conversion process. The activation process gives the characteristics of the secondary battery by repeating the charging and discharging process several times so that the first assembled battery cell can store electrical energy.

However, if the temperature of the battery cell rises above a critical level during charging and discharging of the battery cell, the efficiency or performance of the battery cell decreases, durability decreases, and safety accidents such as thermal explosion may occur. Accordingly, in order to prevent such a problem, the battery charging/discharging apparatus includes a cooling apparatus that discharges heat generated during the charging/discharging process of the battery cells, and discharges heat generated during charging/discharging of the battery cells.

Conventional cooling devices have a fan that blows air into the battery cells, and the blowing fan operates at a constant speed regardless of the temperature of the surrounding battery cells, and a number of battery cells have different heat generated during the charging and discharging process. Therefore, under a conventional charging/discharging device equipped with a cooling device, temperature variation between the battery cells has inevitably occurred. In addition, when the blowing fan is operated regardless of the individual temperature of the battery cells, since the blowing is made to the battery cells that do not require cooling, it is not preferable in terms of energy efficiency.

If temperature deviation occurs between battery cells, it is difficult to manage the process of the battery cells, and it is not desirable in terms of energy efficiency. Therefore, it is necessary to develop a charging/discharging device technology that can minimize the temperature difference between battery cells during charging and discharging. It is a necessary situation.

Korean Patent Publication 2017-0100341 Japanese Patent 5011645

An object of the present invention is to solve the problems of the prior art and technical problems that have been requested from the past.

Accordingly, an object of the present invention is to provide a charging/discharging apparatus for a secondary battery capable of uniformly controlling battery cell temperature while effectively discharging heat generated during charging and discharging in an apparatus for charging and discharging a plurality of battery cells. will be.

In addition, an object of the present invention is to save energy by appropriately controlling the flow rate or on-off state of the blowing fan according to the individual temperature of the battery cell.

The charging/discharging apparatus of the present invention for solving the above problem includes: an activation tray for accommodating a plurality of battery cells side by side; A charge/discharge operation unit provided to be electrically connected to the positive electrode and the negative electrode of the battery cells accommodated in the activation tray; A cooling unit including a blower fan for cooling the battery cells in which charging and discharging are performed to control the temperature of the battery cells; A plurality of temperature sensors disposed around the battery cells in which charging and discharging are performed; And a controller configured to receive a temperature signal sensed by the temperature sensor, analyze it, and control an operation of the cooling unit.

In one embodiment of the present invention, the cooling unit, a plurality of blowing fans for blowing air by rotation; A duct through which air for cooling the battery cell is introduced; And a blower for discharging the air introduced into the duct.

In an embodiment of the present invention, the blowing fan may be an axial-flow fan or a cross-flow fan.

When the air blowing fan is an axial flow fan, the cooling unit includes a first cooling unit installed on one side of the activation tray and a second cooling unit installed on the other side, and the air outlet of the first cooling unit and the second cooling unit It may be arranged so that the air vents are misaligned.

In one embodiment of the present invention, the cooling unit is supported by the charge/discharge operation unit and is tiltably coupled to a corresponding position at which the battery cells accommodated in the activation tray are supported to adjust the direction of air flow.

In one embodiment of the present invention, the charging/discharging apparatus of the present invention may further include a flow path guide installed between the air outlet and the activation tray and guiding air discharged from the air outlet to be injected into the battery cells.

In an embodiment of the present invention, the control unit may control the operation of the blowing fan by an on-off method.

In an embodiment of the present invention, the control unit may control the operation of the blowing fan in a manner that adjusts the rotation speed (rpm).

In an embodiment of the present invention, there are two or more activation trays, and each of the trays is stacked in a vertical direction with respect to the ground in a state in which battery cells are mounted.

In an embodiment of the present invention, the temperature sensor is equal to the number of battery cells.

In the charging/discharging apparatus of the present invention, the control unit controls the on-off state or the flow rate of the blowing fan according to the temperature condition of the individual battery cells, so that the temperature of the battery cell becomes uniform, thereby improving the reliability of the manufacturing process. Can be improved.

In addition, since the air supply by the blowing fan is temporarily stopped for battery cells that do not require cooling due to high temperature, it is preferable in terms of energy efficiency.

1 is a block diagram showing the concept of a charging and discharging apparatus for a secondary battery according to an embodiment of the present invention.
2 is a schematic diagram of an apparatus for charging and discharging a secondary battery according to an embodiment of the present invention.
3 is a conceptual diagram showing the principle of the control unit of the present invention to control the temperature.
4 is a schematic diagram of a cooling unit according to an embodiment of the present invention.
5 is a schematic diagram of a charging and discharging apparatus according to an embodiment of the present invention.
6 is a schematic diagram of a flow path guide constituting a charging/discharging device according to another embodiment of the present invention.
7 is a schematic diagram of an axial flow fan.
8 is a schematic diagram of a cross flow fan.
9 is a schematic diagram of an apparatus for charging and discharging a secondary battery according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention. It should be understood that there may be equivalents and variations.

1 is a block diagram showing the concept of a charging/discharging apparatus for a secondary battery according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a charging/discharging apparatus for a secondary battery according to an embodiment of the present invention. Referring to these drawings, the charging/discharging apparatus 100 for a secondary battery according to the present invention is a charging/discharging apparatus for a secondary battery for charging and discharging battery cells during an activation process of a battery cell, and a plurality of battery cells 10 An activation tray 110 for receiving them side by side; A charge/discharge operation unit 120 provided to be electrically connected to the positive and negative electrodes of the battery cells accommodated in the activation tray; A cooling unit 130 including a blower fan 131 for cooling the battery cells in which charging and discharging are performed to control the temperature of the battery cells; A plurality of temperature sensors 140 disposed around the battery cells in which charging and discharging are performed; And a controller 150 for controlling the cooling unit based on the temperature sensed by the temperature sensor.

In the charging and discharging apparatus of the present invention, the control unit analyzes the temperature data sensed by the temperature sensor, and based on this, the operation of the blowing fan around the individual battery cells so that the temperature of the individual battery cells is within a set temperature range. By controlling the, there is an effect of making the temperature of a plurality of battery cells uniform.

The charging/discharging apparatus of the present invention applies a current to the battery cells for a set time to activate the battery cells to be in a usable state after a plurality of battery cells finish the manufacturing process, and charges and discharges at a set voltage. Perform.

Referring to FIG. 2, there are two or more activation trays 110, and each of the trays is stacked in a vertical direction with respect to the ground in a state in which battery cells are mounted. Among the trays, an activation tray at a lower portion may have a mounting portion for fixing and mounting an activation tray stacked thereon.

The charge/discharge operation unit 120 includes connection pins (not shown) connected to electrode tabs of battery cells, and is disposed around an upper activation tray and a lower activation tray, respectively, and the charge/discharge device 100 ) In a state in which the activation trays are mounted, they are spaced apart from the positive electrode tabs and the negative electrode tabs of the battery cells. This separation distance is for the activation trays 110 to be easily mounted on the charging/discharging device 100, and after the activation trays are mounted, the charging/discharging operation unit moves to be adjacent to the activation trays and thus the battery cells 10 To be electrically connected.

Referring to FIG. 2, the cooling unit 130 is disposed above and on the left and right sides of the activation tray 110, respectively. The upper cooling unit 170 disposed on the top is for cooling the battery cells mounted on the upper tray, and the cooling units 130 disposed on the left and right sides of the tray respectively cool the battery cells mounted on the lower tray.

Referring to FIG. 9, the cooling unit 130 may be disposed on the left and right sides of the lower tray and on the left and right sides of the upper tray, respectively.

The cooling unit includes a plurality of blowing fans (not shown), a duct through which air for cooling the battery cell is introduced (not shown), and a blower (not shown) through which the air introduced through the duct is discharged. The introduced air is discharged to the battery cell through the ventilation opening, and is configured to lower the temperature of the battery cell in the vicinity of the ventilation opening.

The cooling unit is positioned along the arrangement direction of the plurality of battery cells 10 so that cooling air can be blown to the plurality of battery cells as a whole. The length of the region from which the wind is discharged from the cooling unit (Z axis direction) is preferably equal to or greater than the length of both ends of the plurality of battery cells in the arrangement direction (Z axis direction).

The cooling unit 130 may be supported on a support frame of the charging/discharging device separately from the charging/discharging operation unit 120 as shown in FIG. 2. And, of course, the direction of the air of the cooling unit 130 can be adjusted manually or automatically. In addition, the cooling unit may be tiltably coupled to the charging/discharging operation unit 120 so as to adjust the direction of the flow of air discharged from the air outlet. It may include bolts and nuts that can move along the slots or grooves and fix the cooling section.

3 is a conceptual diagram showing a principle of controlling a temperature by a temperature sensor, a control unit, and a cooling unit constituting the charging/discharging device of the present invention. Referring to FIG. 3, in the charging/discharging apparatus of the present invention, in order to reduce the temperature deviation between a plurality of battery cells, a temperature signal sensed by the temperature sensor 140 is transmitted to the controller 150, and the controller By analyzing the transmitted temperature data, a battery cell outside the set temperature deviation is recognized. In addition, the control unit can reduce the temperature deviation by controlling the operation of the blowing fan 131 around the corresponding battery cell. Accordingly, the charging/discharging apparatus of the present invention has an effect of improving the reliability of a battery manufacturing process by reducing temperature variations between battery cells.

In an embodiment of the present invention, the control unit may control the temperature of the battery cell by turning the blowing fan on-off. The control unit analyzes the temperature data and maintains the operation of the surrounding blowing fan in the on state for battery cells lower than the lower limit temperature of the set temperature range, while the surrounding air conditioner for battery cells higher than the upper limit temperature of the set temperature range. Switches the operating state of the blowing fan to the off state. Accordingly, a plurality of battery cells can be controlled to maintain a temperature within a set temperature range.

In one embodiment of the present invention, the control unit controls the temperature of the battery cell by adjusting the rotational speed (rpm) of the blowing fan when the temperature measured by the temperature sensor is out of the set temperature deviation range. You may. The control unit analyzes the temperature data to reduce the rotational speed (rpm) of the surrounding blowing fan for the battery cells lower than the lower limit temperature of the set temperature range, while the surrounding air blower for the battery cells higher than the upper limit temperature of the set temperature range. By increasing the rotational speed (rpm) of the fan, it is possible to control the temperature of the battery cells to be uniform.

Meanwhile, the temperature sensor detects the temperature of the space around the cell. In an embodiment of the present invention, the number of temperature sensors may be the same as the number of battery cells. As the number of temperature sensors is large, it is possible to more accurately analyze the temperature of the space around the battery cell, and based on this, it will be possible to precisely control the temperature through the control unit.

4 is a schematic diagram of a cooling unit according to an embodiment of the present invention, and FIG. 8 is a schematic diagram of a cross flow fan constituting the cooling unit of FIG. 4. Referring to these drawings, the cooling unit 130, a plurality of blowing fans 131 for blowing air by rotation; A duct 132 through which air for cooling the battery cell is introduced; And a blower 133 for discharging the air introduced into the duct toward the battery cell. The cross-flow fan has an advantage of discharging air having the same direction and the same air volume throughout the entire length.

5 is a schematic diagram of a charging and discharging apparatus according to an embodiment of the present invention, and FIG. 7 is a schematic diagram of an axial-flow fan constituting the cooling unit of FIG. 5. Referring to these drawings, the cooling unit 130 includes a first cooling unit 130a installed on one side of the activation tray 110 and a second cooling unit 130b installed on the other side, and the first The air outlet 133a of the cooling part and the air outlet 133b of the second cooling part are arranged so as to be misaligned. At this time, the air outlet of the first cooling unit and the air outlet of the second cooling unit face each other. In addition, there is a separation distance between the air outlet and the air outlet.

The axial flow fan discharges air generated by the blowing fan 131 through the duct 132 to the air outlet 133. Therefore, when the blower fan is an axial flow fan, since air is not blown between the air outlet and the air outlet, the battery cells located between the air outlet and the air outlet may have a relatively small effect of being cooled by the air discharged from the air outlet. In addition, if the ventilation ports of the cooling units located on the left and right sides of the activation tray are arranged in a row on the same line, there is a concern that the battery cells located between the ventilation ports and the ventilation ports may not receive a sufficient amount of air to cool the left and right sides.

Accordingly, in the present invention, as shown in FIG. 5, the cooling air can be uniformly sprayed to the battery cells by configuring the air outlet of the cooling unit on one side and the air outlet of the cooling unit on the other side to be misaligned. Therefore, on the basis of the battery cell, even if relatively less cooling air is injected from one side of the battery cell, the cooling air is directly injected from the other side, so that the cooling air is uniformly distributed to a number of battery cells as a whole. will be.

The charging/discharging apparatus of the present invention may further include a flow path guide 160 for guiding the air discharged from the air outlet 133 to be injected into the battery cell. 6(a) is a front view of the flow path guide viewed from the side toward the battery cell, and FIG. 6(b) is a perspective view of the flow path guide, and referring to these drawings, one end of the flow path guide 160 of the present invention is coupled to the air outlet. And, the other end extends toward the battery cell, has a hollow structure having an empty space therein, and includes a rib 161 therein. The flow path guide uniformly guides the flow direction of air discharged from the air outlet, and the ribs 161 function to reduce turbulence of air flowing between the flow path guides. In addition, the shape of the rib disclosed in FIG. 6 is one specific example, and the shape of the rib may be changed and is not limited to the shape disclosed in FIG. 6.

The battery cell 10 in which the charging/discharging process is performed by the charging/discharging apparatus of the present invention may include various types, but may be a lithium secondary battery including a positive electrode, a separator, and a negative electrode as a representative.

The positive electrode may be prepared, for example, by applying a mixture of a positive electrode active material, a conductive material, and a binder on a positive electrode current collector and then drying it, and if necessary, a filler may be further added to the mixture.

The positive electrode active material is a material capable of causing an electrochemical reaction, as a lithium transition metal oxide, containing two or more transition metals, for example, lithium cobalt oxide (LiCoO ₂ ) substituted with one or more transition metals, lithium Layered compounds such as nickel oxide (LiNiO _{2 );} Lithium manganese oxide substituted with one or more transition metals; Formula LiNi _1-y MyO ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn or Ga, and including at least one of the above elements, 0.01≤y≤0.7) Lithium nickel-based oxide to be used; Li _1+z Ni _1/3 Co _1/3 Mn _1/3 O ₂ , Li _1+z Ni _0.4 Mn _0.4 Co _0.2 O ₂ Li _1+z Ni _b Mn _c Co _{1-(b+c+d )} MdO _(2-e) A _e (where -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1 Where M = Al, Mg, Cr, Ti, Si or Y, and A = F, P or Cl) lithium nickel cobalt manganese composite oxide; Formula Li _1+x M _{1-y M'y} PO _4-z X _z (where M = transition metal, preferably Fe, Mn, Co or Ni, M'= Al, Mg or Ti, X = F, S, or N, and -0.5≦x≦+0.5, 0≦y≦0.5, 0≦z≦0.1, and the like), but are not limited thereto.

The conductive material is typically added in an amount of 1 to 20% by weight based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery, and examples thereof include graphite such as natural graphite or artificial graphite; Carbon blacks such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives may be used.

The filler is selectively used as a component that suppresses the expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical changes to the battery, and examples thereof include olefin-based polymers such as polyethylene and polypropylene; Fibrous materials such as glass fiber and carbon fiber are used.

In addition, the negative electrode is prepared by, for example, applying a mixture of a negative electrode active material, a conductive material, and a binder on a negative electrode current collector, followed by drying, and if necessary, a filler may be further added to the mixture. In addition, the negative active material may be at least one selected from the group consisting of graphite-based carbon, coke-based carbon, and hard carbon.

Those of ordinary skill in the field to which the present invention belongs will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

10: battery cell
100: charging and discharging device
110: activation tray
120: charge/discharge operation unit
130: cooling unit
131: blowing fan
132: duct
133: vent
140: temperature sensor
150: control unit
160: Euro guide
161: rib
170: upper cooling part

Claims (11)

As a charging/discharging device for secondary batteries for charging and discharging battery cells during the battery cell activation process
An activation tray accommodating a plurality of battery cells side by side;
A charge/discharge operation unit provided to be electrically connected to the positive electrode and the negative electrode of the battery cells accommodated in the activation tray;
A cooling unit including a blower fan for cooling the battery cells in which charging and discharging are performed to control the temperature of the battery cells;
A plurality of temperature sensors disposed around the battery cells in which charging and discharging are performed; And
Charging and discharging apparatus for a secondary battery comprising a control unit configured to receive a temperature signal sensed by the temperature sensor, analyze it, and control an operation of the cooling unit.
The method of claim 1, wherein the cooling unit,
A plurality of blowing fans for blowing air by rotation;
A duct through which air for cooling the battery cell is introduced; And
Charging and discharging apparatus for a secondary battery comprising a vent for discharging the air introduced into the duct.
The charging and discharging apparatus of claim 1, wherein the blowing fan is an axial-flow fan or a cross-flow fan.
The charging and discharging apparatus of claim 1, wherein the blowing fan is an axial flow fan.
The method of claim 4, wherein the cooling unit comprises a first cooling unit installed on one side of the activation tray and a second cooling unit installed on the other side,
The charging and discharging apparatus of a secondary battery, characterized in that the air outlet of the first cooling unit and the air outlet of the second cooling unit are arranged so as to be misaligned.
The secondary according to claim 1, wherein the cooling unit is supported by the charge/discharge operation unit and is tiltably coupled to a corresponding position at which the battery cells accommodated in the activation tray are supported to adjust the direction of air flow. Battery charging and discharging device.
The charging/discharging apparatus of claim 2, further comprising a flow path guide installed between the air outlet and the activation tray and guiding the air discharged from the air outlet to be injected into the battery cell.
The charging/discharging apparatus of claim 1, wherein the control unit controls the operation of the blowing fan by an on-off method.
The charging and discharging apparatus of claim 1, wherein the control unit controls the operation of the blowing fan in a manner that adjusts a rotation speed (rpm).
The charging and discharging apparatus of claim 1, wherein the activation tray is two or more, and the trays are stacked in a vertical direction with respect to the ground while each of the battery cells is mounted.
The charging/discharging apparatus of claim 1, wherein the temperature sensor is the same as the number of the battery cells.

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