Battery system and method of controlling the same

Abstract

A battery system and a method of controlling the same are provided, the battery system including a battery management module, a battery module, and a controller. The battery management module includes a main switch between an external terminal and a battery terminal and a heating switch between the external terminal and a heating terminal. The battery module includes a cell, a heating element, and a control switch connected to the heating element. The controller is configured to detect connection with a charger, detect a temperature of the cell, turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element when the temperature is lower than a first value, and turn off the heating switch and turn on the main switch to supply charging power from the charger to the cell when the temperature becomes higher than a second value by the heating element.

Description

TECHNICAL FIELD

[0001] One or more embodiments relate to a battery system and a method of controlling the same. BACKGROUND

[0002] Lead-acid batteries can be used for light electric vehicles (LEVs) such as golf carts, industrial cleaning carts, forklifts, and aerial work platforms, but use of lithium-ion batteries instead of lead-acid batteries is increasing due to environmental concerns and to improve energy efficiency. Due to the nature of the product working in an outdoor environment, LEVs should be reliable in low-temperature and high-temperature environments ranging from about -40℃ to 40℃. In addition, fast charging at 1 C-rate or higher can be desirable in order to improve the usability of the product. SUMMARY

[0003] Embodiments are directed to a battery system including a battery management module including an external terminal, a battery terminal, a heating terminal, a main switch between the external terminal and the battery terminal, and a heating switch between the external terminal and the heating terminal, at least one battery module including at least one battery cell connected to the battery terminal, a heating element, and a control switch between the heating element and the heating terminal, and a controller configured to detect connection with a charger and detect a cell temperature of the at least one battery cell. When the cell temperature is lower than a first reference value, the controller can turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element, and when the cell temperature is higher than a second reference value, the controller can turn off the heating switch and turn on the main switch to supply charging power from the charger to the at least one battery cell.

[0004] The controller can include a microcontroller mounted on the battery management module and configured to control the main switch and the heating switch, and at least one analog front end mounted on the at least one battery module, respectively, and configured to detect the cell temperature, transmit the detected cell temperature to the microcontroller, and output a control signal to the control switch according to control of the microcontroller.

[0005] The control signal can be a pulse width modulation signal, and the microcontroller can be configured to determine a duty cycle of the control signal according to the cell temperature.

[0006] The at least one battery module can include a first battery module including at least one first battery cell, a first heating element, and a first control switch between the first heating element and the heating terminal, and a second battery module including at least one second battery cell, a second heating element, and a second control switch between the second heating element and the heating terminal.

[0007] The at least one first battery cell and the at least one second battery cell can be connected in series with each other, the controller can be configured to request the charger to supply a heating voltage when one of a first cell temperature of the at least one first battery cell and a second cell temperature of the at least one second battery cell is lower than a first reference value, and the controller can be configured to request the charger to supply a charging voltage higher than the heating voltage when both the first cell temperature and the second cell temperature are higher than a second reference value.

[0008] The controller can be configured to output a first control signal having a first duty ratio to the first control switch and a second control signal having a second duty ratio higher than the first duty ratio to the second control switch when the first cell temperature of the at least one first battery cell reaches the second reference value and the second cell temperature of the at least one second battery cell is lower than the second reference value.

[0009] The second reference value can be equal to or higher than the first reference value.

[0010] The heating element can be a film heater having a plurality of regions having different heating values per unit area, and the at least one battery cell can include a plurality of battery cells arranged on the film heater.

[0011] The heating value per unit area of a central region of the film heater can be lower than the heating value per unit area of an edge region of the film heater.

[0012] The heating element can include a first film heater and a second film heater surrounding at least a portion of the first film heater, the at least one battery module can include a first control switch between the first film heater and the heating terminal and a second control switch between the second film heater and the heating terminal, and the controller can be configured to output a second control signal having a duty ratio higher than a duty ratio of the first control signal output to the first control switch to the second control switch.

[0013] Embodiments are also directed to a method of controlling a battery system of an embodiment, the method including detecting connection with a charger, detecting a cell temperature of the at least one battery cell, operating a controller to turn off a main switch and turn on a heating switch and a control switch when the cell temperature is lower than a first reference value, thereby supplying heating power from the charger to a heating element, and operating the controller to turn off the heating switch and turn on the main switch when the cell temperature is higher than a second reference value, thereby supplying charging power from the charger to the at least one battery cell.

[0014] Supplying the heating power from the charger to the heating element can include detecting the cell temperature below a first reference value, turning off the main switch, requesting the charger to output a heating voltage, detecting the heating voltage applied to the external terminal, turning on the heating switch, and adjusting a duty cycle of a control signal for controlling the control switch.

[0015] Supplying the charging power from the charger to the at least one battery cell can include detecting that the cell temperature remains above a second reference value for a preset time, turning off the heating switch, requesting the charger to output a charging voltage, detecting the charging voltage applied to the external terminal, and turning on the main switch. BRIEF DESCRIPTION OF DRAWINGS

[0016] The features will become apparent to one of ordinary skill in the art upon examining the detailed description of the example embodiments, taken in conjunction with the accompanying drawings in which:

[0017] Figure 1 A battery system according to an example embodiment is shown;

[0018] Figure 2 A battery system according to another example embodiment is shown;

[0019] Figure 3 A battery module according to an example embodiment is shown;

[0020] Figure 4A A film heater according to an example embodiment is shown;

[0021] Figure 4B A film heater according to another example embodiment is shown;

[0022] Figures 5A to 5D A heating element according to an example embodiment is shown;

[0023] Figure 6 A battery module including a heating element according to an example embodiment is shown; Figures 5A to 5D

[0024] Figure 7 is a flowchart for describing a method of controlling a battery system according to an example embodiment; and

[0025] Figure 8 is a flowchart for describing a method of controlling a battery system according to another example embodiment. DETAILED DESCRIPTION

[0026] ​Example implementations will now be described more fully with reference to the accompanying drawings; however, they can be implemented in different forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided as example(s) so that this disclosure will be thorough and complete, and will fully convey the example to those skilled in the art.

[0027] In the drawings, the size of layers and regions can be exaggerated for clarity. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers can also be present. Furthermore, it will be understood that when a layer is referred to as being "under" another layer, it can be directly under the other layer, and one or more intervening layers can also be present. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers can also be present. Like reference numerals refer to like elements throughout.

[0028] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding the

[0029] The terminology used in the present specification has been used for describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In the present specification, it will be understood that terms such as "including" or "having," etc. are intended to indicate the existence of the mentioned feature(s) or component(s) in the specification, and are not intended to preclude the presence or addition of one or more other feature(s), component(s), step(s), action(s), or group thereof (collectively, another "feature"). It will be understood that although the terms "first" and "second" can be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another.

[0030] Figure 1 A battery system according to an example embodiment is shown.

[0031] Referring to Figure 1 The battery system 100 can include a battery management module 110, at least one of battery modules 130 and 150, and controllers 120, 140, and 160. The battery system 100 can be charged by being connected to a charger 10, and discharged by being connected to a load.

[0032] The battery management module 110 can include external terminals 101a and 101b, battery terminals 111a and 111b, heating terminals 112a and 112b, a main switch 114 between the external terminal 101a and the battery terminal 111a, and a heating switch 117 between the external terminal 101a and the heating terminal 112a.

[0033] The battery modules 130 and 150 can include a first battery module 130 and a second battery module 150.

[0034] The first battery module 130 can include at least one first battery cell 131 connected to the battery terminals 111a and 111b, a first heating element 132, and a first control switch 134 between the first heating element 132 and the heating terminal 112a.

[0035] The second battery module 150 can include at least one second battery cell 151 connected to the battery terminals 111a and 111b, a second heating element 152, and a second control switch 154 between the second heating element 152 and the heating terminal 112a.

[0036] In Figure 1 , the battery system 100 includes two battery modules 130 and 150. However, the battery system 100 can include only one battery module, or can include three or more battery modules connected in series or in parallel.

[0037] The controllers 120, 140, and 160 can include a microcontroller (MCU) 120 and at least one of an analog front end (AFE) 140 and 160.

[0038] In Figure 1 , two analog front ends 140 and 160 are included in the battery system 100, corresponding to the two battery modules 130 and 150. The number of analog front ends can correspond to the number of battery modules.

[0039] The microcontroller 120 can be mounted on the battery management module 110, and the first analog front end 140 and the second analog front end 160 can be mounted on the first battery module 130 and the second battery module 150, respectively.

[0040] The external terminals 101a and 101b can output power stored in the battery system 100 to an external device, such as a load, or can receive power to be stored in the battery system 100 from an external device, such as a charger 10. The external terminals 101a and 101b can be configured to be connected to the charging terminals 11a and 11b of the charger 10. In an example, the first external terminal 101a is positive and the second external terminal 101b is negative, but this is only an example.

[0041] The battery terminals 111a and 111b can be configured to be connected to the first battery module 130 and the second battery module 150. The first battery unit 131 of the first battery module 130 and the second battery unit 151 of the second battery module 150 can be connected in parallel between the battery terminals 111a and 111b. The first battery unit 131 and the second battery unit 151 can receive a charging current and output a discharging current through the battery terminals 111a and 111b.

[0042] The first switching circuit 113 can be arranged between the external terminal 101a and the battery terminal 111a. The first switching circuit 113 can include a main switch 114 and a main fuse 115.

[0043] The main switch 114 can be connected between the external terminal 101a and the battery terminal 111a. The main switch 114 can be controlled by a main control signal 121 output by the microcontroller 120.

[0044] The first switching circuit 113 can include a current sensor that can detect a charging current input to the external terminals 101a and 101b and / or a discharging current output from the external terminals 101a and 101b, thereby providing sensing data 123 to the microcontroller 120. The first switching circuit 113 can include a voltage sensor that detects a voltage between the external terminals 101a and 101b, and the voltage sensor can provide the sensing data 123.

[0045] According to another example, the first switching circuit 113 can be arranged between the external terminal 101b and the battery terminal 111b.

[0046] The heating terminals 112a and 112b can be configured to be connected to the first battery module 130 and the second battery module 150. The first heating element 132 of the first battery module 130 and the second heating element 152 of the second battery module 150 can be connected in parallel between the heating terminals 112a and 112b.

[0047] According to another example, the heating terminal 112b can be omitted, and the first heating element 132 and the second heating element 152 can be connected between the heating terminal 112a and the battery terminal 111b.

[0048] The second switching circuit 116 can be arranged between the external terminal 101a and the heating terminal 112a. The second switching circuit 116 can include a heating switch 117 and a fuse 118.

[0049] The heating switch 117 can be connected between the external terminal 101a and the heating terminal 112a. The heating switch 117 can be controlled by a heating control signal 122 output by the microcontroller 120.

[0050] According to another example, the second switching circuit 116 can be arranged between the external terminal 101b and the heating terminal 112b.

[0051] The microcontroller 120 can receive the sensing data 123, can output a main control signal 121 for controlling the main switch 114, and can output a heating control signal 122 for controlling the heating switch 117. The microcontroller 120 can communicate with the first analog front end 140 and the second analog front end 160 through a first communication line 124. The first communication line 124 can be a communication line for performing controller area network (CAN) communication.

[0052] The microcontroller 120 can communicate with the charger 10 through a second communication line 125. The microcontroller 120 can detect connection with the charger 10 through the second communication line 125, and can request the charger 10 to output a voltage in order to operate in a charging mode. For example, the microcontroller 120 can request the charger 10 to supply a heating voltage, or can request the charger 10 to supply a charging voltage. According to another example, the microcontroller 120 can detect that a voltage is being applied to the external terminals 101a and 101b through the sensing data 123, thereby operating in a charging mode.

[0053] According to an example, the microcontroller 120 can be woken up by a signal output by the charger 10 through the second communication line 125. According to another example, the microcontroller 120 can be woken up in response to a voltage applied to the external terminals 101a and 101b.

[0054] The first battery cell 131 and the second battery cell 151 can be rechargeable secondary batteries. For example, the first battery cell 131 and the second battery cell 151 can be lithium ion batteries. In other embodiments, the first battery cell 131 and the second battery cell 151 can include nickel-cadmium batteries, nickel-metal hydride batteries (NiMH), lithium polymer batteries, etc.

[0055] The first battery cell 131 can be connected to the battery terminals 111a and 111b, and a fuse 135 can be connected in series to the first battery cell 131. The second battery cell 151 can be connected to the battery terminals 111a and 111b, and a fuse 155 can be connected in series to the second battery cell 151.

[0056] In Figure 1 each of the first battery cell 131 and the second battery cell 151 is connected in series. However, this is only an example, and the first battery cell 131 and the second battery cell 151 can be connected in parallel to each other or in series and in parallel. The number of the first battery cell 131 and the number of the second battery cell 151 are not limited to the examples described herein.

[0057] The first and second heating elements 132 and 152 can be connected between the heating terminals 112a and 112b, and can be elements that generate heat by dissipating power supplied through the heating terminals 112a and 112b.

[0058] The first and second heating elements 132 and 152 can be, for example, film heaters. The film heaters can include a heating element pattern disposed on an insulating film. The heating element can include, for example, a metallic heating element, a non-metallic heating element, other heating elements, etc.

[0059] When a voltage is applied to the heating element pattern, heat can be emitted to raise the temperature of the first and second battery cells 131 and 151. The first and second heating elements 132 and 152 can be disposed adjacent to the first and second battery cells 131 and 151.

[0060] The first and second control circuits 133 and 153 can be respectively arranged to control the operation of the first and second heating elements 132 and 152. The first control circuit 133 can be arranged between the first heating element 132 and the heating terminal 112a, and the second control circuit 153 can be arranged between the second heating element 152 and the heating terminal 112a. The first control circuit 133 can include a first control switch 134 controlled by a first control signal 141 output by a first analog front end 140, and the second control circuit 153 can include a second control switch 154 controlled by a second control signal 161 output by a second analog front end 160.

[0061] The first and second control signals 141 and 161 can be, for example, pulse width modulation (PWM) signals having a duty ratio. The first and second analog front ends 140 and 160 can adjust the duty ratio of the first and second control signals 141 and 161, thereby adjusting the heating value of heat generated by the first and second heating elements 132 and 152. The duty ratio of the first and second control signals 141 and 161 can be determined by the microcontroller 120.

[0062] The first and second analog front ends 140 and 160 can receive battery sensing data 142 and 162 and heater sensing data 143 and 163.

[0063] The battery sensing data 142 and 162 can include first and second cell voltage values of the first and second battery cells 131 and 151, first and second cell temperature values of the first and second battery cells 131 and 151, and a cell current value of the first and second battery cells 131 and 151.

[0064] The heating sensing data 143 and 163 can include first and second heater temperatures of the first and second heating elements 132 and 152 and heater current values of the first and second heating elements 132 and 152.

[0065] The first and second battery modules 130 and 150 can include, respectively, cell temperature sensors for detecting first and second cell temperatures and heater temperature sensors for detecting first and second heater temperatures. The first and second battery modules 130 and 150 can include, respectively, cell current sensors for detecting cell current values of the first and second battery cells 131 and 151 and heater current sensors for detecting heater current values of the first and second heating elements 132 and 152.

[0066] The first and second analog front-ends 140 and 160 can communicate with each other through a third communication line 144. The third communication line 144 can be a communication line for performing CAN communication. CAN communication can be performed between the microcontroller 120 and the first and second analog front-ends 140 and 160 through the first communication line 124 and the third communication line 144. The first and second analog front-ends 140 and 160 can transmit battery sensing data 142 and 162 and heater sensing data 143 and 163 to the microcontroller 120 through the first communication line 124 and the third communication line 144. The microcontroller 120 can transmit control instructions to the first and second analog front-ends 140 and 160 through the first communication line 124 and the third communication line 144. The control instructions can be, for example, instructions for adjusting duty cycles of the first and second control signals 141 and 161.

[0067] The microcontroller 120 can detect connection with the charger 10. For example, the microcontroller 120 can detect connection with the charger 10 through the second communication line 125. The microcontroller 120 can detect first and second cell temperatures of the first and second battery cells through the battery sensing data 142 and 162 received from the first and second analog front-ends 140 and 160.

[0068] When the first and second cell temperatures are lower than the first reference value, the microcontroller 120 can turn off the main switch 114 and turn on the heating switch 117. According to an example, when any one of the first and second cell temperatures is lower than the first reference value, the microcontroller 120 can turn off the main switch 114 and turn on the heating switch 117. For example, the first reference value can be 0 degree Celsius. However, according to the temperature characteristics of the first and second battery cells 131 and 151, the first reference value can be set to a temperature lower or higher than 0 degree Celsius. Turning off the main switch 114 means that the main switch 114 is opened such that the external terminal 101a and the battery terminal 111a are isolated from each other. Turning on the heating switch 117 means that the heating switch 117 is short-circuited or closed such that the external terminal 101a and the heating terminal 112a are electrically connected to each other.

[0069] When the first and second cell temperatures are lower than the first reference value, the microcontroller 120 can request the charger 10 to supply the heating power before turning on the heating switch 117. The charger 10 can output the heating voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the heating voltage applied to the external terminals 101a and 101b, and then can turn on the heating switch 117. In this case, the main switch 114 can be in an off state.

[0070] Further, the microcontroller 120 can turn on the first and second control switches 134 and 154 through the first and second analog front ends 140 and 160, thereby supplying the heating power from the charger 10 to the first and second heating elements 132 and 152. The microcontroller 120 can determine the duty ratios of the first and second control signals 141 and 161 output by the first and second analog front ends 140 and 160 based on the first and second cell temperatures to control the first and second control switches 134 and 154.

[0071] For example, when the first cell temperature is higher than the second cell temperature, the microcontroller 120 can determine that the duty ratio of the first control signal 141 is lower than that of the second control signal 161. For example, when the first cell temperature reaches the second reference value in a state in which the second cell temperature does not reach the second reference value, the microcontroller 120 can transmit a control instruction for reducing the duty ratio of the first control signal 141 to the first analog front end 140. The duty ratio of the first control signal 141 can be lower than that of the second control signal 161.

[0072] When the first and second cell temperatures are raised by the first and second heating elements 132 and 152, and the first and second cell temperatures are higher than the second reference value, the microcontroller 120 can be configured to supply the charging power from the charger 10 to the first and second battery cells 131 and 151 by turning off the heating switch 117 and turning on the main switch 114. According to an example, when the first and second cell temperatures are higher than the second reference value, the microcontroller 120 can turn off the heating switch 117 and turn on the main switch 114. The second reference value can be higher than the first reference value, and can be, for example, 5 degrees Celsius. However, the second reference value can be set to be lower or higher than 5 degrees Celsius according to the temperature characteristics of the first and second battery cells 131 and 151. In an example, the second reference value can be equal to the first reference value.

[0073] According to an example, the voltage of the charging power and the voltage of the heating power can be the same. According to another example, the voltage of the charging power and the voltage of the heating power can be different from each other, for example, the voltage of the charging power can be higher than the voltage of the heating power.

[0074] According to another example, when the first and second cell temperatures are higher than the second reference value, the microcontroller 120 can turn off the heating switch 117, and can request the charger 10 to supply the charging power. The charger 10 can output the charging voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the charging voltage applied to the external terminals 101a and 101b, and then can turn on the main switch 114.

[0075] As described above, according to an example, when the first and second cell temperatures are equal to or higher than a preset first reference value, the first and second battery cells 131 and 151 can be charged. Accordingly, it is possible to prevent rapid deterioration of the first and second battery cells 131 and 151 when the first and second battery cells 131 and 151 are charged in a low temperature state.

[0076] Further, according to an example, the heating power for raising the first and second cell temperatures of the first and second battery cells 131 and 151 can not be supplied by the first and second battery cells 131 and 151, but can be supplied by the charger 10. Accordingly, it is possible to prevent a situation in which the first and second battery cells 131 and 151 are discharged or over-discharged to raise the first and second cell temperatures.

[0077] Figure 2 A battery system according to another example embodiment is illustrated.

[0078] Referring to Figure 2The battery system 100a can include a battery management module 110, at least one battery module 130 and 150, and controllers 120, 140, and 160. The battery system 100a is substantially the same as the battery system 100 of Figure 1 except that the first battery module 130 and the second battery module 150 are connected in series. For the same components, repetitive descriptions thereof can be omitted.

[0079] The first battery cell 131 of the first battery module 130 and the second battery cell 151 of the second battery module 150 can be connected in series between the battery terminals 111a and 111b. A charging voltage for charging the first battery cell 131 and the second battery cell 151 connected in series as described above can be approximately twice a charging voltage for charging the first battery cell 131 and the second battery cell 151 connected in parallel as described above. Figure 1 In the example embodiment of FIG. 1, the voltage of the charging power and the voltage of the heating power are the same, according to Figure 1 In the embodiment of FIG. 1, the voltage of the charging power and the voltage of the heating power are the same, according to Figure 2 In the embodiment of FIG. 1, the voltage of the charging power and the voltage of the heating power are the same, according to

[0080] The microcontroller 120 can detect connection with the charger 10 through the second communication line 125. The microcontroller 120 can detect first and second cell temperatures of the first and second battery cells through the first analog front end 140 and the second analog front end 160. In this case, the main switch 114 can be in an off state.

[0081] When the first and second cell temperatures are lower than a first reference value, the microcontroller 120 can request the charger 10 to supply a heating voltage. The charger 10 can output the heating voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the heating voltage applied to the external terminals 101a and 101b, and then can turn on the heating switch 117. The microcontroller 120 can turn on the first control switch 134 and the second control switch 154 through the first analog front end 140 and the second analog front end 160, thereby supplying the heating power from the charger 10 to the first heating element 132 and the second heating element 152.

[0082] When the first and second cell temperatures are raised by the first and second heating elements 132 and 152, and the first and second cell temperatures are higher than the second reference value, the microcontroller 120 can turn off the heating switch 117, and can request the charger 10 to supply the charging power. The charger 10 can output the charging voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the charging voltage applied to the external terminals 101a and 101b, and then can turn on the main switch 114, thereby supplying the charging power from the charger 10 to the first and second battery cells 131 and 151.

[0083] According to the current example embodiment, even if the charging voltage and the heating voltage are different from each other, since communication is performed between the microcontroller 120 and the charger 10, the first and second battery cells 131 and 151 can be charged after the temperature of the first and second battery cells 131 and 151 is safely raised to be higher than the second reference value.

[0084] Figure 3 A battery module according to an example embodiment is illustrated.

[0085] Referring to Figure 3 , the battery module 200 can include a battery main case 210, battery cells 220, a heat conductive pad 230, a heat plate 240, a film heater 250, an insulator 260, and a cover case 270. The battery module 200 can correspond to Figure 1 and Figure 2 the first and second battery modules 130 and 150.

[0086] The battery main case 210 and the cover case 270 can protect the battery cells 220 and a protection circuit, etc. from external impact, moisture, etc. The protection circuit can be mounted on the battery main case 210. The protection circuit can include an analog front end, a current and temperature sensor, a battery balancing circuit, a communication terminal, etc. The protection circuit can be mounted on a circuit board fixed to the battery main case 210. The battery cells 220 can be disposed in the battery main case 210, and the battery cells 220 can correspond to Figure 1 and Figure 2 the first and second battery cells 131 and 151.

[0087] The heat conductive pad 230 can be disposed on the battery cells 220. The heat conductive pad 230 can transfer heat generated in the film heater 250 to the battery cells 220. The heat conductive pad 230 can dissipate heat generated in the battery cells 220 to the outside. The heat conductive pad 230 can insulate the film heater 250 and the battery cells 220 from each other. Instead of the heat conductive pad 230, a thermal adhesive can also be used.

[0088] The thermal plate 240 can be disposed on the thermal pad 230. The thermal plate 240 can fix the film heater 250 and can diffuse heat generated in the film heater 250 to the battery cell 220.

[0089] The film heater 250 can be disposed on the thermal plate 240. The film heater 250 can include a heating element pattern disposed on an insulating film. When a heating voltage is applied to the heating element pattern, heat can be emitted so that the temperature of the battery cell 220 can increase. As shown, the battery cell 220 can be disposed adjacent to the film heater 250. The film heater 250 can correspond to Figure 1 and Figure 2 the first and second heating elements 132 and 152. The film heater 250 will be described in greater detail below with reference to Figures 4A to 5D

[0090] The insulator 260 can be disposed on the film heater 250. The insulator 260 can prevent heat generated by the film heater 250 from being dissipated to the outside. The cover case 270 can be disposed on the insulator 260. The cover case 270 can be coupled to the battery main case 210 by plastic laser welding.

[0091] Figure 4A A film heater according to an example embodiment is illustrated.

[0092] Referring to Figure 4A , the film heater 300a can include an insulating film 320 and a heating element pattern 310a disposed on the insulating film 320 to have a desired heating size. Connection terminals 311a and 311b to which a heating voltage can be applied can be disposed at both ends of the heating element pattern 310a.

[0093] The insulating film 320 can include a plastic film made of one or more plastic materials selected from, for example, polyethylene terephthalate (PET), polyimide (PI), polyacrylonitrile (PAN), polyurethane (PU), silicon, polycarbonate (PC), Teflon, liquid crystal polymer (LCP), polyether ether ketone (PEEK), polyether sulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyarylate, cellulose triacetate (CTA), and cellulose acetate propionate (CAP).

[0094] ​The heating element pattern 310a can be a planar heating element having a small width. The heating element pattern 310a can have a substantially constant width according to an extension direction. According to another example, the heating element pattern 310a can have different widths according to an extension direction, so that a heating value per unit area of a certain region can be differently set when the same current flows through the heating element pattern 310a.

[0095] The planar heating element can be formed using, for example, a ceramic resistor. The planar heating element can be, for example, a carbon-based heating element, and can be formed of a material such as a carbon pulp heating paper, a carbon fiber knitted heating element, or a carbon cotton heating element. The planar heating element can be formed by, for example, knitting a fine metal wire.

[0096] The heating element pattern 310a can be formed by printing a heating element composition on the upper surface of the insulating film 320. The heating element pattern 310a can be formed by printing a heating element composition on the upper surface of the insulating film 320 and then heat-curing and aging. As a printing method of the heating element composition, screen printing, gravure printing (or roll-to-roll gravure printing), blade coating (or roll-to-roll blade coating), flexo, stamping, offset printing, or the like can be used. The curing can be performed at, for example, 100°C to 180°C, and the aging can be performed at, for example, 250°C to 350°C.

[0097] According to an example, the heating element composition can include a mixed binder, conductive particles, an organic solvent, and a dispersant. The conductive particles can include silver powder and carbon nanotube particles, and can further include graphite particles. The heating element composition can have a density of, for example, 2 g / cm 3 or less. According to another example, the heating element composition can include a mixed binder, carbon particles, metal powder, an organic solvent, and a dispersant. The carbon particles can include carbon nanotube particles and graphite particles. By controlling the amount of the organic solvent used, the heating element composition can be realized in the form of a paint, an ink, or a paste.

[0098] According to another example, the heating element pattern 310a can be formed of a conductive wire. The conductive wire can include at least a metal wire. The metal wire can be covered with a self-adhesive insulating film. For example, a metal wire such as copper, iron, gold, copper-nickel, nickel-chromium, iron-nickel-chromium, or the like can be used, but other materials can also be used as long as they have electrical conductivity. In consideration of resistance, durability, and cost, copper or a copper alloy in which zinc, lead, tin, silver, aluminum, nickel, beryllium, zirconium, or the like is alone or in multiple combinations can be used as the metal wire.

[0099] The film heater 300a can have a plurality of heating regions HR1, HR2, and HR3 having different heating values per unit area. The third heating region HR3 can be defined adjacent to the center of the film heater 300a, and the heating element pattern 310a can be arranged such that the density of the heating element pattern 310a is low to have the lowest heating value per unit area, or the interval distance between adjacent linear patterns is large. The first heating region HR1 can be defined adjacent to the periphery of the film heater 300a, and the heating element pattern 310a can be arranged such that the density of the heating element pattern 310a is high to have the highest heating value per unit area, or the interval distance between adjacent linear patterns is small. The second heating region HR2 can be arranged between the first heating region HR1 and the third heating region HR3, and the heating element pattern 310a can be arranged to have a heating value smaller than that of the first heating region HR1 and larger than that of the third heating region HR3.

[0100] The film heater 300a can have a rectangular planar shape. As Figure 4A indicated, the second heating region HR2 and the third heating region HR3 can have a circular planar shape. The film heater 300a can have a plurality of heating regions HR1, HR2, and HR3 having different heating values per unit area, so that the temperature of the battery cell arranged in the film heater 300a can be continuously increased.

[0101] Figure 4B A film heater according to another example embodiment is illustrated.

[0102] Referring to Figure 4A , the film heater 300b can include an insulating film 320 and a heating element pattern 310b arranged on the insulating film 320 to have a desired heating size. Connection terminals 311a and 311b to which a heating voltage can be applied can be arranged at both ends of the heating element pattern 310b. The film heater 300b can be substantially the same as the film heater 300a of Figure 4A except for the planar shape of the heating element pattern 310b, and the same components will not be repeatedly described. The material for the heating element pattern 310b can be the same as the heating element pattern 310a of Figure 4A .

[0103] The film heater 300b can have a plurality of heating regions HR1 and HR2 having different heating values per unit area. The first heating region HR1 can be defined adjacent to a periphery of the film heater 300b, and the heating element pattern 310b can be arranged such that the density of the heating element pattern 310b is high, the spacing distance between adjacent heating element patterns 310b is small, or the width of the heating element pattern 310b is large to have the highest heating value per unit area. The second heating region HR2 can be defined adjacent to a center of the film heater 300b, and the heating element pattern 310b can be arranged such that the density of the heating element pattern 310b is low, the spacing distance between adjacent heating element patterns 310b is large, or the width of the heating element pattern 310b is small to have the lowest heating value per unit area.

[0104] The first heating region HR1 and the second heating region HR2 can have a rectangular planar shape to correspond to a planar shape of the film heater 300b, as shown in Figure 4B The film heater 300b can have a plurality of heating regions HR1 and HR2 having different heating values per unit area, such that the temperature of the battery cell disposed in the film heater 300b can be continuously increased.

[0105] Figures 5A to 5D A heating element according to an example embodiment is illustrated.

[0106] Referring to Figure 5A The heating element 400a can include a first film heater 410a located at a periphery of the heating element 400a and a second film heater 420a located inside the first film heater 410a. The first film heater 410a can surround the second film heater 420a. The first film heater 410a can include first connection terminals 411a and 411b, and the second film heater 420a can include second connection terminals 421a and 421b. The heating values applied to the first connection terminals 411a and 411b and the heating values applied to the second connection terminals 421a and 421b can be independent of each other. For example, the heating power supplied to the first film heater 410a can be greater than the heating power supplied to the second film heater 420a.

[0107] Referring to Figure 5BThe heating element 400b can include a first film heater 410b located at the periphery of the heating element 400b and a second film heater 420b located inside the first film heater 410b. The first film heater 410b can surround three edges of the second film heater 420b. The first film heater 410b can include first connection terminals 411a and 411b, and the second film heater 420b can include second connection terminals 421a and 421b. Heating power supplied to the first film heater 410b and heating power supplied to the second film heater 420b can be different from each other.

[0108] Referring to Figure 5C The heating element 400c can include a first film heater 410c located at the periphery of the heating element 400c and a second film heater 420c surrounded by the first film heater 410c. The heating element 400c has a rectangular planar shape, but the second film heater 420c can have a circular planar shape. The first film heater 410c can include first connection terminals 411a and 411b, and the second film heater 420c can include second connection terminals 421a and 421b. Heating power supplied to the first film heater 410c and heating power supplied to the second film heater 420c can be different from each other.

[0109] Referring to Figure 5D The heating element 400d can include a first film heater 410d located at the periphery of the heating element 400d and a second film heater 420d having an elliptical planar shape and surrounded by the first film heater 410d. The first film heater 410d can include first connection terminals 411a and 411b, and the second film heater 420d can include second connection terminals 421a and 421b. Heating power supplied to the first film heater 410d and heating power supplied to the second film heater 420d can be different from each other.

[0110] Figure 6 A battery module including a heating element according to an example embodiment is illustrated. Figures 5A to 5D The heating element 400b can include a first film heater 410b located at the periphery of the heating element 400b and a second film heater 420b located inside the first film heater 410b. The first film heater 410b can surround three edges of the second film heater 420b. The first film heater 410b can include first connection terminals 411a and 411b, and the second film heater 420b can include second connection terminals 421a and 421b. Heating power supplied to the first film heater 410b and heating power supplied to the second film heater 420b can be different from each other.

[0111] Referring to Figure 6, the battery module 130a can include at least one first battery cell 131, a first film heater 132a and a second film heater 132b, a first control circuit 133a between the first film heater 132a and the heating terminal 112a, a second control circuit 133b between the second film heater 132b and the heating terminal 112a, and a first analog front end 140 outputting a first control signal 141a to a first control switch 134a and a second control signal 141b to a second control switch 134b. The first control circuit 133a can include the first control switch 134a, and the second control circuit 133b can include the second control switch 134b.

[0112] In the battery module 130a, when compared to the first battery module 130 of Figure 1 , the battery module 130a is substantially the same as the first battery module 130 of Figure 1 except for using the first film heater 132a and the second film heater 132b instead of the first heating element 132 and using the first control switch 134a and the second control switch 134b instead of the control switch 134. Redundant descriptions of the same components can be omitted.

[0113] The first analog front end 140 can independently output the first control signal 141a and the second control signal 141b to the first control switch 134a and the second control switch 134b, respectively. The first analog front end 140 can receive heater sensing data 143a from the first film heater 132a, and can receive heater sensing data 143b from the second film heater 132b.

[0114] As shown in Figures 5A to 5D , a heating element including the first film heater 132a and the second film heater 132b can be used. Heating power can be independently supplied to the first film heater 132a and the second film heater 132b through the first control switch 134a and the second control switch 134b, and the first control switch 134a and the second control switch 134b can be controlled by the first control signal 141a and the second control signal 141b.

[0115] The first control signal 141a and the second control signal 141b can be pulse width modulation signals having a duty ratio. The second film heater 132b located inside the first heating element 132 can generate less heat than the first film heater 132a located at the periphery of the first heating element 132, and accordingly, the duty ratio of the first control signal 141a can be higher than the duty ratio of the second control signal 141b.

[0116] Figure 7 is a flowchart for describing a method of controlling a battery system according to an example embodiment.

[0117] Referring to Figure 7 and Figure 1 The microcontroller 120 can be woken up (S10). According to an embodiment, the microcontroller 120 can be woken up in response to a wake-up signal output by the charger 10 through the second communication line 125, and can detect that the charger 10 has been connected to the microcontroller 120 through the second communication line 125. According to another example, the microcontroller 120 can be woken up in response to a voltage applied to the external terminals 101a and 101b. According to another example, the microcontroller 120 can be woken up in response to a user's input or a signal from another controller.

[0118] The microcontroller 120 can collect data (S20). For example, the microcontroller 120 can collect a voltage value applied to the external terminals 101a and 101b through the sensing data 123, and collect charging and discharging current values input and output through the external terminals 101a and 101b. The microcontroller 120 can communicate with the first analog front end 140 and the second analog front end 160 through the first communication line 124 and the third communication line 144, and can collect a cell voltage value and a first cell temperature value of the first battery cell 131, a current value and a heater temperature value of the first heating element 132, a cell voltage value and a second cell temperature value of the second battery cell 151, and a current value and a heater temperature value of the second heating element 152.

[0119] The microcontroller 120 can collect a voltage value applied to the external terminals 101a and 101b through the sensing data 123, and can detect whether the charger 10 has been connected to the microcontroller 120 based thereon.

[0120] The microcontroller 120 can determine whether the current operation mode is a charging mode (S30).

[0121] When the current operation mode is not the charging mode, the microcontroller 120 can determine whether the current operation mode is a discharging mode (S31).

[0122] When the current operation mode is the discharging mode, the microcontroller 120 can perform a normal operation (S32). For example, the microcontroller 120 can turn on the main switch 114.

[0123] When the current operation mode is not the discharging mode, the microcontroller 120 can operate in a standby mode (S33).

[0124] Referring back to operation S30, when the current operation mode is the charging mode (S30-Yes), the microcontroller 120 can compare the first cell temperature value and the second cell temperature value with a first temperature (S40). The first temperature can be a first reference value, for example, 0 degrees Celsius.

[0125] When one of the first and second cell temperature values is lower than the first temperature, the microcontroller 120 can operate in a heating operation mode (S50). For example, the microcontroller 120 can turn off the main switch 114, and can turn on the heating switch 117. The microcontroller 120 can turn on the first and second control switches 134 and 154 through the first and second analog front ends 140 and 160, thereby supplying heating power from the charger 10 to the first and second heating elements 132 and 152. The first and second cell temperatures are increased by heat generated from the first and second heating elements 132 and 152.

[0126] The microcontroller 120 can compare the first and second cell temperature values with a second temperature (S60). The second temperature can be a second reference value, for example, 5 degrees Celsius, which is higher than the first temperature. When one of the first and second cell temperature values is lower than the second temperature, the microcontroller 120 can continuously perform the heating operation mode.

[0127] When both of the first and second cell temperature values are higher than the second temperature, the microcontroller 120 can stop the heating operation mode and start normal charging (S70).

[0128] Further, referring again to operation S40, when both of the first and second cell temperature values are higher than the first temperature, the microcontroller 120 can skip the heating operation mode and start normal charging (S70). The microcontroller 120 can be configured to turn off the heating switch 117 and turn on the main switch 114, thereby supplying charging power from the charger 10 to the first and second battery cells 131 and 151.

[0129] Figure 8 is a flowchart for describing a method of controlling a battery system according to another example embodiment.

[0130] Referring to Figure 8 and Figure 1 , the microcontroller 120 can perform operations S10 to S40 described above with reference to Figure 7

[0131] ​When one of the first cell temperature value and the second cell temperature value is lower than the first temperature, the microcontroller 120 can prepare a heating operation (S51). For example, the microcontroller 120 can turn off the main switch 114 and request the charger 10 to supply a heating voltage through the second communication line 125. The charger 10 can output the heating voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. When the heating voltage applied to the external terminals 101a and 101b is detected, the microcontroller 120 can turn on the heating switch 117. The microcontroller 120 can turn on the first control switch 134 and the second control switch 154 through the first analog front end 140 and the second analog front end 160, thereby supplying the heating power from the charger 10 to the first heating element 132 and the second heating element 152 (S52).

[0132] The microcontroller 120 can control the heating operation based on the first cell temperature and the second cell temperature (S53). The first analog front end 140 and the second analog front end 160 can output the first control signal 141 and the second control signal 161 having a duty ratio, thereby controlling the first control switch 134 and the second control switch 154. For example, the first cell temperature can not reach the second temperature; when the second cell temperature first reaches the second temperature, the duty ratio of the second control signal 161 can decrease. In this case, the duty ratio of the second control signal 161 can be lower than the duty ratio of the first control signal 141. According to another example, the microcontroller 120 can adjust the duty ratios of the first control signal 141 and the second control signal 161 based on the first cell temperature and the second cell temperature. For example, when the first cell temperature and the second cell temperature increase, the microcontroller 120 can decrease the duty ratios of the first control signal 141 and the second control signal 161. The first and second cell temperatures can increase by the heat generated by the first heating element 132 and the second heating element 152.

[0133] The microcontroller 120 can compare the first cell temperature value and the second cell temperature value with the second temperature (S60). When one of the first cell temperature value and the second cell temperature value is lower than the second temperature, the microcontroller 120 can continuously control the heating operation (S53).

[0134] When both the first cell temperature value and the second cell temperature value are higher than the second temperature, the microcontroller 120 can stop the heating operation (S61). The microcontroller 120 can check whether both the first cell temperature value and the second cell temperature value remain higher than the second temperature for a preset time (e.g., one minute). When both the first cell temperature value and the second cell temperature value remain higher than the second temperature for the preset time (e.g., one minute), the microcontroller 120 can turn off the first control switch 134 and the second control switch 154 through the first analog front end 140 and the second analog front end 160. The microcontroller 120 can turn off the heating switch 117, and can request the charger 10 to supply the charging power through the second communication line 125. The charger 10 can output the charging voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the charging voltage applied to the external terminals 101a and 101b, and then can turn on the main switch 114, thereby supplying the charging power from the charger 10 to the first battery cell 131 and the second battery cell 151, thus starting normal charging (S70).

[0135] Referring again to operation S40, when both the first cell temperature value and the second cell temperature value are higher than the first temperature, the microcontroller 120 can turn off the heating switch 117, and can request the charger 10 to supply the charging power through the second communication line 125. The charger 10 can output the charging voltage to the external terminals 101a and 101b in response to the request of the microcontroller 120. The microcontroller 120 can detect the charging voltage applied to the external terminals 101a and 101b, and then can turn on the main switch 114, thereby supplying the charging power from the charger 10 to the first battery cell 131 and the second battery cell 151, thus starting normal charging (S70).

[0136] By summarizing and reviewing, as the characteristics of the lithium ion battery, when the battery is rapidly charged in a low temperature environment, the degradation of the battery can be accelerated.

[0137] As described above, by raising the cell temperature using the power supplied from the charger, the battery can be charged, and thus a battery system capable of rapidly charging even in a low temperature environment can be provided.

[0138] For the sake of brevity, conventional electronic devices, control systems, software development and other functional aspects of the systems can not be described in detail herein. Moreover, the connecting lines, or connectors shown in the various figures presented are intended to represent example functional relationships and / or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections can be present in a practical device.

[0139] Furthermore, unless otherwise indicated herein, the description herein of any range of values is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, and each separate value is incorporated in the specification as if it were individually recited herein. Finally, the steps of any of the methods described herein can be carried out in any suitable order, unless otherwise indicated herein or otherwise clearly contradicted by context, and are not limited to the order described. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate embodiments and does not pose a limitation on the scope of the embodiments unless otherwise claimed.

[0140] Having disclosed example embodiments, although in terms of a particular implementation, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the examples can be made, each falling within the spirit of the implementations, and each falling within the scope of the appended claims.

Claims

1. A battery system, comprising: A battery management module includes an external terminal, a battery terminal, a heating terminal, a main switch between the external terminal and the battery terminal, and a heating switch between the external terminal and the heating terminal. At least one battery module includes at least one battery cell connected to the battery terminal, a heating element, a first control switch and a second control switch, the heating element including a first membrane heater and a second membrane heater at least partially surrounded by the first membrane heater, the first control switch being between the first membrane heater and the heating terminal of the heating element, and the second control switch being between the second membrane heater and the heating terminal of the heating element; as well as The controller is configured to detect connection to the charger and detect the cell temperature of the at least one battery cell. When the unit temperature is lower than a first reference value, the controller is configured to turn off the main switch, turn on the heating switch, and output a first control signal and a second control signal to the first control switch and the second control switch, respectively, to supply heating power from the charger to the first membrane heater and the second membrane heater of the heating element, respectively. The first control signal has a higher duty cycle than the second control signal. When the temperature of the cell is higher than the second reference value, the controller turns off the heating switch and turns on the main switch to supply charging power from the charger to the at least one battery cell.

2. The battery system according to claim 1, wherein the controller comprises: A microcontroller is mounted on the battery management module and configured to control the main switch and the heating switch; as well as At least one analog front end is installed on the at least one battery module and configured to detect the cell temperature, transmit the detected cell temperature to the microcontroller, and output the first control signal and the second control signal to the first control switch and the second control switch respectively according to the control of the microcontroller.

3. The battery system according to claim 2, wherein: Each of the first control signal and the second control signal is a pulse width modulation signal, and The microcontroller is configured to determine the duty cycle of the first control signal and the duty cycle of the second control signal based on the unit temperature.

4. The battery system according to claim 3, wherein the at least one battery module comprises: The first battery module includes at least one first battery cell, a first heating element, and a third control switch between the first heating element and the heating terminal; as well as The second battery module includes at least one second battery cell, a second heating element, and a fourth control switch between the second heating element and the heating terminal.

5. The battery system according to claim 4, wherein: The at least one first battery cell and the at least one second battery cell are connected in series with each other. When one of the first cell temperature of the at least one first battery cell and the second cell temperature of the at least one second battery cell is lower than the first reference value, the controller is configured to request the charger to supply heating voltage, and When both the temperature of the first unit and the temperature of the second unit are higher than the second reference value, the controller is configured to request the charger to supply a charging voltage higher than the heating voltage.

6. The battery system according to claim 5, wherein, When the temperature of the first cell of the at least one first battery cell reaches the second reference value and the temperature of the second cell of the at least one second battery cell is lower than the second reference value, the controller is configured to output a third control signal with a first duty cycle to the third control switch and a fourth control signal with a second duty cycle higher than the first duty cycle to the fourth control switch.

7. The battery system of claim 1, wherein the second reference value is equal to or higher than the first reference value.

8. The battery system according to claim 1, wherein: The heating element is a membrane heater having multiple regions with different heating values ​​per unit area, and The at least one battery cell includes a plurality of battery cells arranged on the membrane heater.

9. The battery system of claim 8, wherein the heating value per unit area of ​​the central region of the membrane heater is lower than the heating value per unit area of ​​the edge region of the membrane heater.

10. A method for controlling a battery system according to claim 1, the method comprising: Detect the connection with the charger; Detect the cell temperature of at least one battery cell; When the unit temperature is lower than the first reference value, the controller is operated to turn off the main switch, turn on the heating switch, and output the first control signal and the second control signal to the first control switch and the second control switch respectively, thereby supplying the heating power from the charger to the first membrane heater and the second membrane heater of the heating element respectively. The first control signal has a higher duty cycle than the second control signal. as well as When the unit temperature is higher than the second reference value, the controller is operated to turn off the heating switch and turn on the main switch, thereby supplying the charging power from the charger to the at least one battery unit.

11. The method of claim 10, wherein supplying the heating power from the charger to the heating element comprises: Detect the unit temperature below the first reference value; Turn off the main switch; The charger is requested to output a heating voltage; Detect the heating voltage applied to the external terminal; Turn on the heating switch; as well as Adjust the duty cycle of the control signal used to control the control switch.

12. The method of claim 10, wherein supplying the charging power from the charger to the at least one battery cell comprises: The unit temperature was detected to remain above the second reference value for a preset time. Turn off the heating switch; Request the charger to output charging voltage; Detect the charging voltage applied to the external terminal; as well as Turn on the main switch.

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