Method and apparatus for generating quick charge map

Abstract

Provided are a method and an apparatus for generating a quick charge map. The method for generating a quick charge map, according to the present invention, comprises the steps of: obtaining a plurality of charging-test results each associated with a plurality of charging conditions that are combinations of a plurality of current rates and a plurality of outside air temperatures; analyzing the plurality of charging-test results to determine a plurality of charging-characteristic profiles each associated with an outside air temperature; and analyzing the plurality of charging-characteristic profiles to determine a plurality of charging-control profiles individually associated with a plurality of temperatures of interest, wherein the quick charge map is a set of the plurality of charging-control profiles.

Description

Method and device for generating a rapid charging map

[0001] The present invention relates to a technique for generating a map for controlling rapid charging of a battery.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0073265, filed on June 4, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of battery systems, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] As the demand for high-capacity and high-output batteries increases, technologies for charging batteries as quickly as possible to shorten charging times are being continuously proposed.

[0006] Charging the battery with excessively high current, voltage, or power can cause irreversible damage to the battery due to severe overheating.

[0007] To address these issues, a rapid charge map is required that adaptively adjusts the charge intensity (e.g., current rate) to match the changing state of the battery (e.g., SOC) during charging.

[0008] Existing rapid charging maps are usually created assuming that the battery temperature during charging remains constant at the battery temperature or the ambient temperature at the start of charging.

[0009] However, fully charging a completely discharged battery can take from several tens of minutes to several hours, and the ambient temperature can fluctuate irregularly during charging. Furthermore, even if the battery temperature and ambient temperature are consistent at the start of charging, the battery temperature gradually rises during charging. Consequently, even if the ambient temperature remains constant, a difference between the battery temperature and the ambient temperature inevitably arises during charging. Therefore, using existing rapid charging maps based on ambient temperature makes it difficult to sufficiently ensure the safety of rapid charging for batteries.

[0010] The present invention has been devised to solve the above problems, and provides a method and device for generating a rapid charging map as information usable for charging control based on real-time battery temperature rather than external temperature by analyzing a plurality of charging test result information corresponding to a plurality of charging conditions having different external temperatures.

[0011] Other uses and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the uses and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0012] A method for generating a rapid charging map according to one aspect of the present invention comprises the steps of: obtaining a plurality of charging test results individually associated with a plurality of charging conditions by combinations of a plurality of current rates and a plurality of ambient temperatures; analyzing the plurality of charging test results to determine a plurality of charging characteristic profiles individually associated with the plurality of ambient temperatures; and analyzing the plurality of charging characteristic profiles to determine a plurality of charging control profiles individually associated with a plurality of temperatures of interest, wherein the rapid charging map is a set of the plurality of charging control profiles.

[0013] The lowest outdoor temperature among the plurality of outdoor temperatures may be equal to or higher than the lower limit of a predetermined allowable temperature range. The highest outdoor temperature among the plurality of outdoor temperatures may be equal to or lower than the upper limit of the allowable temperature range. The minimum current rate among the plurality of current rates may be equal to or higher than the lower limit of a predetermined allowable current range. The maximum current rate among the plurality of current rates may be equal to or lower than the upper limit of the allowable current range.

[0014] Each of the plurality of charging test results may indicate a depth of charge and a temperature of the battery when the battery is charged under any one of the plurality of charging conditions. The depth of charge of each of the plurality of charging test results may indicate a maximum SOC of the battery that can be charged without lithium precipitation. The battery temperature of each of the plurality of charging test results may indicate a temperature of the battery at a timing corresponding to the depth of charge.

[0015] The step of determining the plurality of charging characteristic profiles may include the step of grouping the plurality of charging test results according to the plurality of external temperatures to determine a plurality of charging test result sets; and the step of individually applying a mathematical operation to the plurality of charging test result sets to determine the plurality of charging characteristic profiles.

[0016] The above mathematical operation may be a curve fitting based on a polynomial having a predetermined highest degree.

[0017] Each of the plurality of charging characteristic profiles may represent a three-dimensional relationship between the current rate, the depth of charge, and the battery temperature according to any one of the plurality of ambient temperatures.

[0018] The step of determining the plurality of charge control profiles may include the following steps, which are individually executed for the plurality of temperatures of interest: when a predetermined number or more of charge characteristic profiles having a battery temperature range to which the temperature of interest belongs among the plurality of charge characteristic profiles are determined, a step of determining a data set of interest including a predetermined number or more of data points of interest having a battery temperature equal to the temperature of interest from the predetermined number or more of charge characteristic profiles; and a step of applying a mathematical operation to the data set of interest to determine the charge control profile associated with the temperature of interest.

[0019] The above mathematical operation may be a curve fitting based on a polynomial having a predetermined highest degree.

[0020] The step of determining the plurality of charge control profiles may include the following steps, which are individually executed for the plurality of temperatures of interest: applying a mathematical operation to an extended data set of interest including charge test results of each charge characteristic profile having a battery temperature range to which the temperature of interest belongs and charge test results of at least one charge characteristic profile having a battery temperature range to which the temperature of interest does not belong, when the number of charge characteristic profiles having a battery temperature range to which the temperature of interest belongs is less than a predetermined number among the plurality of charge characteristic profiles, thereby determining a surface function of interest; and using the temperature of interest as an input value for the surface function of interest, thereby determining the charge control profile associated with the temperature of interest.

[0021] Each of the plurality of charge control profiles may represent a relationship between a current rate and a charge depth according to one of the plurality of temperatures of interest.

[0022] According to another aspect of the present invention, a rapid charging map generation device comprises: a data input / output unit for obtaining a plurality of charging test results individually associated with a plurality of charging conditions by combinations of a plurality of current rates and a plurality of ambient temperatures; and a processor for analyzing the plurality of charging test results to determine a plurality of charging characteristic profiles individually associated with the plurality of ambient temperatures. The processor analyzes the plurality of charging characteristic profiles to determine a plurality of charging control profiles individually associated with a plurality of temperatures of interest. The rapid charging map is a set of the plurality of charging control profiles.

[0023] The processor may group the plurality of charging test results according to the plurality of external temperatures to determine a plurality of sets of charging test results. The processor may individually apply mathematical operations to the plurality of sets of charging test results to determine the plurality of charging characteristic profiles.

[0024] The processor may individually execute a procedure for each of the plurality of temperatures of interest, including an operation of determining a data set of interest including a predetermined number or more of data points of interest having a battery temperature equal to the temperature of interest from among the plurality of charging characteristic profiles, when a predetermined number or more of charging characteristic profiles having a battery temperature range to which the temperature of interest belongs are present; and an operation of applying a mathematical operation to the data set of interest to determine the charging control profile associated with the temperature of interest. The plurality of charging control profiles may be determined by individually executing the procedure for each of the plurality of temperatures of interest.

[0025] The processor may individually execute a procedure for each of the plurality of temperatures of interest, including: when the number of charging characteristic profiles having a battery temperature range to which the temperature of interest belongs is less than a predetermined number among the plurality of charging characteristic profiles, applying a mathematical operation to an extended data set of interest including charge test results of each charging characteristic profile having a battery temperature range to which the temperature of interest belongs and charge test results of at least one charging characteristic profile having a battery temperature range to which the temperature of interest does not belong, thereby determining a surface function of interest; and using the temperature of interest as an input value for the surface function of interest, thereby determining the charge control profile associated with the temperature of interest, thereby determining the plurality of charge control profiles.

[0026] A charging system according to another aspect of the present invention includes the rapid charging map generating device.

[0027] According to at least one embodiment of the present invention, by analyzing a plurality of charge test result information (see FIG. 21) corresponding to a plurality of charge conditions with different ambient temperatures, a rapid charge map (see FIG. 29) can be generated as information usable for charge control based on real-time battery temperature rather than ambient temperature. By utilizing the rapid charge map generated according to the present invention, charge control that matches the actual temperature of the battery becomes possible, thereby reducing safety issues caused by excessive charge intensity.

[0028] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0030] Figure 1 is a drawing exemplarily showing the configuration of a charging system according to the present invention.

[0031] FIG. 2a and FIG. 2b are flowcharts exemplarily showing a charging test method according to the first embodiment of the present invention.

[0032] Figures 3 to 7 are drawings for reference in explaining the methods of Figures 2a and 2b.

[0033] Fig. 8 is a flowchart exemplarily showing a charging test method according to a second embodiment of the present invention.

[0034] Figures 9 to 13 are graphs showing resistance profiles as examples for reference in explaining the method of Figure 8.

[0035] Figures 14 to 16 are drawings for reference in explaining the relationship between lithium deposition and impedance during charging of a battery.

[0036] Figures 17 and 18 are drawings showing an example of the structure of a test jig for battery charging testing.

[0037] FIG. 19 and FIG. 20 are drawings for reference in explaining the results of a charging test using the test jig illustrated in FIG. 17 and FIG. 18.

[0038] Figure 21 is a three-dimensional graph exemplarily showing the results of multiple charging tests according to multiple charging conditions.

[0039] FIG. 22 is a flowchart for reference in exemplifying a method for generating a rapid charging map according to one embodiment of the present invention.

[0040] FIG. 23 is a flowchart for reference to exemplarily explain an example of subroutines that can be included in step S2320 of FIG. 22.

[0041] Figure 24 is a graph referenced in explaining the method of Figure 23.

[0042] FIG. 25 and FIG. 26 are flowcharts for reference to exemplarily explain an example of subroutines that can be included in step S2230 of FIG. 22.

[0043] Figures 27 to 29 are graphs referenced in explaining the methods of Figures 25 and 26.

[0044] In some of the accompanying drawings, corresponding components are designated by the same reference numerals. Those skilled in the art will appreciate that the drawings illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to facilitate understanding of various embodiments, the dimensions of some elements depicted in the drawings may be exaggerated relative to other elements. Furthermore, elements of known technology that are useful or essential in commercially feasible embodiments may often not be depicted so as not to obscure the spirit of various embodiments of the present invention.

[0045] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0046] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0047] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0048] Throughout the specification, when a part is said to "include" a component, this does not exclude other components, unless otherwise stated, but rather implies the inclusion of other components. Furthermore, terms such as "control unit" described in the specification mean a unit that processes at least one function or operation, and may be implemented using hardware, software, or a combination of hardware and software.

[0049] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0050] Rapid charging using a high-rate charging current for battery charging can significantly reduce the charging time compared to slow charging using a low-rate charging current, but it has the disadvantage of causing significant damage to the battery, shortening its lifespan.

[0051] The higher the charging current, the more likely it is that lithium ions inside the battery will accumulate as lithium metal on the surface of the cathode, which is called "lithium plating." This phenomenon reduces the amount of lithium ions available for charge and discharge reactions by the amount of lithium plating, and worsens the potential imbalance between the positive and negative electrodes. Furthermore, the excessively grown lithium metal can tear the separator, increasing the possibility of an internal short circuit failure. This internal short circuit failure increases the risk of battery explosion and fire.

[0052] In the present invention, a method is proposed to derive a rapid charging protocol capable of avoiding lithium deposition by obtaining battery characteristic information (e.g., SOC-internal resistance relationship) related to the possibility of lithium deposition throughout the entire life of the battery after its manufacture without manufacturing a separate test cell (e.g., a three-electrode monocell) and using the information to obtain the depth of charge of rapid charging.

[0053] For example, in the case of medium- to large-sized pouch cells used in electric vehicles, lithium metal precipitates form on the anode surface with repeated use. The resistance of the lithium metal precipitates is synthesized in parallel with the resistance of the anode surface. Consequently, if lithium metal precipitates form, the total resistance on the anode surface of the pouch cell may decrease. In this case, the impedance of the battery changes, and using the changed impedance graph, such as EIS (Electrochemical Impedance Spectroscopy), the reference frequency can be determined to correspond to the charging conditions at the start of the intermittent charging process. Based on the reference frequency of the intermittent charging process, the appropriate pause period applied during the intermittent charging process can be determined. During the appropriate pause period, for example, voltage changes and resistance changes due to the internal resistance of the battery can be observed, and these can be used to determine the depth of charge of the battery. The theoretical background of lithium precipitation and the surface resistance of the battery, as well as the method for determining the appropriate pause period, are explained in more detail below.

[0054] Figure 1 is a diagram exemplifying the configuration of a charging system according to one embodiment of the present invention. The charging system described below can obtain necessary battery (11) characteristic information, for example, by connecting to a commercial secondary battery through a test jig or directly to the secondary battery without a test jig.

[0055] Referring to FIG. 1, the charging system (1) may be a concept term encompassing not only a test system used for confirming / verifying the electrical characteristics of a battery, but also an electrical system in which a battery is used as a power source, such as an electric vehicle.

[0056] The charging system (1) includes a charger (3), a charging test device (100), and a rapid charging map generation device (200). The charging system (1) may further include at least one of a system controller (Electronic Control Unit, ECU) (2), a switch (20), an inverter (30), and an electric motor (40).

[0057] The charge / discharge terminals (P+, P-) of the battery (11) can be electrically connected to the inverter (30) and / or the charger (3) via a charging cable or the like.

[0058] The system controller (2) is configured to transmit a key-on signal to the charging test device (100) in response to a start button (not shown) provided in the charging system (1) being turned to the ON position by a user. The system controller (2) is configured to transmit a key-off signal to the charging test device (100) in response to a start button being turned to the OFF position by a user. The charger (3) can communicate with the system controller (2) and supply charging power to the battery (11) through the charge / discharge terminals (P+, P-) according to at least one charging protocol (e.g., constant current charging, constant voltage charging, and / or constant power charging).

[0059] The charging test device (100) may also perform the functions of a battery management system (BMS).

[0060] The battery (11) may refer to a single battery cell (BC) or an assembly (12) of two or more battery cells (BC). The type of battery cell (BC) is not particularly limited, as long as it is capable of repeated charging and discharging, such as a lithium ion cell. When the battery (11) includes multiple battery cells (BC), these multiple battery cells may be connected in series, in parallel, or in a mixed series-parallel configuration.

[0061] The battery (11) further includes a case (13). The case (13) defines the overall appearance of the battery (11) and provides an internal space in which a cell group (12) can be arranged. The case (13) is fixed to a battery room provided in the charging system (1) using bolts or the like.

[0062] The switch (20) is electrically connected in series to the battery (11) via a power path connecting the battery (11) and the inverter (30). In Fig. 1, the switch (20) is illustrated as being connected between the positive terminal of the battery (11) and the charge / discharge terminal (P+). The switch (20) is turned on and off in response to a switching signal from the charging test device (100). According to one embodiment of the present invention, the switch (20) may be a mechanical contactor that is turned on and off by the magnetic force of a coil, or a semiconductor switch such as a MOSFET (Metal Oxide Semiconductor Field Effect transistor).

[0063] An inverter (30) is provided to convert direct current from a battery (11) into alternating current in response to a command from a charging test device (100) or a system controller (2).

[0064] An electric motor (40) is an example of an electric load driven by AC power from an inverter (30). For example, a three-phase AC motor can be used as the electric motor (40).

[0065] A charging test device (100) is provided for the purpose of performing a charging test according to a plurality of charging conditions to be described later. The charging test device (100) includes a voltage sensor (111), a current sensor (113), a temperature sensor (115), a control unit (130), and a memory (140). The charging test device (100) may further include a temperature sensor (117). The charging test device (100) may further include a communication circuit (150).

[0066] The voltage sensor (111) is connected in parallel to the battery (11), measures the battery voltage, which is the voltage across both terminals of the battery (11), and is configured to generate a voltage signal representing the measured battery voltage.

[0067] The current sensor (113) is connected in series to the battery (11) via a current path between the battery (11) and the inverter (30). The current sensor (113) is configured to measure the battery current, which is the current flowing through the battery (11), and generate a current signal representing the measured battery current. The current sensor (113) may be implemented as one or a combination of two or more of known current measuring elements, such as a shunt resistor, a Hall effect element, etc.

[0068] The temperature sensor (115) is configured to measure the temperature of the battery (11) and generate a temperature signal representing the measured battery temperature. The temperature sensor (115) may be attached to the surface of the battery (11) so as to measure a temperature close to the actual temperature of the battery (11). For reference, the term "temperature measurement value" simply described herein may refer to a battery temperature measurement value.

[0069] The temperature sensor (117) is configured to measure the outside temperature (ambient temperature), which is the temperature at a predetermined location away from the battery (11) where heat exchange between the battery (11) and the outside air takes place, and to generate a temperature signal representing the measured outside temperature.

[0070] A set of one or more of a voltage sensor (111), a current sensor (113), a temperature sensor (115), and a temperature sensor (117) may be referred to as a 'sensing unit'.

[0071] Each of the temperature sensors (115, 117) may be implemented as a combination of one or two or more temperature measuring elements, such as a thermocouple, a thermistor, a bimetal, etc.

[0072] The communication circuit (150) is configured to support wired or wireless communication between the control unit (130) and the system controller (2). The wired communication may be, for example, CAN (controller area network) communication, and the wireless communication may be, for example, Zigbee or Bluetooth communication. Of course, as long as it supports wired or wireless communication between the control unit (130) and the system controller (2), the type of communication protocol is not particularly limited. The communication circuit (150) may include an output device (e.g., a display, a speaker) that provides information received from the control unit (130) and / or the system controller (2) in a form recognizable to the user.

[0073] The control unit (130) is operably coupled to a switch (20), a voltage sensor (111), a current sensor (113), a temperature sensor (115), a temperature sensor (117), and a communication circuit (150). The fact that the two components are operably coupled means that the two components are directly or indirectly connected so as to be able to transmit and receive signals in one direction or both directions.

[0074] The control unit (130) can collect a voltage signal from a voltage sensor (111), a current signal from a current sensor (113), a temperature signal from a temperature sensor (115) (which may be referred to as a 'battery temperature signal'), and / or a temperature signal from a temperature sensor (117) (which may be referred to as an 'outside temperature signal'). The control unit (130) can convert and record each analog signal collected from the sensors (111, 113, 115, 117) into a digital value using an ADC (Analog to Digital Converter) provided therein.

[0075] The control unit (130) may be referred to as a 'control circuit' or a 'battery controller', and may be implemented in hardware using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), microprocessors, and other electrical units for performing functions.

[0076] The memory (140) may include at least one type of storage medium among, for example, a flash memory type, a hard disk type, an SSD (Solid State Disk type), an SDD (Silicon Disk Drive type), a multimedia card micro type, a RAM (random access memory), a SRAM (static random access memory), a ROM (read-only memory), an EEPROM (electrically erasable programmable read-only memory), and a PROM (programmable read-only memory). The memory (140) may store data and a program required for an operation by the control unit (130). The memory (140) may store data representing a result of an operation by the control unit (130). In FIG. 1, the memory (140) is illustrated as being physically independent from the control unit (130), but may also be built into the control unit (130).

[0077] The control unit (130) can turn on the switch (20) in response to a key-on signal. The control unit (130) can turn off the switch (20) in response to a key-off signal. The key-off signal is a signal that induces a transition from a cycle state, which refers to a state in which the battery (11) is being charged and discharged, to a rest state, which refers to a state in which the charging and discharging of the battery (11) is stopped. Alternatively, the on / off control of the switch (20) may be performed by the system controller (2) instead of the control unit (130).

[0078] When the inverter (30) or the charger (3) is operating while the switch (20) is turned on, the battery (11) enters a cycle state. Conversely, when the switch (20) is turned off or the operation of the inverter (30) and the charger (3) is stopped, the battery (11) enters a rest state.

[0079] The control unit (130) determines a voltage measurement value, a current measurement value, a battery temperature measurement value, and an outside temperature measurement value based on a voltage signal, a current signal, a battery temperature signal, and an outside temperature signal while the battery (11) is in a cycle state and / or an idle state, and then determines (estimates) a state of charge (SOC: State Of Charge) of the battery (11) based on the voltage measurement value, the current measurement value, and / or the battery temperature measurement value.

[0080] If the charger (3) is operating in a constant current charging mode, the current rate (which may be referred to as 'C-rate') of the charging current supplied to the battery (11) is a predetermined constant value, so that in estimating the SOC of the battery (11), the current value of the constant current output from the charger (3) can be used instead of the current measurement value obtained using the current sensor (113).

[0081] SOC is the ratio of the remaining capacity to the full charge capacity (maximum capacity) of the battery (11), and is usually processed in the range of 0 to 1 or 0 to 100%. For example, methods such as ampere counting, OCV (Open Circuit Voltage)-SOC curve, and / or Kalman filter can be utilized to determine SOC.

[0082] The charging system (1) may further include an EIS device (4). The EIS device (4) is provided to apply an AC signal to the battery (11) and measure the response characteristics of the battery (11) to the applied AC signal. Although the EIS device (4) is illustrated in FIG. 1 as being connected in parallel to the battery (11), the present invention is not limited thereto. For example, the EIS device (4) may be selectively connected to the battery (11) by a separate switching circuit.

[0083] The above-described charging system is connected to a commercial secondary battery, for example, a medium-to-large pouch cell used in an electric vehicle, through a test jig, etc., and an 'intermittent charging process' is performed by applying the appropriate rest period described above, and the process of acquiring characteristic information of the battery (11) in the rest mode of the intermittent charging process is described.

[0084] FIGS. 2A and 2B are flowcharts exemplarily showing a charging test method according to a first embodiment of the present invention, and FIGS. 3 to 7 are drawings referenced for explaining the method of FIGS. 2A and 2B.

[0085] The method of FIG. 2A can be executed by the charging test device (100) illustrated in FIG. 1, provided that the battery temperature of the battery (11) matches the ambient temperature according to the charging conditions. The set of steps S210 to S250 included in FIG. 2A can be collectively referred to as a control step of the 'intermittent charging process'. The method of FIG. 2A can be repeatedly performed until the SOC of the battery (11) reaches a predetermined lower limit SOC (which may be referred to as a 'charging start SOC') to a predetermined upper limit SOC (which may be referred to as a 'charging end SOC').

[0086] Each of the lower limit SOC and the upper limit SOC can be set according to the size of the charging current (i.e., current rate) used in the charging mode of the method of FIG. 2a and the ambient temperature at the start time of the method of FIG. 2a.

[0087] For example, the lower limit SOC and the upper limit SOC may be set to 88% and 97% when the current rate and the ambient temperature are 0.5C and 25°C, 68% and 77% when the current rate and the ambient temperature are 2C and 25°C, and 63% and 72% when the current rate and the ambient temperature are 2C and 10°C. The relationship data of the lower limit SOC and the upper limit SOC for the charging conditions defined by the current rate and the ambient temperature may be pre-recorded in the memory (140) in the form of a lookup table and / or a function.

[0088] Referring to FIGS. 1, 2A, and 2B, in step S210, the control unit (130) controls the charger (3) to a charging mode that supplies a charging current to the battery (11). For example, the control unit (130) transmits a charging request signal to the charger (3) through the communication circuit (150), and the charger (3) operates in the charging mode in response to the charging request signal, and supplies a charging current having a current rate requested by the charging request signal to the battery (11). Here, the charging mode may be, for example, a constant current charging mode that charges the battery (11) with a charging current of a predetermined current rate.

[0089] In step S220, the control unit (130) determines whether a first transition condition for transitioning from the charging mode to the idle mode is satisfied. The first transition condition may be a time-based condition or a SOC-based condition. For example, the first transition condition may be determined to be satisfied in response to the duration of the charging mode (e.g., the elapsed time from the start time of the charging mode) reaching a first reference time. In another example, the first transition condition may be determined to be satisfied in response to the SOC increase amount of the battery (11) due to the charging mode (i.e., the difference between the SOC at the start time of the current charging mode and the current SOC) reaching a reference increase amount (e.g., 0.5%). If the value of step S220 is “No,” step S220 may be repeatedly re-performed. If the value of step S220 is “Yes,” that is, if it is determined in S220 that the first transition condition is satisfied, the process proceeds to step S230.

[0090] In step S230, the control unit (130) controls the charger (3) to idle mode. Accordingly, the intermittent charging process switches from the charging mode to the idle mode. For example, when the control unit (130) transmits a charging stop signal to the charger (3) via the communication circuit (150), the charger (3) enters the idle mode in response to the charging stop signal. In the idle mode, the supply of charging current from the charger (3) to the battery (11) is cut off. The control unit (130) can record the SOC of the battery (11) at the time of switching from the charging mode to the idle mode in the memory (140).

[0091] In step S240, the control unit (130) determines whether a second switching condition for switching from the idle mode to the charging mode is satisfied. The second switching condition may be a time-based condition. For example, the second switching condition may be determined to be satisfied in response to the duration of the idle mode (i.e., the elapsed time from the start time of the idle mode) reaching a second reference time. The second reference time may be a predetermined fixed time or a variable period adjusted by the control unit (130) based on electrochemical characteristic data of the battery (11). The adjustment of the second reference time will be described separately with reference to FIG. 14. If the value of step S240 is “No,” that is, if the duration of the idle mode has not reached the second reference time, step S240 may be repeatedly re-performed. If the value of step S240 is “Yes,” that is, if the duration of the idle mode has reached the second reference time, the process may proceed to step S250.

[0092] In step S250, the control unit (130) determines whether the SOC of the battery (11) has reached the charge termination SOC. If the value of step S250 is "NO", the process may return to step S210. For example, the intermittent charging process may switch from idle mode to charging mode, and repeat the charging mode and idle mode until the SOC of the battery (11) reaches the charge termination SOC. On the other hand, if the value of step S250 is "YES", for example, if the SOC of the battery (11) has reached the charge termination SOC, the method according to FIG. 2A may be terminated.

[0093] As described above, by repeating the charging mode and the rest mode through the steps according to Fig. 2(a), a voltage (V) graph according to time (minutes) as shown in Fig. 3 can be obtained. The part shown as a cross-hatched pattern in Fig. 3 is a schematic representation of the rest period of the intermittent charging process as exemplified in Fig. 4.

[0094] The method of Fig. 2b can be executed under the condition that the judgment value in step S240 of Fig. 2a is "yes." For example, the method of Fig. 2b can execute step S260 described below before proceeding to step S250 if the second transition condition is satisfied in step S240.

[0095] In step S260, the control unit (130) calculates the internal resistance of the battery (11) based on the voltage change amount of the battery (11) in the resting state. In step S270, the control unit (130) records the internal resistance calculated in step S260 in relation to the SOC of the battery (11).

[0096] During execution of the method according to FIGS. 2a and 2b, the battery temperature of the battery (11) can be measured periodically or aperiodically, and the history data of the measured battery temperature can be recorded in the memory (140) by the control unit (130).

[0097] The method according to FIGS. 2a and 2b can be individually executed for multiple charging conditions.

[0098] Fig. 3 is a graph exemplarily showing the history of changes in battery voltage during a charging test period in which an intermittent charging process is executed. As can be seen from Fig. 3, the voltage of the battery (11) generally shows an upward trend throughout the charging test period, and as indicated by the cross-hatched patterns in the graph, a voltage increase section while the charger (3) is operating in charging mode and a voltage decrease section while the charger (3) is operating in idle mode are alternately repeated.

[0099] Figure 4 shows the voltage drop section (S) in the idle mode, which is the dotted box area marked in Figure 3. drop ) is an enlarged graph. In Fig. 4, t r1The time at which the charger (3) is requested to switch from charging mode to idle mode (or the time at which a switching event from charging mode to idle mode occurs), t r2 Δt is the time at which the charger (3) is requested to switch from idle mode to charge mode or the time at which a switch event from idle mode to charge mode occurs. rest is the duration in idle mode (the length of the idle period), V r1 Silver t r1 Battery voltage at, V r2 Silver t r2 Battery voltage at, ΔV rest Each indicates the amount of voltage change in the rest mode. That is, V r1 V is the battery voltage measured just before switching from charge mode to idle mode. r2 Each represents the battery voltage measured immediately before switching from idle mode to charge mode. Δt rest = t r2 - t r1 and ΔV rest = V r1 - V r2 am.

[0100] The control unit (130) can calculate (estimate) the internal resistance for each rest period using the following equation 1.

[0101] <Formula 1>

[0102]

[0103] In the above equation 1, I CC is the charging current (e.g., constant current at a given current rate), R CT represent the internal resistance respectively.

[0104] In step S270, the control unit (130) associates the internal resistance obtained in step S260 with the SOC of the battery (11) and records it in the memory (140). The SOC associated with the internal resistance may be the SOC of the battery (11) at the time of transition from the charging mode to the idle mode (i.e., the execution time of step S230).

[0105] As shown in FIG. 3, the idle mode is performed multiple times (i.e., multiple idle periods are sequentially granted during the charging test period) during charging in the SOC range of interest (i.e., from the lower limit SOC to the upper limit SOC), and the estimated value of the internal resistance in the idle period occurring each time the idle mode is performed can be sequentially recorded in the memory (140) in chronological order.

[0106] Accordingly, when the SOC of the battery (11) reaches the upper limit SOC, a resistance time series data set (which may be referred to as an 'internal resistance map') representing the temporal change history of the internal resistance may be recorded in the memory (140). Each data point of the resistance time series data set may represent a relationship pair between the internal resistance and the SOC determined at a specific rest period within the charging test period.

[0107] FIGS. 5 to 7 are graphs (500, 600, 700) that exemplarily show three typical patterns of resistance time series data sets obtained by repeating the intermittent charging process using three different charging conditions individually. For example, the charge transfer resistance (Charge Transfer Resistance) pattern obtained from the evaluation of the present invention can be classified into the three cases of FIGS. 5, 6, and 7 described below, and each drawing is an example of the evaluation conditions and environment. However, it is not necessary to measure under the corresponding conditions, and intermittent charging may be performed under conditions other than the conditions exemplified below for evaluation. In the description below, a more accurate charge depth can be confirmed when the charge depth decreases in the order of FIGS. 5, 6, and 7 (charge transfer resistance inferiority of the battery).

[0108] Figure 5 illustrates a resistance time series data set (500) acquired by executing an intermittent charging process under a first charging condition where the current rate of the charging current is 0.5 C and the battery temperature (e.g., the temperature measured at the initial start of the intermittent charging process) is 25° C. ΔSOC int1 is the SOC range of interest (e.g., 88-97%) in the resistance pattern associated with the first charge condition.

[0109] Figure 6 illustrates a resistance time series data set (600) acquired by executing an intermittent charging process under a second charging condition where the current rate of the charging current is 2C and the battery temperature (e.g., the temperature measured at the initial start of the intermittent charging process) is 25°C. ΔSOC int2 is the SOC range of interest (e.g., 68-77%) in the resistance pattern associated with the second charging condition.

[0110] Figure 7 illustrates a resistance time series data set (700) acquired by executing an intermittent charging process under a third charging condition where the current rate of the charging current is 2C and the battery temperature (e.g., the temperature measured at the initial start of the intermittent charging process) is 10°C. ΔSOC int3 is the SOC range of interest (e.g., 63-72%) in the resistance pattern associated with the third charging condition.

[0111] The upper limit of each SOC range of interest may be referred to as the charge limit SOC.

[0112] Comparing FIGS. 5 and 6, the first and second charging conditions have the same battery temperature, but the first charging condition has a lower current rate than the second charging condition. Therefore, since the first charging condition is less harsh on the battery (11) than the second charging condition, the upper limit SOC (97%) associated with the first charging condition is set higher than the upper limit SOC (77%) associated with the second charging condition.

[0113] Comparing FIGS. 6 and 7, the second and third charging conditions have the same current rate, but the third charging condition is at a lower temperature than the second charging condition, and the electrochemical reaction of the battery (11) may be relatively slower in the second charging condition than in the third charging condition. Therefore, the upper limit SOC (72%) associated with the third charging condition is illustrated as being lower than the upper limit SOC (77%) associated with the second charging condition.

[0114] In FIGS. 5 to 7, the change history of the internal resistance (reflecting the charge transfer resistance) in a wider range than the SOC range of interest corresponding to each charging condition is shown, but this is only for the purpose of helping understanding, and in reality, it is acceptable to acquire only the change history of the internal resistance limited to the SOC range of interest corresponding to each charging condition.

[0115] Fig. 8 is a flowchart exemplarily showing a charging test method according to a second embodiment of the present invention, and Figs. 9 to 13 are graphs exemplarily showing resistance profiles referenced in explaining the method of Fig. 8. The method of Fig. 8 can be executed after a resistance time series data set for a charging test period is acquired by the charging test method according to the first embodiment described above with reference to Figs. 2a and 2b.

[0116] Referring to FIG. 8, in step S810, the control unit (130) curve-fits a resistance time series data set to generate a resistance profile (which may also be referred to as an 'internal resistance profile') representing the relationship between the SOC and the internal resistance of the battery (11). Curve fitting may refer to a procedure or logic that approximates an input data set with a polynomial having a predetermined degree. In other words, the resistance profile may be a type of function whose input is SOC and whose output is internal resistance.

[0117] Figures 9 to 11 illustrate three resistance profiles (900, 1000, 1100) obtained by individually curve-fitting the three resistance time series data sets (500, 600, 700) described above with reference to Figures 5 to 7, respectively, with a 9th-order polynomial. To aid understanding, the three resistance profiles (900, 1000, 1100) are represented as three SOC ranges of interest (ΔSOC int1 , ΔSOC int2 , ΔSOC int3 ) is shown for the range from 50% of the lower limit SOC to the upper limit SOC.

[0118] In step S820, the control unit (130) determines the depth of charge of the battery (11) based on the pattern of the resistance profile. The depth of charge represents the maximum state of charge (SOC) that can be charged without lithium deposition (which may be within the SOC range of interest). Data points as a pair of the depth of charge determined in step S820 and the corresponding battery temperature may be recorded in the memory (140) as a charge test result.

[0119] First, we describe the operation of identifying the depth of charge from the resistance profile (900) shown in Fig. 9 obtained by curve fitting the time series data set of Fig. 5. Referring to Fig. 9, the SOC range of interest (ΔSOC int1 ), the internal resistance is continuously increasing without a decreasing section. As in Fig. 9, when a continuous increasing pattern of internal resistance is identified according to an increase in SOC, the control unit (130) determines the end point (P) on the resistance profile (900). A ) in SOC(Z A ) is the depth of charge (Z) A ) can be determined. That is, in the case of a pattern shape such as Fig. 9, the filling depth (Z A ) is the SOC range of interest (ΔSOC int1 ) can be determined to be the same as the upper limit SOC. An increasing pattern of a certain profile (or curve) may mean that the first derivative of that profile is positive.

[0120] Next, we describe the operation of identifying the depth of charge from the resistance profile (1000) shown in Fig. 10 obtained by curve fitting the time series data set of Fig. 6. Referring to Fig. 10, the SOC range of interest (ΔSOC int2) is different from the resistance profile (900) illustrated in Fig. 9 in that the rate of increase in the internal resistance gradually becomes gentle in the early part and then gradually decreases starting from a specific SOC. As in Fig. 10, when the increase section and the decrease section of the internal resistance are adjacent, the control unit (130) can obtain a differential resistance profile by first differentiating the resistance profile (1000) with respect to the SOC. For example, the differential resistance profile (1200) in Fig. 12 is illustrated as a result of first differentiation of the resistance profile (1000) in Fig. 10. The control unit (130) obtains a differential resistance value (dR) from the differential resistance profile (1200). CT / dSOC) is the boundary point where the value changes from positive to negative as the SOC increases, that is, the differential resistance value (dR CT / dSOC) is a feature point (P) that becomes 0 B ) is the same as the SOC in the depth of charge (Z B ) can be determined. The depth of charge (Z) determined from the differential resistance profile (1200) of Fig. 12 B ) can be determined to be equal to the SOC at the boundary point between the increasing pattern and the decreasing pattern of the internal resistance in the resistance profile (1000) of FIG. 10. Note that a decreasing pattern of a certain profile (or curve) may mean that the first derivative of the profile is negative.

[0121] Next, we describe the operation of identifying the depth of charge from the resistance profile (1100) shown in Fig. 11 obtained by curve fitting the time series data set of Fig. 7. Referring to Fig. 11, the SOC range of interest (ΔSOC int3) is different from the resistance profile (900) of FIG. 9 and the resistance profile (1000) of FIG. 10 in that the internal resistance continuously decreases without an increasing section. As in FIG. 11, when the internal resistance only shows a decreasing pattern in the SOC range of interest, the control unit (130) can obtain a differential resistance profile (1300) as illustrated in FIG. 13 by second differentiating the resistance profile (1100) with respect to the SOC. For reference, the differential resistance profile (1300) is distinguished from the differential resistance profile (1200), which is a first differentiation result with respect to the resistance profile (1000), in that it is a second differentiation result with respect to the resistance profile (1100).

[0122] The control unit (130) determines the second differential resistance value (d) in the differential resistance profile (1300). 2 R CT / dSOC 2 ) is the point where the value changes from positive to negative as the SOC increases, i.e. the second derivative resistance value (d 2 R CT / dSOC 2 ) is a feature point (P) that becomes 0 C ) is the same as the SOC in the depth of charge (Z C ) can be determined. Feature points (P C ) may be the point where the absolute value of the resistance change rate is the largest in the resistance profile (1100).

[0123] The depth of charge (Z) shown in Figs. 9 to 13 A , Z B , Z C ) represents the SOC at which the battery (11) can be charged without lithium deposition during constant current charging at a current rate (e.g., 2C) associated with each of them. For example, if charging under the same charging conditions continues even though the SOC of the battery (11) has reached the depth of charge, lithium deposition may occur on the negative electrode surface of the battery (11).

[0124] In step S830, the control unit (130) may record a charging test result indicating the charging depth determined in step S820 and the battery temperature (cell temperature) at a timing corresponding to the charging depth in the memory (140). The charging test result may be a two-dimensional data point defined by the charging depth and the battery temperature.

[0125] The control unit (130) can record the determined charge depth and battery temperature for specific charging conditions (e.g., current rate and ambient temperature of 0.5 C and 25 C, respectively) in the memory (140) as a charge test result for the specific charging conditions.

[0126] The methods of FIGS. 2A, 2B, and 8 may be performed each time for each charging event according to a plurality of charging conditions, and thus, a plurality of charging test results individually associated with the plurality of charging conditions may be obtained. The rapid charging map generation device (200) described below may generate a rapid charging map for a battery cell (BC) or another battery cell manufactured to have electrochemical characteristics of the same specification, based on the plurality of charging test results.

[0127] After the creation of the rapid charging map is completed, the control unit (130) determines the charging depth (e.g., Z) according to the battery temperature (cell temperature) and current rate of the battery cell (BC) being charged. A ) is identified from the rapid charge map, and the SOC of the battery is determined based on the identified charge depth (e.g., Z A ) or more, the charging of the battery (11) can be stopped. For example, when the SOC of the battery reaches the identified charging depth, the control unit (130) can control the switch (20) to the off state or transmit a charging stop request to the charger (3).

[0128] The methods of FIG. 2a, FIG. 2b and FIG. 8 can be performed under the condition that a predetermined diagnosis-requiring event occurs, such as the SOH (State Of Health) of the battery decreasing by a predetermined value or more from the previous SOH.

[0129] Figures 14 to 16 are drawings for reference in explaining the relationship between lithium deposition and impedance during charging of a battery.

[0130] First, Fig. 14 is a schematic diagram illustrating the formation of lithium metal deposits on the negative electrode of a battery (11). Referring to Fig. 14, during charging under any charging condition, lithium ions may be deposited as lithium metal on the negative electrode surface of the battery (11). When lithium metal deposits are formed, lithium intercalation and lithium deposits proceed simultaneously on the negative electrode surface of the battery (11), and accordingly, the path of the charging current may be expanded compared to when there is no lithium metal deposit.

[0131] Fig. 15 is a graph used as an example to explain the change in impedance of a battery (11) depending on the presence or absence of lithium deposition in the battery (11). Each of the two complex impedance curves (1510, 1520) illustrated in Fig. 15 can be obtained by repeatedly measuring the impedance of each battery when an AC signal is applied to a battery without lithium deposition and a battery with lithium deposition using EIS equipment (4) under identical environmental conditions. For example, Fig. 15 may be a Nyquist plot showing the change in impedance of a battery depending on the frequency change of the AC signal. The process of obtaining multiple impedance curves of the battery (11) is performed once before the intermittent charging process for the battery (11) is initiated, and since the AC signal by the EIS equipment (4) is applied to the battery for only a short time, it causes little damage to the battery.

[0132] In one embodiment, the complex impedance curve (1510) may be obtained for a battery before lithium deposition occurs, and the complex impedance curve (1520) may be obtained for a battery after lithium deposition occurs.

[0133] R S It represents the electrolyte resistance of the battery and is hardly affected by the presence or absence of lithium deposition. R p_i and R p_f R represents the interfacial resistance of the battery when lithium deposition does not occur and when lithium deposition occurs, respectively. A and R B represents the internal resistance of the battery when lithium deposition does not occur and when lithium deposition occurs, respectively, and R A = R S + R p_i and R B = R S + R p_f .

[0134] Interfacial resistance is the total resistance due to the solid electrolyte interphase (SEI), charge transfer, and double layer, and is greatly affected by charge accumulation on the positive and negative electrode surfaces of the battery.

[0135] As described above with reference to Fig. 14, the resistance of lithium metal precipitates on the negative electrode surface is synthesized in parallel with the resistance on the negative electrode surface, so that as a result, when lithium metal precipitates are generated, the total resistance on the negative electrode surface of the battery can be reduced. Therefore, as can be confirmed through Fig. 15, R p_f is R p_i is smaller than the resistance difference between the two (ΔR p ) can be said to have a positive correlation with the amount of lithium metal precipitates generated.

[0136] Meanwhile, the control unit (130) can determine the reference frequency from the complex impedance curve (1510). For example, the complex impedance curve (1510) can be divided into a convex section and a slope section. Here, the convex section is the interface resistance (R p_i ) may be a section related to the diffusion resistance (R) of the battery. The inclined section is a straight section extending to the right of the convex section. diff ) is shown. The boundary point (R) of the convex section and the inclined section A The frequency of the AC signal applied in the reference can be determined as the reference frequency.

[0137] The inventors of the present invention have recognized that during the intermittent charging process, the SOC of the battery (11) gradually increases, and that there is a characteristic in which the frequency at the boundary point between the convex section and the slope section gradually increases as the SOC increases. If the reference frequency is determined to correspond to the charging conditions at the start of the intermittent charging process, the pause provided during the intermittent charging process can last for an appropriate time required to observe the voltage change due to the internal resistance of the battery (11). Therefore, it is possible to prevent a decrease in the accuracy of the internal resistance due to the pause time being set too short or too long.

[0138] The control unit (130) can determine a second reference time representing the duration of the idle mode based on the reference frequency. The reference frequency and the second reference time may have a predetermined negative correspondence. Relationship data that can be expressed by the following equation 2 can be used to determine the second reference time.

[0139] <Formula 2>

[0140]

[0141] In the above equation 2, f i-d is the reference frequency, w is a given margin constant (can be greater than or equal to 1), Δt R2represent the second reference time respectively. Therefore, the second reference time is the reference frequency (f i-d ) may be set to be equal to or greater than the value obtained by multiplying the margin constant (w) by the reciprocal of the second reference time. The second reference time may be the duration of each rest period required to observe the voltage change due to the internal resistance of the battery (11).

[0142] The memory (140) may have a reference frequency for each charging condition and lower limit SOC recorded in advance. The control unit (130) may acquire the reference frequency associated with the charging condition of the intermittent charging process to be performed on the battery (11) and the lower limit SOC of the SOC range of interest from the memory (140) and determine the second reference time.

[0143] The memory (140) may store relationship data between SOC, battery temperature, and reference frequency. The relationship data between SOC, battery temperature, and reference frequency may be replaced with relationship data between SOC, battery temperature, and a second reference time.

[0144] Figure 16 is a graph used as a reference to explain the relationship between battery temperature and reference frequency when the SOC of the battery (11) is set to a specific value (e.g., lower limit SOC 10%).

[0145] Referring to Fig. 16, when other factors of the charging condition (e.g., current rate, upper limit SOC) are assumed to be the same, the higher the battery temperature of the charging condition, the higher the associated reference frequency may be. In other words, the battery temperature and the reference frequency may have a positive correlation.

[0146] Referring to the aforementioned Equation 2, since the reference frequency and the second reference time are inversely proportional, the higher the battery temperature of the battery (11) at the time when control of the intermittent charging process is initiated, the shorter the duration of the idle mode (i.e., the second reference time) can be set.

[0147] In FIG. 1, the charging test device (100) is exemplified as being included as a sub-component of the charging system, but is not limited thereto. For example, the charging test device (100) may also be utilized as a sub-component of a charging performance test device for deriving a charging depth according to the charging conditions of the battery (11). In this case, the charging performance test device may include the charging test device (100) and the charger (3).

[0148] Figures 17 and 18 are drawings showing an example of the structure of a test jig for battery charging testing.

[0149] Referring to FIGS. 17 and 18, a test jig (1700) includes a first plate (1711), a second plate (1712), and a connecting member (1730). The connecting member (1730) includes at least one bolt (1731) and a nut (1732). The charging test device (100) used as a charging test device can perform the intermittent charging process described above to derive a rapid charging protocol of a battery (11) connected to the test jig (1700). At this time, another charger (3) having a function corresponding to the charger (3) can be separately provided for supplying charging current.

[0150] A first plate (1711) and a second plate (1712) are arranged on both sides (e.g., upper and lower) of a battery (11). At least one coupling hole is formed in each of the first plate (1711) and the second plate (1712). The thread of a bolt (1731) passes through the coupling hole formed in each of the second plate (1712) and the first plate (1711), and a nut (1732) is rotatably coupled to the end of the thread of the bolt (1731). FIG. 17 illustrates an example in which six bolts and six nuts are coupled one-to-one. Accordingly, the battery (11) can be firmly fixed between the first plate (1711) and the second plate (1712).

[0151] The test jig (1700) may further include at least one foam pad (1751, 1752). The foam pad (1751, 1752) may be provided for the purpose of insulation to prevent heat generated from the battery (11) during charging from being released to the outside. For example, when the foam pad (1751) is inserted between the first plate (1711) and the battery (11), and the foam pad (1752) is inserted between the second plate (1712) and the battery (11), the first plate (1711) and the second plate (1712) are pressed from both sides by the joining member (1730), thereby completing the fastening between the test jig (1700) and the battery (11). Of course, only one of the two foam pads (1751, 1752) may be inserted between the first plate (1711) or the second plate (1712) and the battery (11), or neither of the two foam pads (1751, 1752) may be inserted. When only one of the two foam pads (1751, 1752) is inserted, heat dissipation from the battery (11) to the outside is more smoothly performed than when both foam pads (1751, 1752) are inserted. In addition, when neither of the two foam pads (1751, 1752) is inserted, heat dissipation from the battery (11) to the outside is maximized than when only one of the two foam pads (1751, 1752) is inserted. That is, by varying the insertion conditions of the two foam pads (1751, 1752) to diversify the heat generation environment during charging of the battery (11), the charging depth can be derived according to the heat generation environment.

[0152] FIG. 19 and FIG. 20 are drawings for reference in explaining the results of a charging test using the test jig illustrated in FIG. 17 and FIG. 18.

[0153] First, referring to FIG. 19, three temperature curves (1911, 1912, 1913) are graphs showing changes in the surface temperature of the test jig (1700) with respect to the SOC when the battery (11) is charged from 0% to 100% SOC at three current rates of 2.25C, 2.5C, and 2.75C while the battery (11) is fastened to the test jig (1700) with neither foam pad (1751, 1752) inserted. The surface temperature of the test jig (1700) can be measured using a temperature sensor inserted into the test jig (1700) or positioned within a predetermined distance from the test jig (1700).

[0154] The remaining three temperature curves (1921, 1922, 1923) are graphs showing the change in battery temperature with respect to SOC when the battery (11) is charged from 0% to 100% SOC at three current rates of 2.25C, 2.5C, and 2.75C while the battery (11) is fastened to a test jig (1700) with both foam pads (1751, 1752) inserted.

[0155] Comparing the temperature curves (1911, 1912, 1913) and the temperature curves (1921, 1922, 1923), it can be seen that there is a difference in the heat generation environment during charging of the battery (11) depending on whether the foam pad (1751, 1752) is inserted, and as a result, a temperature difference of approximately 5℃ occurs in the later stages of charging.

[0156] Next, referring to FIG. 20, each of the two SOC curves (2010, 2020) is a graph showing the change in the depth of charge obtained through a charging test using a number of current rates selected from the range of 0.5 C to 2.75 C one at a time while the battery (11) is fastened to the test jig (1700).

[0157] The SOC curve (2010) shows the change in the depth of charge according to the current rate when the battery (11) is fastened to a test jig (1700) in which neither foam pad (1751, 1752) is inserted.

[0158] The SOC curve (2020) shows the change in the depth of charge according to the current rate when the battery (11) is fastened to a test jig (1700) with both foam pads (1751, 1752) inserted.

[0159] Comparing the two SOC curves (2010, 2020), when the foam pads (1751, 1752) are inserted, the heat generated during charging of the battery (11) placed inside the test jig (1700) is insulated by the two foam pads (1751, 1752), so that the battery (11) is charged at a higher temperature than when the foam pads (1751, 1752) are not inserted. Due to the insulating effect when the foam pads (1751, 1752) are inserted, the surface temperature increase of the test jig (1700) is confirmed to be approximately 5℃ lower than when the foam pads (1751, 1752) are not inserted, while the depth of charge is confirmed to be higher.

[0160] On the other hand, when neither foam pad (1751, 1752) is inserted, the heat generated during charging of the battery (11) is quickly released to the outside by being thermally conducted to the first plate (1711) and the second plate (1712), so that the surface temperature of the test jig (1700) is observed to be relatively higher than when the foam pads (1751, 1752) are inserted. Accordingly, the temperature rise due to the heat generation of the battery (11) is resolved compared to when the foam pads (1751, 1752) are inserted, and the depth of charge is reduced.

[0161] When the charging test procedure described above with reference to FIGS. 1 to 20 is repeated for multiple charging conditions (which may also be referred to as 'charge test conditions'), multiple charging test results individually associated with the multiple charging conditions can be obtained.

[0162] The rapid charging map generation device (200) can generate a rapid charging map based on multiple charging test results through collaboration with the charging test device (100). The rapid charging map generation device (200) includes a data input / output unit (210) and a processor (220), as illustrated in FIG. 1.

[0163] The data input / output unit (210) includes at least one of a wired communication interface and a wireless communication interface that can be operably coupled to the charging test device (100).

[0164] The processor (220) may be implemented in hardware using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), microprocessors, and other electrical units for performing functions.

[0165] The built-in memory of the processor (220) may include at least one type of storage medium among, for example, a flash memory type, a hard disk type, an SSD (Solid State Disk type), an SDD (Silicon Disk Drive type), a multimedia card micro type, a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), and a programmable read-only memory (PROM). The memory may store data and a program required for an operation by the processor (220). The memory may store data indicating a result of an operation by the processor (220).

[0166] Meanwhile, the method for obtaining multiple charging test results used to generate the rapid charging map described below is not limited to the method described above with reference to FIGS. 1 to 20. That is, any method capable of providing information on the depth of charge and battery temperature for each charging condition can be utilized to obtain charging test results for generating the rapid charging map.

[0167] Figure 21 is a three-dimensional graph exemplarily showing the results of multiple charging tests according to multiple charging conditions.

[0168] Referring to FIG. 21, a total of 42 data points (charge test results) are identified, which individually correspond to a total of 42 charging conditions by combinations of a total of 6 current rates (which can be sequentially assigned signs of C1 to C6) spaced at 0.5C intervals in the range of 0.5C to 3.0C and a total of 7 ambient temperatures (which can be sequentially assigned signs of T1 to T7) spaced at 5°C intervals in the range of 15°C to 45°C.

[0169] The maximum current rate of the plurality of charging conditions may be less than or equal to the upper limit of a given allowable current range, and the minimum current rate of the plurality of charging conditions may be greater than or equal to the lower limit of the allowable current range.

[0170] The highest ambient temperature of the plurality of charging conditions may be lower than or equal to the upper limit of a predetermined allowable temperature range, and the lowest ambient temperature of the plurality of charging conditions may be higher than or equal to the lower limit of the allowable temperature range.

[0171] A data point associated with a certain charging condition may represent a pair of charge depth and battery temperature (cell temperature) according to that charging condition.

[0172] FIG. 22 is a flowchart for reference in exemplifying a method for generating a rapid charging map according to one embodiment of the present invention.

[0173] Referring to FIG. 22, in step S2210, the data input / output unit (210) obtains, from the charging test device (100), a plurality of charging test results (see data points of FIG. 21) individually associated with a plurality of charging conditions. A set of the plurality of charging test results obtained from the charging test device (100) may be referred to as 'charging test result information'.

[0174] In step S2220, the processor (220) may analyze the plurality of charging test results obtained in step S2210 to determine a plurality of charging characteristic profiles individually associated with a plurality of external temperatures used as charging conditions.

[0175] In step S2230, the processor (220) analyzes the plurality of charging characteristic profiles determined in step S2220 to determine a plurality of charging control profiles individually associated with a plurality of temperatures of interest. The plurality of temperatures of interest may be predetermined in consideration of a predetermined appropriate operating temperature range for the battery.

[0176] The plurality of charging control profiles determined in step S2230 may be recorded in the memory of the processor (220), and in the present invention, the 'rapid charging map' may refer to a set of the plurality of charging control profiles. The processor (220) may share the rapid charging map (QCM, see FIG. 29) with the charging test device (100) through the data input / output unit (210).

[0177] FIG. 23 is a flowchart for illustrative purposes explaining an example of subroutines that can be included in step S2320 of FIG. 22, and FIG. 24 is a graph for illustrative purposes explaining the method of FIG. 23.

[0178] Referring to FIG. 23, in step S2310, the processor (220) determines a plurality of sets of charging test results by grouping a plurality of charging test results according to a plurality of ambient temperatures used as charging conditions. That is, the plurality of charging test results may be grouped together with those associated with charging conditions having the same ambient temperature. For example, charging test results indicated by the same symbol in FIG. 21 may be classified into a common group. Accordingly, the number of sets of charging test results determined in step S2310 may be equal to the number of ambient temperature values ​​used as charging conditions.

[0179] In step S2320, the processor (220) individually applies a first mathematical operation to a plurality of sets of charging test results to determine a plurality of charging characteristic profiles individually associated with a plurality of current rates. The first mathematical operation may be a polynomial-based curve fitting having a predetermined highest degree.

[0180] The charge characteristic profile associated with a specific ambient temperature can represent a three-dimensional relationship between the current rate, charge depth, and battery temperature of the battery (11) according to the ambient temperature. FIG. 24 shows seven charge characteristic profiles (CL) individually associated with seven ambient temperatures (T1 to T7). T1 ~CL T7 ) is exemplified.

[0181] The processor (220) can determine the battery temperature range for each charging characteristic profile. The battery temperature range of any charging characteristic profile can be defined by the lowest battery temperature and the highest battery temperature of the charging characteristic profile. The lowest battery temperature and the highest battery temperature of any charging characteristic profile can be the same as the battery temperatures at both end points. For example, in FIG. 24, the charging characteristic profile (CL T1 ) the battery temperature at one end point is 15℃, which is the same as the ambient temperature (T1), and the charge characteristic profile (CL T1 ) the battery temperature at the other end point may be 22℃, in which case the charge characteristic profile (CL T1 ) battery temperature range can be 15~22℃.

[0182] FIGS. 25 and 26 are flowcharts used to exemplarily explain an example of subroutines that can be included in step S2230 of FIG. 22, and FIGS. 27 to 29 are graphs used to explain the method of FIGS. 25 and 26. The method according to FIGS. 25 and 26 can be individually executed for a plurality of predetermined temperatures of interest. In explaining the method according to FIGS. 25 and 26, FIG. 24 may be referred to again.

[0183] First, referring to FIG. 25, in step S2510, the processor (220) generates a plurality of charge characteristic profiles (CL) based on the temperature of interest. T1 ~CL T7 ) are classified into a first profile group or a second profile group. In detail, a plurality of charge characteristic profiles (CL T1 ~CL T7 ) each charge characteristic profile having a battery temperature range to which the temperature of interest belongs may be classified into a first profile group, and each other charge characteristic profile may be classified into a second profile group. For example, if the temperature of interest = 35℃, the charge characteristic profile (CL) of FIG. 24 T4 , CL T5 ) is the first profile group, and the remaining charge characteristic profiles (CL T1~ CL T3 , CL T6 , CL T7 ) can be classified into the second profile group.

[0184] In step S2520, the processor (220) determines whether the number of charging characteristic profiles included in the first profile group is equal to or greater than a predetermined number. Here, the predetermined number may be equal to or greater than the highest degree of the second mathematical operation used in step S2540, which will be described later. If the value of step S2520 is "Yes," the process may proceed to step S2530. If the value of step S2520 is "No," the method according to FIG. 25 may be terminated or proceed to step S2610. Referring again to FIG. 24, for example, if the temperature of interest is 35°C and the predetermined number is 3 or greater, two charging characteristic profiles (CL T4 , CL T5 ) is classified as the first profile group, so the value of step S2520 becomes “No”.

[0185] In step S2530, the processor (220) determines a data set of interest including a predetermined number or more of data points of interest having a battery temperature equal to the temperature of interest from a predetermined number or more of charging characteristic profiles of the first profile group. Each charging characteristic profile of the first profile group has a temperature of interest within its battery temperature range. Accordingly, a number of data points of interest equal to the total number of charging characteristic profiles included in the first profile group can be determined in step S2530.

[0186] In step S2540, the processor (220) applies a second mathematical operation to the data set of interest determined in step S2530 to determine a charge control profile associated with the temperature of interest. The second mathematical operation may be a polynomial-based curve fitting having a predetermined highest degree. The highest degree for the second mathematical operation may be 2 or greater, and the highest degree for the first mathematical operation and the highest degree for the second mathematical operation may be the same as or different from each other.

[0187] Next, referring to FIG. 26, in step S2610, the processor (220) generates an extended data set of interest including charge test results of each charge characteristic profile having a battery temperature range to which the temperature of interest belongs and charge test results of at least one charge characteristic profile having a battery temperature range to which the temperature of interest does not belong. That is, the extended data set of interest may be a data set of interest including charge test results of less than a predetermined number of charge characteristic profiles classified into a first profile group, in which charge test results of at least one charge characteristic profile classified into a second profile group are added. For example, if the temperature of interest is 35°C, the extended data set of interest may include two charge characteristic profiles (CL) of the first profile group. T4 , CL T5 ) contains the results of 12 charging tests, and the remaining charging characteristic profiles (CL T1~ CL T3 , CL T6 , CL T7 ) at least one charge characteristic profile (e.g., CL T3 ) further includes charging test results.

[0188] The processor (220) can identify a first reference temperature and a second reference temperature of the data set of interest associated with the charging characteristic profiles of the first profile group. The first reference temperature may be the highest battery temperature associated with the minimum current rate (C1), and the second reference temperature may be the lowest battery temperature associated with the highest current rate (C7).

[0189] If the first reference temperature is less than the temperature of interest, the processor (220) may select at least one charging characteristic profile from the second profile group in which the battery temperature associated with the minimum current rate (C1) is greater than or equal to the temperature of interest.

[0190] If the second reference temperature is above the temperature of interest, the processor (220) may select at least one charging characteristic profile from the second profile group in which the battery temperature associated with the highest current rate (C7) is below the temperature of interest.

[0191] For example, referring to Figure 27, the first profile group includes two charge characteristic profiles (CL T4 , CL T5 ), the first reference temperature of the first profile group includes the charge characteristic profile (CL T5 ) is 35℃, which is the battery temperature associated with the current rate (C1), and the second reference temperature of the first profile group is the charge characteristic profile (CL T4 ) is 37°C, which is the battery temperature associated with the current rate (C7). Assuming that the temperature of interest is 35°C, the first reference temperature of 35°C is equal to the temperature of interest, and the second reference temperature of 37°C is higher than the temperature of interest. Therefore, the processor (220) determines the charge characteristic profile (CL) in the second profile group. T3 ) and select the selected charge characteristic profile (CL T3 ) can be added to the above data set of interest (i.e., 6 data points) to determine the extended data set of interest.

[0192] In step S2620, the processor (220) applies a third mathematical operation to the extended interest data set to determine a surface function of interest. The third mathematical operation may utilize a known surface fitting logic. In FIG. 27, the shaded three-dimensional region (CS TI ) is an example of a 3D surface fitted to the above extended interest data set, and the interest surface function represents the 3D surface.

[0193] In step S2630, the processor (220) determines a charge control profile associated with the temperature of interest by using the temperature of interest as an input value for a surface function of interest. Since the surface function of interest represents a three-dimensional relationship between the depth of charge, the current rate, and the battery temperature, once the temperature of interest is specified, the surface function of interest can be simplified into a charge control profile representing a two-dimensional relationship between the current rate and the battery temperature.

[0194] Fig. 28 is a three-dimensional curved surface (CS) of Fig. 27 TI ) is obtained by specifying the battery temperature of the surface function of interest as 35℃, which is the same as the temperature of interest, as the charge control profile (QL). 35℃ ) is an example.

[0195] Fig. 29 is a charge control profile (QL) of Fig. 28 35℃ ) and charge control profiles for two additional temperatures of interest, 25°C and 45°C (QL 25℃ , QL 45℃ ) is exemplified. The Quick Charge Map (QCM) is a set of charge control profiles (QL) individually associated with every temperature of interest. 25℃ , QL 35℃ , QL 45℃ ) may be a set. The quick charge map (QCM) may be stored in a battery management system mounted on an electric vehicle, etc., and in this case, the battery management system may use the quick charge map (QCM) to control a quick charging procedure for a battery cell (BC) provided as a power source for the electric vehicle, etc.

[0196] A charge control method of a battery cell (BC) based on a quick charge map (QCM) that can be executed in a battery management system is briefly described with reference to FIG. 29 as follows.

[0197] During charging of a battery cell (BC), the temperature of the battery cell (BC) can be monitored in real time. For example, in response to the temperature of the battery cell (BC) being monitored to be 35°C during charging, the charge control profile (QL) of the quick charge map (QCM) 35℃ ) can be identified a specific depth of charge associated with a current rate corresponding to the charging current flowing through the battery cell (BC). If the SOC of the battery cell (BC) is greater than the identified depth of charge, the battery management system can immediately execute a control action to stop charging the battery cell (BC) or to adjust the current rate of the charging current downward (e.g., change from C3 to C2).

[0198] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0199] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

Claims

1. In the method of creating a rapid charging map, A step of obtaining a plurality of charging test results individually associated with a plurality of charging conditions by combinations of a plurality of current rates and a plurality of external temperatures; A step of analyzing the results of the plurality of charging tests to determine a plurality of charging characteristic profiles individually associated with the plurality of external temperatures; and A step of analyzing the plurality of charging characteristic profiles to determine a plurality of charging control profiles individually associated with a plurality of temperatures of interest, wherein the rapid charging map is a set of the plurality of charging control profiles; A method for generating a rapid charging map, comprising:

2. In paragraph 1, The lowest outdoor temperature among the above multiple outdoor temperatures is higher than the lower limit of the specified allowable temperature range, The highest outdoor temperature among the above plurality of outdoor temperatures is below the upper limit of the above allowable temperature range, The minimum current rate among the above multiple current rates is greater than or equal to the lower limit of a predetermined allowable current range, A method for generating a rapid charging map, wherein the maximum current rate among the plurality of current rates is less than or equal to the upper limit of the allowable current range.

3. In paragraph 1, Each of the above plurality of charging test results represents the depth of charge and the battery temperature of the battery when charging the battery under one of the plurality of charging conditions. Each of the above charging depths of the above multiple charging test results represents the maximum SOC of the battery that can be charged without lithium precipitation. A method for generating a rapid charging map, wherein each of the battery temperatures of the plurality of charging test results represents the temperature of the battery at a timing corresponding to the charging depth.

4. In paragraph 1, The step of determining the plurality of charging characteristic profiles is: A step of grouping the plurality of charging test results according to the plurality of external temperatures to determine a plurality of charging test result sets; and A method for generating a rapid charge map, comprising the step of individually applying mathematical operations to the plurality of sets of charge test results to determine the plurality of charge characteristic profiles.

5. In paragraph 4, The above mathematical operation is, A method for generating a rapid charging map, which is a polynomial-based curve fitting having a predetermined highest degree.

6. In paragraph 1, A method for generating a rapid charging map, wherein each of the plurality of charging characteristic profiles represents a three-dimensional relationship between a current rate, a depth of charge, and a battery temperature according to one of the plurality of ambient temperatures.

7. In paragraph 1, The step of determining the plurality of charging control profiles is: The following steps are performed individually for each of the above multiple temperatures of interest: When there are a predetermined number or more of charging characteristic profiles having a battery temperature range to which the temperature of interest belongs among the plurality of charging characteristic profiles, a step of determining a data set of interest including a predetermined number or more of data points of interest having a battery temperature equal to the temperature of interest from the predetermined number or more of charging characteristic profiles; and applying a mathematical operation to the above data set of interest to determine the charge control profile associated with the temperature of interest; A method for generating a rapid charging map, comprising:

8. In paragraph 7, The above mathematical operation is, A method for generating a rapid charging map, which is a polynomial-based curve fitting having a predetermined highest degree.

9. In paragraph 1, The step of determining the plurality of charging control profiles is: The following steps are performed individually for each of the above multiple temperatures of interest: When the number of charging characteristic profiles having a battery temperature range to which the temperature of interest belongs among the plurality of charging characteristic profiles is less than a predetermined number, a step of applying a mathematical operation to an extended data set of interest including charging test results of each charging characteristic profile having a battery temperature range to which the temperature of interest belongs and charging test results of at least one charging characteristic profile having a battery temperature range to which the temperature of interest does not belong, thereby determining a surface function of interest; and A step of determining the charge control profile associated with the temperature of interest by using the temperature of interest as an input value for the surface function of interest; A method for generating a rapid charging map, comprising:

10. In paragraph 1, A method for generating a rapid charging map, wherein each of the plurality of charging control profiles represents a relationship between a current rate and a charging depth according to one of the plurality of temperatures of interest.

11. In a device for generating a rapid charging map, A data input / output unit for obtaining multiple charging test results individually associated with multiple charging conditions by combinations of multiple current rates and multiple ambient temperatures; and A processor that analyzes the plurality of charging test results and determines a plurality of charging characteristic profiles individually associated with the plurality of external temperatures, The above processor, A rapid charging map generation device that analyzes the plurality of charging characteristic profiles to determine a plurality of charging control profiles individually associated with a plurality of temperatures of interest, wherein the rapid charging map is a set of the plurality of charging control profiles.

12. In paragraph 11, The above processor, Grouping the plurality of charging test results according to the plurality of external temperatures to determine a plurality of charging test result sets, A rapid charging map generation device that individually applies mathematical operations to the plurality of charging test result sets to determine the plurality of charging characteristic profiles.

13. In paragraph 11, The above processor, When there are a predetermined number or more of charging characteristic profiles having a battery temperature range to which the temperature of interest belongs among the plurality of charging characteristic profiles, an operation of determining a data set of interest including a predetermined number or more of data points of interest having a battery temperature equal to the temperature of interest from the charging characteristic profiles of the predetermined number or more; and An operation of applying a mathematical operation to said set of data of interest to determine said charge control profile associated with said temperature of interest; A rapid charge map generation device, which determines the plurality of charge control profiles by individually executing a procedure including the plurality of temperatures of interest.

14. In paragraph 11, The above processor, An operation of determining a surface function of interest by applying a mathematical operation to an extended data set of interest including charge test results of each charge characteristic profile having a battery temperature range to which the temperature of interest belongs and charge test results of at least one charge characteristic profile having a battery temperature range to which the temperature of interest does not belong, when the number of charge characteristic profiles having a battery temperature range to which the temperature of interest belongs is less than a predetermined number among the plurality of charge characteristic profiles; and An operation of determining the charge control profile associated with the temperature of interest by using the temperature of interest as an input value for the surface function of interest; A rapid charge map generation device, which determines the plurality of charge control profiles by individually executing a procedure including the plurality of temperatures of interest.

15. A charging system comprising a rapid charging map generating device according to any one of claims 11 to 14.

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