Rapid charging control device and method

Abstract

A quick charge control device according to one embodiment of the present invention includes a measurement unit configured to measure a voltage of a battery; and a control unit configured to estimate a SOC of the battery based on the voltage of the battery, determine a charge C-RATE corresponding to the estimated SOC based on a charging profile preset to indicate a correspondence relationship between the SOC and a charge C-RATE, and cut off charging of the battery for a predetermined time if the charge C-RATE corresponding to the estimated SOC is changed.

Description

[Technical Field]

[0001] The present invention relates to a rapid charge control device and method, and more particularly to a rapid charge control device and method for efficiently rapid charging a battery.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0148250, filed on November 8, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Recently, as demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has surged and development of electric vehicles, energy storage batteries, robots, and satellites has gained momentum, research into high-performance batteries that can be repeatedly charged and discharged is actively underway.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Of these, lithium batteries are attracting attention due to their advantages over nickel-based batteries, such as almost no memory effect, freedom in charging and discharging, a very low self-discharge rate, and high energy density.

[0005] As power-driven devices such as electric vehicles, electric motorcycles, and electric bicycles are becoming more commercially available, there is an increasing demand for high-capacity and high-performance batteries. However, as battery capacity increases, the time required to charge the battery also increases. To address this issue, rapid battery charging technologies are under development, but rapid charging may accelerate battery degradation.

[0006] In particular, during the rapid charging process of a battery, lithium deposition on the surface of the negative electrode (lithium plating) can occur. The deposition of lithium on the surface of the negative electrode can cause side reactions with the electrolyte and a change in the kinetic balance of the battery, resulting in battery degradation. Furthermore, the deposition of lithium metal on the surface of the negative electrode can cause an internal short circuit in the battery, which can lead to fires and explosions.

[0007] Therefore, there is a need to develop technology that can prevent the deposition of lithium metal on the surface of the negative electrode and enable rapid charging of the battery. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above problems, and has an object to provide a rapid charge control device and method that can efficiently rapid charge a battery.

[0009] Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 2 is a block diagram of a semiconductor device according to an embodiment of the present invention; [Means for solving the problem]

[0010] A quick charge control device according to one aspect of the present invention may include a measurement unit configured to measure a voltage of a battery; and a control unit configured to estimate a SOC of the battery based on the voltage of the battery, determine a charge C-RATE corresponding to the estimated SOC based on a charge profile preset to indicate a correspondence relationship between the SOC and a charge C-RATE, and cut off charging of the battery for a predetermined time if the charge C-RATE corresponding to the estimated SOC is changed.

[0011] The charging profile may be configured to include a plurality of SOC intervals with corresponding charging C-RATEs.

[0012] The control unit may be configured to, as the estimated SOC increases, cut off charging of the battery for the predetermined time when the estimated SOC reaches an upper limit value of a current SOC interval to which the estimated SOC belongs, and change a charge C-RATE for the battery to a charge C-RATE corresponding to a next SOC interval.

[0013] The controller may be configured to resume charging the battery at a modified charging C-RATE after the predetermined time has elapsed.

[0014] The charge C-RATE may be set to decrease as the estimated SOC increases and the SOC range to which the estimated SOC belongs changes.

[0015] The control unit may be configured to calculate a resistance value of the battery based on the voltage change during the predetermined time, and to diagnose the state of the battery based on the calculated resistance value.

[0016] The control unit may be configured to calculate the resistance value each time charging of the battery is interrupted for the predetermined time in multiple charging cycles, and compare the resistance values ​​of the same corresponding charging C-RATE to diagnose the state of the battery.

[0017] The control unit may be configured to diagnose that lithium metal has been deposited in the battery based on a resistance value calculated from successive charging cycles among the resistance values ​​of the same corresponding charging C-RATE.

[0018] The control unit may be configured to calculate a resistance variation rate of the resistance value with respect to a BOL (Beginning of Life) resistance value calculated from an initial charge cycle of the battery, and diagnose that lithium metal has been deposited in the battery if a difference in the resistance variation rates calculated from the successive charge cycles is equal to or greater than a predetermined critical value.

[0019] The control unit may be configured to diagnose that lithium metal has been deposited in the battery if a ratio of the resistance difference to the BOL resistance value calculated from the first charge cycle of the battery is equal to or greater than a preset critical value.

[0020] The charging profile may be set to indicate a correspondence relationship between the charging C-RATE and an SOC corresponding to a maximum point or an inflection point of a resistance profile preset to correspond to the charging C-RATE.

[0021] The resistance profile may be set to indicate a correspondence relationship between a resistance value corresponding to the charging C-RATE and an SOC.

[0022] The charging profile may be set such that, if the maximum point exists in the resistance profile, the SOC corresponding to the maximum point corresponds to the charging C-RATE.

[0023] If the resistance profile does not have the maximum point but has the inflection point, the charging profile may be set so that the SOC corresponding to the inflection point corresponds to the charging C-RATE.

[0024] The charging profile may be configured such that as the charging C-RATE decreases, the SOC corresponding to the charging C-RATE increases.

[0025] A battery pack according to another aspect of the present invention may include a fast charge controller according to one aspect of the present invention.

[0026] According to another aspect of the present invention, a fast charge control method may include a voltage measurement step of measuring a voltage of a battery; an SOC estimation step of estimating an SOC of the battery based on the voltage of the battery; a charge C-RATE determination step of determining a charge C-RATE corresponding to the estimated SOC based on a predetermined charge profile indicating a correspondence relationship between the SOC and the charge C-RATE; and a charge cut-off step of cutting off charging of the battery for a predetermined time if the charge C-RATE corresponding to the estimated SOC is changed.

[0027] According to another aspect of the present invention, the quick charging method may further include a resistance value calculation step of calculating a resistance value of the battery based on a voltage change during the predetermined time period after the charging cut-off step, and a battery diagnosis step of diagnosing a state of the battery based on the calculated resistance value. [Effects of the Invention]

[0028] According to one aspect of the present invention, fast charging of a battery can be controlled according to a charging profile that is set to prevent lithium metal deposition in the battery during fast charging, thereby effectively preventing lithium metal deposition during fast charging.

[0029] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0030] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a diagram illustrating a quick charge control device according to an embodiment of the present invention; [Figure 2]FIG. 4 is a diagram illustrating a charging profile according to an embodiment of the present invention. [Figure 3] 3A and 3B are diagrams illustrating a charging process of a battery according to an embodiment of the present invention; [Figure 4] FIG. 4 is a diagram schematically illustrating resistance variation rates of a first battery and a second battery according to an embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating the resistance variation rates of the third and fourth batteries according to an embodiment of the present invention. [Figure 6] FIG. 2 is a diagram illustrating a first resistance profile according to an embodiment of the present invention. [Figure 7] FIG. 2 is a schematic diagram illustrating a first differential profile of a first resistance profile according to an embodiment of the present invention. [Figure 8] FIG. 4 is a schematic diagram illustrating a second resistance profile according to an embodiment of the present invention. [Figure 9] FIG. 4 is a schematic diagram illustrating a first differential profile of a second resistance profile according to an embodiment of the present invention. [Figure 10] FIG. 4 is a schematic diagram illustrating a second differential profile of a second resistance profile according to an embodiment of the present invention. [Figure 11] FIG. 2 is a schematic diagram illustrating a number of resistance profiles according to an embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 13] FIG. 10 is a schematic diagram illustrating an exemplary configuration of a vehicle according to yet another embodiment of the present invention. [Figure 14] FIG. 10 is a schematic diagram illustrating an exemplary configuration of an energy storage device according to yet another embodiment of the present invention. [Figure 15] FIG. 10 is a diagram illustrating a quick charge control method according to another embodiment of the present invention. [Figure 16] FIG. 10 is a diagram illustrating a quick charge control method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best explain the invention.

[0033] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0034] Furthermore, if a detailed description of known functions or configurations related to the present invention is deemed to obscure the gist of the present invention, that description will be omitted.

[0035] Terms including ordinal numbers such as "first," "second," etc. are used to distinguish one of various components from the rest, and do not limit the components.

[0036] Furthermore, throughout the specification, when a part is said to "include" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified.

[0037] Furthermore, throughout this specification, when a part is said to be "coupled" to another part, this includes not only "directly coupled" but also "indirectly coupled" via another element in between.

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0039] FIG. 1 is a diagram illustrating a quick charge control device 100 according to an embodiment of the present invention.

[0040] Here, a battery refers to a single independent cell that has a negative terminal and a positive terminal and can be physically separated. As an example, a lithium ion battery or a lithium polymer battery may be considered a battery. A battery may also refer to a battery module in which multiple cells are connected in series and / or parallel. For convenience of explanation, a battery will be described below as meaning a single independent cell.

[0041] Referring to FIG. 1, the quick charge control device 100 may include a measurement unit 110 and a control unit 120.

[0042] The measurement unit 110 may be configured to measure the voltage of the battery.

[0043] Specifically, the measurement unit 110 may be connected to the positive and negative terminals of the battery. The measurement unit 110 may be configured to measure the voltage of the battery by measuring the positive and negative voltages of the battery. For example, the measurement unit 110 may measure the voltage of the battery according to a preset voltage measurement period.

[0044] The measurement unit 110 may be communicatively connected to the control unit 120. For example, the measurement unit 110 may be connected to the control unit 120 by wire and / or wirelessly. The measurement unit 110 may then transmit information related to the measured battery voltage to the control unit 120.

[0045] The control unit 120 may be configured to estimate the state of charge (SOC) of the battery based on the voltage of the battery.

[0046] Specifically, the control unit 120 may receive the battery voltage from the measurement unit 110 and estimate the battery SOC from the received voltage. Preferably, the battery voltage and SOC may be preset according to a correspondence relationship between them. For example, an SOC profile indicating the correspondence relationship between voltage and SOC may be provided in advance. The control unit 120 may determine the SOC corresponding to the voltage received from the measurement unit 110 in the SOC profile and estimate the determined SOC as the battery SOC.

[0047] Here, the SOC indicates the state of charge of the battery, and may be preset so that the SOC corresponds to the battery voltage. Such an SOC may be expressed as a value between 0% and 100%, or a value between 0 and 1. For the sake of convenience, the following description will be given assuming that the SOC has a value between 0% and 100%.

[0048] The control unit 120 can be configured to determine a charge C-RATE (Current rate) corresponding to the estimated SOC based on a charging profile that is preset to indicate the correspondence relationship between the SOC and the charge C-RATE.

[0049] Here, the charging profile may be preset to indicate a correspondence relationship between the SOC and the charging C-RATE, which is the C-RATE at which the battery is charged, and may be determined by the SOC of the battery.

[0050] Specifically, a corresponding charge C-RATE may be preset for a predetermined SOC interval, and the control unit 120 may determine an SOC interval to which the current SOC of the battery belongs from the charge profile, and determine a charge C-RATE corresponding to the determined SOC interval.

[0051] 2 is a diagram illustrating a charging profile according to an embodiment of the present invention. Specifically, the charging profile may be configured to include multiple SOC intervals with corresponding charging C-RATEs.

[0052] In the example of Figure 2, it is assumed that the battery is charged from 8% to 80% SOC. The charging profile may include a first SOC interval of 8% to 25% SOC, a second SOC interval of 25% to 40% SOC, a third SOC interval of 40% to 55% SOC, a fourth SOC interval of 55% to 70% SOC, and a fifth SOC interval of 70% to 80% SOC. A 3-second (0.05-minute) rest period may be included between each SOC interval.

[0053] 2, if the SOC of the battery is estimated to be 20%, the SOC of the battery may fall within the first SOC interval, and the control unit 120 may determine the charge C-RATE for the battery to be 2.5C.

[0054] The control unit 120 may be configured to cut off charging of the battery for a predetermined time if the charging C-RATE corresponding to the estimated SOC is changed.

[0055] Specifically, the control unit 120 may determine a charge C-RATE corresponding to the estimated SOC based on the charging profile each time the control unit 120 estimates the SOC of the battery. For example, the control unit 120 may estimate the SOC each time the control unit 120 receives the battery voltage from the measurement unit 110 and determine a charge C-RATE based on the estimated SOC. If the charge C-RATE corresponding to the estimated SOC is changed, the control unit 120 may interrupt charging of the battery for a predetermined time.

[0056] Preferably, the charge C-RATE may be set to decrease as the estimated SOC increases and the SOC interval to which the estimated SOC belongs changes. In the embodiment of FIG. 2, the magnitude of the corresponding charge C-RATE may decrease in the order of the first SOC interval, the second SOC interval, the third SOC interval, the fourth SOC interval, and the fifth SOC interval. That is, as the SOC of the battery increases (i.e., as the battery is charged), the charge C-RATE for the battery may decrease.

[0057] Specifically, as the estimated SOC increases, when the estimated SOC reaches the upper limit value of the current SOC interval to which the estimated SOC belongs, the control unit 120 may be configured to cut off charging of the battery for a predetermined time and change the charging C-RATE for the battery to the charging C-RATE corresponding to the next SOC interval.

[0058] For example, in the embodiment of FIG. 2, assume that the battery's SOC is estimated to be 20% at time t1. The control unit 120 may determine that the charge C-RATE for the battery at time t1 is 2.5C. If the battery's SOC is then estimated to be 25% at time t2, the control unit 120 may determine that the battery's SOC has reached the upper limit of the first SOC interval at time t2. The control unit 120 may interrupt charging of the battery for a predetermined time period at time t2 and change the charge C-RATE for the battery to 1.5C, which corresponds to the second SOC interval.

[0059] Here, the predetermined time means a charging interruption time set to calculate the charge transfer resistance based on the voltage drop immediately after the battery charging is interrupted. For example, the predetermined time may be set to any value between 0.1 seconds and 3 seconds.

[0060] After a predetermined time has elapsed, the controller 120 may be configured to resume charging the battery at the modified charging C-RATE.

[0061] Specifically, the battery may be charged at a changed charge C-RATE for the new SOC interval to which the SOC of the battery belongs.

[0062] For example, in the above-described embodiment, assume that the charging C-RATE for the battery is changed to 1.5 C. The control unit 120 may control the battery to be charged at the charging C-RATE of 1.5 C until the SOC of the battery reaches the upper limit (40%) of the second SOC range.

[0063] For example, if a battery is charged from 8% SOC to 80% according to the embodiment of FIG. 2, the total charging time for the battery may be 44.55 minutes (ie, 44 minutes 33 seconds).

[0064] According to an embodiment of the present invention, the quick charge control device 100 may change the charge C-RATE for each SOC section to quick charge the battery. In particular, the quick charge control device 100 may control the quick charge of the battery so that a rest period of a predetermined time is provided each time the charge C-RATE is changed during the quick charge process.

[0065] Meanwhile, the control unit 120 included in the quick charging control device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. Furthermore, when the control logic is embodied as software, the control unit 120 may be embodied as a collection of program modules. In this case, the program modules may be stored in a memory and executed by the control unit 120. The memory may be internal or external to the control unit 120 and may be connected to the control unit 120 by various known means.

[0066] The quick charge control device 100 may further include a storage unit 130. The storage unit 130 may store data and programs required for each component of the quick charge control device 100 to operate and function, or data generated during the operation and function. The storage unit 130 may be any known information storage means capable of recording, erasing, updating, and reading data. Examples of the information storage means include RAM, flash memory, ROM, EEPROM, and registers. The storage unit 130 may also store program code that defines processes executable by the control unit 120.

[0067] The control unit 120 may be configured to calculate the resistance value of the battery based on the voltage change over a predetermined period of time.

[0068] Specifically, the control unit 120 may calculate the resistance value of the battery based on the change in the voltage of the battery during the time that charging of the battery is interrupted. Preferably, the control unit 120 may be configured to calculate the resistance value each time charging of the battery is interrupted for a predetermined time over multiple charging cycles.

[0069] The control unit 120 can use Ohm's law to calculate the resistance value of the battery based on the charging current and voltage just before the charging of the battery is interrupted and the voltage at a predetermined time after the charging of the battery is interrupted.

[0070] 3 is a diagram illustrating a battery charging process according to an embodiment of the present invention. For example, assume that a battery is charged with a current I1 until time Ts, battery charging is interrupted from time Ts to time Td, and battery charging is resumed with a current I2 from time Td. The battery voltage at time Ts may be Vs [V], and the battery voltage at time Td may be Vd [V]. That is, the battery voltage during the rest period when battery charging is interrupted may decrease from Vs [V] to Vd [V]. The control unit 120 may calculate the battery resistance value using the formula "(Vs - Vd) ÷ I1."

[0071] The control unit 120 may then be configured to diagnose the state of the battery based on the calculated resistance value.

[0072] Preferably, the control unit 120 may be configured to diagnose the battery condition by comparing the resistance values ​​of the same corresponding charging C-RATE. For example, in the embodiment of FIG. 2, the battery may have a total of five rest periods during the process of charging from 8% to 80% SOC. Because the SOC of the battery corresponding to each rest period is different, the battery condition may be diagnosed by comparing the resistance values ​​of the same corresponding charging C-RATE.

[0073] Generally, excessive fast charging can cause a lithium plating phenomenon in which lithium metal is deposited on the surface of the negative electrode of the battery. Therefore, the control unit 120 can diagnose the battery state (especially the presence or absence of lithium deposition) based on the resistance value during the rest period of the fast charging process. That is, the control unit 120 can diagnose the battery state in real time during fast charging of the battery.

[0074] Specifically, the control unit 120 may be configured to diagnose lithium metal deposition in the battery based on the resistance values ​​calculated from successive charging cycles among the resistance values ​​of the same corresponding charging C-RATE.

[0075] For example, the control unit 120 may diagnose the state of the battery based on the difference in resistance variation rate or resistance difference for the resistance values ​​of successive charging cycles.

[0076] Here, the difference in resistance variation may refer to the ratio of the calculated battery resistance to the beginning of life (BOL) resistance calculated from the battery's first charging cycle. For example, if the BOL resistance is R0 and the calculated battery resistance is Rn, the resistance variation may be expressed by the formula (R0-Rn) / Rn×100 or (R0-Rn) / Rn. The resistance variation of the battery resistance R1 calculated at time t1 is (R1-R0) / Rn×100, and the resistance variation of the battery resistance R2 calculated at time t2 (the time subsequent to time t1) is (R2-R0) / Rn×100. The difference in resistance variation may be calculated by (R1-R2) / Rn×100.

[0077] The resistance difference may refer to the difference between the resistance values ​​in successive charging cycles. For example, if the resistance value of the battery calculated at time t1 is R1 and the resistance value of the battery calculated at time t2 (the time subsequent to time t1) is R2, the resistance difference may be calculated as "R1 - R2".

[0078] In one embodiment, the control unit 120 may be configured to calculate a resistance variation rate of the resistance value with respect to the BOL resistance value calculated from the first charge cycle of the battery, and may be configured to diagnose that lithium metal has been deposited in the battery if the difference in the resistance variation rates calculated from successive charge cycles is equal to or greater than a predetermined critical value.

[0079] That is, when the resistance variation rate calculated from successive charging cycles decreases to a critical value or more, the control unit 120 may diagnose the battery state as an abnormal state where lithium metal is deposited.

[0080] 4 is a diagram illustrating the resistance variation rate of a first battery B1 and a second battery B2 according to an embodiment of the present invention. Specifically, the first battery B1 is a normal battery in which lithium metal is not deposited, and the second battery B2 is an abnormal battery in which lithium metal is deposited after the 21st charge cycle. For example, the first battery B1 and the second battery B2 are the same type of battery, but lithium metal is deposited on the negative electrode of the second battery B2 from the 21st charge cycle onward to understand the change in the resistance variation rate when lithium metal is deposited.

[0081] 4 shows the one-second resistance fluctuation rate of the first battery B1 and the second battery B2. That is, the time for which charging of the first battery B1 and the second battery B2 is interrupted is set to one second, the resistance values ​​of the first battery B1 and the second battery B2 are calculated based on the voltage change over one second, and the resistance fluctuation rate is calculated based on the calculated resistance values.

[0082] The resistance variation rate of the second battery B2 at the 20th charge cycle may be RF1%, and the resistance variation rate at the 21st charge cycle may be RF2%. Here, the control unit 120 may calculate the difference between the resistance variation rates at the 20th charge cycle and the 21st charge cycle as "RF1-RF2". Then, the control unit 120 may compare the calculated difference in resistance variation rate with a preset critical value.

[0083] Here, the critical value may be set as a value that indicates a rapid change in the resistance variation rate between successive charging cycles. Specifically, the critical value may be preset to a value of 0.5% or more based on the type of battery, the intended use of the battery, etc. Preferably, the critical value may be preset to a value of 1% or more. Hereinafter, it is assumed that the critical value is set to 1%.

[0084] 4, the difference in resistance variation rate between successive charge cycles of the first battery B1 is not greater than a critical value (1%). Therefore, the control unit 120 can diagnose the first battery B1 as a normal battery without lithium metal deposition. On the other hand, the difference in resistance variation rate RF1-RF2 between the 20th and 21st charge cycles of the second battery B2 is greater than the critical value (1%). Therefore, the control unit 120 can diagnose the second battery B2 as an abnormal battery with lithium metal deposition.

[0085] 5 is a diagram illustrating the resistance variation rates of the third battery B3 and the fourth battery B4 according to an embodiment of the present invention. Specifically, the third battery B3 is a normal battery in which lithium metal is not deposited, and the fourth battery B4 is an abnormal battery in which lithium metal is deposited after the 21st charge cycle. For example, the third battery B3 and the fourth battery B4 are the same type of battery, but lithium metal is deposited on the negative electrode of the fourth battery B4 after the 21st charge cycle in order to understand the change in the resistance variation rate when lithium metal is deposited.

[0086] 5 shows the 3-second resistance fluctuation rate of the third battery B3 and the fourth battery B4. That is, the time for which charging of the third battery B3 and the fourth battery B4 is cut off is set to 3 seconds, the resistance values ​​of the third battery B3 and the fourth battery B4 are calculated based on the voltage change over 3 seconds, and the resistance fluctuation rate is calculated based on the calculated resistance values.

[0087] 5, the difference in resistance variation rate between successive charge cycles of the third battery B3 is not greater than a critical value (1%). Therefore, the controller 120 can diagnose the third battery B3 as a normal battery without lithium metal deposition. On the other hand, the difference in resistance variation rate between the 20th and 21st charge cycles of the fourth battery B4, RF3-RF4, is greater than the critical value (1%). Therefore, the controller 120 can diagnose the fourth battery B4 as an abnormal battery with lithium metal deposition.

[0088] In another embodiment, the control unit 120 may be configured to diagnose that lithium metal has been deposited in the battery if the ratio of the resistance difference to the BOL resistance value calculated from the first charge cycle of the battery is equal to or greater than a preset critical value.

[0089] For example, as in the above-described embodiment, assume that the BOL resistance is R0, the battery resistance calculated at time t1 is R1, and the battery resistance calculated at time t2 (the time point subsequent to time t1) is R2. The control unit 120 may calculate the resistance difference between time t2 and time t1 as "R1 - R2." Then, the control unit 120 may calculate the ratio of the resistance difference to the BOL resistance using the formula "(R1 - R2) ÷ R0 × 100." Then, if the calculated value is equal to or greater than a critical value, the control unit 120 may diagnose that lithium metal has been deposited in the battery.

[0090] The fast charge control device 100 according to an embodiment of the present invention has an advantage in that it can diagnose the battery status in real time during the fast charge process based on the resistance value of the same corresponding charge C-RATE. In particular, the battery status can be diagnosed by taking into account not only the difference in resistance between two consecutive charge cycles but also the battery's BOL resistance. This has the advantage of enabling accurate diagnosis of the battery status in real time based on the battery's initial resistance (BOL resistance), the resistance value of the previous charge cycle, and the resistance value of the current charge cycle.

[0091] An embodiment in which the SOC section is set for each charging C-RATE will be described below.

[0092] The charging profile may be set to indicate a correspondence relationship between the charging C-RATE and the SOC corresponding to a maximum or inflection point of the resistance profile preset to correspond to the charging C-RATE.

[0093] Here, the resistance profile may be set to indicate the relationship between the resistance value corresponding to the charge C-RATE and the SOC. The relationship between the battery resistance value and the SOC may vary depending on the charge C-RATE. Therefore, preferably, a resistance profile may be provided for each charge C-RATE. For example, the resistance profile may be displayed as an XY graph in which the X-axis represents the SOC and the Y-axis represents the resistance value.

[0094] Specifically, the correspondence relationship between the charge C-RATE and the SOC can be set depending on whether or not there is a maximum point or an inflection point in the resistance profile.

[0095] More specifically, the local maximum point refers to a point corresponding to a differentiable local maximum in the resistance profile, i.e., a local maximum point is a point where the instantaneous rate of change of resistance with respect to SOC is 0, and the instantaneous rate of change of resistance with respect to SOC can change from positive to negative around the local maximum point.

[0096] For example, the charging profile may be set so that if there is a local maximum point in the resistance profile, the SOC corresponding to the local maximum point corresponds to the charging C-RATE.

[0097] FIG. 6 is a diagram schematically illustrating a first resistance profile PR1 according to an embodiment of the present invention.

[0098] FIG. 7 is a diagram schematically illustrating a first differential profile PF1' of a first resistance profile PR1 according to an embodiment of the present invention.

[0099] Specifically, the first resistance profile PR1 is a profile showing the relationship between SOC and resistance obtained while charging the battery at a charge rate C-RATE of 0.75 C. The first differential profile PF1' of the first resistance profile PR1 is a profile obtained by first-order differentiation of the first fitting profile PF1 obtained by performing polynomial curve fitting on the first resistance profile PR1.

[0100] Specifically, by differentiating the first resistance profile PR1 according to the embodiment of FIG. 6, the first differential profile PF1' according to the embodiment of FIG. 7 can be derived.

[0101] 7, considering the first derivative value of the first differential profile PF1′, it can be seen that the first resistance profile PR1 has a local maximum point. The SOC at the local maximum point of the first resistance profile PR1 is tSOC1 (75.09764%). For example, the upper limit value of the SOC section corresponding to a charge C-RATE of 0.75 C can be set to 75% (75.09764% rounded to the nearest decimal place).

[0102] In another example, the charging profile may be set such that if there is no maximum point in the resistance profile but there is an inflection point, the SOC corresponding to the inflection point corresponds to the charging C-RATE.

[0103] Generally, as the charge C-RATE increases, the overvoltage within the battery increases, which can cause the resistance profile to show a different shape. In this case, the resistance profile for the battery may not have a maximum point. Therefore, if the upper limit of the SOC range corresponding to the charge C-RATE in the charge profile is set based on the maximum point, the battery may be fast-charged due to an incorrectly set SOC range, which may induce lithium metal deposition in the battery's negative electrode. Therefore, if the resistance profile does not have a maximum point, the upper limit of the SOC range corresponding to the charge C-RATE may be set based on the presence or absence of an inflection point.

[0104] FIG. 8 is a schematic diagram of a second resistance profile PR2 according to an embodiment of the present invention.

[0105] FIG. 9 is a diagram schematically illustrating a first differential profile PF2' of the second resistance profile PR2 according to an embodiment of the present invention.

[0106] FIG. 10 is a diagram schematically illustrating a second differential profile PF2' of the second resistance profile PR2 according to an embodiment of the present invention.

[0107] Specifically, the second resistance profile PR2 is a profile showing the correspondence relationship between SOC and resistance obtained while charging the battery at a charge rate C-RATE of 2C. The first differential profile PF2' of the second resistance profile PR2 is a profile obtained by first differentiating the second fitting profile PF2 obtained by performing polynomial curve fitting on the second resistance profile PR2. The second differential profile PF2" of the second resistance profile PR2 is a profile obtained by second differentiating the second fitting profile PF2. In other words, the second differential profile PF2" of the second resistance profile PR2 is a profile obtained by further differentiating the first differential profile PF2' of the second resistance profile PR2.

[0108] Specifically, by differentiating the second resistance profile PR2 according to the embodiment of FIG. 8, a first differential profile PF2′ according to the embodiment of FIG. 9 can be derived. And, by differentiating the first differential profile PF2′ according to the embodiment of FIG. 9, a second differential profile PF2″ according to the embodiment of FIG. 10 can be derived.

[0109] In the example of FIG. 9, when the first derivative value of the first derivative profile PF2′ is considered, it can be seen that there is no maximum point in the first resistance profile PR1. However, in the example of FIG. 10, when the second derivative value of the second derivative profile PF2″ is considered, it can be seen that there is an inflection point in the first resistance profile PR1. The SOC at the inflection point of the second resistance profile PR2 is tSOC2 (36.35072%). For example, the upper limit value of the SOC section corresponding to a charging C-RATE of 2C can be set to 36% (36.35072% rounded to the nearest decimal place).

[0110] For example, assume that the charge C-RATEs included in the charge profile are 2C, 0.75C, and 0.5C, and the battery is charged at an SOC of 8% to 80%. Also assume that the upper limit of the SOC section corresponding to a 2C charge C-RATE is an SOC of 36%, the upper limit of the SOC section corresponding to a 0.75C charge C-RATE is an SOC of 75%, and the upper limit of the SOC section corresponding to a 0.5C charge C-RATE is an SOC of 80%. The charge profile may be configured so that the battery is charged at a 2C charge C-RATE from 8% to 36% SOC, at a 0.75C charge C-RATE from 36% to 75% SOC, and at a 0.5C charge C-RATE from 75% to 80% SOC.

[0111] The quick charge control device 100 according to an embodiment of the present invention can control the quick charge of a battery using a charging profile set to prevent lithium metal deposition in the battery during the quick charge process, thereby effectively preventing lithium metal deposition due to quick charge.

[0112] On the other hand, the charging profile may be configured such that the SOC corresponding to the charging C-RATE increases as the charging C-RATE decreases.

[0113] FIG. 11 is a schematic diagram illustrating multiple resistance profiles according to one embodiment of the present invention.

[0114] Specifically, the example of Figure 11 shows the resistance profile and upper limit value of the SOC range (indicated by ★) corresponding to charging C-RATEs of 0.5C, 0.75C, 1C, 1.25C, 1.5C, 1.75C, 2C, 2.25C, 2.5C, 2.75C and 3C.

[0115] 11, as the charge C-RATE increases, the upper limit of the SOC section corresponding to the charge C-RATE may decrease. Conversely, as the charge C-RATE decreases, the upper limit of the SOC section corresponding to the charge C-RATE may increase.

[0116] In the example of FIG. 11, the resistance profile and upper limit value of the SOC section are shown for charge C-RATEs from 0.5C to 3C in increments of 0.25C, but the upper limit value of the SOC section can be preset for more various charge C-RATEs in the charge profile.

[0117] The quick charge control device 100 according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention may include the above-described quick charge control device 100. In this configuration, at least some of the components of the quick charge control device 100 may be implemented by complementing or adding functions of components included in a conventional BMS. For example, the measurement unit 110, the control unit 120, and the storage unit 130 of the quick charge control device 100 may be implemented as components of the BMS.

[0118] The quick charge control device 100 according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the quick charge control device 100 and one or more battery cells. The battery pack may further include electrical components (relays, fuses, etc.), a case, etc.

[0119] FIG. 12 is a diagram schematically illustrating an exemplary configuration of a battery pack 10 according to another embodiment of the present invention.

[0120] The positive terminal of the battery 11 may be connected to the positive terminal P+ of the battery pack 10, and the negative terminal of the battery 11 may be connected to the negative terminal P- of the battery pack 10.

[0121] The relay 12 may be located in a charge / discharge path of the battery 11. Specifically, the relay 12 may be located in a large current path of the battery 11. For example, one end of the relay 12 may be electrically connected to the positive terminal of the battery 11, and the other end of the relay 12 may be electrically connected to the positive terminal P+ of the battery pack 10. Then, the charge / discharge path of the battery 11 may be opened or closed depending on the operating state of the relay 12.

[0122] The control unit 120 may control the operation state of the relay 12 to a turned-on or turned-off state. For example, the control unit 120 may control the operation state of the relay 12 to a turned-on state while charging the battery 11. The control unit 120 may also control the operation state of the relay 12 to a turned-off state while cutting off the charging of the battery 11.

[0123] The measurement unit 110 may be connected to the first sensing line SL1, the second sensing line SL2, and the third sensing line SL3. Specifically, the measurement unit 110 may be connected to the positive terminal of the battery 11 via the first sensing line SL1 and to the negative terminal of the battery 11 via the second sensing line SL2. The measurement unit 110 may measure the voltage of the battery 11 based on the voltages measured on the first sensing line SL1 and the second sensing line SL2.

[0124] The measurement unit 110 may be connected to a current measurement unit A via a third sensing line SL3. For example, the current measurement unit A may be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery 11.

[0125] One end of the charging device 20 may be connected to the positive terminal P+ of the battery pack 10, and the other end may be connected to the negative terminal P- of the battery pack 10. Therefore, the positive terminal of the battery 11, the positive terminal P+ of the battery pack 10, the charging device 20, the negative terminal P- of the battery pack 10, and the negative terminal of the battery 11 may be electrically connected.

[0126] The charging device 20 may be communicatively connected to the control unit 120. For example, the charging device 20 and the control unit 120 may be communicatively connected using power line communication (PLC). The control unit 120 may transmit the determined charging C-RATE to the charging device 20, and the charging device 20 may output a charging current corresponding to the received charging C-RATE to the battery 11.

[0127] FIG. 13 is a schematic diagram illustrating an exemplary configuration of a vehicle 1300 in accordance with yet another embodiment of the present invention.

[0128] 13 , a battery pack 1310 according to an embodiment of the present invention may be included in a vehicle 1300 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 1310 may drive the vehicle 1300 by supplying power to a motor via an inverter provided in the vehicle 1300. The battery pack 1310 may also be provided with a quick charge control device 100 to control quick charging of the battery pack 1310.

[0129] FIG. 14 is a schematic diagram illustrating an exemplary configuration of an energy storage system (ESS) 1400 in accordance with yet another embodiment of the present invention.

[0130] 14, an energy storage device 1400 includes a plurality of battery modules 1420 and a rack case 1410. The plurality of battery modules 1420 may be configured to be housed in the rack case 1410 in a vertically arranged form. For example, a quick charge control device 100 may be provided for each of the plurality of battery modules 1420, and the quick charge control device 100 may control the quick charge of the corresponding battery module 1420.

[0131] 15 and 16 are diagrams schematically illustrating a rapid charge control method according to still another embodiment of the present invention.

[0132] Preferably, each step of the quick charge control method may be performed by the quick charge control device 100. Hereinafter, for the sake of convenience, the overlapping content with the above content will be omitted or will be briefly described.

[0133] Referring to FIG. 15, the fast charge control method may include a voltage measurement step S100, a SOC estimation step S200, a charge C-RATE determination step S300, and a charge cut-off step S400.

[0134] The voltage measurement step S100 is a step of measuring the voltage of the battery, and may be performed by the measurement unit 110.

[0135] For example, the measurement unit 110 may measure the voltage of the battery according to a preset voltage measurement period.

[0136] The SOC estimation step S200 is a step of estimating the SOC of the battery based on the voltage of the battery, and may be performed by the control unit 120.

[0137] For example, the control unit 120 can estimate the SOC for the voltage measured in the voltage measuring step S100 based on an SOC profile that indicates the correspondence between the voltage and the SOC.

[0138] The charge C-RATE determination step S300 is a step of determining a charge C-RATE corresponding to an estimated SOC based on a charging profile that is preset to indicate the correspondence between SOC and charge C-RATE, and can be performed by the control unit 120.

[0139] For example, the control unit 120 may determine an SOC interval to which the current SOC of the battery belongs in the charging profile, and determine a charging C-RATE corresponding to the determined SOC interval.

[0140] The charge cut-off step S400 is a step of cutting off the charging of the battery for a predetermined time when the charging C-RATE corresponding to the estimated SOC is changed, and may be performed by the control unit 120.

[0141] For example, if the charge C-RATE corresponding to the estimated SOC is changed, the control unit 120 may cut off the charging of the battery for a predetermined time period. That is, if the estimated SOC reaches the upper limit of the SOC range to which the estimated SOC currently belongs, the control unit 120 may cut off the charging of the battery for a predetermined time period.

[0142] A method for controlling fast charging according to an embodiment of the present invention may control fast charging of a battery so that a rest period of a predetermined time is provided whenever the charge C-RATE is changed during the fast charging process.

[0143] Referring to FIG. 16, the rapid charging control method may further include a resistance value calculation step S500 and a battery diagnosis step S600.

[0144] The resistance value calculation step S500 is a step of calculating the resistance value of the battery based on the voltage change for a predetermined time period after the charge cut-off step S400, and may be performed by the control unit 120.

[0145] For example, the control unit 120 may use Ohm's law to calculate the resistance value of the battery based on the change in the voltage of the battery during the time that charging of the battery is interrupted.

[0146] In the embodiment of FIG. 3, the control unit 120 may calculate the resistance value of the battery using the formula "(Vs-Vd)÷I1".

[0147] The battery diagnosis step S600 is a step of diagnosing the state of the battery based on the calculated resistance value, and can be performed by the control unit 120.

[0148] In one embodiment, the control unit 120 may be configured to calculate a resistance variation rate of the resistance value with respect to the BOL resistance value calculated from the first charge cycle of the battery, and may be configured to diagnose that lithium metal has been deposited in the battery if the difference in the resistance variation rates calculated from successive charge cycles is equal to or greater than a predetermined critical value.

[0149] In another embodiment, the control unit 120 may be configured to diagnose that lithium metal has been deposited in the battery if the ratio of the resistance difference to the BOL resistance value calculated from the first charge cycle of the battery is equal to or greater than a preset critical value.

[0150] That is, the fast charge control method according to an embodiment of the present invention has an advantage that the battery state can be diagnosed in real time during the fast charge process based on the resistance value of the same corresponding charge C-RATE.

[0151] The embodiments of the present invention described above are not necessarily embodied through devices and methods, but may be embodied through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation should be easily embodied by a person skilled in the art to which the present invention pertains from the description of the above-mentioned embodiments.

[0152] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and various modifications and variations can be made by a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the scope of the claims.

[0153] Furthermore, since the above-mentioned present invention can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs without departing from the technical concept of the present invention, it is not limited to the above-mentioned embodiments and the attached drawings, and can be configured by selectively combining all or part of each embodiment to make various modifications. [Explanation of symbols]

[0154] 10 Battery Pack 11 Battery 12 Relay 20 Charging device 100 Fast charging control device 110 Measuring section 120 control section 130 Preservation Department 1300 cars 1310 Battery Pack 1400 Energy Storage Device 1410 Rack Case 1420 Battery Module

Claims

1. a measuring unit for measuring the voltage of the battery; a control unit configured to estimate an SOC of the battery based on a voltage of the battery, determine a charge C-RATE corresponding to the estimated SOC based on a charge profile preset to indicate a correspondence relationship between the SOC and the charge C-RATE, and cut off charging of the battery for a predetermined time if the charge C-RATE corresponding to the estimated SOC is changed.

2. The charging profile comprises: The charging system is configured to include a plurality of SOC sections each having a corresponding charging C-RATE set thereto; The control unit 2. The quick charge control device according to claim 1, wherein, when the estimated SOC increases and reaches an upper limit of a current SOC range to which the estimated SOC belongs, charging of the battery is stopped for the predetermined time, and a charge C-RATE for the battery is changed to a charge C-RATE corresponding to a next SOC range.

3. The control unit 3. The quick charge control device according to claim 2, wherein the quick charge control device is configured to resume charging the battery at the changed charge C-RATE after the predetermined time has elapsed.

4. The charging C-RATE is The quick charge control device according to claim 2, wherein the estimated SOC is set to decrease as the estimated SOC increases and the SOC range to which the estimated SOC belongs is changed.

5. The control unit 2. The quick charge control device according to claim 1, further comprising: a resistance value of the battery calculated based on the voltage change during the predetermined time; and a diagnosis of the state of the battery based on the calculated resistance value.

6. The control unit 6. The quick charge control device according to claim 5, wherein the resistance value is calculated each time charging of the battery is interrupted for the predetermined time in a plurality of charging cycles, and the resistance values ​​of the same corresponding charging C-RATE are compared to diagnose the state of the battery.

7. The control unit The rapid charge control device according to claim 6, characterized in that it is configured to diagnose that lithium metal has been deposited in the battery based on a resistance value calculated from consecutive charging cycles among the resistance values ​​of the same corresponding charging C-RATE.

8. The control unit 8. The quick charge control device according to claim 7, further comprising: a resistance variation rate of the resistance value with respect to a BOL resistance value calculated from an initial charge cycle of the battery; and a diagnosis that lithium metal has been deposited in the battery if a difference between the resistance variation rates calculated from the successive charge cycles is equal to or greater than a predetermined critical value.

9. The control unit 8. The quick charge control device according to claim 7, further comprising a step of diagnosing that lithium metal has been deposited in the battery if a ratio of a resistance difference to a BOL resistance value calculated from an initial charge cycle of the battery is equal to or greater than a predetermined critical value.

10. The charging profile is a resistance profile that is preset to correspond to the charging C-RATE and an SOC that corresponds to a maximum point or an inflection point of the charging C-RATE; The resistance profile is 2. The quick charge control device according to claim 1, wherein the charge C-RATE is set to indicate a correspondence relationship between the resistance value corresponding to the charge C-RATE and the SOC.

11. The charging profile comprises: If the maximum point exists in the resistance profile, an SOC corresponding to the maximum point is set to correspond to the charging C-RATE; 11. The quick charge control device according to claim 10, wherein, when the maximum point does not exist in the resistance profile but the inflection point does exist, an SOC corresponding to the inflection point is set to correspond to the charge C-RATE.

12. The charging profile comprises: The quick charge control device according to claim 11, wherein the SOC corresponding to the charge C-RATE increases as the charge C-RATE decreases.

13. A battery pack comprising the rapid charge control device according to any one of claims 1 to 12.

14. a voltage measurement stage for measuring the voltage of the battery; an SOC estimating step of estimating an SOC of the battery based on a voltage of the battery; a charge C-RATE determination step of determining a charge C-RATE corresponding to the estimated SOC based on a charge profile that is preset to indicate a correspondence relationship between the SOC and the charge C-RATE; and cutting off charging of the battery for a predetermined time if a charging C-RATE corresponding to the estimated SOC is changed.

15. a resistance value calculation step of calculating a resistance value of the battery based on a voltage change during the predetermined time period after the charging interruption step; The method of claim 14, further comprising: diagnosing a battery state based on the calculated resistance value.

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