Battery diagnostic equipment, battery packs, battery testing devices, and battery diagnostic methods

Abstract

A battery diagnostic device according to an embodiment of the present invention includes: a curve generation unit configured to acquire a battery curve representing the correspondence between the voltage and capacity of a battery, and to generate a differential curve representing the correspondence between the voltage and the differential capacity relative to the voltage based on the acquired battery curve; and a control unit configured to receive the differential curve from the curve generation unit, determine a target peak value in the differential curve, compare the voltage of a reference peak value of a preset reference curve with the voltage of the determined target peak value for the battery, and determine whether the battery has generated a side reaction based on the comparison result.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application 10-2020-0152317, filed in Korea on November 13, 2020, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery diagnostic device and method, and more specifically, to a battery diagnostic device and method capable of diagnosing whether a battery is experiencing a side reaction. Background Technology

[0003] Recently, demand for portable electronic products such as laptops, cameras, and mobile phones has increased dramatically, and electric vehicles, energy storage batteries, robots, and satellites have also seen significant development. Therefore, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available commercial batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries, and also have a very low self-discharge rate and high energy density.

[0005] Such batteries may gradually degrade because side reactions can occur when the battery is exposed to low or high temperatures for extended periods, or when it is repeatedly charged and discharged.

[0006] Side reactions can occur at both the positive and negative electrodes of a battery, and for various reasons. Therefore, to improve battery life, it is essential to check for side reactions and their causes, and to appropriately control the battery's operating conditions accordingly. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to address the problems of the prior art. Therefore, this disclosure aims to provide a battery diagnostic device and method that can control and optimize battery usage conditions by diagnosing whether side reactions occur in the battery and what causes these side reactions.

[0009] These and other objects and advantages of this disclosure will become apparent from the following detailed description and will become more apparent from exemplary embodiments thereof. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means set forth in the appended claims and combinations thereof.

[0010] Technical solution

[0011] A battery diagnostic device according to one aspect of this disclosure may include: a curve generation unit configured to obtain a battery curve representing the correspondence between the voltage and capacity of a battery, and to generate a differential curve representing the correspondence between the voltage and the differential capacity relative to the voltage based on the obtained battery curve; and a control unit configured to receive the differential curve from the curve generation unit, determine a target peak value in the differential curve, compare the voltage of the determined target peak value with the voltage of a standard peak value of a preset standard curve for the battery, and determine whether a side reaction has occurred in the battery based on the comparison result.

[0012] The control unit can be configured to compare the voltage of the standard peak value and the target peak value, and determine whether a negative electrode side reaction or a positive electrode side reaction occurs in the battery based on the comparison result.

[0013] The control unit can be configured to determine that the negative electrode side reaction has occurred in the battery when the voltage of the target peak exceeds the voltage of the standard peak.

[0014] The control unit can be configured to determine that the positive electrode side reaction has occurred in the battery when the voltage of the target peak is lower than the voltage of the standard peak.

[0015] The control unit can be configured to determine that the electrolyte included in the battery is partially decomposed when the negative electrode side reaction or the positive electrode side reaction is determined to occur.

[0016] The control unit can be configured to change the usage conditions, including at least one of the battery's charge rate (C-rate), available state of charge (SOC), and upper limit temperature, when it is determined that a side reaction has occurred in the battery.

[0017] The control unit can be configured to reduce the upper limit of the charging rate C of the battery when it is determined that the negative electrode side reaction has occurred.

[0018] The control unit can be configured to reduce the upper limit of the available SOC of the battery when it is determined that the positive electrode side reaction has occurred.

[0019] The control unit can be configured to reduce the upper limit temperature of the battery when it is determined that the side reaction is occurring in the battery.

[0020] The control unit can be configured to determine the target peak value in a predetermined voltage range based on the voltage of the standard peak value in the differential curve.

[0021] A battery pack according to another aspect of this disclosure may include the battery diagnostic device described in one aspect of this disclosure.

[0022] A battery testing apparatus according to another aspect of this disclosure may include the battery diagnostic device described in one aspect of this disclosure.

[0023] A battery diagnostic method according to another aspect of this disclosure may include: a battery curve acquisition step, wherein the battery curve acquisition step acquires a battery curve representing the correspondence between the battery's voltage and capacity; a differential curve generation step, wherein the differential curve generation step generates a differential curve representing the correspondence between the voltage and the differential capacity relative to the voltage based on the battery curve acquired in the battery curve acquisition step; a target peak determination step, wherein the target peak determination step determines a target peak value in the differential curve generated in the differential curve generation step; a voltage comparison step, wherein the voltage of the determined target peak value is compared with the voltage of a standard peak value of a preset standard curve for the battery; and a side reaction occurrence judgment step, wherein the side reaction occurrence judgment step determines whether the battery has experienced a side reaction based on the comparison result of the voltage comparison step.

[0024] Beneficial effects

[0025] According to one aspect of this disclosure, its advantage lies in the ability to quickly diagnose whether a side reaction has occurred in the battery and what type of side reaction it is based on the behavior included in a peak in the differential curve.

[0026] Furthermore, according to one aspect of this disclosure, an advantage is that the expected lifespan of the battery can be increased by setting appropriate operating conditions for the battery in which side reactions occur.

[0027] The effects of this disclosure are not limited to those described above; other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. Attached Figure Description

[0028] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the illustrations.

[0029] Figure 1 This is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present disclosure.

[0030] Figure 2 This is a schematic diagram illustrating a first differential curve and a standard curve according to one embodiment of the present disclosure.

[0031] Figure 3 This is a schematic diagram illustrating a second differential curve and a standard curve according to one embodiment of the present disclosure.

[0032] Figure 4 This is a schematic diagram showing a battery curve corresponding to a first differential curve according to an embodiment of the present disclosure.

[0033] Figure 5 This is a schematic diagram showing a battery curve corresponding to a second differential curve according to an embodiment of the present disclosure.

[0034] Figure 6 This is a diagram schematically illustrating a battery diagnostic method according to another embodiment of the present disclosure. Detailed Implementation

[0035] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather are interpreted according to their meanings and concepts corresponding to the technical aspects of this disclosure, based on the principle that inventors are allowed to make appropriate definitions of the terms to obtain the best interpretation.

[0036] Therefore, the description presented herein is merely a preferred embodiment for illustrative purposes and is not intended to limit the scope of the disclosure. It should be understood that other equivalents and modifications may be made to this disclosure without departing from its scope.

[0037] Furthermore, in the description of this disclosure, detailed descriptions of relevant known elements or functions are omitted where such detailed descriptions would obscure the key subject matter of this disclosure.

[0038] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various elements, but are not intended to limit elements by means of terms.

[0039] Throughout this specification, when a section is referred to as “containing” or “including” any element, it means that the section may additionally include other elements, without excluding other elements, unless otherwise specifically stated.

[0040] Furthermore, terms such as "control unit" as described in this specification refer to a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0041] Furthermore, throughout the specification, when one part is referred to as being "connected" to another part, it is not limited to the case where they are "directly connected," but also includes the case where they are "indirectly connected" by inserting another element between them.

[0042] The preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0043] Figure 1This is a schematic diagram illustrating a battery diagnostic device 100 according to one embodiment of the present disclosure.

[0044] refer to Figure 1 The battery diagnostic device 100 may include a curve generation unit 110 and a control unit 120.

[0045] The curve generation unit 110 can be configured to obtain a battery curve representing the relationship between the battery's voltage and capacity.

[0046] Here, a battery refers to a physically separable, independent battery cell with negative and positive terminals. For example, a pouch-type lithium polymer battery can be considered a battery.

[0047] For example, the battery curve obtained by the curve generation unit 110 can be a curve generated to map the corresponding voltage and capacity of the battery.

[0048] The curve generation unit 110 can be configured to generate a differential curve representing the correspondence between voltage and differential capacity relative to voltage based on the obtained battery curve.

[0049] The curve generation unit 110 can calculate the differential capacity (dQ / dV) by differentiating the battery capacity based on the battery voltage. Furthermore, the curve generation unit 110 can generate a differential curve representing the correspondence between voltage and differential capacity by mapping the voltage and differential capacity of the corresponding battery.

[0050] Figure 2 This is a schematic diagram showing the first differential curve DP1 and the standard curve R according to one embodiment of the present disclosure. Figure 3 This is a schematic diagram illustrating the second differential curve DP2 and the standard curve R according to one embodiment of the present disclosure.

[0051] For example, refer to Figure 2 and Figure 3 When X is set as voltage and Y is set as differential capacity, the first differential curve DP1 and the second differential curve DP2 generated by the curve generation unit 110 can be represented as an XY curve diagram.

[0052] The control unit 120 can be configured to receive differential curves from the curve generation unit 110.

[0053] For example, the control unit 120 and the curve generation unit 110 can be interconnected to enable communication. The curve generation unit 110 can transmit the generated differential curve to the control unit 120, and the control unit 120 can receive the differential curve from the curve generation unit 110.

[0054] The control unit 120 can be configured to determine a target peak value in the differential curve.

[0055] Specifically, the differential curve may include multiple peaks. Here, a peak is the point where the instantaneous rate of change of the differential capacitance with respect to voltage is 0, and can also be the point where the instantaneous rate of change with respect to the peak changes from positive to negative. That is, the peak can be a point in the differential curve that has an upward convex shape.

[0056] The control unit 120 can determine any one of the multiple peaks included in the differential curve as the target peak.

[0057] Preferably, the control unit 120 can be configured to determine a target peak value within a predetermined voltage range based on the voltage of the standard peak value RP in the differential curve. For example, the control unit 120 can determine the target peak value within the range of -0.1V to +0.1V based on the voltage of the standard peak value RP. That is, if the voltage of the standard peak value RP is 3.45V, then the target peak value within the range of 3.35V to 3.55V can be determined.

[0058] For example, in Figure 2 In this implementation, the control unit 120 can determine multiple peaks in the first differential curve DP1. Furthermore, the control unit 120 can determine a first target peak TP1, which is included in a predetermined voltage range, based on the voltage of a standard peak RP among the determined multiple peaks.

[0059] As another embodiment, in Figure 3 In this implementation, the control unit 120 can determine multiple peaks in the second differential curve DP2. Furthermore, the control unit 120 can determine a second target peak TP2, which is included within a predetermined voltage range, based on the voltage of a standard peak RP among the multiple determined peaks.

[0060] The control unit 120 can be configured to compare the voltage of a standard peak RP of a preset standard curve R for the battery with the voltage of a determined target peak.

[0061] That is, the control unit 120 can compare the voltage corresponding to the standard peak value RP with the voltage corresponding to the target peak value.

[0062] Preferably, the control unit 120 can determine whether the voltage of the target peak differs from the voltage of the standard peak RP by a preset standard voltage or more. For example, when measuring the voltage and capacity of a battery, due to measurement errors caused by noise, there may be an error between the voltage of the target peak and the actual voltage. Therefore, the control unit 120 can determine, taking into account this error, whether the voltage of the target peak is greater than the standard peak RP by a standard voltage or less than the standard peak RP by a standard voltage.

[0063] For example, in Figure 2 In one implementation, the control unit 120 can compare the voltage of the standard peak RP and the voltage of the first target peak TP1 to determine that the voltage of the first target peak TP1 is greater than the voltage of the standard peak RP.

[0064] As another embodiment, in Figure 3 In one implementation, the control unit 120 can compare the voltages of the standard peak RP and the second target peak TP2 to determine that the voltage of the second target peak TP2 is less than the voltage of the standard peak RP.

[0065] The control unit 120 can be configured to determine whether a side reaction has occurred in the battery based on the comparison results.

[0066] Specifically, the control unit 120 can be configured to determine whether a negative electrode side reaction or a positive electrode side reaction is occurring in the battery based on a comparison between the standard peak voltage and the target peak voltage.

[0067] More specifically, when the voltage of the target peak exceeds the voltage of the standard peak, the control unit 120 can be configured to determine that a negative electrode side reaction has occurred in the battery.

[0068] Conversely, when the voltage of the target peak is less than the voltage of the standard peak, the control unit 120 can be configured to determine that a positive electrode side reaction has occurred in the battery.

[0069] For example, in Figure 2 In this implementation, the voltage of the first target peak TP1 may exceed the voltage of the standard peak RP. Therefore, the control unit 120 can determine that a negative electrode side reaction has occurred in the battery corresponding to the first differential curve DP1.

[0070] As another embodiment, in Figure 3 In this implementation, the voltage of the second target peak TP2 may be lower than the voltage of the standard peak RP. Therefore, the control unit 120 can determine that a positive electrode side reaction has occurred in the battery corresponding to the second differential curve DP2.

[0071] The battery diagnostic device 100 according to one embodiment of the present disclosure has the advantage of being able to quickly and non-destructively diagnose whether a side reaction has occurred in the battery and what type of side reaction it is (positive electrode side reaction or negative electrode side reaction) based on behavior including a peak in a differential curve.

[0072] Meanwhile, the control unit 120 provided to the battery diagnostic device 100 may optionally include processors, application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices known in the art, to execute the various control logics performed in this disclosure. Furthermore, when the control logic is implemented in software, the control unit 120 may be implemented as a set of program modules. In this case, the program modules may be stored in a memory and executed by the control unit 120. This memory may be located inside or outside the control unit 120 and may be connected to the control unit 120 by various known means.

[0073] Furthermore, the battery diagnostic device 100 may further include a storage unit 130. The storage unit 130 may store data or programs required for the operation and function of each component of the battery diagnostic device 100, data generated during the execution of operations or functions, etc. The type of storage unit 130 is not particularly limited, as long as it is a known information storage means capable of recording, erasing, updating, and retrieving data. As an embodiment, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit 130 may store program code that defines processes executable by the control unit 120.

[0074] For example, storage unit 130 can store the battery curve obtained by curve generation unit 110 and the differential curve generated by curve generation unit 110. In addition, control unit 120 can directly receive the differential curve from curve generation unit 110, or can access storage unit 130 to obtain the differential curve.

[0075] In the following text, when a side reaction is determined to occur in the battery, the specific reasons for the side reaction diagnosed by the control unit 120 will be described.

[0076] When a negative electrode side reaction is detected, the control unit 120 can be configured to determine that some of the electrolyte contained in the battery has been decomposed.

[0077] Specifically, the control unit 120 can determine that a negative electrode side reaction occurs because some of the electrolyte contained in the battery is reduced and decomposed.

[0078] As one implementation of the negative electrode side reaction, the control unit 120 can be configured to determine that a portion of the electrolyte has decomposed, thereby causing lithium to deposit on the negative electrode of the battery. That is, when a negative electrode side reaction is determined to occur, the control unit 120 can be configured to determine that lithium has been deposited on the negative electrode of the battery.

[0079] When the voltage of the target peak exceeds the voltage of the standard peak RP, the control unit 120 can determine that a negative electrode side reaction has occurred in the battery, and that the negative electrode side reaction is caused by the lithium plating due to the reduction and decomposition of part of the electrolyte.

[0080] Specifically, when a lithium plating layer appears on the negative electrode of a battery, the negative electrode capacity may be lost in the high SOC range (e.g., 90% to 100% SOC). That is, metallic lithium deposits on the negative electrode, potentially leading to a loss of capacity in the high SOC range. In this case, to compensate for voltage loss (to maintain the battery voltage), the capacity of the negative electrode in the low SOC range (e.g., 0% to 10% SOC) can be further utilized during battery charging. For this reason, the voltage corresponding to the target peak value shifts to a higher voltage, potentially exceeding the standard voltage.

[0081] That is, the form of the battery curve may change due to the occurrence of negative electrode side reactions. In addition, the voltage of the target peak included in the differential curve corresponding to the battery curve with the changed form can be shifted to a higher voltage.

[0082] Figure 4 This is a schematic diagram showing the battery curve corresponding to the first differential curve DP1 according to one embodiment of the present disclosure.

[0083] exist Figure 4 In this embodiment, the first battery curve BP1, the first negative electrode curve NP1, and the first positive electrode curve PP1 can be curves of a battery in the BOL (early life) state. Furthermore, the second battery curve BP2 and the second positive electrode curve PP2 can be curves of a battery in the MOL (mid life) state. That is, when a lithium plating layer appears on the negative electrode of the battery, due to the loss of negative electrode capacity in the high SOC range R1 of the battery, the first positive electrode curve PP1 changes like the second positive electrode curve PP2, and the first battery curve BP1 can change like the second battery curve BP2.

[0084] In addition, Figure 4 In this implementation, the first SOC S1 can be the SOC corresponding to the target peak value of the battery in the BOL state and MOL state. Additionally, the first voltage V1 can be the voltage corresponding to the target peak value of the battery in the BOL state, and the second voltage V2 can be the voltage corresponding to the target peak value of the battery in the MOL state.

[0085] That is, the voltage of the first battery curve BP1 corresponding to the first SOC S1 can be the first voltage V1, and the voltage of the second battery curve BP2 corresponding to the first SOC S1 can be the second voltage V2.

[0086] Specifically, refer to Figure 2 and Figure 4 , Figure 4 The first voltage V1 can be corresponding to Figure 2 The standard peak voltage RP, and the second voltage V2 can be the voltage corresponding to Figure 2 The voltage of the first target peak TP1. That is, when a lithium plating layer appears on the negative electrode of the battery, the voltage of the first target peak TP1 may be greater than the voltage of the standard peak RP because the voltage corresponding to the first target peak TP1 shifts to a higher voltage.

[0087] Therefore, when the target peak voltage exceeds the standard voltage, the control unit 120 can determine that a negative electrode side reaction has occurred in the battery, and can also specifically diagnose that the cause of the negative electrode side reaction is the lithium plating layer generated on the negative electrode.

[0088] The control unit 120 can be configured to determine that some of the electrolyte in the battery has been decomposed when a positive electrode side reaction is detected.

[0089] Specifically, the control unit 120 can determine that some of the electrolyte in the battery has been oxidized and decomposed, thus causing a positive electrode side reaction.

[0090] Generally, when a battery is exposed to high temperatures for an extended period, the electrolyte within it decomposes, and lithium ions may be supplied to the positive electrode from this decomposed electrolyte. In this situation, the positive electrode can receive lithium ions from both the negative electrode and the decomposed electrolyte. Therefore, due to the supply of lithium ions from the negative electrode and the decomposed electrolyte, the high-voltage capacity of the battery's positive electrode may not be usable.

[0091] In an embodiment concerning positive electrode side reactions, the control unit 120 may be configured to determine that a portion of the electrolyte has been decomposed, thereby increasing the unused capacity of the battery positive electrode.

[0092] Specifically, when some of the electrolyte contained in the battery is oxidized and decomposed, the lithium ions released from the decomposed electrolyte can be supplied to the positive electrode. In this case, due to the self-discharge of the positive electrode in the high SOC range (e.g., 90% to 100% SOC range), positive electrode side reactions may occur during battery charging, and the high SOC range of the positive electrode is not used when positive electrode side reactions occur.

[0093] Furthermore, since the positive electrode side reactions prevent the positive electrode from being used in the high SOC range, the low SOC range of the positive electrode can be further used for voltage compensation during battery charging. Therefore, the shape of the battery profile may change due to the positive electrode side reactions. Additionally, the voltage of the target peak included in the differential curve corresponding to the modified battery profile can be shifted to a lower voltage.

[0094] Figure 5This is a schematic diagram showing the battery curve corresponding to the second differential curve DP2 according to one embodiment of the present disclosure.

[0095] exist Figure 5 In this embodiment, the first battery curve BP1, the first negative electrode curve NP1, and the first positive electrode curve PP1 can be curves of a battery in the BOL (Best in Least Oxide) state. Furthermore, the second battery curve BP2, the second negative electrode curve NP2, and the second positive electrode curve PP2 can be curves of a battery in the MOL (Most Oxide) state. That is, when a positive electrode side reaction occurs in the battery, the positive electrode in the high SOC range R2 is not used, thus the first positive electrode curve PP1 can change like the second positive electrode curve PP2, the first negative electrode curve NP1 can change like the second negative electrode curve NP2, and the first battery curve BP1 can change like the second battery curve BP2.

[0096] exist Figure 5 In the implementation, the first SOC S1 and the first voltage V1 are the SOC and voltage corresponding to the target peak value of the battery in the BOL state, and the second SOC S2 and the second voltage V2 are the SOC and voltage corresponding to the target peak value of the battery in the MOL state.

[0097] On the other hand, Figure 5 In this embodiment, the second positive electrode curve PP2, the second negative electrode curve NP2, and the second battery curve BP2 are represented by dashed lines in the high SOC range R2 to indicate that the positive electrode is not used in the high SOC range R2.

[0098] That is, the voltage of the first battery curve BP1 corresponding to the first SOC S1 can be the first voltage V1, and the voltage of the second battery curve BP2 corresponding to the second SOC S2 can be the second voltage V2.

[0099] Specifically, refer to Figure 3 and Figure 5 , Figure 5 The first voltage V1 can be corresponding to Figure 3 The standard peak voltage RP, and the second voltage V2 can be the voltage corresponding to Figure 3 The voltage of the second target peak TP2. That is, when a side reaction occurs at the positive electrode of the battery, the voltage corresponding to the second target peak TP2 shifts to a lower voltage, so the voltage of the second target peak TP2 may be less than the voltage of the standard peak RP.

[0100] Therefore, if the target peak voltage is less than the standard voltage, the control unit 120 can determine that a positive electrode side reaction has occurred in the battery, and specifically diagnose that the positive electrode side reaction is caused by the oxidation and decomposition of some of the electrolyte contained in the battery.

[0101] refer to Figure 1 According to one embodiment of the present disclosure, the battery diagnostic device 100 may further include a temperature measurement unit 140.

[0102] The temperature measurement unit 140 can be configured to measure the temperature of the battery. For example, the temperature measurement unit 140 can periodically measure the temperature of the battery, and can measure the temperature of the battery even when it is not in a temperature measurement cycle, when outputting a temperature measurement signal.

[0103] The temperature information of the battery measured by the temperature measurement unit 140 can be cumulatively stored in the storage unit 130.

[0104] The control unit 120 can determine whether the battery has been exposed to high temperatures for an extended period, taking into account the battery temperature information stored in the storage unit 130. If the battery is maintained at or above the standard temperature for an extended period, the control unit 120 can determine that the positive electrode side reaction occurring in the battery is caused by electrolyte decomposition due to exposure to high temperatures.

[0105] On the other hand, when a side reaction is detected in the battery, the control unit can be configured to change the operating conditions, which include at least one of the battery's charge rate (current rate), available state of charge (SOC), and upper limit temperature.

[0106] Specifically, when a negative electrode side reaction is detected, the control unit 120 can be configured to reduce the upper limit of the battery's charging rate C.

[0107] As described above, the control unit 120 can determine that the negative electrode side reaction is caused by a lithium plating layer formed on the negative electrode of the battery. Therefore, the control unit 120 can reduce the upper limit of the battery's charge rate (C-rate) to prevent further lithium plating layer formation on the negative electrode.

[0108] Preferably, the control unit 120 can reduce the upper limit of the battery's charging C-rate and the upper limit of its discharging C-rate to prevent the formation of lithium plating.

[0109] Furthermore, when a positive electrode side reaction is detected, the control unit 120 can be configured to reduce the upper limit of the battery's available state of charge (SOC).

[0110] As described above, the control unit 120 can determine that the positive electrode side reaction is caused by the oxidative decomposition of the electrolyte contained in the battery. Therefore, the control unit 120 can reduce the upper limit of the battery's usable SOC to prevent further decomposition of the electrolyte.

[0111] Furthermore, when a side reaction is detected in the battery, the control unit 120 can be configured to reduce the upper limit temperature of the battery.

[0112] That is, when it is determined that a negative electrode side reaction or a positive electrode side reaction occurs in the battery, the control unit 120 can be configured to lower the upper limit temperature of the battery in order to suppress the occurrence of the side reaction.

[0113] Therefore, the battery diagnostic device 100 according to one embodiment of this disclosure has the advantage of specifically diagnosing whether side reactions occur in the battery and what type of side reactions they are, and setting optimal operating conditions for the battery based on the diagnostic results. When the battery operates under the operating conditions set by the battery diagnostic device 100, the occurrence of side reactions in the battery can be suppressed (or delayed), thereby increasing the battery's lifespan.

[0114] The battery diagnostic device 100 according to one embodiment of this disclosure can be applied to a BMS (Battery Management System). That is, the BMS according to this disclosure may include the battery diagnostic device 100 described above. In this configuration, at least some components of the battery diagnostic device 100 can be implemented by supplementing or adding configuration functions included in a conventional BMS. For example, the curve generation unit 110, control unit 120, storage unit 130, and temperature measurement unit 140 of the battery diagnostic device 100 can be implemented as components of a BMS.

[0115] Furthermore, the battery diagnostic device 100 according to this disclosure can be provided to a battery pack. That is, the battery pack according to this disclosure may include the aforementioned battery diagnostic device 100 and at least one battery cell. In addition, the battery pack may further include electrical devices (relays, fuses, etc.) and a housing.

[0116] That is, the optimal operating conditions for the battery are set by the battery diagnostic device 100 included in the battery pack, and the batteries included in the battery pack can operate according to the set operating conditions. Therefore, side reactions in the battery are prevented, and battery life can be increased.

[0117] Furthermore, the battery diagnostic device 100 according to one embodiment of this disclosure may be included in a battery testing apparatus. The battery testing apparatus can diagnose whether a side reaction has occurred in the battery and what type of side reaction it is, and set optimal operating conditions for the battery. The operating conditions set by the battery testing apparatus can be stored in a server and / or BMS of the battery pack to which the battery is to be installed. Therefore, the battery can be operated according to the set operating conditions.

[0118] Figure 6 This is a diagram schematically illustrating a battery diagnostic method according to another embodiment of the present disclosure.

[0119] Preferably, each step of the battery diagnostic method can be performed by the battery diagnostic device 100. In the following description, for ease of explanation, content overlapping with the preceding description will be omitted or briefly described.

[0120] refer to Figure 6 The battery diagnostic method may include a battery curve acquisition step (S100), a differential curve generation step (S200), a target peak determination step (S300), a voltage comparison step (S400), a side reaction occurrence judgment step (S500), and a battery usage condition setting step (S600).

[0121] The battery curve acquisition step (S100) is a step of obtaining a battery curve representing the correspondence between the battery's voltage and capacity, and can be performed by the curve generation unit 110.

[0122] For example, in Figure 4 In one implementation, the curve generation unit 110 can obtain the second battery curve BP2.

[0123] As another embodiment, in Figure 5 In one implementation, the curve generation unit 110 can acquire the second battery curve BP2.

[0124] The differential curve generation step (S200) is a step of generating a differential curve representing the correspondence between voltage and differential capacity based on the battery curve obtained in the battery curve acquisition step (S100), and can be performed by the curve generation unit 110.

[0125] For example, in Figure 2 In one implementation, the curve generation unit 110 can generate a first differential curve DP1 based on the obtained battery curve.

[0126] As another embodiment, in Figure 3 In one implementation, the curve generation unit 110 can generate a second differential curve DP2 based on the acquired battery curve.

[0127] The target peak determination step (S300) is a step of determining the target peak from the differential curve generated in the differential curve generation step (S200), and can be performed by the control unit 120.

[0128] For example, in Figure 2 In one implementation, the control unit 120 can determine the first target peak value TP1 within a predetermined voltage range based on the voltage of the standard peak value RP in the first differential curve DP1.

[0129] As another embodiment, in Figure 3 In one implementation, the control unit 120 can determine the second target peak value TP2 within a predetermined voltage range based on the voltage of the standard peak value RP in the second differential curve DP2.

[0130] The voltage comparison step (S400) is a step of comparing the voltage of the standard peak value RP of the preset standard curve R for the battery with the voltage of the determined target peak value, and can be performed by the control unit 120.

[0131] For example, in Figure 2 In one implementation, the control unit 120 can determine that the voltage corresponding to the first target peak TP1 is greater than the voltage corresponding to the standard peak RP.

[0132] As another embodiment, in Figure 3 In one implementation, the control unit 120 can determine that the voltage corresponding to the second target peak TP2 is less than the voltage corresponding to the standard peak RP.

[0133] The side reaction occurrence judgment step (S500) is a step to determine whether a negative electrode side reaction or a positive electrode side reaction has occurred in the battery based on the comparison result of the voltage comparison step (S400), and it can be performed by the control unit 120.

[0134] Specifically, when the target peak voltage exceeds the standard peak voltage, the control unit 120 can determine that a negative electrode side reaction has occurred in the battery. Conversely, when the target peak voltage is less than the standard peak voltage, the control unit 120 can determine that a positive electrode side reaction has occurred in the battery.

[0135] For example, in Figure 2 In this implementation, since the voltage of the first target peak TP1 exceeds the voltage of the standard peak RP, the control unit 120 can determine that a negative electrode side reaction has occurred in the battery.

[0136] As another embodiment, in Figure 3 In this implementation, since the voltage of the second target peak TP2 is less than the voltage of the standard peak RP, the control unit 120 can determine that a positive electrode side reaction has occurred in the battery.

[0137] After the side reaction occurrence determination step (S500), a battery usage condition setting step (S600) may be further included.

[0138] The battery usage condition setting step (S600) is a step that sets the battery usage conditions when it is determined that a side reaction has occurred in the battery, and it can be performed by the control unit 120.

[0139] Specifically, when a side reaction is detected in the battery, the control unit 120 can change the operating conditions, which include at least one of the battery's charge rate (C-rate), available state of charge (SOC), and upper limit temperature. Therefore, when the battery operates according to the changed operating conditions, its lifespan can be increased.

[0140] The embodiments described above can be implemented not only by devices and methods, but also by a program or a recording medium that implements functions corresponding to the construction of the embodiments of this disclosure. Such a program or recording medium can be readily implemented by those skilled in the art based on the description of the embodiments above.

[0141] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific embodiments illustrate preferred embodiments of this disclosure, they are given by way of illustration only, as various variations and modifications within the scope of this disclosure will become apparent to those skilled in the art from the detailed description.

[0142] Furthermore, those skilled in the art can make many substitutions, modifications and alterations to the present disclosure without departing from its technical aspects, and the present disclosure is not limited to the above-described embodiments and drawings. Each embodiment can be selectively combined in part or in whole to achieve various variations.

[0143] (See attached image labels)

[0144] 100: Battery diagnostic equipment

[0145] 110: Curve generation unit

[0146] 120: Control Unit

[0147] 130: Storage unit

[0148] 140: Temperature Measurement Unit

Claims

1.A battery diagnosis device comprising: a curve generation unit configured to obtain a battery curve representing a correspondence between a voltage and a capacity of a battery, and generate a differential curve representing a correspondence between the voltage and a differential capacity with respect to the voltage based on the obtained battery curve; and a control unit configured to receive the differential curve from the curve generation unit, determine a target peak in the differential curve, compare a voltage of the determined target peak with a voltage of a standard peak of a standard curve preset for the battery, and judge whether or not a side reaction occurs in the battery based on a result of the comparison, wherein the control unit is configured to compare the voltages of the standard peak and the target peak, and judge whether a negative electrode side reaction or a positive electrode side reaction occurs in the battery according to a result of the comparison. 2.The battery diagnosis device according to claim 1, wherein the control unit is configured to judge that the negative electrode side reaction occurs in the battery when the voltage of the target peak exceeds the voltage of the standard peak, and wherein, wherein the control unit is configured to judge that the positive electrode side reaction occurs in the battery when the voltage of the target peak is lower than the voltage of the standard peak. 3.The battery diagnosis device according to claim 1, wherein the control unit is configured to judge that an electrolyte included in the battery is partially decomposed when it is judged that the negative electrode side reaction or the positive electrode side reaction occurs. wherein 4.The battery diagnosis device according to claim 1, wherein the control unit is configured to change a use condition of at least one of a charge C rate, an available SOC, and an upper limit temperature of the battery when it is judged that a side reaction occurs in the battery. wherein 5.The battery diagnosis device according to claim 4, wherein the control unit is configured to decrease an upper limit of the charge C rate of the battery when it is judged that the negative electrode side reaction occurs, and wherein wherein the control unit is configured to decrease an upper limit of the available SOC of the battery when it is judged that the positive electrode side reaction occurs. 6.The battery diagnosis device according to claim 4, wherein the control unit is configured to decrease the upper limit temperature of the battery when it is judged that the side reaction occurs in the battery. wherein, 7.The battery diagnosis device according to claim 1, wherein the control unit is configured to determine the target peak in a predetermined voltage range based on the voltage of the standard peak in the differential curve. wherein 8.A battery pack comprising the battery diagnosis device according to any one of claims 1 to 7. 9.A battery detection apparatus comprising the battery diagnosis device according to any one of claims 1 to 7. 10.A battery diagnosis method comprising: a battery curve obtaining step of obtaining a battery curve representing a correspondence between a voltage and a capacity of a battery; and ​ a differential curve generation step of generating a differential curve representing a correspondence between the voltage and a differential capacity with respect to the voltage, based on the battery curve obtained in the battery curve obtaining step; a target peak value determination step of determining a target peak value in the differential curve generated in the differential curve generation step; a voltage comparison step of comparing a voltage of the determined target peak value with a voltage of a standard peak value of a standard curve preset for the battery; and a side reaction occurrence judgment step of judging whether a side reaction occurs in the battery, based on a comparison result of the voltage comparison step, wherein the side reaction occurrence judgment step further includes the steps of: comparing the voltage of the standard peak value with the voltage of the target peak value; and judging whether a negative electrode side reaction or a positive electrode side reaction occurs in the battery, according to the comparison result.

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