Battery diagnostic equipment and methods

Abstract

The invention relates to a method for diagnosing a battery comprising a first generation step to create a second characteristic curve by dividing the first characteristic curve representing the correlation between the state of charge (SOC) and the battery voltage into a first component corresponding to the first material and a second component corresponding to the second material, and then removing the first component from the first characteristic curve; a second generation step to create a third characteristic curve by estimating the correlation between SOC and the battery voltage over the entire SOC range of the battery based on the second characteristic curve; and a diagnostic step to diagnose the battery based on the calculated capacity, wherein which this capacity is provided by the first material in the total capacity provided by the electrode-active material based on the third characteristic curve.

Description

Battery diagnostic device and method

[0001] This application claims priority from Korean Patent Application No. 10-2024-0009037, filed January 19, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a secondary battery diagnostic device and method, and more particularly, to a battery diagnostic device and method for non-destructively diagnosing the state of a rechargeable battery.

[0003] Recently, with the rapid increase in demand for portable electronic products such as laptops, digital cameras, and mobile phones, and the full-scale development of electric vehicles, energy storage systems, robots, and satellites, research on high-performance rechargeable batteries is actively being conducted.

[0004] Rechargeable batteries include lithium batteries that utilize lithium ions, such as lithium-ion batteries and lithium-ion polymer batteries, as well as nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. Among these, lithium batteries offer a relatively long lifespan due to minimal memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density. Consequently, their application scope is gradually expanding.

[0005] The positive and negative electrodes of these batteries gradually deteriorate, losing their original electrical capacity as they undergo repeated charge and discharge cycles. Therefore, accurate diagnosis of battery condition is essential to accurately predict the battery's usable lifespan, remaining service life, and replacement timing.

[0006] However, existing technologies have a problem in accurately diagnosing batteries that use materials as electrode active materials, such as silicon or silicon oxide, that deform the shape of the profile representing the relationship between the battery's SOC and voltage in various directions as the battery deteriorates. This is because, if the shape of the battery's profile deforms in various directions rather than shrinking in one direction as the battery deteriorates, approximation using a predetermined reference profile is difficult.

[0007] In addition, for batteries that use a negative active material blended with silicon or silicon oxide and graphite, existing technologies have the problem of not being able to provide a method for diagnosing the deterioration state of silicon or silicon oxide separately from graphite.

[0008] The technical problem to be solved by the present invention is to provide a battery diagnosis device and method capable of quickly and accurately diagnosing a battery that uses a material, such as silicon or silicon oxide, as an electrode active material that changes the shape of a profile showing the relationship between the SOC and voltage of the battery in various directions according to the degradation of the battery.

[0009] Another technical problem to be solved by the present invention is to provide a battery diagnostic device and method capable of diagnosing the deterioration state of silicon or silicon oxide separately from graphite in a battery in which an electrode active material blended with silicon or silicon oxide and graphite is applied.

[0010] Another technical problem to be solved by the present invention is to provide a battery pack and a vehicle including a battery diagnostic device according to the present invention.

[0011] A battery diagnosis method according to one aspect of the present invention is a method for diagnosing a battery to which an electrode active material blended with a first material and a second material is applied, the method comprising: a first generation step of dividing a first profile indicating a relationship between a State of Charge (SOC) and voltage of the battery into a first portion corresponding to the first material and a second portion corresponding to the second material, and generating a second profile by removing the first portion from the first profile; a second generation step of generating a third profile based on the second profile, which estimates a relationship between the SOC and voltage of the battery in the entire SOC range of the battery; and a diagnosis step of calculating a capacity provided by the first material among the entire capacity provided by the electrode active material based on the third profile, and diagnosing the battery based on the calculated capacity.

[0012] In one embodiment, the battery diagnosis method may further include, before the first generation step, a step of generating the first profile based on voltage values ​​of the battery measured while the battery is discharged.

[0013] In one embodiment, in the first generation step, the first profile can be divided into the first part and the second part based on a predetermined SOC value.

[0014] In one embodiment, the first generation step may include, before generating the second profile, generating a differential profile indicating a correspondence between the SOC of the battery and a differential voltage obtained by differentiating the voltage of the battery with respect to the capacity; detecting a predetermined peak point or valley point among peak points and valley points appearing in the differential profile, and determining an SOC value corresponding to the detected peak point or valley point; and dividing the first profile into the first portion and the second portion based on the determined SOC value.

[0015] In one embodiment, the second generation step may include, before generating the third profile, adjusting a reference positive electrode profile indicating a correspondence between the SOC and the positive electrode potential of a predetermined reference battery and a reference negative electrode profile indicating a correspondence between the SOC and the negative electrode potential of the reference battery to generate an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the second profile; and generating the third profile based on the adjusted positive electrode profile and the adjusted negative electrode profile.

[0016] In one embodiment, the adjusted anode profile and the adjusted cathode profile can be generated by adjusting at least one of the position, scale, and shape of the reference anode profile and the reference cathode profile, respectively, on a predetermined coordinate axis.

[0017] In one embodiment, the third profile can be generated by calculating the potential difference by SOC between the adjusted positive electrode profile and the adjusted negative electrode profile.

[0018] In one embodiment, in the diagnostic step, the capacity provided by the first substance can be calculated by subtracting the capacity provided by the second substance from the total capacity.

[0019] In one embodiment, the diagnostic step may include a step of diagnosing the battery by comparing the calculated capacity with a predetermined reference capacity.

[0020] In one embodiment, the first material may be silicon or silicon oxide, and the second material may include graphite.

[0021] According to another aspect of the present invention, a battery diagnosis device is a device for diagnosing a battery to which an electrode active material blended with a first material and a second material is applied, the device comprising: a first generation unit for dividing a first profile indicating a relationship between a State of Charge (SOC) and voltage of the battery into a first portion corresponding to the first material and a second portion corresponding to the second material, and generating a second profile by removing the first portion from the first profile; a second generation unit for generating a third profile by estimating a relationship between the SOC and voltage of the battery in the entire SOC range of the battery based on the second profile; and a diagnosis unit for calculating a capacity provided by the first material among the entire capacity provided by the electrode active material based on the third profile, and diagnosing the battery based on the calculated capacity.

[0022] In one embodiment, the first generation unit may be configured to divide the first profile into the first part and the second part based on a predetermined SOC value, and generate a second profile by removing the first part from the first profile.

[0023] In one embodiment, the second generation unit may include an adjustment module configured to adjust a reference positive electrode profile indicating a correspondence between the SOC and the positive electrode potential of a given reference battery and a reference negative electrode profile indicating a correspondence between the SOC and the negative electrode potential of the reference battery, thereby generating an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the second profile; and a third profile generation module configured to generate the third profile based on the adjusted positive electrode profile and the adjusted negative electrode profile.

[0024] A battery pack according to another aspect of the present invention includes the battery diagnostic device described above.

[0025] A vehicle according to another aspect of the present invention includes the battery diagnostic device described above.

[0026] The present invention, when diagnosing a battery to which an electrode active material blended with a first material and a second material is applied, divides a first profile indicating a correspondence between the SOC and voltage of the battery into a first part corresponding to the first material and a second part corresponding to the second material, generates a second profile by removing the first part from the first profile, and diagnoses the battery based on this second profile, thereby enabling rapid and accurate diagnosis even when the first material is a material that deforms the shape of the profile of the battery in various directions as the battery deteriorates, such as silicon or silicon oxide.

[0027] In addition, the present invention can diagnose the degradation state of the first material separately from the overall state of the battery by calculating the capacity provided by the first material among the total capacity provided by the electrode active material and diagnosing the battery based on the calculated capacity. That is, the present invention can diagnose the degradation state of silicon or silicon oxide separately from the graphite in a battery to which an anode active material blending silicon or silicon oxide and graphite is applied.

[0028] Furthermore, those skilled in the art will readily understand from the following description that various embodiments of the present invention can solve various technical problems not mentioned above.

[0029] FIG. 1 is a block diagram showing a battery diagnostic device according to one embodiment of the present invention.

[0030] Figure 2 is a drawing showing a first profile of a target battery.

[0031] Figure 3 is a drawing showing the differential profile of the target battery.

[0032] Figure 4 is a drawing showing a first profile divided into multiple parts.

[0033] Figure 5 is a drawing showing a second profile generated from the first profile of Figure 4.

[0034] FIG. 6 is a drawing showing an adjusted anode profile and an adjusted cathode profile corresponding to the second profile of FIG. 5.

[0035] Fig. 7 is a drawing showing a third profile generated based on the adjusted anode profile and the adjusted cathode profile of Fig. 5.

[0036] Figure 8 is a drawing showing a differential profile obtained from the third profile of Figure 7.

[0037] Figure 9 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention.

[0038] FIG. 10 is a drawing showing a battery pack according to one embodiment of the present invention.

[0039] Fig. 11 is a drawing showing a vehicle according to one embodiment of the present invention.

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings to clarify solutions addressing the technical challenges of the present invention. However, if a description of a related known technology obscures the essence of the present invention, the description thereof may be omitted.

[0041] Additionally, the terms used in this specification are defined based on their functions within the present invention, and may vary depending on the intent or custom of the designer, manufacturer, etc. Therefore, the definitions of terms described below should be based on the contents throughout this specification.

[0042] FIG. 1 is a block diagram showing a battery diagnostic device (100) according to one embodiment of the present invention.

[0043] As illustrated in FIG. 1, a battery diagnostic device (100) according to one embodiment of the present invention is a device configured to diagnose the state of a rechargeable battery, and includes a first generation unit (110), a second generation unit (120), and a diagnostic unit (130), and may further include a charge / discharge control unit (140) according to an embodiment.

[0044] The battery (hereinafter, “target battery”) to be diagnosed by the battery diagnosis device (100) according to the present invention may be a battery cell corresponding to a basic unit of charging and discharging, a battery module in which multiple battery cells are connected in series and / or parallel, or a battery pack in which multiple battery cells or multiple battery modules are connected in series and / or parallel.

[0045] In this case, the target battery may include an electrode assembly in which a positive electrode and a negative electrode are mutually stacked with a separator interposed therebetween, and a case that accommodates the electrode assembly together with an electrolyte material.

[0046] Meanwhile, the positive electrode forming the electrode assembly of the target battery may include a positive electrode substrate made of a material including aluminum, and a positive electrode active material applied to the positive electrode substrate. The positive electrode active material may include a lithium-based oxide. The positive electrode active material may be applied to the positive electrode substrate together with a conductive material, a binder, and the like.

[0047] The negative electrode of the above electrode assembly may include a negative electrode substrate made of a material including copper, and a negative electrode active material applied to the negative electrode substrate. The negative electrode active material may be silicon (Si) or silicon oxide (SiO x ) and graphite. That is, the negative electrode active material may be a mixture in which a silicon-based material and graphite are each blended at a predetermined composition ratio. This negative electrode active material may be applied to the negative electrode substrate together with a conductive material, a binder, etc.

[0048] In this way, silicon (Si) or silicon oxide (SiO x ) is included in the negative active material of the battery, thereby increasing the electrical capacity provided by the same weight of negative active material and increasing the energy density of the battery cell.

[0049] Meanwhile, silicon (Si) or silicon oxide (SiO x ) as an electrode active material, the profile showing the correspondence between the SOC (State of Charge) and voltage of a battery does not simply shrink in one direction as the battery deteriorates, but rather deforms in multiple directions.

[0050] Also, silicon (Si) or silicon oxide (SiO x ) as an electrode active material, mainly silicon (Si) or silicon oxide (SiO x ) occurs due to the degeneration of silicon (Si) or silicon oxide (SiO). Therefore, when diagnosing the battery, x ) needs to be diagnosed separately from the graphite with which it is blended.

[0051] A battery diagnostic device (100) according to the present invention is configured to diagnose a battery to which an electrode active material blended with a first material and a second material is applied.

[0052] That is, the first generation unit (110) is configured to divide the first profile, which represents the relationship between the SOC (State of Charge) and voltage of the target battery, into a first part corresponding to the first material and a second part corresponding to the second material, and to generate a second profile by removing the first part from the first profile.

[0053] The second generation unit (120) is configured to generate a third profile that estimates the correspondence between the SOC and voltage of the battery in the entire SOC range of the battery based on the second profile.

[0054] The above diagnostic unit (130) is configured to calculate the capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile, and to diagnose the battery based on the calculated capacity.

[0055] In one embodiment, the first generation unit (110) may include a first profile generation module (112) and a second profile generation module (114).

[0056] In this case, the first profile generation module (112) may be configured to generate the first profile based on voltage values ​​of the target battery measured while the target battery is being charged or discharged.

[0057] For example, the first material may be silicon (Si) or silicon oxide (SiO). x ) and when the second material is graphite, the first profile generation module (112) can generate the first profile based on the voltage values ​​of the target battery measured while the target battery is 'discharged'.

[0058] As will be explained further below, silicon (Si) or silicon oxide (SiO x ) operates over the entire SOC range of the target battery during charging, but only in the lower SOC range of the entire SOC range of the target battery during discharging. Therefore, in the first profile obtained while the target battery is being discharged, silicon (Si) or silicon oxide (SiO x ) can be easily distinguished from the remaining parts.

[0059] For reference, the current capacity of the target battery can be calculated by applying the current integration method to the charging current or discharging current of the target battery.

[0060] Next, the second profile generation module (114) may be configured to divide the first profile into the first part and the second part based on a predetermined SOC value, and generate a second profile by removing the first part from the first profile.

[0061] In one embodiment, the SOC value that determines the portion to be removed of the first profile may be determined in advance according to the composition ratio of the first material and the second material.

[0062] In another embodiment, the SOC value may be determined based on a differential profile representing a correspondence between the SOC of the target battery and a differential voltage obtained by differentiating the voltage of the target battery with respect to its capacity.

[0063] In this case, the second profile generation module (114) may include first to third sub-modules (not shown). The first sub-module may be configured to generate the differential profile before generating the second profile. The second sub-module may be configured to detect a predetermined peak point or valley point among peak points and valley points appearing in the differential profile, and determine an SOC value corresponding to the detected peak point or valley point. The third sub-module may be configured to divide the first profile into the first part and the second part based on the determined SOC value, and generate a second profile by removing the first part from the first profile.

[0064] In one embodiment, the second generation unit (120) may include an adjustment module (122) and a third profile generation module (124).

[0065] The above adjustment module (122) may be configured to adjust a reference positive electrode profile indicating a correspondence between the SOC and the positive electrode potential of a predetermined reference battery and a reference negative electrode profile indicating a correspondence between the SOC and the negative electrode potential of the reference battery before generating the third profile, thereby generating an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the second profile. The reference battery may be a target battery at the beginning of life (BOL) point in time or a battery in a normal state with the same configuration as the target battery.

[0066] For example, the adjustment module (122) can generate an adjusted anode profile and an adjusted cathode profile by adjusting at least one of the position, scale, and shape of each of the reference anode profile and the reference cathode profile on a predetermined coordinate axis.

[0067] In this case, among various candidate anode profiles and various candidate cathode profiles generated by moving or deforming the reference anode profile and the reference cathode profile on a plane having a horizontal axis representing the SOC of the target battery and a vertical axis representing the voltage of the target battery, respectively, the candidate anode profile and the candidate cathode profile that generate a curve with the smallest error from the second profile by mutual combination can be selected as the above-described adjusted anode profile and adjusted cathode profile, respectively.

[0068] Next, the third profile generation module (124) can be configured to generate the third profile based on the adjusted positive profile and the adjusted negative profile.

[0069] For example, the third profile generation module (124) may be configured to generate the third profile by calculating the potential difference by SOC between the adjusted positive profile and the adjusted negative profile.

[0070] As a result, the diagnostic unit (130) can diagnose the target battery based on the third profile.

[0071] That is, the diagnostic unit (130) may be configured to calculate the capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile, and to diagnose the battery based on the calculated capacity.

[0072] In this case, the diagnostic unit (130) can calculate the capacity provided by the first material by excluding the capacity provided by the second material from the total capacity.

[0073] Additionally, the diagnostic unit (130) may be configured to diagnose the target battery by comparing the calculated capacity with a predetermined reference capacity. The reference capacity may be a capacity provided by the first material of the target battery at the BOL point in time, or a capacity intended to be provided by the first material during the design of the target battery.

[0074] In one embodiment, the battery diagnostic device (100) may further include a charge / discharge control unit (140).

[0075] The above charge / discharge control unit (140) may be configured to control the charge / discharge conditions of the target battery, such as the voltage at full charge of the target battery, or the current rate of the charge / discharge current of the target battery, according to the diagnosis result of the above-described diagnosis unit (130). For example, when the target battery is diagnosed as deteriorated, the charge / discharge control unit (140) may control a charge / discharge unit (not shown) that charges / discharges the target battery to lower the voltage at full charge of the target battery, or reduce the current rate of the charge / discharge current.

[0076] In one embodiment, among the first material and the second material included in the electrode active material of the target battery, the first material is silicon (Si) or silicon oxide (SiO x ), and the second material may be a material including at least graphite.

[0077] The first generation unit (110), second generation unit (120), diagnosis unit (130), and charge / discharge control unit (140) of the above-described battery diagnosis device (100) may be implemented as a combination of a processor and a program executed by the processor. The battery diagnosis device (100) may be implemented as a single processor, or as two or more processors that are interconnected.

[0078] In one embodiment, the battery diagnostic device (100) according to the present invention can be configured to be linked with various sensors, such as a voltage sensor (12a) that senses the voltage of the battery, a current sensor (12b) that senses the charge / discharge current of the battery, etc.

[0079] In addition, the battery diagnosis device (100) according to the present invention may be configured to interwork with a communication unit (14) that performs communication with another device located remotely. In this case, the communication unit (14) may be configured to receive data transmitted from a remote server or communication terminal via a wired / wireless communication network and transmit the data to the battery diagnosis device (100), or to transmit data generated by the battery diagnosis device (100) to another server or communication terminal. To this end, the communication unit (14) may include a communication modem that performs wired or wireless communication.

[0080] In addition, the battery diagnostic device (100) according to the present invention may be configured to be linked with a storage unit (16) capable of storing programs or data required for battery diagnosis. In this case, the storage unit (16) may include one or two or more types of recording media such as RAM, ROM, EEPROM, flash memory, registers, etc.

[0081] In another embodiment, the battery diagnostic device (100) according to the present invention may be configured to include one or two or more of the voltage sensor (12a), current sensor (12b), communication unit (14), and storage unit (16) described above.

[0082] Figure 2 is a drawing showing the first profile (BP1) of the target battery.

[0083] As illustrated in FIG. 2, the first generation unit (110) can first generate a first profile (BP1) indicating a correspondence relationship between the SOC and voltage of the target battery.

[0084] For example, the first profile generation module (112) of the first generation unit (110) can generate the first profile based on voltage values ​​of the target battery measured while the target battery is being charged or discharged.

[0085] In particular, the first material is silicon (Si) or silicon oxide (SiO x ), and when the second material is graphite, the first profile generation module (112) can generate the first profile (BP1) based on the voltage values ​​of the target battery measured while the target battery is 'discharged'.

[0086] For reference, silicon (Si) or silicon oxide (SiO x ) operates over the entire SOC range of the target battery during charging, but only operates in a lower SOC range of the entire SOC range of the target battery during discharging. Therefore, in the first profile (BP1) obtained while the target battery is being discharged, silicon (Si) or silicon oxide (SiO x ) can be easily distinguished from the remaining parts.

[0087] For example, in order to diagnose the condition of a target battery, a simulation program that fits the anode profile and cathode profile that best represent the battery condition by shifting or contracting the reference anode profile and the reference cathode profile in a predetermined direction, respectively, must be used to obtain the anode profile (PP) and cathode profile (NP) of the target battery corresponding to the first profile (BP1). Here, the anode profile (PP) is a profile that estimates the correspondence between the SOC of the target battery and the cathode potential, and the cathode profile (NP) is a profile that estimates the correspondence between the SOC of the target battery and the cathode potential.

[0088] However, as the battery deteriorates, the shape of the battery's profile changes in various directions, such as silicon (Si) or silicon oxide (SiO). x ) as an electrode active material, a large error occurs in the positive electrode profile (PP) and negative electrode profile (NP) obtained from the first profile (BP1).

[0089] Figure 3 is a drawing showing the differential profile (DP2) of the target battery.

[0090] As illustrated in FIG. 3, the differential profile (DP2) represents a correspondence between the SOC of the target battery and the differential voltage obtained by differentiating the voltage of the target battery with respect to its capacity.

[0091] For example, among the first and second materials included in the negative active material of the target battery, if the first material is silicon (Si) or silicon oxide (SiOx) and the second material is graphite, the differential profile (DP2) obtained using the above-described simulation program has a significant error in the high SOC range (ΔS2) as well as the low SOC range (ΔS1) when compared to the actual differential profile (DP1) of the experimentally generated target battery.

[0092] Accordingly, the second profile generation module (114) of the first generation unit (110) divides the first profile (BP1) into a first part corresponding to the first material and a second part corresponding to the second material, in order to remove an error caused by the first material, and generates a second profile by removing the first part from the first profile (BP1). In this case, the second profile generation module (114) can divide the first profile (BP1) into the first part and the second part based on a predetermined SOC value (x).

[0093] Figure 4 is a drawing showing a first profile (BP1) divided into multiple parts.

[0094] As illustrated in Fig. 4, the second profile generation module (114) can divide the first profile (BP1) into a first portion (P1) and a second portion (P2) based on a predetermined SOC value (x). The first portion (P1) corresponds to a first material that operates in a relatively low SOC range when discharging the target battery, and the second portion (P2) corresponds to a second material that operates in a relatively high SOC range.

[0095] Next, the second profile generation module (114) generates a second profile by removing the first portion (P1) from the first profile (BP1).

[0096] In one embodiment, the SOC value (x) that determines the portion to be removed of the first profile (BP1) can be determined in advance according to the composition ratio of the first material and the second material.

[0097] In another embodiment, the SOC value (x) may be determined based on a differential profile representing a correspondence between the SOC of the target battery and a differential voltage obtained by differentiating the voltage of the target battery with respect to its capacity. To this end, the first to third sub-modules (not shown) of the second profile generation module (114) may be included.

[0098] In this case, the first sub-module can generate a differential profile of the target battery before generating the second profile.

[0099] Next, the second sub-module can detect a predetermined peak point or valley point among the peak points and valley points appearing in the generated differential profile, and determine an SOC value (x) corresponding to the detected peak point or valley point.

[0100] For example, as illustrated in FIG. 3, the second sub-module can detect a valley point that appears at the lowest SOC among the peak points and valley points appearing in the differential profile, and determine an SOC value (x) corresponding to the detected valley point.

[0101] Next, the third sub-module can divide the first profile (BP1) into a first part (P1) and a second part (P2) based on the determined SOC value (x), and generate a second profile by removing the first part (P1) from the first profile (BP1). In this case, the third sub-module can find a point (y) corresponding to the SOC value (x) in the first profile (BP1), and determine a part of the first profile (BP1) located in an SOC range lower than the point (y) as the first part (P1), and determine a part of the first profile (BP1) located in an SOC range higher than the point (y) as the second part (P2).

[0102] Figure 5 is a drawing showing a second profile (BP2) generated from the first profile of Figure 4.

[0103] As illustrated in FIG. 5, when a second profile (BP2) is generated by removing the first portion (P1) from the first profile (BP1), the second generation unit (120) can generate a third profile that estimates the correspondence between the target battery SOC and voltage in the entire SOC range of the target battery based on the second profile (BP2). To this end, the second generation unit (120) can include an adjustment module (122) and a third profile generation module (124).

[0104] The above adjustment module (122) may be configured to adjust a reference positive electrode profile (RP) indicating a correspondence between the SOC and positive electrode potential of a given reference battery and a reference negative electrode profile (RN) indicating a correspondence between the SOC and negative electrode potential of the reference battery before generating the third profile, thereby generating an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the second profile (BP2). The reference battery may be a target battery at the beginning of life (BOL) point in time or a battery in a normal state with the same configuration as the target battery.

[0105] In this case, the adjustment module (122) can generate an adjusted anode profile and an adjusted cathode profile by adjusting at least one of the position, scale, and shape of each of the reference anode profile and the reference cathode profile on a predetermined coordinate axis.

[0106] FIG. 6 is a drawing showing an adjusted anode profile (AP) and an adjusted cathode profile (AN) corresponding to the second profile of FIG. 5.

[0107] As illustrated in FIG. 6, the adjustment module (122) can select, among various candidate anode profiles and various candidate cathode profiles generated by moving or contracting the reference anode profile (RP) and the reference anode profile (RP) respectively on a plane having a horizontal axis representing the SOC of the target battery and a vertical axis representing the voltage of the target battery, a candidate anode profile and a candidate cathode profile that generate a curve with the smallest error with the second profile (B2) through mutual combination as the above-described adjusted anode profile (AP) and the adjusted cathode profile (AN), respectively.

[0108] Next, the third profile generation module (124) can generate a third profile based on the adjusted positive profile (AP) and the adjusted negative profile (AN).

[0109] FIG. 7 is a drawing showing a third profile (BP3) generated based on the adjusted positive and negative profiles of FIG. 5.

[0110] As illustrated in FIG. 7, the third profile generation module (124) can generate a third profile (BP3) by calculating the potential difference for each SOC between the adjusted positive profile (AP) and the adjusted negative profile (AN).

[0111] Next, the diagnostic unit (130) can diagnose the target battery based on the third profile (BP3).

[0112] For example, when the negative active material of the target battery includes silicon (Si) or silicon oxide (SiOx) and graphite, the diagnostic unit (130) can find an initiation potential (pi) corresponding to the initiation point of the third profile (BP3) in the adjusted positive electrode profile (AP) with a relatively small error, and then infer the initiation potential (ni) of the adjusted negative electrode profile (AN) from the initiation potential (pi) and the initiation voltage of the third profile (BP3).

[0113] In this way, the diagnostic unit (130) can diagnose the target battery using the diagnostic information obtained based on the third profile (BP3). The diagnostic information may include at least one of the starting potential (pi), the ending potential (pf), and the shrinkage (ps) of the adjusted positive electrode profile (AP), and the starting potential (ni), the ending potential (nf), and the shrinkage (ns) of the adjusted negative electrode profile (AN).

[0114] Here, the shrinkage (ps) of the adjusted anode profile (AP) represents the degree to which the adjusted anode profile (AP) shrinks in the SOC axis direction compared to the reference anode profile (RP).

[0115] Additionally, the shrinkage (ns) of the adjusted cathode profile (AN) indicates the degree to which the adjusted cathode profile (AN) shrinks in the SOC axis direction compared to the reference cathode profile (RN).

[0116] The above diagnostic unit (130) can diagnose the target battery by comparing the above diagnostic information with pre-stored reference information. In this case, the reference information may include at least one of the starting potential, ending potential, and shrinkage of the reference positive electrode profile (RP), and the starting potential, ending potential, and shrinkage of the reference negative electrode profile (RN).

[0117] In particular, the diagnostic unit (130) can calculate the capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile (BP3), and diagnose the target battery based on the calculated capacity.

[0118] In this case, the diagnostic unit (130) can calculate the capacity provided by the first material by excluding the capacity provided by the second material from the total capacity.

[0119] Fig. 8 is a drawing showing a differential profile (DP3) obtained from the third profile of Fig. 7.

[0120] As shown in Fig. 8, compared with the actual differential profile (DP1) of the experimentally obtained target battery, the differential profile (DP3) has some error in the low SOC range (ΔS1') where the first material mainly acts, but the error is minimized in the high SOC range (ΔS2') where the second material mainly acts.

[0121] For example, when the first material is silicon (Si) or silicon oxide (SiOx) and the second material is graphite, most of the capacity provided by the first material is provided in the low SOC range (ΔS1'). Additionally, most of the capacity provided by the second material is provided in the high SOC range (ΔS2').

[0122] Therefore, the capacity provided by the first material can be calculated by excluding the capacity provided by the second material from the total capacity provided by the electrode active material in which the first material and the second material are blended. In this case, the total capacity can be calculated by converting the SOC value of the target battery shown in the third profile (BP3) or the differential profile (DP3) into a capacity value, or by applying the current integration method to the charge current or discharge current of the target battery. In addition, the capacity provided to the second material can be calculated by converting the SOC change amount from the boundary value (x') between the SOC range where the first material acts and the SOC range where the second material acts to the maximum SOC value of the target battery into a capacity.

[0123] Next, the diagnostic unit (130) can diagnose the target battery by comparing the capacity of the calculated first material with a predetermined reference capacity. The reference capacity may be the capacity provided by the first material of the target battery at the BOL point in time, or the capacity intended to be provided by the first material when the target battery is designed.

[0124] In one embodiment, the battery diagnostic device (100) may further include a charge / discharge control unit (140).

[0125] In this case, the charge / discharge control unit (140) can control the charge / discharge conditions of the target battery, such as the voltage at full charge of the target battery, or the current rate of the charge / discharge current of the target battery, based on the diagnosis result according to the above-described diagnosis process. For example, if the target battery is diagnosed as deteriorated, the charge / discharge control unit (140) can control the charge / discharge unit (not shown) that charges and discharges the target battery to lower the voltage at full charge of the target battery, or reduce the current rate of the charge / discharge current.

[0126] Figure 9 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention.

[0127] As illustrated in FIG. 9, the battery diagnosis method according to the present invention is a method for diagnosing a rechargeable battery in a non-destructive manner, and can be performed by a processor.

[0128] In addition, the target battery to be diagnosed by the battery diagnosis method according to the present invention is a battery to which an electrode active material blended with a first material and a second material is applied, and may be a battery cell corresponding to a basic unit of charge and discharge, a battery module in which a plurality of battery cells are connected in series and / or parallel, or a battery pack in which a plurality of battery cells or a plurality of battery modules are connected in series and / or parallel.

[0129] The processor can divide the first profile representing the relationship between the SOC and voltage of the target battery into a first part (P1) corresponding to the first material and a second part (P2) corresponding to the second material, and generate a second profile by removing the first part from the first profile.

[0130] To this end, the processor generates a first profile (BP1) indicating a correspondence between the SOC and voltage of the target battery (S10).

[0131] At this time, the processor can generate the first profile based on the voltage values ​​of the target battery measured while the target battery is being charged or discharged. In particular, the first material may be silicon (Si) or silicon oxide (SiO x ), and if the second material is graphite, the processor can generate the first profile (BP1) based on voltage values ​​of the target battery measured while the target battery is 'discharged'.

[0132] Next, the processor divides the first profile (BP1) into a first part (P1) and a second part (P2) based on a predetermined SOC value (x), and generates a second profile (BP2) by removing the first part (P1) from the first profile (BP1) (S20).

[0133] As described with respect to FIG. 4, the first portion (P1) may be a portion corresponding to a first material that operates in a relatively low SOC range during discharge of the target battery, and the second portion (P2) may be a portion corresponding to a second material that operates in a relatively high SOC range.

[0134] In one embodiment, the SOC value (x) that determines the portion to be removed of the first profile (BP1) can be determined in advance according to the composition ratio of the first material and the second material.

[0135] In another embodiment, the SOC value (x) may be determined based on a differential profile representing a correspondence between the SOC of the target battery and a differential voltage obtained by differentiating the voltage of the target battery with respect to its capacity.

[0136] In this case, the processor may generate a differential profile of the target battery before generating the second profile (BP2), detect a predetermined peak point or valley point among peak points and valley points appearing in the generated differential profile, and determine an SOC value (x) corresponding to the detected peak point or valley point.

[0137] Next, the processor generates a third profile (BP3) that estimates the correspondence between the SOC and voltage of the target battery in the entire SOC range of the target battery based on the second profile (BP2) (S30).

[0138] In this case, before generating the third profile (BP3), the processor may adjust the reference positive profile (RP) indicating the correspondence between the SOC and the positive electrode potential of a given reference battery, and the reference negative profile (RN) indicating the correspondence between the SOC and the negative electrode potential of the reference battery, to generate an adjusted positive electrode profile (AP) and an adjusted negative electrode profile (AN) corresponding to the second profile (BP2). The reference battery may be a target battery at the beginning of life (BOL) point in time, or a battery in a normal state with the same configuration as the target battery.

[0139] For example, the processor can adjust at least one of the position, scale, and shape of the reference anode profile (RP) and the reference cathode profile (RN) on a predetermined coordinate axis to generate an adjusted anode profile (AP) and an adjusted cathode profile (AN).

[0140] That is, the processor, as described in relation to FIG. 6, shifts or contracts the reference positive electrode profile (RP) and the reference positive electrode profile (RP) in a predetermined direction on a plane having a horizontal axis representing the SOC of the target battery and a vertical axis representing the voltage of the target battery, respectively, and generates various candidate positive electrode profiles and various candidate negative electrode profiles, and selects the candidate positive electrode profile and the candidate negative electrode profile that generate a curve with the smallest error with the second profile (B2) through mutual combination as the above-described adjusted positive electrode profile (AP) and the adjusted negative electrode profile (AN), respectively.

[0141] In addition, the processor can generate a third profile (BP3) based on the adjusted positive profile (AP) and the adjusted negative profile (AN). For example, the processor can generate the third profile (BP3) by calculating the potential difference by SOC between the adjusted positive profile (AP) and the adjusted negative profile (AN).

[0142] Next, the processor calculates the capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile (BP3), and diagnoses the target battery based on the calculated capacity (S40).

[0143] For example, when the negative active material of the target battery includes silicon (Si) or silicon oxide (SiOx) and graphite, the processor can find an initiation potential (pi) corresponding to the initiation point of the third profile (BP3) in the adjusted positive electrode profile (AP) with a relatively small error, and then infer the initiation potential (ni) of the adjusted negative electrode profile (AN) from the initiation potential (pi) and the initiation voltage of the third profile (BP3).

[0144] In this way, the processor can diagnose the target battery using the diagnostic information obtained based on the third profile (BP3). The diagnostic information may include at least one of the initiation potential (pi), the end potential (pf), and the shrinkage (ps) of the adjusted positive electrode profile (AP), and the initiation potential (ni), the end potential (nf), and the shrinkage (ns) of the adjusted negative electrode profile (AN).

[0145] Here, the shrinkage (ps) of the adjusted anode profile (AP) represents the degree to which the adjusted anode profile (AP) shrinks in the SOC axis direction compared to the reference anode profile (RP).

[0146] Additionally, the shrinkage (ns) of the adjusted cathode profile (AN) indicates the degree to which the adjusted cathode profile (AN) shrinks in the SOC axis direction compared to the reference cathode profile (RN).

[0147] Additionally, the processor can diagnose the target battery by comparing the diagnostic information with pre-stored reference information. In this case, the reference information may include at least one of the starting potential, ending potential, and shrinkage of the reference positive electrode profile (RP), and the starting potential, ending potential, and shrinkage of the reference negative electrode profile (RN).

[0148] In particular, the processor can calculate the capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile (BP3), and diagnose the target battery based on the calculated capacity.

[0149] In this case, the processor can calculate the capacity provided by the first material by subtracting the capacity provided by the second material from the total capacity.

[0150] Next, the processor can adjust the charging and discharging conditions of the target battery, such as the voltage of the target battery when fully charged, or the current rate of the charging current or discharging current of the target battery, based on the diagnosis results for the target battery.

[0151] For example, if the target battery is diagnosed as degenerated (S50), the processor can control a charging / discharging unit (not shown) that charges / discharges the target battery to lower the voltage at full charge of the target battery or reduce the current rate of the charging / discharging current (S60).

[0152] The above processor can repeat the above-described processes (S10 to S60) until the use of the target battery is stopped (S70).

[0153] FIG. 10 is a drawing showing a battery pack (10) according to one embodiment of the present invention.

[0154] As illustrated in FIG. 10, the battery pack (10) includes a rechargeable battery (B) and a battery diagnostic device (100) according to the present invention. In one embodiment, the battery pack (10) may optionally further include a measuring unit (12), a communication unit (14), a storage unit (16), and a charging / discharging unit (18).

[0155] The above measurement unit (12) may be configured to measure the voltage and / or current of the battery (B). To this end, the measurement unit (12) may include a voltage sensor (12a) and a current sensor (12b) described with reference to FIG. 1.

[0156] This measuring unit (12) can measure the voltage of the battery (B) through the first sensing line (SL1) and the second sensing line (SL2). In addition, the measuring unit (12) can measure the current of the battery (B) through the third sensing line (SL3) connected to the current measuring circuit (A). The current measuring circuit (A) may include a shunt resistor.

[0157] A battery diagnostic device (100) according to one embodiment of the present invention can obtain voltage values ​​of a battery (B) through the measuring unit (12).

[0158] The above communication unit (14) may be configured to perform communication with another device located remotely. For example, the communication unit (14) may be configured to receive data transmitted from a remote server or communication terminal via a wired / wireless communication network and transmit the data to the battery diagnosis device (100), or to transmit data generated in the battery diagnosis device (100) to another server or communication terminal. To this end, the communication unit (14) may include a communication modem that performs wired / wireless communication.

[0159] The above storage unit (16) may be configured to store programs or data required for battery diagnosis. In this case, the storage unit (16) may include one or more of various types of recording media, such as RAM, ROM, EEPROM, flash memory, registers, etc.

[0160] The above charging and discharging unit (18) may be configured to charge and / or discharge the battery (B). To this end, the charging and discharging unit (18) may include a charger for charging the battery (B), a discharger for discharging the battery (B), at least one switch for electrically connecting the battery (B) to terminals (T1, T2) of the battery pack (10), etc.

[0161] The battery diagnostic standby (100) according to one embodiment of the present invention can control the charging / discharging unit (18) to proceed or stop charging or discharging of the battery (B), set charging / discharging conditions, or change the set charging / discharging conditions.

[0162] Fig. 11 is a drawing showing a vehicle (2) according to one embodiment of the present invention.

[0163] As illustrated in FIG. 11, a vehicle (2) according to one embodiment of the present invention may include a battery pack (10) that provides electric energy required for the operation of the vehicle, and a battery diagnostic device (100) according to the present invention.

[0164] In this case, the battery diagnostic device (100) may be configured to be linked with an ECU (Electronic Control Unit) that controls the operation of the vehicle (2) or a BMS (Battery Management System) of the battery pack (10).

[0165] Additionally, the battery diagnostic device (100) may be configured to receive data transmitted from a remote server (4) via a wired / wireless communication network, or to transmit data generated by the battery diagnostic device (100) to the server (4).

[0166] For reference, the battery diagnostic device (100) according to the present invention can be applied to various electrical devices or electrical systems other than vehicles, and can also be applied to ESS (Energy Storage System).

[0167] As described above, the present invention, when diagnosing a battery to which an electrode active material blended with a first material and a second material is applied, divides a first profile indicating a correspondence between the SOC and voltage of the battery into a first part corresponding to the first material and a second part corresponding to the second material, generates a second profile by removing the first part from the first profile, and diagnoses the battery based on this second profile, thereby enabling rapid and accurate diagnosis even when the first material is a material that deforms the shape of the profile of the battery in various directions as the battery deteriorates, such as silicon or silicon oxide.

[0168] In addition, the present invention can diagnose the degradation state of the first material separately from the overall state of the battery by calculating the capacity provided by the first material among the total capacity provided by the electrode active material and diagnosing the battery based on the calculated capacity. That is, the present invention can diagnose the degradation state of silicon or silicon oxide separately from the graphite in a battery to which an anode active material blending silicon or silicon oxide and graphite is applied.

[0169] Furthermore, it goes without saying that embodiments according to the present invention can solve various technical problems other than those mentioned in the present specification, not only in the relevant technical field but also in related technical fields.

[0170] The present invention has been described with reference to specific embodiments. However, those skilled in the art will clearly understand that various modifications can be implemented within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered illustrative rather than limiting. In other words, the true scope of the present invention is set forth in the claims, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0171] [Explanation of symbols]

[0172] 2: Vehicle

[0173] 10: Battery pack

[0174] 100: Battery Diagnostic Device

[0175] 110: First Generation Unit

[0176] 120: Second Generation Unit

[0177] 130: Diagnostic Department

[0178] 140: Charge / discharge control unit

Claims

1. A battery diagnosis method for diagnosing a battery to which an electrode active material blended with a first material and a second material is applied, A first generation step of generating a second profile by dividing a first profile showing a relationship between the SOC (State of Charge) and voltage of the battery into a first part corresponding to the first material and a second part corresponding to the second material, and removing the first part from the first profile; A second generation step for generating a third profile that estimates the correspondence between the SOC and voltage of the battery over the entire SOC range of the battery based on the second profile; and A battery diagnosis method comprising a diagnosis step of calculating a capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile and diagnosing the battery based on the calculated capacity.

2. In paragraph 1, Before the first generation step, A battery diagnosis method, characterized in that it further comprises a step of generating the first profile based on voltage values of the battery measured while the battery is discharged.

3. In paragraph 1, A battery diagnosis method, characterized in that in the first generation step, the first profile is divided into the first part and the second part based on a predetermined SOC value.

4. In paragraph 1, The above first generation step is, Before generating the second profile, a step of generating a differential profile showing a correspondence between the SOC of the battery and the differential voltage obtained by differentiating the voltage of the battery with respect to the capacity; A step of detecting a predetermined peak point or valley point among peak points and valley points shown in the above differential profile, and determining a SOC value corresponding to the detected peak point or valley point; and A battery diagnosis method, characterized by including a step of dividing the first profile into the first part and the second part based on the determined SOC value.

5. In paragraph 1, The second generation step is: Before generating the third profile, a step of adjusting a reference anode profile representing a correspondence between the SOC and the anode potential of a given reference battery and a reference cathode profile representing a correspondence between the SOC and the cathode potential of the reference battery to generate an adjusted cathode profile and an adjusted cathode profile corresponding to the second profile; and A battery diagnosis method, characterized by comprising a step of generating the third profile based on the adjusted positive electrode profile and the adjusted negative electrode profile.

6. In paragraph 5, A battery diagnosis method, characterized in that the adjusted positive electrode profile and the adjusted negative electrode profile are generated by adjusting at least one of the position, scale, and shape of each of the reference positive electrode profile and the reference negative electrode profile on a predetermined coordinate axis.

7. In paragraph 5, A battery diagnosis method, characterized in that the third profile is generated by calculating the potential difference by SOC between the adjusted positive electrode profile and the adjusted negative electrode profile.

8. In paragraph 1, A battery diagnosis method, characterized in that in the above diagnosis step, the capacity provided by the first material is calculated by subtracting the capacity provided by the second material from the total capacity.

9. In paragraph 1, A battery diagnosis method, characterized in that the above diagnosis step includes a step of diagnosing the battery by comparing the calculated capacity with a predetermined reference capacity.

10. In any one of paragraphs 1 to 9, The above first material is silicon or silicon oxide, A battery diagnostic method, characterized in that the second material comprises graphite.

11. A battery diagnostic device for diagnosing a battery to which an electrode active material blended with a first material and a second material is applied. A first generation unit that divides a first profile showing a relationship between the SOC (State of Charge) and voltage of the battery into a first part corresponding to the first material and a second part corresponding to the second material, and generates a second profile by removing the first part from the first profile; A second generation unit for generating a third profile that estimates the relationship between the SOC and voltage of the battery over the entire SOC range of the battery based on the second profile; and A battery diagnostic device including a diagnostic unit that calculates a capacity provided by the first material among the total capacity provided by the electrode active material based on the third profile and diagnoses the battery based on the calculated capacity.

12. In paragraph 11, A battery diagnostic device, characterized in that the first generation unit is configured to divide the first profile into the first part and the second part based on a predetermined SOC value, and generate a second profile by removing the first part from the first profile.

13. In paragraph 11, The above second generating unit, An adjustment module configured to adjust a reference anode profile representing a correspondence between the SOC and the anode potential of a given reference battery, and a reference cathode profile representing a correspondence between the SOC and the cathode potential of the reference battery, thereby generating an adjusted cathode profile and an adjusted cathode profile corresponding to the second profile; and A battery diagnostic device characterized by including a third profile generation module configured to generate the third profile based on the adjusted positive electrode profile and the adjusted negative electrode profile.

14. A battery pack comprising a battery diagnostic device according to any one of claims 11 to 13.

15. A vehicle comprising a battery diagnostic device according to any one of claims 11 to 13.

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