Patent Description:
The present disclosure relates to a battery diagnosing apparatus and method, and more particularly, to a battery diagnosing apparatus and method capable of diagnosing a state of a negative electrode of a battery.

While a battery is being charged, a polarization phenomenon occurs internally in the battery. The polarization phenomenon depends on various resistance components of the battery (e.g., ohmic resistance, charge transfer resistance, diffusion resistance). The reason that the battery voltage during charging is higher than the open circuit voltage (OCV) is that overvoltage (over-potential) is formed by the polarization phenomenon.

As the battery is degraded, the polarization phenomenon tends to intensify. Therefore, even if the charging conditions (e.g., charging current, temperature) are the same, the magnitude of the overvoltage may increase as the degree of degradation of the battery increases. If the overvoltage is increased excessively, there is a problem that the degradation of the battery is accelerated. For example, during charging, the voltage of the negative electrode of the battery gradually drops. Here, if the voltage of the negative electrode of the battery drops below <NUM> V due to overvoltage, lithium metal is rapidly precipitated on the negative electrode, and as a result, the amount of loss of lithium ions that may participate in a charging and discharging reaction may increase.

In addition, the negative electrode (e.g., graphite) of the battery may undergo a stabilizing process in which the reaction area is increased through contraction and expansion during the initial charging/discharging process. During the stabilizing process, the overvoltage of the negative electrode may be reduced compared to the initial stage due to the increase of the reaction area of the negative electrode. That is, the increase in the reaction area of the negative electrode in the initial charging/discharging process is due to the contraction and expansion of the negative electrode, which causes a decrease in overvoltage.

Conversely, the overvoltage of the negative electrode may gradually increase as the battery is degraded. For example, the overvoltage of the negative electrode may gradually increase due to the influence of the reduction decomposition of the electrolyte and the generation of solid electrolyte interphase (SEI) according to the degradation of the battery.

Therefore, in order to prevent the battery from being rapidly degraded and to increase the lifespan of the battery, it is necessary to develop a technology that may diagnose the negative electrode state of the battery more specifically based on the difference caused by the stabilizing process and the degradation of the battery. <CIT> is known from the prior art and it discloses a battery deterioration determination system which calculates the capacity decrease amount of the battery from the difference value △dQ/dV based on the dQ/dV value corresponding to the initial Vp, and determines whether rapid battery degradation has occurred by comparing the calculated capacity reduction amount with the threshold.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery diagnosing apparatus and method capable of diagnosing a negative electrode state of a battery more specifically based on the voltage and capacity of the battery.

A battery diagnosing apparatus according to one aspect of the present disclosure may comprise: a profile generating unit configured to generate a differential profile representing a corresponding relationship between a voltage of a battery and a differential capacity for the voltage of the battery; and a control unit configured to receive the differential profile from the profile generating unit, determine a target peak in the differential profile, determine a behavior pattern of the target peak based on a reference peak included in a preset reference profile, and diagnose a state of a negative electrode of the battery by comparing the behavior pattern determined for the target peak with a plurality of preset behavior types, wherein the control unit is configured to determine the behavior pattern of the target peak by comparing the voltages of the reference peak and the target peak and comparing the differential capacities of the reference peak and the target peak.

The control unit may be configured to diagnose the state of the negative electrode of the battery as an overvoltage state or a stabilized state according to the behavior type corresponding to the behavior pattern among the plurality of behavior types.

The plurality of behavior types may include: a first behavior type in which a voltage of the target peak exceeds a voltage of the reference peak and a differential capacity of the target peak is less than a differential capacity of the reference peak; and a second behavior type in which the voltage of the target peak is less than the voltage of the reference peak and the differential capacity of the target peak is equal to or greater than the differential capacity of the reference peak.

The control unit may be configured to diagnose the state of the negative electrode of the battery as the overvoltage state, when the behavior pattern determined for the target peak corresponds to the first behavior type.

The control unit may be configured to diagnose the state of the negative electrode of the battery as the stabilized state, when the behavior pattern determined for the target peak corresponds to the second behavior type.

When a plurality of peaks are present within a predetermined voltage region based on the voltage of the target peak, the control unit may be configured to select the plurality of peaks, and when a differential capacity of each of the plurality of selected peaks is less than the differential capacity of the reference peak and a voltage of each of the plurality of peaks exceeds the voltage of the reference peak, the control unit may be configured to diagnose the state of the negative electrode of the battery as the overvoltage state.

The control unit may be configured to determine the plurality of peaks within the predetermined voltage region, when the behavior pattern determined for the target peak corresponds to the first behavior type.

The control unit may be configured to determine a first target peak and a second target peak having different voltages in the differential profile, determine a first behavior pattern of the first target peak for a first reference peak included in the reference profile and a second behavior pattern of the second target peak for a second reference peak included in the reference profile, and diagnose the state of the negative electrode of the battery as the stabilized state when both the first behavior pattern and the second behavior pattern correspond to the second behavior type.

The control unit may be configured to determine the first target peak and the second target peak, when the behavior pattern determined for the target peak corresponds to the second behavior type.

The control unit may be configured to decrease at least one of an available SOC region and a maximum allowable temperature of the battery, when the state of the negative electrode of the battery is diagnosed as the stabilized state.

The control unit may be configured to determine a peak having a maximum differential capacity in the differential profile as the target peak.

A battery pack according to another aspect of the present disclosure may comprise the battery diagnosing apparatus according to one aspect of the present disclosure.

A battery diagnosing method according to still another aspect of the present disclosure may comprise: a differential profile generating step of generating a differential profile representing a corresponding relationship between a voltage of a battery and a differential capacity for the voltage of the battery; a target peak determining step of determining a target peak in the differential profile; a behavior pattern determining step of determining a behavior pattern of the target peak based on a reference peak included in a preset reference profile; and a negative electrode state diagnosing step of diagnosing a state of a negative electrode of the battery by comparing the behavior pattern determined for the target peak with a plurality of preset behavior types, wherein the behavior pattern determining step is a step of determining the behavior pattern of the target peak by comparing the voltages of the reference peak and the target peak and comparing the differential capacities of the reference peak and the target peak.

According to one aspect of the present disclosure, there is an advantage of diagnosing a state of a negative electrode of a battery as an overvoltage state or a stabilized state based on the voltage and capacity of the battery.

In addition, according to one aspect of the present disclosure, since the usage condition corresponding to the battery may be set according to the diagnosed the state of the negative electrode of the battery, there is an advantage that the degradation of the battery may be prevented and the lifespan may be increased.

The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure.

Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, whereby the invention is defined by the appended claims.

In addition, terms such as a control unit described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

<FIG> is a diagram schematically showing a battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure.

Referring to <FIG>, the battery diagnosing apparatus <NUM> may include a profile generating unit <NUM> and a control unit <NUM>.

The profile generating unit <NUM> may be configured to generate a differential profile representing a corresponding relationship between a voltage of a battery and a differential capacity for the voltage of the battery.

Here, the battery means a physically separable one independent cell having a negative electrode terminal and a positive electrode terminal. For example, one pouch-type lithium polymer cell may be regarded as a battery.

Specifically, the profile generating unit <NUM> may obtain a voltage profile representing a corresponding relationship between voltage and capacity of a battery. In addition, the profile generating unit <NUM> may calculate a differential capacity (dQ/dV) by differentiating the capacity with respect to the voltage of the battery. The profile generating unit <NUM> may generate a differential profile representing a corresponding relationship between the voltage of the battery and the calculated differential capacity.

<FIG> is a diagram schematically showing an embodiment for diagnosing a state of a negative electrode of a battery based on a reference profile Pa and a differential profile PDa by the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure.

Referring to <FIG>, the differential profile PDa generated by the profile generating unit <NUM> may be expressed as an X-Y graph when the voltage of the battery is set to X and the differential capacity to the voltage of the battery is set to Y. Here, the differential capacity is a value obtained by differentiating the capacity of the battery with a voltage, and may be expressed as [dQ/dV].

The control unit <NUM> may be configured to receive the differential profile PDa from the profile generating unit <NUM>.

Specifically, the control unit <NUM> and the profile generating unit <NUM> may be connected to communicate with each other. The profile generating unit <NUM> may transmit the generated differential profile PDa to the control unit <NUM>, and the control unit <NUM> may receive the differential profile PDa.

The control unit <NUM> may be configured to determine a target peak TPa in the differential profile PDa.

Here, the peak may be a point having an upwardly convex form in the differential profile PDa. Specifically, the peak may be a point at which the instantaneous change rate of the differential capacity with respect to voltage is <NUM> in the differential profile PDa, where the instantaneous change rate of a low voltage side based on the peak may be positive and the instantaneous change rate of a high voltage side may be negative.

For example, in the embodiment of <FIG>, a plurality of peaks may be included in the differential profile PDa. The control unit <NUM> may determine any one of the plurality of peaks included in the differential profile PDa as a target peak TPa. Preferably, the control unit <NUM> may be configured to determine a peak having a maximum differential capacity in the differential profile PDa as the target peak TPa.

In the embodiment of <FIG>, the target peak TPa having a maximum differential capacity in the differential profile PDa may have a voltage of V2, and the differential capacity may be a2.

In addition, the control unit <NUM> may be configured to determine a behavior pattern of the target peak TPa based on a reference peak RPa included in a preset reference profile Pa.

Specifically, the control unit <NUM> determines the behavior pattern of the target peak TPa by comparing the voltages of the reference peak RPa and the target peak TPa and comparing the differential capacities thereof.

For example, the control unit <NUM> may determine whether the voltage of the target peak TPa is less than or greater than the voltage of the reference peak RPa. In addition, the control unit <NUM> may determine whether the differential capacity of the target peak TPa is less than or greater than the differential capacity of the reference peak RPa.

In the embodiment of <FIG>, the voltage of the reference peak RPa may be V1, and the differential capacity may be a1. In addition, the voltage of the target peak TPa may be V2, and the differential capacity may be a2. The control unit <NUM> may determine that the voltage of the target peak TPa exceeds the voltage of the reference peak RPa, and that the differential capacity of the target peak TPa is less than the differential capacity of the reference peak RPa.

The control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery by comparing the behavior pattern determined for the target peak with a plurality of predetermined behavior types.

Specifically, the control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery as an overvoltage state or a stabilized state according to a behavior type corresponding to the behavior pattern among the plurality of behavior types.

For example, the plurality of behavior types may include a first behavior type corresponding to the overvoltage state and a second behavior type corresponding to the stabilized state.

Here, the overvoltage state may be a state in which the battery is degraded so that overvoltage is generated at the negative electrode of the battery compared to the negative electrode of the battery in a BOL (Beginning of Life) state. The stabilized state may be a state in which the negative electrode of the battery contracts and expands during the initial charging/discharging process.

The control unit <NUM> may determine the behavior pattern of the target peak TPa for the reference peak RPa, and specifically diagnose whether the state of the negative electrode of the battery is an overvoltage state or a stabilized state based on the determined behavior pattern.

Therefore, the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure has an advantage of specifically classifying and diagnosing the state of the negative electrode of the battery based on the differential profile for the battery.

Meanwhile, the control unit <NUM> provided to the battery diagnosing apparatus <NUM> may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, and a data processing device, and the like, known in the art to execute various control logics performed in the present disclosure. In addition, when the control logic is implemented in software, the control unit <NUM> may be implemented as a set of program modules. At this time, the program module may be stored in a memory and executed by the control unit <NUM>. The memory may be provided in or out of the control unit <NUM>, and may be connected to the control unit <NUM> by various well-known means.

In addition, the battery diagnosing apparatus <NUM> may further include a storage unit <NUM>. The storage unit <NUM> may store data or programs necessary for operation and function of each component of the battery diagnosing apparatus <NUM>, data generated in the process of performing the operation or function, or the like. The storage unit <NUM> is not particularly limited in its kind as long as it is a known information storage means that can record, erase, update and read data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, and the like. In addition, the storage unit <NUM> may store program codes in which processes executable by the control unit <NUM> are defined.

For example, the storage unit <NUM> may store the reference profile and the voltage profile for the battery. The profile generating unit <NUM> may access the storage unit <NUM> to obtain a voltage profile and then generate a differential profile based on the obtained voltage profile. As another example, the profile generating unit <NUM> may directly receive a voltage profile from the outside.

In addition, the storage unit <NUM> may store the differential profile generated by the profile generating unit <NUM>. In addition, the control unit <NUM> may directly receive the differential profile from the profile generating unit <NUM>, or may access the storage unit <NUM> to obtain the differential profile stored in the storage unit <NUM>. In addition, the control unit <NUM> may access the storage unit <NUM> to obtain the reference profile for the battery.

Hereinafter, a plurality of behavior types and a process of diagnosing the state of the negative electrode of the battery according to the behavior types will be described in detail.

The plurality of behavior types may include a first behavior type in which a voltage of the target peak exceeds a voltage of the reference peak and a differential capacity of the target peak is less than a differential capacity of the reference peak.

The control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery as the overvoltage state, when the behavior pattern determined for the target peak corresponds to the first behavior type.

For example, in the embodiment of <FIG>, the voltage of the target peak TPa may be V2, and the voltage of the reference peak RPa may be V1. In addition, the differential capacity of the target peak TPa may be a2, and the differential capacity of the reference peak RPa may be a1. Since the voltage of the target peak TPa exceeds the voltage of the reference peak RPa and the differential capacity of the target peak TPa is less than the differential capacity of the reference peak RPa, the control unit <NUM> may judge that the behavior pattern of the target peak TPa corresponds to the first behavior type. Accordingly, the control unit <NUM> may diagnose the state of the negative electrode of the battery of <FIG> as the overvoltage state.

Also, the plurality of behavior types may include a second behavior type in which a voltage of the target peak TPb is less than a voltage of the reference peak RPb and a differential capacity of the target peak TPb is equal to or greater than a differential capacity of the reference peak RPb.

The control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery as the stabilized state, when the behavior pattern determined for the target peak corresponds to the second behavior type.

<FIG> is a diagram schematically showing another embodiment for diagnosing a state of the negative electrode of the battery based on the reference profile Pb and the differential profile PDb by the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure.

The reference profile Pb and the differential profile PDb of <FIG> may be different from the reference profile Pa and the differential profile PDa of <FIG>. For example, the target batteries of <FIG> and <FIG> may be different batteries.

The reference profile may be set for each battery, and preferably may be preset by reflecting the BOL state of the battery. That is, the reference profile is not uniformly set for the same type of batteries, but may be individually set for each battery by reflecting the BOL state of the battery. Accordingly, the state of the negative electrode of the battery diagnosed by the control unit <NUM> may be determined in consideration of the BOL state of the battery that is a target for diagnosing the state of the negative electrode.

In the embodiment of <FIG>, the voltage of the target peak TPb may be Vb, and the voltage of the reference peak RPb may be Va. In addition, the differential capacity of the target peak TPb may be b2, and the differential capacity of the reference peak RPb may be b1. Since the voltage of the target peak TPb is less than the voltage of the reference peak RPb and the differential capacity of the target peak TPb is equal to or greater than the differential capacity of the reference peak RPb, the control unit <NUM> may judge that the behavior pattern of the target peak TPb corresponds to the second behavior type. Accordingly, the control unit <NUM> may judge the state of the negative electrode of the battery of <FIG> as the stabilized state.

When a plurality of peaks are present within a predetermined voltage region based on the voltage of the target peak, the control unit <NUM> may be configured to select the plurality of peaks.

<FIG> is a diagram schematically showing still another embodiment for diagnosing a state of the negative electrode of the battery based on the reference profile and the differential profile by the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure. Hereinafter, it is assumed that the reference profile and the differential profile of <FIG> and <FIG> are the same.

In the embodiment of <FIG>, a first peak TPa1 and a second peak TPa2 may be included in the predetermined voltage region of the differential profile PDa based on the voltage of the target peak TPa. Here, the first peak TPa1 may be the target peak TPa.

For example, the predetermined voltage region may be a <NUM>. 2V region based on the voltage of the target peak TPa. The control unit <NUM> may select the first peak TPa1 and the second peak TPa2 within the voltage region of <NUM>. 2V based on V2, which is the voltage of the target peak TPa. Preferably, the control unit <NUM> may select a peak having a differential capacity closest to the first peak TPa1 within the predetermined voltage region as the second peak TPa2.

When the differential capacity of each of the plurality of selected peaks is less than the differential capacity of the reference peak RPa and the voltage of each of the plurality of peaks exceeds the voltage of the reference peak RPa, the control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery as the overvoltage state.

For example, in the embodiment of <FIG>, the voltage of the first peak TPa1 may be V2, the voltage of the second peak TPa2 may be V3, and the voltage of the reference peak RPa may be V1. In addition, the differential capacity of the first peak TPa1 may be a2, the differential capacity of the second peak TPa2 may be a3, and the differential capacity of the reference peak RPa may be a1. Since the voltages of the first peak TPa1 and the second peak TPa2 exceed the voltage of the reference peak RPa and the differential capacities of the first peak TPa1 and the second peak TPa2 are less than the differential capacity of the reference peak RPa, the control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery of <FIG> as the overvoltage state.

Meanwhile, the control unit <NUM> may be configured to determine a plurality of peaks within the predetermined voltage region, when the behavior pattern determined for the target peak TPa corresponds to the first behavior type.

For example, referring to <FIG> and <FIG>, the voltage of the target peak TPa may exceed the voltage of the reference peak RPa, and the differential capacity of the target peak TPa may be less than the differential capacity of the reference peak RPa. Accordingly, the control unit <NUM> may determine the behavior pattern of the target peak TPa first, and then determine the first peak TPa1 and the second peak TPa2 when the behavior pattern determined for the target peak TPa corresponds to the first behavior type.

That is, when the behavior pattern of the target peak TPa is the first behavior type, the control unit <NUM> may additionally compare the behavior patterns of the first peak TPa1 and the second peak TPa2 with the plurality of behavior types in order to more accurately diagnose the state of the negative electrode of the battery.

Accordingly, the control unit <NUM> may more specifically and accurately diagnose the state of the negative electrode of the battery by further considering the behavior pattern of the second peak TPa2 as well as the behavior pattern of the first peak TPa1.

The control unit <NUM> may be configured to determine a first target peak and a second target peak having different voltages in the differential profile.

Specifically, the voltage bands in which the first target peak and the second target peak appear may be different from each other. For example, the first target peak may appear near about <NUM>. 7V, and the second target peak may appear near about <NUM>. Here, the first target peak may be the target peak.

<FIG> is a diagram schematically showing still another embodiment for diagnosing a state of the negative electrode of the battery based on the reference profile and the differential profile by the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure.

For example, in the embodiment of <FIG>, the voltage of the first target peak TPb1 may be Vb, and the differential capacity may be b2. The voltage of the second target peak TPb2 may be Vd, and the differential capacity may be b4.

Preferably, the control unit <NUM> may determine the target peak TPb as the first target peak TPb1. In addition, the control unit <NUM> may determine a peak having a largest differential capacity as the second target peak TPb2 in a voltage region less than the voltage of the target peak TPb.

The control unit <NUM> may be configured to determine a first behavior pattern of the first target peak TPb1 for a first reference peak RPb1 included in the reference profile PDb and a second behavior pattern of the second target peak TPb2 for a second reference peak RPb2 included in the reference profile PDb.

For example, in the embodiment of <FIG>, the voltage of the first target peak TPb1 may be Vb, the voltage of the first reference peak RPb1 may be Va, the voltage of the second target peak TPb2 may be Vd, and the voltage of the second reference peak RPb2 may be Vc. In addition, the differential capacity of the first target peak TPb1 may be b2, the differential capacity of the first reference peak RPb1 may be b1, the differential capacity of the second target peak TPb2 may be b4, and the differential capacity of the second reference peak RPb2 may be b3.

In addition, the voltage of the first target peak TPb1 may be smaller than the voltage of the first reference peak RPb1, and the differential capacity of the first target peak TPb1 may be greater than the differential capacity of the first reference peak RPb1. In addition, the voltage of the second target peak TPb2 may be smaller than the voltage of the second reference peak RPb2, and the differential capacity of the second target peak TPb2 may be greater than the differential capacity of the second reference peak RPb2.

The control unit <NUM> may be configured to diagnose the state of the negative electrode of the battery as the stabilized state, when both the first behavior pattern and the second behavior pattern correspond to the second behavior type.

For example, in the embodiment of <FIG>, both the first behavior pattern of the first target peak TPb1 and the second behavior pattern of the second target peak TPb2 may correspond to the second behavior type. Accordingly, the control unit <NUM> may diagnose the state of the negative electrode of the battery of <FIG> as the stabilized state.

The control unit <NUM> may be configured to determine the first target peak TPb1 and the second target peak TPb2, when the behavior pattern determined for the target peak TPb corresponds to the second behavior type.

For example, referring to <FIG> and <FIG>, the voltage of the target peak TPb may be less than the voltage of the reference peak RPb, and the differential capacity of the target peak TPb may be greater than or equal to the differential capacity of the reference peak RPb. Therefore, the control unit <NUM> may determine the behavior pattern of the target peak TPb first, and then determine the first target peak TPb1 and the second target peak TPb2 when the behavior pattern determined for the target peak TPb corresponds to the second behavior type.

That is, when the behavior pattern of the target peak TPb corresponds to the second behavior type, the control unit <NUM> may additionally compare the behavior patterns of the first target peak TPb1 and the second target peak TPb2 with a plurality of behavior types in order to more accurately diagnose the state of the negative electrode of the battery.

Therefore, the control unit <NUM> may more concretely and accurately diagnose the state of the negative electrode of the battery by judging whether the behavior pattern of the target peak TPb corresponds to the second behavior type and then judging whether the behavior pattern of the second target peak TPb2 corresponds to the second behavior type.

The control unit <NUM> may be configured to decrease at least one of an available SOC region and a maximum allowable temperature of the battery, when the state of the negative electrode of the battery is diagnosed as the stabilized state.

For example, when the state of the negative electrode of the battery is diagnosed as the stabilized state, the reaction area of the negative electrode may be increased compared to the initial state. Since the stabilized state is a state in which the negative electrode contracts and expands during the initial charging and discharging process, lithium plating in which lithium is precipitated on the negative electrode is less likely to occur. Therefore, in the stabilized state, the charge/discharge C-rate control for reducing the occurrence of lithium plating may not be required.

However, even if the state of the negative electrode is diagnosed as the stabilized state, the positive electrode of the battery may be degraded, and loss of positive electrode capacity may occur due to this degradation of the positive electrode. In order to prevent this positive electrode capacity loss in advance, that is, to slow down the degradation of the positive electrode, the control unit <NUM> may decrease at least one of the available SOC region and the maximum allowable temperature of the battery when the state of the negative electrode is diagnosed as the stabilized state.

That is, the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure may set an optimal usage condition for the battery according to the diagnosed state of the negative electrode. Accordingly, since the battery may be operated according to the usage condition set by the battery diagnosing apparatus <NUM>, the lifespan of the battery may be increased.

For example, the usage condition set by the battery diagnosing apparatus <NUM> may be stored in a server or in a battery management system (BMS) provided to a battery pack including the corresponding battery. In addition, since the battery is operated according to the set usage condition, the lifespan of the battery may be increased resultantly.

The battery diagnosing apparatus <NUM> according to the present disclosure may be applied to a BMS (Battery Management System). That is, the BMS according to the present disclosure may include the battery diagnosing apparatus <NUM> described above. In this configuration, at least some components of the battery diagnosing apparatus <NUM> may be implemented by supplementing or adding functions of the configuration included in the conventional BMS. For example, the profile generating unit <NUM>, the control unit <NUM> and the storage unit <NUM> of the battery diagnosing apparatus <NUM> may be implemented as components of the BMS.

<FIG> is a diagram schematically showing an exemplary configuration of a battery pack <NUM> including the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure.

In addition, the battery diagnosing apparatus <NUM> according to the present disclosure may be provided to a battery pack <NUM>. That is, the battery pack <NUM> according to the present disclosure may include the above-described battery diagnosing apparatus <NUM>, a measuring unit <NUM>, a charging and discharging unit <NUM> and at least one battery cell B. In addition, the battery pack may further include electrical equipment (a relay, a fuse, etc.) and a case.

The measuring unit <NUM> may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3.

Specifically, the first sensing line SL1 may be connected to the positive electrode of the battery cell B and the measuring unit <NUM>. Also, the second sensing line SL2 may be connected to the negative electrode of the battery cell B and the measuring unit <NUM>. The measuring unit <NUM> may measure the voltage of the battery cell B by calculating the difference between the voltage of the positive electrode of the battery cell B measured through the first sensing line SL1 and the voltage of the negative electrode of the battery cell B measured through the second sensing line SL2.

Also, the measuring unit <NUM> may measure the charging current and/or the discharging current of the battery cell B through a current measuring unit A connected to the third sensing line SL3. For example, the current measuring unit A may be a shunt resistor or an ammeter.

The charging and discharging unit <NUM> may be configured to charge and/or discharge the battery cell B. In the process of charging and/or discharging the battery cell B by the charging and discharging unit <NUM>, the measuring unit <NUM> may measure the voltage and current of the battery cell B.

The voltage and current of the battery cell B measured by the measuring unit <NUM> may be transmitted to the battery diagnosing apparatus <NUM>. Specifically, the profile generating unit may receive the voltage and current of the battery cell B from the measuring unit <NUM>. The profile generating unit may generate a differential profile representing a corresponding relationship between the voltage of the battery cell B and a differential capacity based on the received voltage and current of the battery cell B. Here, it should be noted that the prior art may be applied to a process in which the profile generating unit calculates the capacity and the differential capacity of the battery cell B based on the voltage and current of the battery cell B, and thus a detailed description thereof will be omitted.

<FIG> is a diagram schematically showing a battery diagnosing method according to another embodiment of the present disclosure.

Preferably, each step of the battery diagnosing method according to another embodiment of the present disclosure may be performed by the battery diagnosing apparatus <NUM> according to an embodiment of the present disclosure. Hereinafter, content overlapping with the previously described content will be omitted or briefly described.

Referring to <FIG>, the battery diagnosing method may include a differential profile generating step (S100), a target peak determining step (S200), a behavior pattern determining step (S300), and a negative electrode state diagnosing step (S400).

The differential profile generating step (S100) is a step of generating a differential profile representing a corresponding relationship between a voltage of a battery and a differential capacity for the voltage of the battery, and may be performed by the profile generating unit <NUM>.

For example, in the embodiment of <FIG>, the profile generating unit <NUM> may generate a differential profile PDa representing a corresponding relationship between the voltage of the battery and the differential capacity.

The target peak determining step (S200) is a step of determining a target peak in the differential profile, and may be performed by the control unit <NUM>.

For example, in the embodiment of <FIG>, the control unit <NUM> may determine a peak having a maximum differential capacity in the differential profile PDa as the target peak TPa. A voltage corresponding to the target peak TPa may be V2, and a corresponding differential capacity may be a2.

The behavior pattern determining step (S300) is a step of determining a behavior pattern of the target peak based on a reference peak included in a preset reference profile, and may be performed by the control unit <NUM>.

For example, in the embodiment of <FIG>, the control unit <NUM> may determine the behavior pattern of the target peak TPa so that the voltage V2 exceeds the voltage V1 of the reference peak RPa and the differential capacity a2 is less than the differential capacity a1 of the reference peak RPa.

The negative electrode state diagnosing step (S400) is a step of diagnosing a state of a negative electrode of the battery by comparing the behavior pattern determined for the target peak with a plurality of preset behavior types, and may be performed by the control unit <NUM>.

Specifically, the control unit <NUM> may diagnose the state of the negative electrode of the battery as an overvoltage state or a stabilized state according to a behavior type corresponding to the behavior pattern among the plurality of behavior types.

For example, the plurality of behavior types may include a first behavior type and a second behavior type according to voltages and differential capacities of the target peak and the reference peak. The first behavior type may be a behavior type in which the voltage of the target peak exceeds the voltage of the reference peak and the differential capacity of the target peak is less than the differential capacity of the reference peak. The second behavior type may be a behavior type in which the voltage of the target peak is less than the voltage of the reference peak and the differential capacity of the target peak is equal to or greater than the differential capacity of the reference peak.

In the embodiment of <FIG>, the control unit <NUM> may determine that the behavior pattern of the target peak TPa corresponds to the first behavior type. In addition, since the behavior pattern of the target peak TPa corresponds to the first behavior type, the control unit <NUM> may diagnose the state of the negative electrode of the battery of <FIG> as the overvoltage state.

As another example, in the embodiment of <FIG>, the voltage Vb of the target peak TPb may be less than the voltage Va of the reference peak RPb, and the differential capacity b2 of the target peak TPb may be greater than or equal to the differential capacity b1 of the reference peak RPb. Accordingly, the control unit <NUM> may determine that the behavior pattern of the target peak TPb corresponds to the second behavior pattern. In addition, the control unit <NUM> may diagnose the state of the negative electrode of the battery of <FIG> as the stabilized state.

The battery diagnosing method has an advantage of diagnosing the state of the negative electrode of the battery to be specifically classified into an overvoltage state or a stabilized state according to the behavior pattern of the target peak.

Claim 1:
A battery diagnosing apparatus (<NUM>), comprising:
a profile generating unit (<NUM>) configured to generate a differential profile (PDa, PDb) representing a corresponding relationship between a voltage (V) of a battery and a differential capacity (dQ/dV) for the voltage (V) of the battery; and
a control unit (<NUM>) configured to receive the differential profile (PDa, PDb) from the profile generating unit (<NUM>), determine a target peak (TPa, TPb) in the differential profile (PDa, PDb), determine a behavior pattern of the target peak (TPa, TPb) based on a reference peak (RPa, RPb) included in a preset reference profile (Pa, Pb), and diagnose a state of a negative electrode of the battery by comparing the behavior pattern determined for the target peak (TPa, TPb) with a plurality of preset behavior types,
characterized in that
the control unit (<NUM>) is configured to determine the behavior pattern of the target peak (TPa, TPb) by comparing the voltages (V) of the reference peak (RPa, RPb) and the target peak (TPa, TPb) and comparing the differential capacities (dQ/dV) of the reference peak (RPa, RPb) and the target peak (TPa, TPb).