KR-20260062732-A - METHOD AND APPARATUS FOR PREDICTING POINT OF DETERIORATION OF BATTERY LIFE, AND BATTERY PACK

KR20260062732AKR 20260062732 AKR20260062732 AKR 20260062732AKR-20260062732-A

Abstract

A method for predicting the point of rapid decline in battery life may be provided. The method for predicting the point of rapid decline in battery life includes the steps of: estimating the state of health (SoH) of a battery cell for each of a plurality of charge-discharge cycles; calculating a derivative value representing the change in the SoH of the battery cell for each of the plurality of charge-discharge cycles; calculating a threshold value for predicting the point of rapid decline of the battery cell; and determining the point at which the SoH derivative curve representing the derivative value of the battery cell for each of the plurality of charge-discharge cycles intersects the threshold value as the point of rapid decline in the battery cell's life.

Inventors

김해민
이동율
장준호
고영훈
이상관
이유진
권영웅

Assignees

삼성에스디아이 주식회사

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (15)

A step of estimating the state of health (SoH) of a battery cell in each of multiple charge/discharge cycles, A step of calculating a differential value representing the change in SoH of the battery cell in each of the plurality of charge/discharge cycles, A step of calculating a threshold value for predicting the point of rapid decline of the battery cell, and A step of determining the point at which the SoH differential curve representing the differential value of the battery cell for each of the plurality of charge/discharge cycles intersects the threshold value as the point of rapid decline in the lifespan of the battery cell. A method for predicting the point of rapid decline in battery life, including
In paragraph 1, The step of calculating the threshold value includes the step of calculating the threshold value using the derivative value of a portion of the charge/discharge cycle interval of the SoH derivative curve. Method for predicting the point of rapid decline in battery life.
In paragraph 2, The above partial section includes the period from the start time of the plurality of charge/discharge cycles or after an initial partial charge/discharge cycle including the start time of the above point, up to the charge/discharge cycle before derating is applied. Method for predicting the point of rapid decline in battery life.
In paragraph 2, The step of calculating the threshold value using the derivative value of the partial charge/discharge cycle interval includes the step of setting the average value of the derivative value of the partial charge/discharge cycle interval as the threshold value. Method for predicting the point of rapid decline in battery life.
In paragraph 2, The step of calculating the above threshold further includes the step of filtering the above SoH derivative curve, Method for predicting the point of rapid decline in battery life.
In paragraph 5, The above filtering step includes a step of using at least one of a Gaussian filter and a bidirectional filter, Method for predicting the point of rapid decline in battery life.
A battery cell that is charged or discharged according to multiple charge/discharge cycles, A measuring instrument for measuring the characteristic value of the battery cell being charged or discharged in each of the plurality of charge/discharge cycles above, and A control unit that estimates the state of health (SoH) of the battery cell for each of the plurality of charge-discharge cycles based on characteristic values of the battery cell measured at each of the plurality of charge-discharge cycles, generates a SoH derivative curve representing the derivative value of the battery cell's SoH at each of the plurality of charge-discharge cycles, and determines the point at which the SoH derivative curve meets a threshold value for predicting the point of rapid decline of the battery cell's lifespan as the point of rapid decline of the battery cell. A battery life drop point prediction device including
In Paragraph 7, The control unit sets the average value of the derivative of a portion of the charge/discharge cycle section of the SoH derivative curve as the threshold value. Battery life drop prediction device.
In paragraph 8, The above partial section includes the period from the start time of the plurality of charge/discharge cycles or after an initial partial charge/discharge cycle including the start time of the above point, up to the charge/discharge cycle before derating is applied. Battery life drop prediction device.
In Paragraph 7, The above control unit filters the SoH derivative curve before determining the point of rapid decline in the lifespan of the battery cell, Battery life drop prediction device.
In Paragraph 7, The above characteristic value includes at least one of the discharge capacity, internal resistance, and OCV (Open Circuit Voltage) of the battery cell, Battery life drop prediction device.
A battery module comprising at least one battery cell, A switch connected to the battery module according to a plurality of charge/discharge cycles, and A battery life decline prediction device that measures characteristic values of a battery cell in each of the plurality of charge-discharge cycles, estimates the state of health (SoH) of the battery cell for each of the plurality of charge-discharge cycles using the characteristic values of the battery cell measured in each of the plurality of charge-discharge cycles, generates a SoH derivative curve representing the derivative value of the battery cell's SoH in each of the plurality of charge-discharge cycles, and determines the point at which the SoH derivative curve meets a threshold value for predicting the point of decline of the battery cell as the point of decline in the battery cell's life. A battery pack including
In Paragraph 12, The above battery life drop point prediction device sets the average value of the derivative values of some charge/discharge cycle intervals of the above SoH derivative curve as the threshold value. Battery pack.
In Paragraph 13, The above partial section includes the period from the start time of the plurality of charge/discharge cycles or after an initial partial charge/discharge cycle including the start time of the above point, up to the charge/discharge cycle before derating is applied. Battery pack.
In Paragraph 12, A battery management system that controls the switch and the battery module according to the plurality of charge/discharge cycles. A battery pack including more.

Description

Method and apparatus for predicting the point of rapid decline in battery life, and battery pack This description relates to a method and apparatus for predicting the point of rapid decline in battery life, and to a battery pack. As a battery is used, the state of health (SoH), which indicates battery life, exhibits a decreasing characteristic. The decline in SoH appears linear up to a certain point, but becomes non-linear thereafter; consequently, the battery life tends to decrease rapidly from that point onward. The point at which the decline in SoH becomes non-linear is called the onset point. When presenting performance related to battery life characteristics, the point of SoH drop is used as an important indicator in battery life characteristics because it is necessary to present the end of life (EOL) or guarantee that no drop occurs within a specific cycle. FIG. 1 is a drawing showing a battery life drop point prediction device according to one embodiment. FIG. 2 is a flowchart illustrating a method for predicting the point of rapid decline in battery life according to an embodiment. Figure 3 is a diagram showing an example of a SoH curve for each charge/discharge cycle according to an embodiment. Figure 4 is a diagram showing an example of a SoH differential curve for each charge/discharge cycle according to an embodiment. FIG. 5 is a diagram showing an example of a filtered SoH differential curve for each charge/discharge cycle according to an embodiment. FIG. 6 is a diagram illustrating a method for determining a threshold value according to an embodiment. Figure 7 is a diagram showing the point at which the lifespan of a battery cell drops sharply according to an embodiment. FIG. 8 is a diagram showing an example of a battery pack to which a battery life drop point prediction device according to one embodiment is applied. FIG. 9 is a diagram showing a battery life drop point prediction device according to another embodiment. Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are given similar reference numerals. In the flowcharts described with reference to the drawings, the order of operations may be changed, various operations may be merged or certain operations may be divided, and specific operations may not be performed. Throughout the specification and claims, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, expressions written in the singular form may be interpreted as singular or plural unless explicit expressions such as "one" or "singular" are used. Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, the first component may be named the second component, and similarly, the second component may be named the first component. Furthermore, when it is stated that one component is "connected" to another component, this includes not only cases where they are "directly or physically connected," but also cases where they are "indirectly or non-contactually connected" with another component in between, or where they are "electrically connected." On the other hand, when it is stated that one component is "directly connected" to another component, it should be understood that there is no other component present in between. FIG. 1 is a drawing showing a battery life drop point prediction device according to one embodiment. Referring to FIG. 1, a battery life decline time prediction device (100) can predict the time of decline in the life of a battery cell (110) and may include a control unit (120), a charger/discharger (130), a measuring device (140), and a storage unit (150). The battery cell (110) can be housed inside the chamber. The charging/discharging device (130) can charge or discharge the battery cell (110) based on the control signal of the control unit (120). The control unit (120) can generate a control signal to control the charge/discharger (130) according to the charge/discharge cycle and can transmit the control signal to the charge/discharger (130). Additionally, the control unit (120) can transmit a control signal to a measuring device (140) to measure characteristic values for each charge/discharge cycle. A single charge/discharge cycle may in