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KR-20260062217-A - Apparatus and method for managing battery

KR20260062217AKR 20260062217 AKR20260062217 AKR 20260062217AKR-20260062217-A

Abstract

A battery management device and method can prevent a decrease in usable battery capacity by managing charging and discharging based on the amount of energy stored in the battery rather than voltage, thereby maintaining the same amount of usable energy even when the battery is used for a long period, significantly improving user satisfaction with electric vehicles, and enhancing the market competitiveness of electric vehicles.

Inventors

  • 송기훈

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260507
Application Date
20241028

Claims (15)

  1. A measuring unit for measuring battery status information; and A control unit that manages the charging and discharging of the battery based on the amount of energy stored in the battery, based on the state information of the battery measured through the measuring unit; A battery management device including
  2. In paragraph 1, The above control unit is, Based on the internal resistance of the battery, managing the charging and discharging of the battery, Battery management device.
  3. In paragraph 2, The above control unit is, Based on the state information of the battery, the remaining life (State Of Health, SOH) of the battery is obtained, the internal resistance of the battery is obtained using the obtained remaining life (SOH) of the battery, and the charging and discharging of the battery is managed using the obtained internal resistance of the battery. Battery management device.
  4. In Paragraph 3, The above control unit is, Using a preset relationship between state of health (SOH) and internal resistance, the internal resistance of the battery is obtained based on the state of health (SOH) of the battery. Battery management device.
  5. In paragraph 2, The above control unit is, A charging control voltage is obtained based on the internal resistance and charging current of the battery, and the charging of the battery is managed based on the obtained charging control voltage. Battery management device.
  6. In paragraph 5, The above control unit is, By adding the above-mentioned charge control voltage to the charge start voltage and charge end voltage, respectively, to manage the charging of the battery, Battery management device.
  7. In paragraph 2, The above control unit is, A discharge control voltage is obtained based on the internal resistance and discharge current of the battery, and the discharge of the battery is managed based on the obtained discharge control voltage. Battery management device.
  8. In Paragraph 7, The above control unit is, The discharge control voltage above is subtracted from the discharge start voltage and the discharge end voltage, respectively, to manage the discharge of the battery. Battery management device.
  9. In paragraph 1, The above battery is, Representing one of a battery cell, battery cell group, battery module, battery pack, and battery rack, Battery management device.
  10. Step of measuring battery status information; and A step of managing the charging and discharging of the battery based on the amount of energy stored in the battery, based on the measured state information of the battery; A battery management method including
  11. In Paragraph 10, The above management step is, Based on the internal resistance of the battery, the charging and discharging of the battery is managed. Battery management methods.
  12. In Paragraph 11, The above management step is, The method comprises obtaining the State of Health (SOH) of the battery based on the state information of the battery, obtaining the internal resistance of the battery using the obtained State of Health (SOH), and managing the charging and discharging of the battery using the obtained internal resistance of the battery. Battery management methods.
  13. In Paragraph 11, The above management step is, A method comprising obtaining a charging control voltage based on the internal resistance and charging current of the battery, and managing the charging of the battery based on the obtained charging control voltage. Battery management methods.
  14. In Paragraph 11, The above management step is, A discharge control voltage obtained based on the internal resistance and discharge current of the battery, and a discharge control voltage obtained based on the discharge control voltage, comprising Battery management methods.
  15. A computer program stored on a computer-readable storage medium for executing the battery management method described in any one of paragraphs 10 through 14 on a computer.

Description

Battery management apparatus and method This document relates to a battery management device and method. Currently commercialized rechargeable batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages over nickel-based batteries, such as the almost complete absence of the memory effect, allowing for free charging and discharging, a very low self-discharge rate, and high energy density. Recently, secondary batteries are being widely used for propulsion or energy storage in vehicles such as electric motorcycles and electric vehicles, as well as in medium-to-large devices such as Energy Storage Systems (ESS). As a result, interest in batteries is increasing, and research and development related to batteries is becoming more active. Furthermore, in the case of batteries used in vehicles, commercialization and research on interchangeable battery packs are also being actively conducted. Lithium secondary batteries primarily utilize lithium-based oxides and carbon materials as the positive and negative active materials, respectively. Furthermore, a lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials respectively, are arranged with a separator in between, and an outer casing (i.e., a battery case) that seals and encloses the electrode assembly along with the electrolyte. Depending on the shape of the outer casing, lithium secondary batteries can be classified into can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in a pouch made of an aluminum laminate sheet. Additionally, can-type secondary batteries can be further classified into prismatic and cylindrical secondary batteries based on their shape. A battery module or battery pack can be formed by housing multiple secondary batteries together inside a module case (module housing) or a pack case (pack housing) while electrically connected to each other. In this case, each secondary battery included in the battery module or battery pack may be referred to as a battery cell. It is crucial to diagnose the condition of batteries and take appropriate measures to ensure stable performance for batteries in the form of battery cells, modules, or packs, and to protect devices equipped with batteries or users utilizing them. A representative technology for this purpose is the inclusion of control devices, such as Battery Management Systems (BMS), in battery packs and Energy Storage Systems (ESS) to diagnose the battery and perform related actions. FIG. 1 is a diagram illustrating the charging and discharging operations of a battery, wherein (a) shows the charging operation and (b) shows the discharging operation. Meanwhile, battery charging and discharging terminate when a predefined voltage threshold is reached. When a battery is used for an extended period, its internal resistance increases; consequently, during charging, the charging termination voltage is reached in a shorter time compared to the initial usage, resulting in a decrease in the amount of energy stored. Furthermore, prolonged use also increases the battery's internal resistance, causing the discharge termination voltage to be reached in a shorter time compared to the initial usage, thereby reducing the amount of usable energy available. In other words, since charging and discharging are based on voltage, there is a problem where the usable capacity decreases as the battery degrades. For example, referring to FIG. 1(a), an initial battery can be charged to the capacity specification of the battery. If the battery capacity is "4000mAh", the internal resistance is "0mOhm", the charging start voltage is "3V", the charging end voltage is "4V", and the charging current is "2A", then since the initial battery has no internal resistance, charging starts at "3V" and ends at "4V", and the battery capacity becomes "4000mAh". However, a battery that has been used for a long time cannot be charged to the capacity of the battery. If the battery capacity is "4000mAh", the internal resistance is "100mOhm", the charging start voltage is "3V", the charging end voltage is "4V", and the charging current is "2A", the actual charging start voltage is "3V + 100mOhm * 2A = 3.2V", and since charging starts at "3.2V" and ends when it reaches "4V", the capacity decreases by the "3.0V ~ 3.2V" range. Since only 80% of the total charging range is charged, the usable capacity becomes "4000mAh * 80% = 3200mAh". And, referring to Fig. 1(b), the initial battery can be discharged to the capacity specification of the battery. If the battery capacity is "4000mAh", the internal resistance is "0mOhm", the discharge start voltage is "4V", the discharge end voltage is "3V", and the dis