US-12620644-B2 - Method of detecting an operating condition of a battery system, which may lead to a thermal runaway

Abstract

A battery system includes a battery pack including battery cells and a cooling system including a coolant transfer member for circulating a liquid coolant in a cooling circuit, a first heat exchanger integrated into the cooling circuit and thermally contacting the battery cells, and a pressure sensor for detecting a change in pressure inside the cooling circuit. A battery management system is connected to the pressure sensor and the coolant transfer member and is for performing a detection mode including: detecting an initial pressure with the pressure sensor and switching off the coolant transfer member for a time period; after switching off the coolant transfer member, capturing the pressure with the pressure sensor; and determining a pressure difference between the initial pressure value and the captured pressure, when the pressure difference exceeds a threshold, determining an abnormal condition that could cause a thermal runaway of the battery pack.

Inventors

• Andrej Golubkov

Assignees

• SAMSUNG SDI CO., LTD.

Dates

Publication Date

20260505

Application Date

20220901

Priority Date

20210902

Claims (4)

1. 1 . A method of detecting an abnormal operating condition of a battery system the battery system comprising: a battery pack comprising a plurality of battery cells; a cooling system comprising a coolant transfer member configured to circulate a liquid coolant in a cooling circuit, a first heat exchanger integrated into the cooling circuit and thermally contacting the battery cells, and a pressure sensor configured to detect a change in pressure inside the cooling circuit; and a battery management system connected to the pressure sensor and the coolant transfer member, the detection method comprising: detecting, by the battery management system, an initial pressure with the pressure sensor; switching off the coolant transfer member for a time period; detecting a subsequent pressure with the pressure sensor after switching off the coolant transfer member; and determining a pressure difference between the initial pressure and the subsequent pressure and, when the pressure increases and the pressure difference exceeds a threshold, determining an abnormal condition that could cause a thermal runaway of the battery pack.
2. 2 . A battery system comprising: a battery pack comprising a plurality of battery cells; a cooling system comprising: a coolant transfer member configured to circulate a liquid coolant in a cooling circuit; a first heat exchanger integrated into the cooling circuit and thermally contacting the battery cells; and a pressure sensor configured to detect a change in pressure inside the cooling circuit; and a battery management system connected to the pressure sensor and the coolant transfer member, the battery management system being configured to perform a detection mode for detecting an abnormal operating condition of the battery system, the detection mode comprising: detecting an initial pressure with the pressure sensor; switching off the coolant transfer member for a time period; capturing the pressure with the pressure sensor after switching off the coolant transfer member; and determining a pressure difference between the initial pressure and the captured pressure and, when the pressure increases and the pressure difference exceeds a threshold, determining an abnormal condition that could cause a thermal runaway of the battery pack.
3. 3 . The battery system according to claim 2 , wherein the coolant transfer member is arranged in the cooling circuit upstream from the first heat exchanger, and the pressure sensor is arranged in the cooling circuit downstream from the first heat exchanger.
4. 4 . An electric vehicle comprising the battery system according to claim 2 .

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of European Patent Application No. 21194567.0, filed in the European Patent Office on Sep. 2, 2021, and Korean Patent Application No. 10-2022-0110035, filed in the Korean Intellectual Property Office on Aug. 31, 2022, the entire content of both of which are incorporated herein by reference. BACKGROUND 1. Field Aspects of embodiments of the present disclosure relate to a method of detecting an abnormal operating condition of a battery system, which may lead to a thermal runaway. 2. Description of the Related Art Recently, vehicles for transportation of goods and peoples have been developed that use electric power as a source for motion. Such an electric vehicle is an automobile that is propelled by an electric motor using energy stored in rechargeable batteries. An electric vehicle may be solely powered by batteries or may be a hybrid vehicle powered by, for example, a gasoline generator or a hydrogen fuel power cell. The vehicle may include a combination of electric motor and conventional combustion engine. Generally, an electric-vehicle battery (EVB or traction battery) is a battery used to power the propulsion of battery electric vehicles (BEVs). Electric-vehicle batteries differ from starting, lighting, and ignition batteries in that they are designed to provide power for sustained periods of time. A rechargeable (or secondary) battery differs from a primary battery in that it is designed to be repeatedly charged and discharged, while the latter is designed to provide an irreversible conversion of chemical to electrical energy. Low-capacity rechargeable batteries are used as power supplies for small electronic devices, such as cellular phones, notebook computers, and camcorders, while high-capacity rechargeable batteries are used as power supplies for electric and hybrid vehicles and the like. Generally, rechargeable batteries include an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes, a case receiving (or accommodating) the electrode assembly, and electrode terminals electrically connected to the electrodes of the electrode assembly. An electrolyte solution is injected into the case to enable charging and discharging. The shape of the case, such as cylindrical or rectangular, may be selected based on the battery's intended purpose. Lithium-ion (and similar lithium polymer) batteries, widely known via their use in laptops and consumer electronics, dominate the most recent electric vehicles in development. Rechargeable batteries may be used as a battery module formed of a plurality of unit battery cells coupled together in series and/or in parallel to provide high energy content, such as for electric motor propulsion of vehicles. The battery module is formed by interconnecting the electrode terminals of the plurality of unit battery cells together in an arrangement based on a desired amount of power and to realize a high-power rechargeable battery. Battery modules can be constructed either in a block design or a modular design. In the block design, each battery is coupled to a common current collector structure an arranged in a housing. In the modular design, pluralities of battery cells are connected together to form submodules, and several submodules are connected together to form the battery module. In automotive applications, battery systems often consist of a plurality of battery modules connected together in series to provide a desired voltage. The battery modules may include submodules with a plurality of stacked battery cells, and each battery cell stack includes cells connected in parallel that are, in turn, connected in series (XpYs) or cells connected in series that are, in turn, connected in parallel (XsYp). A battery pack is a set of any number of (usually identical) battery modules. The battery modules may be configured in (or connected in) series, parallel, or a mixture of both to deliver the desired voltage, capacity, and/or power density. Components of the battery packs include the individual battery modules and interconnects, which provide electrical conductivity between the battery modules. A battery system further includes a battery management system (BMS), which is an electronic system that manages the rechargeable battery cells, battery modules, and battery pack such as by protecting the battery cells from operating outside their safe operating area (or safe operating parameters), monitoring their states, calculating secondary data, reporting that data, controlling its environment, authenticating it, and/or balancing it. For example, the BMS may monitor the state of the battery pack, battery modules, or battery cells as represented by voltage (such as total voltage of the battery pack or battery modules or voltages of individual cells), temperature (such as average temperature of the battery pack or