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EP-4542725-B1 - BATTERY SYSTEM AND METHOD FOR MONITORING A BATTERY SYSTEM

EP4542725B1EP 4542725 B1EP4542725 B1EP 4542725B1EP-4542725-B1

Inventors

  • ERHART, MICHAEL

Dates

Publication Date
20260506
Application Date
20231019

Claims (12)

  1. A battery system (100), comprising: a battery pack (10) comprising a housing (11) and a plurality of battery cells (12) accommodated within the housing (11); a cooler (20) connected to the battery cells (12) and an underbody protection structure (30), wherein the cooler (20) is arranged between the underbody protection structure (30) and the battery pack (10), and wherein the cooler (20) comprises at least one cooling channel (22) and at least one pressure detection channel (24) separated from the cooling channel (22) and arranged inside the cooler (20); and a pressure detection device (40) with a pressure sensor (42) connected to the pressure detection channel (24) and adapted to detect an underbody contact or impact event by monitoring the pressure in the pressure detection channel (24) by the pressure sensor (42), wherein the pressure detection channel (24) is filled with a fluid, characterized in that the fluid is a gaseous medium.
  2. The battery system (100) according to claim 1, wherein the cooler (20) comprises two metal sheets (26, 28) connected to each other, wherein the cooling channel (22) and the pressure detection channel (24) are arranged between the two metal sheets (26, 28).
  3. The battery system (100) according to claim 2, wherein the cooling channel (22) and/or the pressure detection channel (24) are implemented in at least one of the sheets (26, 28).
  4. The battery system (100) according to any of the preceding claims, wherein the cooling channel (22) is designed as a meandering cooling channel and the pressure detection channels (24) extend into loops of the meandering cooling channel.
  5. The battery system (100) according to any of the preceding claims, wherein the underbody protection structure (30) comprises at least one support element (32) adapted to distribute a force occurring due to an underbody contact or impact event into the support element (32) via the cooler (20).
  6. The battery system (100) according to claim 5, wherein the support element (32) comprises one or more cross beams (34).
  7. The battery system (100) according to claim 5 or 6, wherein the support element (32) is adapted to distribute a force occurring due to an underbody event into an area of the cooler (20) wherein the pressure detection channel (24) is arranged.
  8. The battery system (100) according to any of the preceding claims, wherein the underbody protection structure (30) comprises protrusions (36) located on the side of the underbody protective structure (30) facing away from the battery pack (10).
  9. The battery system (100) according to any of the preceding claims, wherein the cooler (20) is manufactured by a roll-bonding process.
  10. The battery system (100) according to claim 9, wherein the cooling channel (22) and/or the pressure detection channel (24) are formed by a high-pressure forming process.
  11. An electric vehicle (1) comprising the battery system (100) according to any one of the preceding claims.
  12. A method for monitoring a battery system (100), wherein the method comprises the steps of: a) providing a battery system (100) as defined in claim 1; b) continuously measuring a pressure of a fluid in the at least one pressure detection channel (24); c) detecting an underbody contact or impact event, when a pressure pulse in the at least one pressure detection channel (24) exceeds a threshold value.

Description

Field of the Disclosure The present disclosure relates to a battery system and a method for monitoring the battery system. Technological Background 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 form of hybrid vehicle powered by for example a gasoline generator or a hydrogen fuel power cell. A hybrid vehicle may include a combination of an 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 only an irreversible conversion of chemical to electrical energy. Low-capacity rechargeable batteries are used as a power supplies for small electronic devices, such as cellular phones, notebook computers and camcorders, while high-capacity rechargeable batteries are used as a 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 the electrode assembly, and an electrode terminal electrically connected to the electrode assembly. An electrolyte solution is injected into the case in order to enable charging and discharging of the battery via an electrochemical reaction of the positive electrode, the negative electrode, and the electrolyte solution. The shape of the case such as cylindrical or rectangular, may be selected based on the battery's intended purpose. Lithiumion (and similar lithium polymer) batteries, widely known via their use in laptops and consumer electronics, dominate the most recent group of electric vehicles in development. Rechargeable batteries may be used as a battery module formed of a plurality of unit battery cells coupled to each other in series and/or in parallel so as to provide a high density such as for motor driving of a hybrid vehicle. For example, the battery module may be formed by interconnecting the electrode terminals of the plurality of unit battery cells in an arrangement or configuration depending on a desired amount of power and in order to realize a high-power rechargeable battery. Battery modules can be constructed in either a block design or in a modular design. In the block design each battery is coupled to a common current collector structure and a common battery management system and the unit thereof is 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 generally include of a plurality of battery modules connected in series for providing a desired voltage. The battery modules may include submodules with a plurality of stacked battery cells and each 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 a series, parallel or a mixture of both to deliver the desired voltage, capacity, and/or power density. Components of a battery pack include the individual battery modules, and the interconnects, which provide electrical conductivity between the battery modules. Battery systems according to the related art, despite any modular structure, usually include a battery housing that serves as enclosure to seal the battery system against the environment and provides structural protection of the battery system's components. Housed battery systems are usually mounted as a whole into their application environment, e.g. an electric vehicle. Thus, the replacement of defect system parts, e.g. a defect battery submodule, requires dismounting the whole battery system and removal of its housing first. Even defects of small and/or cheap system parts might then lead to dismounting and replacement of the complete battery system and its separate repair. As high-capacity battery systems are expensive, large and heavy, said procedure proves burdensome and the storage, e.g. in the mechanic's workshop, of the bulky battery systems becomes difficult. A thermal management system to provide thermal control of the battery pack is often included to safely use t