Early Detection of Failing Automotive Batteries Using Gas Sensors

Abstract

Safety for automotive lithium-ion battery (LIB) applications is of crucial importance, especially for electric vehicle applications using batteries with high capacity and high energy density. In case of a defect inside or outside the cell, serious safety risks are possible including extensive heat generation, toxic and flammable gas generation, and consequently fire and explosion. New regulations (GB 38031-2020) require a warning for passengers at least five minutes before serious incidents. This regulation can hardly be fulfilled with state-of-the-art battery monitoring. In this study, gases produced during battery failure before and during a thermal runaway (TR) are investigated in detail and the use of different gas sensors as early detectors of battery incidents is tested and proposed. The response of several commercially available gas sensors is tested in four battery failure cases: unwanted electrolysis of voltage carrying parts, electrolyte vapor, first venting of the cell and the TR. The experiments show that battery failure detection with gas sensors is possible but depends highly on the failure case. The chosen gas sensor can detect H2 produced by unwanted electrolysis and electrolyte vapor and gases produced by degassing of state-of-the-art LIBs. The results may contribute significantly to failure detection and improvement of battery safety.

Additive Manufacturing as a Means of Gas Sensor Development for Battery Health Monitoring

“…Regarding this type of battery, safety is a significant concern and it must be monitored carefully and reliably. Battery safety requires sensors for the detection of many different volatile compounds (e.g., C 4 H 10 O 2 , C 3 H 6 O 3 , 1,2-dimethoxyethane, dimethyl carbonate, C 4 H 8 O 3 ) [13] that could be formed upon battery failure. Especially due to their use in portable electronics, such as computers or smartphones [14,15], or in electric or hybrid vehicles, safety monitoring is even more important and therefore, there is a need of suitable sensors that fit the requirements for the possible application [16].…”

“…In particular, the generation of heat and its accumulation inside the batteries is often accompanied by the generation of inflammable gases, such as CO, H 2 , CH 4 , C 2 H 4 , C 2 H 6 , and C 3 H 8 due to various parasitic reactions depending on temperature, electrolysis, electrolytes and the appearance of thermal leakage [13,20]. Therefore, it is necessary to improve the safety of the batteries by preventing the generation of these gases and/or by the implementation of suitable sensors for early hazard detection and rapid disconnection of the battery.…”

“…Therefore, it is necessary to improve the safety of the batteries by preventing the generation of these gases and/or by the implementation of suitable sensors for early hazard detection and rapid disconnection of the battery. Essl et al [13] investigated, tested, and proposed the use of various gas sensing structures as early detectors of battery deterioration. Here, it is shown that sensing structures based on metal oxide semiconductors (MOX) are the most promising candidates due to their speed of response with high sensitivity, low cost, and their ability to easily connect to the battery management system (BMS) [13].…”

“…Essl et al [13] investigated, tested, and proposed the use of various gas sensing structures as early detectors of battery deterioration. Here, it is shown that sensing structures based on metal oxide semiconductors (MOX) are the most promising candidates due to their speed of response with high sensitivity, low cost, and their ability to easily connect to the battery management system (BMS) [13]. Following the studies, the authors mention that it is possible to detect battery failures with gas sensors, but through the many different failure mechanisms, ongoing study is still necessary [13].…”

“…This work reports on the use of the 3D-DIW printed nanocrystalline films tested as reliable, accurate, and selective sensors for the test of battery electrolytes vapor at relative concentrations. At this stage our input and aim is to promote battery safety through early leak detection, which we consider of high importance, especially for the electrification of the mobility sector and its large-format lithium ion batteries [13,17]. In the future, a tighter control of the reactions occurring inside the battery by monitoring the electrolyte composition via non-intrusive sensors may be a promising approach to improving the batteries' lifetime and performance.…”