Energy Storage Systems (SSE) are complex devices and dealing with them expose to safety hazards of different types (chemical, electrical, thermal) with more or less criticality depending on the technology and the context.
In spite of the widespread application of lithium-ion batteries and their bright future, safety issue is still a severe obstacle in the technology development. These technologies based on organic solvent may cause runaway reactions, which are a major source of industrial accidents. Several dramatic incidents of overheating or battery fires have been reported in consumer products. For example, the global recall of Samsung’s Galaxy Note 7 in October 2016 or the full grounding of the entire Boeing 787 fleet in January 2013. Apart from the failure risks for users, these series of incidents brought battery makers to the forefront and the way they will address safety issues.
Safety / 02.
Safety management approach
The safety of people and equipment is MTA’s number one priority and we pay special attention to the systems under tests. That is why we constantly focus on guaranteeing the highest quality standards, improve our test procedures and methods as well as ensure that our key personnel are properly trained. Before starting any testing, we systematically carry out a safety study, which is valuable information to collaborate effectively with our customers. The purpose of these studies is to advise our clients, to identify the specific risks of their technologies and designs, and to identify simple and concrete solutions to be implemented while conducting tests. We then take care of putting in place these specific solutions adapted to the device under test.
Safety / 03.
Safety management tools
In order to prevent the risks associated with ESS during testing, MTA offers various safety tools and are categorized in three different and complementary types as shown below:
The principle is here to prevent the potential hazard and act upstream. This phase consists of setting up protections against the failure risks and/or unwanted event by controlling the atmosphere of the test. In response, we apply the continuous use of a gas generator by scanning the volume of the test chamber. The ambient atmosphere is sufficiently diluted with an inert atmosphere (in order to reduce the oxygen ratio below the combustible mix limit) and anhydrous atmosphere (without water to avoid the risk of condensation) and thus preserving the test support.
As already mentioned, we first run a customized safety study, which generally leads to the implementation of specific surveillance and safety tools during the testing process. In addition to this phase, we carry out a permanent monitoring of voltages, currents and temperatures during each test. If the safety limits are exceeded, we perform an automatic (and quick, <1s) shutdown of all test equipment (bench, chamber, thermal conditioning, etc.). Without this automatic shutdown, irreversible damage can occur.
In case, neither preventive nor active actions have worked, a third level of safety is implemented: curative security systems for automatic fire suppression. These systems are not only specifically designed for our facilities but also has adapted protection features to prevent potential hazards. Our systems have the benefit of extinguishing SSE fires by injecting inert gas into the test chamber. These automatic fire suppression systems (24/7) are useful to control and prevent the fire from spreading until the arrival of fire response team.