Lithium-ion batteries are to be found everywhere in today’s world, from the mobile phones in our pockets to the electric vehicles on roads and the growing number of energy storage deployments accompanying renewables.
As the batteries have grown bigger and more powerful, so have concerns about their safety. Indeed they have even been identified as the cause of several aviation incidents leading airline companies to restrict or ban bulk shipments.
With this in mind two recently completed European projects, STALLION (Safety Testing Approaches for Large Lithium-Ion battery systems) and STABALID (STAtionary BAtteries LI-ion safe Deployment), have been focused on the safety on Li-ion batteries for large-scale, i.e. 1 MW and above, utility grid applications.
Project STALLION – framework for Li-ion battery safety testing
The EU FP7 supported STALLION project, which was initiated in October 2012, was aimed to set up a complete framework of methodologies and protocols for safety testing of stationary Li-ion batteries.
The project was led by R&D organization EnergyVille/VITO in Belgium and included as partners the French research organization CEA, energy company ABB from Switzerland, consultants DNV GL from the Netherlands, renewable energy companies Dispatch Energy from Germany and Umicore from Belgium, and the German testing and certification organization VDE.
The project developed all the tests and checks that are needed for ensure safety throughout the entire life of the battery. These tests cover everything from the production over installation, exploitation to decommissioning and recycling. The result is the very first comprehensive set of guidelines and standards in this field. This will allow companies to produce and deploy batteries on a large scale, knowing that they are safe and dependable.
Specific results include:
• Setting up a system analysing the risks connected to large batteries
• Developing a toolkit of tests and guidelines on how they should be used
• Testing the newest generation of (safer) battery materials
• Looking into additional technology for monitoring batteries
• Creating a website for battery standards.
STABALID – new battery testing procedure
STABALID, which was also supported under the EU FP7 framework and ran in parallel with STALLION, was focused on developing a new testing procedure for stationary batteries with the aim of becoming a new international standard document for this kind of energy system.
Led by battery manufacturer Saft, partners included Portuguese utility EDP Distribuição, the European Virtual Institute for Integrated Risk Management (EU-VRi), French research body Institut National de l'Environnement Industriel et des Risques (INERIS), the TÜV SÜD Battery Testing institution in Germany, and the Portuguese research laboratory INESC Porto.
The basis for the safety testing procedure was a detailed risk analysis and review of international standards (including those in preparation) applicable for stationary batteries, taking into account on-going research work on Li-ion batteries and on electric vehicle charging at EU and national levels. In addition, the project has proposed a strategy and roadmap to establish a harmonized regulatory framework in order to allow safe implementation, operation and end of life of large Li-ion batteries for grid applications.
Battery safety test handbook
The other combined deliverable of the two projects is a handbook on battery safety for stakeholders, including cities, system integrators and electricity network operators.
Entitled ‘Test protocol, containing detailed descriptions of the tests defined in the FMECA’ (Failure Mode, Effect and Criticality Analysis), the handbook contains combined STALLION and STABALID safety test protocol definitions and sets out details of the tests and instructions for carrying them out. Information covers propagation of thermal runaway, overcharge of a module, polarity reversal, rough handling of the battery container, module cycling without cooling, external short circuit of a module, deformation of a module, flooding of the battery container, and battery management system temperature, current and voltage protection.