In this exclusive interview with Carly Weller, senior battery safety expert Caroline Gaya shares insights into Ineris’ mission and its pivotal role in risk assessment and shaping the future of battery safety.
As Europe accelerates its battery ambitions, France is emerging not only as a manufacturing powerhouse but also as a leader in safety innovation. At the forefront of this effort is Ineris – the French National Institute for Industrial Environment and Risks – whose work spans the entire battery value chain, from materials testing to post-accident analysis.
Gaya’s own journey into the field began with a PhD in electrochemistry, focused on lithium-air batteries for aircraft. “Then I joined Safran, working on thermal runaway. I was project manager for that,” she recalls. She later joined Ineris, drawn by its mission and flexibility. “At Ineris, I can choose the type of project I want to pursue, which is nice.”
“Ineris operates under the ministry responsible for environmental affairs,” Gaya explains. “Our core mission is to advance safety and develop technologies that minimise environmental impact and protect the people working in these sectors.”
The institute’s scope is broad, encompassing everything from evaluating the performance and risks of cathode materials to system-level safety and fire modelling. “We’re involved across the entire battery value chain,” Gaya adds. “Some teams focus on material performance and associated risks – such as determining whether certain cathode materials or powders are explosive and understanding their behaviour under different conditions.”
Gaya herself specialises in battery systems, with a particular emphasis on safety. “I’m part of the battery safety team,” she says. “My work centres on understanding how systems respond under various conditions and designing them to operate safely and reliably.”
Ineris also collaborates closely with industrial engineers to develop safer battery concepts, especially for lithium-ion technologies. “We work at the R&D level,” she notes, “supporting efforts to optimise cell configurations and integration – primarily within lithium-ion systems.”
Beyond research and development, Ineris plays a critical role in post-incident analysis, investigating accidents such as fires involving buses and energy storage systems. “Our goal is to extract insights and develop guidelines that can inform future safety improvements,” Gaya explains.
The institute also monitors emerging battery chemistries, including sodium-ion and solid-state technologies.
“Since our focus is strictly on safety,” she emphasises, “we don’t evaluate performance metrics. Our priority is understanding and mitigating potential risks.”
Battery safety has become a pressing issue, especially in light of high-profile incidents involving electric vehicles and consumer electronics. “You mostly hear the bad stories, don’t you?” Gaya remarks. “It can be difficult to explain, because while these dramatic cases grab attention, the number of fires in electric vehicles is currently comparable to those in conventional thermal cars.” She underscores a fundamental truth: “Any time you store energy, there’s an inherent risk, regardless of the technology.”
Ineris plays a key role in developing safety standards for emerging formats such as solid-state and lithium-metal batteries. “We’re involved in many technical committees, both European and international,” Gaya says. “For example, TC21 and TC120.” One of Ineris’ experts, Guy Marlair, helped advance IEC 62933.5.2, a standard for energy storage safety.
The institute has already investigated incidents involving solid-state batteries, including a fire on Paris’ e-buses. “There was a belief that solid-state batteries posed no risk because they lack flammable liquid electrolytes,” she explains. “But in reality, they present different kinds of risks.”
Ineris is also contributing to a new standard for sodium-ion batteries and continues to update lithium-ion regulations. “We’re involved in regulatory work in France,” Gaya says. “For example, AMPG – a government-led legislative project – includes efforts to define safety distances between ESS units to prevent fire propagation.”
At the EU level, Ineris participates in regulatory discussions around the Battery Passport and the transport of dangerous goods. “One of my colleagues, Arnaud Bordes, is an expert in this area and attends all the meetings,” she adds.
International collaboration is central to Ineris’ mission. “We work with the UK’s Faraday Institute on projects related to post-crash EV accidents and recycling,” Gaya says. The institute also partners with NFPA and Sandia Labs in the US to assess the environmental impact of battery fires. “We’re involved in many research programmes, mostly with EU companies. It’s our way of staying up to date.”
One EU project aims to develop a digital twin to predict cell performance, aging and safety risks. “An industrial partner might run just five abuse tests to calibrate the model, and then use it to predict system behaviour,” Gaya explains.
Ineris’s experimental campaigns include testing extinguishing systems – foam, water spray and others – on lithium-ion and post-lithium technologies. “Since the results will be made public, the goal is to provide insights that help stakeholders choose the best solution for their systems.”
Looking ahead, Gaya is cautiously optimistic about France’s battery industry. “I hope the development of gigafactories in France will help build a complete ecosystem,” she says. She points to regional hubs driving innovation: “There’s Battery Valley, ACC, Verkor, Saft – north of France, near Bordeaux and Grenoble, it’s becoming a real hub.”
She also highlights RS2E, a network of universities and labs, industrial partners and spin-offs including Tiamat, which is developing sodium-ion technology.
Ineris recently hosted a Battery Safety Day in collaboration with EDF, bringing together global experts to share insights. “In safety, you have to talk to people – it’s essential,” Gaya says. “There are too many systems to test everything yourself.”
One UK participant demonstrated that certain extinguishers fail when applied to full battery systems. “Sometimes the best advice is, don’t try – just evacuate,” she recalls. “It’s important that everyone reaches the same level of understanding.”
The event also spotlighted firefighter safety and pollution exposure. “Sandia Lab proposed an analysis of the pollution affecting firefighters and others working near battery fires,” Gaya notes. In France, fire blankets for EVs are gaining traction, although their use might not be relevant in several cases (because of risk of explosion due to gases accumulation beneath the blanket) and their implementation remains challenging. “In a car park, for example, it’s very tricky to deploy them during an incident.”
International partnerships remain essential. “Sometimes you meet people who claim to understand batteries, but they work in isolation,” Gaya says. “To do this properly, you need funding, data and collaboration.”
She believes France brings a unique perspective to the global conversation. “I hope France continues to prioritise environmental aspects. Even if you prevent a fire, what about the gases released? Are they toxic?”
Ineris’s work is a reminder that safety isn’t a constraint, it’s a catalyst for innovation. As Gaya puts it, “We try to push for the best every time. Not just follow standards, but improve them.”
