Meet the Expert: Dr. Yi Ji

Yi Ji
Lead Standards Engineer

Dr. Yi Ji is a Lead Standards Engineer at UL Standards & Engagement, where she works at the forefront of developing safety standards for emerging technologies in batteries, electrification, and clean-energy systems. She focuses on translating complex technical innovation into practical frameworks that support safe adoption, market confidence, and long-term sustainability.

Prior to joining ULSE, Yi worked as a principal scientist at the Albemarle Corporation, leading research and development in lithium metal anode production and battery recycling. Her work has advanced techniques for recovering critical materials from end-of-life batteries and improving the efficiency and economics of recycling processes, which are key priorities in strengthening a more resilient and sustainable energy supply chain.

A published researcher and inventor, Yi holds multiple patents and has contributed to peer-reviewed research on battery materials, hydrometallurgical processes, and circular economy strategies.

Yi holds a Ph.D. in environmental and ecological engineering from Purdue University, where she focused on innovative approaches to recovering cathode materials from used lithium-ion batteries. Her research continues to contribute to industry progress today.

We had the chance to sit down to get to know Yi better. Learn more about her experience and how it’s defining her approach to working for a safer world.

Q: Yi, tell us a little about yourself and your role at UL Standards & Engagement. What does your work focus on day to day? 

A: I earned my Ph.D. from Purdue University, where my research focused on battery recycling. Specifically, recovering materials from spent lithium-ion batteries. After graduating, I joined the Albemarle Corporation, where I worked in two main areas: battery recycling and next-generation lithium-ion battery development. That gave me exposure to the full lifecycle of batteries from materials and product development to end-of-life considerations.

In that role, I was also involved in electrochemical testing and collaborated with leading electric vehicle and mining companies. Those experiences helped me understand both the opportunities and risks associated with battery technologies.

Today, at UL Standards & Engagement, I work as a technical expert focused on electrification. My responsibilities include supporting standards development, conducting hazard assessments, and contributing to white papers and other safety documents. I also participate in international engagement and help communicate technical requirements around batteries, energy storage systems, and emerging electrification technologies.

Q: What first sparked your interest in battery technology and safety? Was there a moment or experience that led you to specialize in this area? 

A: While working on next-generation lithium-ion batteries, I began to see real safety risks, especially fire hazards, associated with these technologies.

One moment that stood out was when a collaborator experienced a major fire at a lithium-related manufacturing facility. That really brought the risks into focus for me. It wasn’t just theoretical anymore; it showed how serious the consequences could be.

That experience made me realize there’s a real need for stronger attention to battery safety, especially as technologies evolve quickly.

Q: For people who might not think about it often, why is battery safety such an important issue right now? 

A: Most people assume batteries are safe — and in most cases, they are — but we’re also seeing rapid innovation where speed threatens to ignore risk. Consumers want higher capacity, faster charging, and lower costs. Those demands can create pressure in manufacturing and design.

For example, differences in manufacturing quality (electrode misalignment, for example) can increase risk. At the same time, lower-cost products might not go through proper safety certification. That means consumers can unknowingly use products that don’t meet high safety standards.

As batteries become more powerful and more common in everyday devices, the potential consequences of failure increase. That’s why safety is becoming more important than ever.

Q: What are some of the biggest risks associated with lithium-ion batteries, and what makes those risks different from other types of products? 

A: The biggest risk is what we call thermal runaway. That’s when a battery generates more heat than it can dissipate, which can lead to smoke, fire, or even explosion.

Lithium-ion batteries are different from traditional batteries because they are rechargeable and more energy-dense. That means they degrade over time, and their safety profile can change with age.

We’re also seeing a lot of new sellers entering the market, especially through e-commerce, who simply don’t understand the risks or regulations. From our research, many are shipping these products in non-compliant ways, often because of a lack of awareness rather than intent.

Another factor is manufacturing consistency. Even small variations can affect safety. Combined with the chemistry of lithium-ion systems, these batteries require more careful design, testing, and control than traditional, non-rechargeable batteries like alkaline cells. Cheaper doesn’t correlate with better or safer when it comes to lithium-ion batteries.

Q: Looking ahead, what gives you confidence that we can continue improving battery safety as these technologies become even more widespread? 

A: What gives me confidence is the number of experts working in this field. There is a strong global community focused on improving battery safety through research, testing, and innovation.

Equally important is the role of third-party organizations like ULSE. Manufacturers don’t just rely on internal quality control. They also look to external standards and certifications to benchmark safety.

In addition, we are seeing improvements not only in battery chemistry, like lithium iron phosphate, but also in system design such as better battery management systems and cooling technologies. All of these contribute to safer products.

Q: What is one safety tip that most people don’t know but need to? 

A: One critical tip: Never put a power bank in a checked bag when flying — or even in the overhead bin.

Power banks store a large amount of energy. If a thermal runaway event occurs in checked luggage that’s inaccessible in the cargo hold, it might go unnoticed and could lead to a serious incident. Keeping it with you and at arm’s reach allows any issue to be identified and addressed quickly.

It’s a simple step, but one that could save lives, including your own.