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X-Rayted Files: Tales from the Files of Lithium-ion Batteries

Lithium-ion batteries have, in part, enabled the continued miniaturization of the devices we love. They have also played an important role in making practical electric cars a reality. But like other approaches to high density energy storage, they do present risks. I experienced this firsthand recently, and my interest in lithium-ion battery safety has been piqued (more on that later). Battery failures, especially those that result in fire, get a lot of attention. Stories of consumer products from vaping devices, hoverboards, smartphones and laptops, to electric cars and even passenger jets have garnered media attention for their sometimes spectacular failures. I’ll tell you a little story about my own experience and take a closer look at why these failures can occur in devices on which so many consumer electronics now depend. 

As electric cars are more widely adopted, the risks associated with lithium-ion battery failures is increasingly important to understand. As a scientist, tinkerer, and motorhead, I couldn’t resist the urge to convert my 1928 Ford Model A into an EV. Like many recent projects, this undertaking was, in part, a product of working from home at the onset of the pandemic and spending a few more of my waking hours than normal out in my garage. Months of research and work went into this conversion, procuring the necessary parts and adapting them to fit my vintage baby. It was a fun project, I learned a lot, and was decidedly proud of the result. 

Unfortunately, I’m still learning. A couple of weeks ago, my converted Model A fell victim to a catastrophic lithium-ion battery fire. The fire happened overnight, without warning nor explanation.  The vehicle was not charging at the time, nor was it exposed to excessive heat or other external forces. The battery pack, repurposed from a Chevy Volt, simply caught fire while tucked away in my garage. While I’m deeply disappointed, I’m feeling two things even more intensely. I’m extremely grateful that the fire was limited to the Model A itself, and did not spread through the garage, nor to my home. I’m also overwhelmingly curious as to what might have instigated this sudden failure of the battery pack and its root causes. This is one of those times (there are, in fact, many) when owning your own X-ray company really comes in handy, as what remains of my vintage EV has been carefully transported to Creative Electron world headquarters for careful examination. I don’t know at this point what we might learn, but we will leave no scorched cells unturned as we investigate.   

Lithium-ion batteries risk overheating, and can result in fire or even explosions. Causes range from excessive heat exposure, vibration, charging at below freezing temperatures, mechanical damage, rapid discharge or overcharging, shorts, or manufacturer defects to name a few. Thermal runaway, when a single cell overheats to the point that it causes adjacent cells to overheat, is a chain reaction that can be difficult to stop. When such fires are successfully suppressed, the remaining cells are at risk of reigniting, sometimes days later, as such cells will retain what is referred to as stranded energy. Such events are most common in off brand, aftermarket, poorly manufactured and underregulated batteries that find their way into cheap consumer products such as those infamous vape pens and hoverboards. But even high quality, name brand batteries produced by safety conscious manufacturers can experience unexpected failures. It’s no surprise that the leading manufacturers of lithium-ion batteries employ tools such as automated X-ray inspection and CT in ensuring the highest quality and safety of their products. Conversely, there are also counterfeit batteries that are difficult for consumers to distinguish from authentic. The bad actors selling counterfeits are not likely to be taking all the same safety precautions in manufacturing as name brand manufacturers who produce premium products. Saving a few bucks on a battery can turn out to be costly. 

At every point in the product lifecycle, the safe handling and storage of lithium-ion batteries is imperative, and as their use pervades, the safe disposal and recycling of these batteries is increasingly important. According to a company called “e-cell secure” which focuses on safe storage, transportation, and recycling of lithium batteries, lithium-ion battery sales will more than double from 2019-2025. In an interview with Waste360, Ronald Butler, the CEO of e-cell secure notes, “There is inherent danger associated with the handling of batteries. In most cases, mechanical damage would probably rank as the highest risk factor for initiating a thermal runaway (fire/explosion) event. Improper handling can result in crush or puncture damage, possibly leading to the release of electrolyte material or short circuiting. These actions could result in thermal runaway and a resulting fire and/or explosion.” 

Lithium-ion batteries are essential to so many modern devices. They demand careful manufacturing, proper care in their use and handling, and perhaps even more care in their eventual disposal. While I for one wouldn’t want to live without them, I now have a slightly altered perspective as to living with them. What remains of my 1928 Model A will eventually rise from the ashes, and I’ll look forward sharing about its restoration, as well as what we learn about its recent misfortune.  Stay safe, everyone!

Dr. Bill Cardoso is CEO of Creative Electron.