A plane in San Francisco experienced evacuation due to a passenger's laptop catching fire, resulting in three people getting injured according to the Carolina Daybook, a weekly newsletter from the University of South Carolina.
The article states that the incident occurred due to the battery inside of the passenger’s laptop igniting. Although the incident is a rare occurrence, it is one of the reasons why researchers at the University of South Carolina are looking for ways to improve lithium-ion batteries.
Lithium-ion batteries are batteries located in common electronic devices, such as cell phones, watches, electric cars, laptops and electric tools. They are essential powerhouses for modern day electronics. Even though lithium-ion batteries are quite reliable and safe, there are some flaws that could face improvement, said Paul Coman, a research associate professor at USC.
According to the South Carolina Daybook, the main cause of lithium-ion batteries catching fire would be a thermal runway. A thermal runway happens when disorderly reactions are activated inside of a battery cell, setting off a series of reactions that turn into fires. These said reactions can be especially dangerous because of the releases of toxic gasses.
Coman and his team have been working with national agencies to find ways to make sure that their battery systems are safe.
Larger battery systems like electric vehicles, contain thousands of battery cells, and if one battery goes ablaze, batteries around it will follow suite, creating an extremely dangerous situation, Coman said.
“We help (those agencies) design those (battery) packs and we aim for something that we call ‘Passive Propagation Resistance,'” Coman said.
Passive Propagation Resistance ensures if one cell in a battery pack fails and catches aflame, the fire will not spread to neighboring cells, Coman said.
“We also try to make our own batteries too, ” said Andrew Weng, a current postdoctoral researcher who used to work at Tesla. “We are trying to understand the relationship between manufacturing quality ... and how batteries perform in the field.”
It is important to have an understanding of the conditions that potentially cause the issues of batteries, Weng said.
David Petrushenko, a Ph.D graduate from the University of South Carolina and a full-time employee at NASA in Houston, Texas, said, “the way we design packs, they're passively propagation resistant, where there’s no active components in there that basically require some type of energy draw or depletion of energy ... They basically add to the capability without adding another failure point.”
There are mistakes people make in regards to battery handling that could trigger thermal runaways, Coman said.
“One of the biggest mistakes that I see and that catches my attention is people putting their phones on the dashboard of their cars or on the car seat," Coman said. "If (the device) is in the sunlight, like in South Carolina, we have the Sun overheating (them).”
Lithium-ion thermal runaways can also be triggered from manufacturing or mechanical problems or charging misuse.
The outside entrance of Molinaroli College of Engineering and Computing on Oct. 28, 2024. The college has been teaching engineering and computing to students for over 50 years.
However, it’s best not to be too alarmed, Weng said, as these accidents are only seldom, not the norm. He wants people to know that they should not be frightened of batteries. He and other researchers believe that it is important that consumers should feel like the products they are purchasing and the batteries inside them are safe. Even though lithium batteries are safe, the team is looking for ways for them to be safer in general, he said.
The researchers are also looking forward to improving the battery life of batteries. As people continue to use a battery by charging and discharging it, they are wearing off the cell of the battery, causing the life of the battery to decrease, Coman said.
“In certain conditions, if you use (a battery) in very low temperatures for instance, you create some internal changes that would create some pathways for short-circuiting. It's called lithium plating,” Coman said.
Lithium plating is when a type of metallic lithium sets and builds up during high or low temperatures on an negative electrode surface which could cause plenty of safety risks, which the team is looking to improve.
"The way I view it ... really, we're dealing with a thermal problem when it comes to battery safety,” Petrushenko said.
The team has been figuring out ways to navigate this problem by designing the battery packs in a way where whenever the first cell fails, energy is absorbed from the neighboring cells. The researchers continue to crack down on the problem through a mathematical model.
The team performs tests where they calculate the amount of heat released from a cell whenever a battery fails Petrushenko said. They use an instrument called a fractional thermal runaway calorimeter that captures energy in different fractions of the cell. They will test the most vulnerable locations first until failure and use the data gathered to make the mathematical model.
“If you set up your model correctly, ... you can calculate out very well which areas of your battery pack are going to be vulnerable,” Petrushenko said.
The researchers will also take the heat released from the instrument and place it in a thermal model, and from the instrument they are able to observe and gather the energy released in a period of time.
The research team continues to figure out ways to improve the design of these lithium-ion batteries hidden in everyday devices.
The subject of safety with lithium-ion batteries is difficult, because accidents due to these batteries are very rare Weng said. However, the team tries to navigate the challenge through hours and months of hard work.
Petrushenko encourages undergraduate students interested in research to venture out and pursue research opportunities.
"The worst thing that happens is you don’t like it, and you know you don't like it. But if you like it, you have a potential to really experience something tremendous ... especially if you are willing to work just a little bit harder.”