Thanks to a Michigan State University (MSU) discovery, consumers worried about the safety of lithium-ion batteries (LIBs) may soon have a more dependable choice.Researchers have used lignin, a naturally occurring material found in wood, to create a safer battery component that lasts longer.The team has developed a barrier that can help avoid short circuits and lower the risk of fires in batteries used in anything from electric vehicles to smartphones by incorporating this material into a thin film separator.
“We were surprised to see that the lignin film also improved the battery’s cycle life. We increased the battery’s cycle life by 60 percent,” said Chengcheng Fang, assistant professor in the College of Engineering at MSU, in a statement.
Lignin boosts performance
Separators play a vital role in LIBs by preventing internal short circuits, reducing the risk of thermal runaway, and supporting overall performance and longevity.However, the polyethylene and polypropylene plastics commonly used in commercial separators have notable drawbacks, including high thermal shrinkage, poor wettability, and limited long-term stability.According to researchers, these weaknesses are especially concerning in high-demand applications like electric vehicles, where overheating can cause the separator to fail, potentially allowing the battery’s cathode and anode to come into contact, triggering a short circuit, fire, or explosion.
In contrast, the lignin-based separators developed by the team remained dimensionally stable at temperatures as high as 300°C (572°F).
“The separator is fabricated using lignosulfonate, a natural polymer derived as a byproduct of chemical pulping and biorefinery processes,” according to the study abstract.Researchers tested different thicknesses of lignin films and found that those measuring 25 micrometers—thinner than a quarter of a human hair—were most effective at maintaining battery stability and reliably preventing contact between the anode and cathode.
Sustainable battery innovation
The use of lignin-based film significantly enhanced both the performance and thermal stability of lithium-ion batteries.The ability of the film to sustain internal stability over time was demonstrated by a significant advantage: a 60 percent improvement in cycle life, or the number of times a battery can be charged and drained. Because of its longer lifespan, the technology is particularly useful for demanding applications like portable gadgets and electric cars.In addition to performance, the research provides a manufacturing advantage that is sustainable. The group created the lignin separators by employing a dry processing technique, which does away with the hazardous solvents usually utilized in the manufacture of conventional separators…