Lignin-based separators improve lithium-ion battery performance
Wood-based separator in a lithium-ion battery versus a typical plastic separator in a lithium-ion battery (Credit: Michigan State University/Molly Killingbeck)
July 8, 2025 – Researchers at Washington State University (WSU) have developed a wood-based separator that improves the safety and lifespan of lithium-ion batteries.
A battery contains a positively charged cathode and a negatively charged anode. These are kept apart by a commercial separator, usually made of polyethylene or polypropylene. A downside of these polymers is that they can shrink at temperatures around 100 °C. Without the protection of a separator, the cathode and anode can touch, potentially causing a short circuit and leading to fire or explosion.
WSU developed separators based on lignin, a component of natural wood. These lignin-based separators were highly stable and did not deform even at temperatures up to 300 °C. In addition, they extended the battery’s lifespan.
The research was published earlier this year in Advanced Materials under the title ‘Lignin-Based Separators for Lithium-Ion Batteries via a Dry Fibrillation Method.’ (doi.org/10.1002/adma.202419694)
WSU has filed a patent for the innovation.
