Wood film boosts EV battery safety and extends cycle life by 60%

Researchers have developed a lignin-based film separator derived from wood that significantly enhances the safety and longevity of lithium-ion batteries (LIBs), particularly for electric vehicles (EVs) and portable electronics. This wood-based separator remains dimensionally stable at temperatures up to 300°C (572°F), outperforming conventional polyethylene and polypropylene separators that suffer from thermal shrinkage and instability. The lignin film prevents internal short circuits and thermal runaway, reducing fire risks, while also extending battery cycle life by 60%, meaning the battery can be charged and discharged many more times before degrading. The lignin separator is produced using a solvent-free dry process, which is environmentally friendly and scalable, generating no waste or emissions. Made from lignosulfonate—a natural polymer byproduct of pulping and biorefinery—the film is thin (about 25 micrometers) yet effective at maintaining battery stability. This sustainable manufacturing approach not only reduces environmental impact but also leverages abundant natural materials without additional processing. Overall