LAUSR

Abstract The development of portable devices and wearable devices leads to the pursuit of lighter and thinner lithium-ion batteries. However, this goal is limited by the battery components, of which the separator is an important part. Here, ultra-light and ultra-thin cellulose nanofibril membranes are prepared using a facile ethanol-soaked process. The weight and thickness of the obtained separators are only half those of conventional polyolefin membranes (Celgard2325), and much smaller than other novel membranes. Equally important, the separators not only have excellent physical properties, but the prepared batteries also have better electrochemical performance than the commercial Celgard2325. This study indicates the alluring prospect of applying cellulose nanofibril membranes into ultra-light-thin lithium-ion batteries.