Improving energy density and thermostability is essential to achieve high-performance lithium batteries. Traditional copper (Cu) current collectors (CCs) made of metal foil possess high mass and cost. The unsatisfactory thermal stability of PP or PE-based separators necessitates the development of new separator materials. In this talk, I will demonstrate a fast and scalable chemical coating method for fabricating ultralight composite Cu CC with a thin Cu layer on an ultrathin polymer scaffold. I will also introduce a lignin-based, thin separator with outstanding thermostability via a dry processing method. The scalability of the chemical coating method for current collectors and the dry processing method for lignin-based separators provide promising solutions for the mass production of these important battery components.