A skin-core hybrid nanocellulose separator for high-energy and high-safety lithium metal batteries

Abstract

It is still a challenge to produce a separator having small pores but high porosity, aiming to high-energy and high-safety lithium metal batteries. A skin-core BC/GF hybrid separator is herein fabricated from bacterial cellulose (BC) nanofibers and glass fibers (GF). The skin layers, a few stack of BC nanofibers, have abundant nanopores for electrode separation and high safety. The core part mainly consists of GF with coarse morphology, contributing to high porosity and fast ion transport. Furthermore, skin layers are modified by polydopamine (PDA) to suppress dendrite growth on lithium metal anodes. As a result, lithium metal batteries with the PDA@BC/GF hybrid separator display superior cycling and rate performance to those with a commercial polypropylene separator.