A vapor-assisted construction of 3D highly porous boron nitride for anchoring and catalyzing polysulfides in lithium-sulfur batteries
Cheng Long, Yang Huang, Yin Sha, Ming Chen, Farzad Seidi, Chao Deng, Huining Xiao
Abstract
Lithium-sulfur batteries (LSBs) have been holding a great potential to serve as high energy density power source in advent of “carbon neutrality” era. However, LSBs nowadays still suffer from the notorious shuttle effect of polysulfides and sluggish redox reactions involving multiphase conversion. Herein, three-dimensional boron nitride (3D BN) with hierarchically porous architecture was innovatively constructed and incorporated into carbon cloth (CC) by means of vapor-assisted spatial growth (denoted as 3D-BN@CC). The as-prepared 3D-BN@CC sulfur host with highly exposed BN active sites exhibits strong adsorption and efficient catalysis toward soluble polysulfides . To further block the polysulfides leaking-out, an ultrathin composite layer composed of graphene (Gr) and nanocellulose (NC) is deliberately coated onto commercial separator (labeled as NC@Gr separator). LSB equipped with S/3D-BN@CC cathode and NC@Gr separator delivers a reversible capacity of 850 mAh/g with a high S loading of 5.36 mg cm −2 . The approach developed in this work to create sophisticated 3D BN scaffold for S and sheds lights on the superiority of 3D-BN@CC in anchoring and catalyzing polysulfides to finally lead to high-performance LSBs.