Hierarchical and lamellar porous carbon as interconnected sulfur host and polysulfide-proof interlayer for Li-S batteries

A robust three-dimensional (3D) interconnected sulfur host and a polysulfide-proof interlayer are key components in high-performance Li-S batteries. Herein, cellulose-based 3D hierarchical porous carbon (HPC) and twodimensional (2D) lamellar porous carbon (LPC) are employed as the sulfur host and polysulfide-proof interlayer, respectively, for a Li-S battery. The 3D HPC displays a cross-linked macroporous structure, which allows high sulfur loading and restriction capability and provides unobstructed electrolyte diffusion channels. With a stackable carbon sheet of 2D LPC that has a large plane view size and is ultrathin and porous, the LPC-coated separator effectively inhibits polysulfides. An optimized combination of the HPC and LPC yields an electrode structure that effectively protects the lithium anode against corrosion by polysulfides, giving the cell a high capacity of 1339.4 mAh g-1 and high stability, with a capacity decay rate of 0.021% per cycle at 0.2C. This work provides a new understanding of biomaterials and offers a novel strategy to improve the performance of Li-S batteries for practical applications.

Automated summary

In this study, cellulose-based 3D hierarchical porous carbon (HPC) is used as the sulfur host and 2D lamellar porous carbon (LPC) as the polysulfide-proof interlayer, significantly improving the performance of Li-S batteries for practical applications.