Wood-derived density-adjustable hierarchical porous carbon frameworks for high-performance lithium-sulfur batteries

Abstract

Lithium-sulfur batteries have the advantages of high specific capacity and low cost, but are subject to poor rate and cycle performance. In this work, we prepared wood-derived hierarchical porous free-standing carbon framework materials as three-dimensional conductive current collectors to assemble high-performance lithium-sulfur batteries. The micron-scale pores of wood are conducive to the diffusion of electrolyte, and the introduction of a large number of nanopores on the carbon skeleton can inhibit the dissolution and shuttle effect of lithium polysulfide, and improve the rate and cycle performance of the batteries. The porous carbon framework is density-adjustable and free-standing, and the battery has a specific capacity of 1120 mAh/g with good rate performance. The capacity decay are only 0.11%/cycle and 0.08%/cycle respectively under 0.5 C and 1 C after 500 cycles. In addition, wood is inexpensive and renewable, and the batteries are assembled without conventional conductive agents, binders and current collectors.