Self-weaving sulfur–carbon composite cathodes for high rate lithium–sulfur batteries

Abstract

Realization of a ubiquitous clean energy future depends critically on the efficient storage and utilization of renewable energies. Lithium-ion batteries are appealing in this regard, but low-cost, abundant, safe, high energy-density electrode materials need to be developed to adopt them. Here we present a sulfur–multi-wall carbon nanotube (MWCNT) composite cathode with high-rate cyclability by a facile binder/current collector-free fabrication process. The composite cathode exhibits high capacities of 1352 mAh g⁻¹ at 1C rate and 1012 mAh g⁻¹ at 4C rate. Due to the self-weaving behavior of MWCNTs, extra cell components such as binders and current collectors are rendered unnecessary, thereby streamlining the electrode manufacturing process and decreasing the cell weight. While the highly conductive MWCNTs improve the active material utilization at high rates, the absorption ability of the cathode framework localizes the electrolyte and suppresses the migration of soluble polysulfides. The cathode design and facile synthesis enhance the feasibility of practical high rate Li–S batteries.