Sustainable Synthesis Of N-Doped Hollow Porous Carbon Spheres Via A Spray-Drying Method For Lithium-Sulfur Storage With Ultralong Cycle Life

Exploring high-efficiency, long-term cycling stability, and cost-effective cathode materials for lithium-sulfur (Li-S) batteries is hugely desirable and challenging. Herein, we have successfully developed a simple solution-based spray-drying method to fabricate nitrogen-doped hollow porous carbon spheres (N-HPCS) with biomass lignin as a carbon precursor and cyanuric acid as a N-dopant and a porogen. The obtained N-HPCS shows a specific surface area of 446.2 m(2) g(-1)and high-level pyrrolic-N doping of 64.13 %. The N-HPCS/S cathode has a high initial discharge capacity of 1535.1 and 1104.0 mA h g(-1)at 0.1 and 1 C, respectively. In addition, the N-HPCS/S electrode exhibits outstanding cycle performance after 1000 cycles at 1 C, with a low capacity decay rate of only 0.041 % per cycle, which is superior to most of the recently reported carbon-based S cathodes. N-doping causes strong Li2Sx-N chemical adhesion in carbon spheres, effectively suppressing the dissolution and "shuttle effect" of the notorious polysulfide of Li-S batteries, in which pyrrolic-N plays a leading role in the capture of polysulfides intermediates. This contribution is of great significance to the exploration of many other structure-property design strategies for ultralong cycle life Li-S energy storage devices.