Sustainable Synthesis of N-Doped Hollow Porous Carbon Spheres via a Spray-Drying Method for Lithium-Sulfur Storage with Ultralong Cycle Life

Graphical A simple solution-based spray-drying method was successfully developed to prepare nitrogen-doped hollow porous carbon spheres (N-HPCS) using biomass lignin as a carbon precursor, cyanuric acid as an N dopant, and a porogen. The N-type doping in N-HPCS materials (especially pyrrolic-N) results in a strong Li 2 S x -N chemisorption force, which effectively suppresses the insolubility and “shuttle effect” of the infamous Li−S battery polysulfide. After 1000 cycles at 1 C, the low volume attenuation rate of each cycle is only 0.041 %. 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 Li 2 S x −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.