Sustainable Synthesis of N‐Doped Hollow Porous Carbon Spheres via a Spray‐Drying Method for Lithium‐Sulfur Storage with Ultralong Cycle Life
Yijian Liu, Hao Guo, Baohua Zhang, Gongyu Wen, Róbert Vajtai, Ling Wu, Pulickel M. Ajayan, Liang Wang
Abstract
Abstract 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.