Constructing multi-doped porous carbon/sulfur cathodes via steam puffing technology for lithium-sulfur batteries

Polar carbon materials play significant roles in electrochemical reactions in virtue of distinctive surface polarity, porous architecture sand multifunctional synergistic properties. In this study, we first propose steam puffing technology to construct versatile multi-doped porous carbon for sulfur hosts. In this design, maltose is utilized as the matrix which can be puffed by the internal moisture, thus endowing the carbon skeleton with hierarchical porous structure. Simultaneously, N, P, B heteroatoms are uniform-distributed in maltose-derived carbon matrix due to the co-puffing process. According to the density functional theory (DFT) calculations, these heteroatoms provide sufficient chemical adsorption and catalytic sites to soluble polysulfides, thus effectively impede the shuttling effect and accelerate the conversion kinetics of polysulfide intermediates. Beneficial from the synergistic effect of polar porous structure, the well-designed NPB-doped maltose derived carbon (NPB-MC) possess superior high-rate properties and long-time cycling stability. This research opens a new avenue for constructing polar carbon materials and high-performance sulfur cathodes in lithium sulfur batteries.