In-situ anchoring sulfiphilic silica nanoparticles onto macro-mesoporouscarbon framework for cost-effective Li-S cathodes

Yajing Liu, Mingqi Chen, Mengfei Hu,Yan fang Gao*, Yayun Zhang*, Donghui Long*

Chemical Engineering Journal, 2020, 126781.

文章链接：https://www.sciencedirect.com/science/article/pii/S1385894720329090

Porous carbons have been the leadingconductive hosts for constructing cathodes of lithium-sulfur batteries but arecurrently challenged by the weak polar surface and cost-effective synthesis.Herein, a 3D hierarchical macro-mesoporous carbon with in-situ silica anchoring(SMC) is prepared via an economical and high-throughput sol-gel approach,followed by the ambient pressure drying and carbonization. The resultantcarbons possess developed porosity with bi-continuous macro-mesoporous network.Moreover, the ultrathin silica nanoparticles are homogeneously anchored ontosurface of macro-mesoporous carbon framework, which can greatly enhance thepolar of carbon surface, thus improving the wettability and dispersion ofsulfur during melt impregnation process. In addition, the polysulfidesmobilization is also dramatically restrained through chemical binding betweensilica nanoparticles and polysulfides. Combined with the 3D conductive macro-mesoporousnetwork, the resultant sulfur cathode could deliver a high reversible capacityof 969.7 mAh g^-1 and enhanced capacity of 625.5 mAhg^-1 with a capacity fading rate of only 0.088% per cycle after 400cycles at 0.2 C. The present work may provide a direct and cost-effectiveapproach to surface chemistry modification of carbon-based sulfur hosts toultimately advance energy conversion and storage system.