Key Words:Sulfur;Atoms - Cathodes - Charge transfer - Cost effectiveness - Graphene - Kinetics - Lithium - Lithium-ion batteries - Nanoclusters - Polysulfides - Reaction kinetics
Abstract:Lithium–sulfur batteries are deemed to be one of the most promising energy storage alternatives due to the high theoretical capacity and cost-effectiveness. The significant challenge in exploring novel sulfur host materials is to simultaneously inhibit the shuttle effect and heighten the reaction kinetics. Herein, a novel hybrid host consisting of W<inf>2</inf>C atomic nanoclusters (NCs) grown on a N/P-codoped graphene framework (W<inf>2</inf>C@N/P-rGO) is designed and fabricated for the first use in lithium–sulfur batteries. By means of first-principle calculations and the kinetics analysis including lithium ion diffusion coefficient and charge transfer resistance, the introduction of W<inf>2</inf>C atomic NCs benefits the enhancement of electrochemical kinetics on a polar hybrid conductor. Furthermore, the intense ability of chemically sequestrating the soluble polysulfides by W<inf>2</inf>C atomic NCs ensures the high utilization of sulfur, making the high capacity retention. With a high sulfur loading of 3.1 mg cm⁻², the W<inf>2</inf>C@N/P-rGO/sulfur composite cathode indicates a significantly enhanced electrochemical performance. This work may open up a new avenue to design novel host candidates for advanced lithium–sulfur batteries.<br/> © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume:6
Issue:9
Translation or Not:no