ZnFe2O4 hollow rods enabling accelerated polysulfide conversion for advanced lithium-sulfur batteries

Electrochimica Acta, vol. 414, pp. 140231

Abstract

The high energy density and favorable cost-effectiveness make lithium-sulfur (Li-S) batteries one of the most attractive energy storage systems. However, the low sulfur utilization and poor cycle life, resulting from the losses of soluble polysulfide intermediates, and their sluggish redox conversion process, severely impede practical applications of reliable Li-S batteries. Effectively inhibiting the polysulfide diffusion and accelerating their conversion is beneficial to enhance the performance of sulfur cathodes. Herein, a novel carbon-free ZnFe2O4 hollow rod has been developed as an advanced host material to confine polysulfides within the cathode and accelerate the redox conversion during cycling. The soluble polysulfides anchored by the ZnFe2O4 hollow rod structure are shown to be rapidly converted to sulfur and lithium sulfides. Detrimental polysulfide diffusion is therefore effectively inhibited. The redox kinetics of sulfur cathodes has been systematically investigated, revealing that the ZnFe2O4 host can improve the activity for Li2S deposition, facilitate lithium-ion diffusion, and lower the reaction energy barriers for the multistep phase transition of sulfur. As a result, the developed [email protected]2O4 composite cathodes exhibit an improved cycling capacity of 1158 mAh g−1. These results demonstrate that the accelerated redox conversion of anchored polysulfides is essential for enhancing the electrochemical performance of Li-S batteries.

Authors 5

1. Lei Zhou

   Jiangsu University · Forschungszentrum Jülich · Eindhoven University of Technology

   Affiliation as printed

   Eindhoven University of Technology, P.O. Box 513, Eindhoven, MB 5600, the Netherland

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, Jülich D-52425, Germany

   School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China

2. Dmitri L. Danilov

   Forschungszentrum Jülich · Eindhoven University of Technology

   Affiliation as printed

   Eindhoven University of Technology, P.O. Box 513, Eindhoven, MB 5600, the Netherland

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, Jülich D-52425, Germany

3. Fen Qiao

   Jiangsu University

   Affiliation as printed

   School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China

4. Rüdiger‐A. Eichel Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, Jülich D-52425, Germany

   Institute of Physical Chemistry, RWTH Aachen University, Aachen D-52074, Germany

5. Peter H. L. Notten corresponding

   University of Technology Sydney · Forschungszentrum Jülich · Eindhoven University of Technology

   Affiliation as printed

   Centre for Clean Energy Technology, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia

   Eindhoven University of Technology, P.O. Box 513, Eindhoven, MB 5600, the Netherland

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, Jülich D-52425, Germany