Affiliation:
1. Institute for Applied Materials (IAM) Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1, D 76344 Eggenstein‐Leopoldshafen Germany
2. Division of Energy Storage Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China
3. Institute for Biological Interfaces 3 (IBG 3) Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1, D 76344 Germany Eggenstein‐Leopoldshafen
4. Institut de Science des Matériaux de Mulhouse UMR 7361 CNRS/ Université de Haute Alsace 15 rue Jean Starcky Mulhouse Cedex 68057 France
5. Fraunhofer Institute for Solar Energy Systems Heidenhofstr. 2 79110 Freiburg Germany
6. Department of Sustainable Systems Engineering (INATECH) University of Freiburg 79110 Freiburg Germany
Abstract
AbstractAlkali metal–sulfur batteries (particularly, lithium/sodium‐ sulfur (Li/Na–S)) have attracted much attention because of their high energy density, the natural abundance of sulfur, and environmental friendliness. However, Li/Na–S batteries still face big challenges, such as limited cycle life, poor conductivity, large volume changes, and the “shuttle effect” caused by the high solubility of Li/Na–polysulfides. Herein, novel organosulfur‐containing materials, i.e., bis(4‐hydroxy‐2,2,6,6‐tetramethylpiperidin‐1‐yl)disulfide (BiTEMPS‐OH) and 2,4‐thiophene/arene copolymer (TAC) are proposed as cathode materials for Li and Na batteries. BiTEMPS‐OH shows an initial discharge/charge capacity of 353/192 mAh g−1 and a capacity of 62 mAh g−1 after 200 cycles at 100 mA g−1 in ether‐based Li‐ion electrolyte. Meanwhile, TAC has an initial discharge/charge capacity of 270/248 mAh g−1 and better cycling performance (106 mAh g−1 after 200 cycles) than BiTEMPS‐OH in the same electrolyte. However, the rate capability of TAC is limited by the slow diffusion of Li‐ions. Both materials show inferior electrochemical performances in Na battery cells compared to the Li analogs. X‐ray powder diffraction reveals that BiTEMPS‐OH loses its crystalline structure permanently upon cycling in Li battery cells. X‐ray photoelectron spectroscopy demonstrates the cleavage and partially reversible formation of S−S bonds in BiTEMPS‐OH and the formation/decomposition of thick solid electrolyte interphase on the electrode surface of TAC.
Funder
Agence Nationale de la Recherche
Deutsche Forschungsgemeinschaft
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry