Enabling Selenium‐Rich SexSy Cathodes to Work in Carbonate‐Based Electrolytes. Issue 1 (25th November 2021)

• Record Type: Journal Article
• Authors: He, Bin; Liu, Dongdong; Cheng, Zexiao; Miao, Ziyun; Rao, Zhixiang; Zhang, Huangwei; Yuan, Lixia; Li, Zhen; Huang, Yunhui
• Is Part Of: Advanced energy materials. Volume 12:Issue 1(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-25
• Subjects: carbonate‐based electrolytes -- enhanced conductivity -- mesoporous carbon -- selenium‐rich SexSy cathodes -- solid‐conversion mechanism; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202102832
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Lithium–sulfur/selenium batteries have attracted broad interest and achieved good performance using ether‐based electrolytes. However, when the ether‐based electrolytes are employed, Li–S/Se battery systems still have several inevitable drawbacks inhibiting their practical applications, such as intermediate product dissolution issues, and a dependency on a high content of electrolyte. Thus, it is urgent to pay attention to the electrochemical properties of Se x S y cathodes in carbonate‐based electrolytes, which may avoid the above mentioned problems. In this work, a series of mesoporous carbon/Se x S y (CMK‐3/Se x S y ) composites with covalent Se‐S bonds and different Se/S molar ratios are prepared and their working mechanism in carbonate‐based electrolytes is systematically investigated by combining experimental analysis and theoretical calculations. This work finds that the Se in the CMK‐3/Se x S y cathode is beneficial for the transportation of Li + ions and forms a thin cathode electrolyte interphase (CEI) during the discharge–charge process. Furthermore, S substitution in Se8 molecules can enhance the specific capacity and lower the bond breaking and lithiation energies. The optimal CMK‐3/Se x S y cathode delivers outstanding performance with a high reversible capacity of 609 mA h g −1 at 1 A g −1 over 300 cycles. Abstract : A series of mesoporous carbon/Se x S y (CMK‐3/Se x S y ) composites with Se‐S bonds and different Se/S molar ratios are prepared to systematically investigate their working mechanism in carbonate‐based electrolytes by combining the experimental analysis and theoretical calculations. The inherent synergistic effect of Se and S with the electrochemical performance of CMK‐3/Se x S y cathodes is revealed, which provides guidance for the rational design of Li–Se x S y batteries.