Lithium sulfur battery exploiting material design and electrolyte chemistry: 3D graphene framework and diglyme solution

• Published in: Journal of power sources Vol. 397; pp. 102 - 112
• Main Authors: Benítez, Almudena, Di Lecce, Daniele, Caballero, Álvaro, Morales, Julián, Rodríguez-Castellón, Enrique, Hassoun, Jusef
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2018
• Subjects: 3D-graphene; Li-S battery; Low flammability; Nitrogen doping; Solvothermal microwave; Li-S battery; 3D-graphene; Nitrogen doping; Low flammability; Solvothermal microwave
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2018.07.002

Herein we investigate a lithium sulfur battery suitably combining alternative cathode design and relatively safe, highly conductive electrolyte. The composite cathode is formed by infiltrating sulfur in a N-doped 3D graphene framework prepared by a microwave assisted solvothermal approach, while the electrolyte is obtained by dissolving lithium bis(trifluoromethane)sulfonimide (LiTFSI) in diethylene glycol dimethyl ether (DEGDME), and upgraded by addition of lithium nitrate (LiNO3) as a film forming agent. The particular structure of the composite cathode, studied in this work by employing various techniques, well enhances the lithium-sulfur electrochemical process leading to very stable cycling trend and specific capacity ranging from 1000 mAh g−1 at the highest rate to 1400 mAh g−1 at the lowest one. The low resistance of the electrode/electrolyte interphase, driven by an enhanced electrode design and a suitable electrolyte, is considered one of the main reasons for the high performance which may be of interest for achieving a promising lithium-sulfur battery. Furthermore, the study reveals a key bonus of the cell represented by the low flammability of the diglyme electrolyte, while comparable conductivity and interface resistance, with respect to the most conventional solution used for the lithium sulfur cell. Table of content image. [Display omitted] •N-doped 3D graphene-sulfur is studied as high energy cathode in Li/S battery.•A microwave assisted solvothermal approach is used for cathode preparation.•A diglyme dissolving LiTFSI and LiNO3 is used as a safe electrolyte.•The cell delivers very stable capacity ranging from 1000 to 1400 mAh g−1.•The low resistance of the electrode/electrolyte interphase leas to high performances.