Hybrid Separators with Mesoporous Carbon-Coatings for Advanced Lithium?Sulfur Batteries

JUAN BALACH; TONY JAUMANN; LARS GIEBELER

Saarbrücken

Workshop; 1st International Network Meeting of the European School of Materials; 2017

Saarland Universität

The lithium-sulfur (Li-S) battery is considered one of the most promising candidates for next-generation rechargeablebatteries due to its high theoretical energy density of 2.6 kWh kg−1, which is up to 5 times higher compared to state-of-the-art lithiumionbatteries. Additionally, sulfur has the enormous advantages of being inexpensive, environmentally benign and naturally abundant.However, its commercialization has been hindered due to the insulating nature of sulfur and the poor cycling stability, mainly causedby the polysulfide shuttle phenomenon.[1]In order to tackle these issues, we focus on the development of functional separators by a straightforward coating modification of acommercial polypropylene separator (Celgard 2500) with a mesoporous carbon (mesoC) material. The Li-S cells with a mesoCcoatedseparator retain capacities of the order of 700 mAh g?1 after 500 cycles at 1 C, despite the use of a simple cathode mixturecontaining a high sulfur/non-porous carbon (Super P) ratio of 7:2. The enhanced electrochemical performance of the Li-S batteries isattributed to the unique features of the mesoC-coating, which physically adsorbs and reutilizes soluble polysulfides/active material.[2-4]