Akademik Veri Yönetim Sistemi
ENERGY & FUELS, cilt.35, sa.15, ss.12619-12627, 2021 (SCI-Expanded)
Lithium sulfur (Li-S) batteries with high theoretical energy density (similar to 2.5 kWh kg(-1)) and high theoretical gravimetric capacity (1672 mAh g(-1)) have drawn great attention as they are promising candidates for large-scale energy storage devices. Unfortunately, some technical obstacles hinder the practical application of Li-S batteries, such as the formation of polysulfide intermediates between the cathode and anode as well as the insulating nature of the sulfur cathode and other discharge products. Glass fiber (GF) separators provide some cavities to withstand the volume change of sulfur during cycling, leading to long-term cycling stability. Here, the application of polar materials with a novel liquid graphene oxide (L-GO) binder rather than the standard poly(vinylidene fluoride) (PVDF) binder as effective coatings on the GF separator of the Li-S cell has been developed to suppress the shuttle effect. The deposition of silicon dioxide (SiO2), titanium dioxide (TiO2), and poly(1,5-diaminoanthraquinone) (PDAAQ) with the L-GO binder on the GF separator was investigated with a polycarboxylate-functionalized graphene (PC-FGF/S) cathode and a Li metal anode. The cells with modified coatings and L-GO as an efficient binder could accelerate conversion of long-chain polysulfides to short-chain polysulfides and significantly suppress the polysulfide dissolution, resulting in capacity retentions of similar to 1020, 1070, and 1190 mAh g(-1) for the cells with SiO2/L-GO-, TiO2/L-GO-, and PDAAQ/L-GO-coated separators after 100 cycles. The results demonstrate that ultrathin SiO2-, TiO2-, and PDAAQ-containing coatings with the L-GO binder on the GF separator can drastically improve the cyclability of the Li-S cells even after a long cycling life.