Ruthenium-based nanomaterials supported on reduced graphene oxide (rGO) have been investigated as air cathodes in non-aqueous electrolyte Li-air cells using a TEGDME-LiCF3SO3 electrolyte. Homogeneously distributed metallic ruthenium and hydrated ruthenium oxide (RuO2·0.64H2O), deposited exclusively on rGO, have been synthesized with average size below 2.5 nm. The synthesized hybrid materials of Ru-based nanoparticles supported on rGO efficiently functioned as electrocatalysts for Li2O2 oxidation reactions, maintaining cycling stability for 30 cycles without sign of TEGDME-LiCF3SO3 electrolyte decomposition. Specifically, RuO2·0.64H2O-rGO hybrids were superior to Ru-rGO hybrids in catalyzing the OER reaction, significantly reducing the average charge potential to ∼3.7 V at the high current density of 500 mA g(-1) and high specific capacity of 5000 mAh g(-1).

A lithium-sulfur battery employing a high performances mesoporous hard carbon spherules-sulfur cathode and a stable, highly conducting electrolyte is reported. The results demonstrate that the battery cycles with very high capacity, i.e., of the order of 750 mAh g − 1 with excellent retention during cycling. In addition, by exploiting the high conductivity of our selected electrolyte, the battery performs very well also at low temperature, i.e., delivering a capacity of 500 mAh g − 1 (S) at 0 ° C for over 170 charge- discharge cycles. We believe that these results may substantially contribute to the progress of the lithium-sulfur battery technology

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Silicon has a great potential as an alternative to graphite which is currently used commercially as an anode material in lithium-ion batteries (LIBs) because of its exceptional capacity and reasonable working potential. Herein, a low-cost and scalable approach is proposed for the production of high-performance silicon–carbon (Si–C) hybrid composite anodes for high-energy LIBs. The Si–C composite material is synthesized using a scalable microemulsion method by selecting silicon nanoparticles, using low-cost corn starch as a biomass precursor and finally conducting heat treatment under C3H6 gas. This produces a unique nano/microstructured Si–C hybrid composite comprised of silicon nanoparticles embedded in micron-sized amorphous carbon balls derived from corn starch that is capsuled by thin graphitic carbon layer. Such a dual carbon matrix tightly surrounds the silicon nanoparticles that provides high electronic conductivity and significantly decreases the absolute stress/strain of the material during multiple lithiation-delithiation processes. The Si–C hybrid composite anode demonstrates a high capacity of 1800 mAh g–1, outstanding cycling stability with capacity retention of 80% over 500 cycles, and fast charge–discharge capability of 12 min. Moreover, the Si–C composite anode exhibits good acceptability in practical LIBs assembled with commercial Li­[Ni0.6Co0.2Mn0.2]­O2 and Li­[Ni0.80Co0.15Al0.05]­O2 cathodes.