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In this work, the development of a novel sulfur-doped graphene aerogel composite reinforced with carbon fibers (CFs) is presented. Sulfur is entrapped between the graphene nanosheets when GO in the presence of sodium sulfide is reduced hydrothermally to rGO forming a stable hydrogel and an aerogel after freeze-drying. The simultaneous incorporation of CFs improves the mechanical stability of the final composite. The as-prepared composite combines the characteristics of graphene aerogels such as porosity, surface area, chemical inertness with the mechanical properties of CFs and the ability of sulfur to capture lithium, thus providing a material with promising electrochemical properties for lithium-ion battery applications. [ABSTRACT FROM AUTHOR]

Carbon paper‐supported graphene aerogels are examined as anode electrodes for lithium‐ion batteries, employing a hydrothermal process and a freeze‐drying step. Triethylenetetramine (TETA) and o‐phenylenediamine (OPD) prove to promote graphene aerogel formation and its chemical bonding onto the surface of carbon paper. The electrochemical results demonstrate that the electrode treated with the former diamine has a remarkable rate capability with higher capacities as compared with the electrode treated with the latter diamine and better stability. [ABSTRACT FROM AUTHOR]

In this work we report the physicochemical and electrochemical properties of Li-Mn spinel-based cathode nanostructures in comparison with the corresponding commercial powder. Well dispersed nanorods (diameter of 17–32 nm and average length of 150 nm) are formed in the case of pure Li 1.276 Mn 2 O 4 , which result in better electrochemical performance compared with the bulk commercial electrode of lithium-ion batteries. Modifications of the structure via substitution with Cu and Αl ions at the octahedral sites further improve the insertion/extraction process of lithium cation, especially in the case of Li 1.068 Al 0.099 Mn 1.901 O 4 . Long term stability test at different charge/discharge rates show that this nanostructure has the highest electrochemical reversibility (∼11.5% capacity loss) among the samples studied followed by Li 1.281 Cu 0.086 Mn 1.914 O 4 (∼22.5% capacity loss), while the nanostructured Li 1.276 Mn 2 O 4 and the commercial LiMn 2 O 4 spinel have ∼28.4% and ∼32.4% capacity loss, respectively. [ABSTRACT FROM AUTHOR]

The present work addresses the issues related to the capacity fading of spinel LiMn2O4, such as Mn leaching and Jahn–Teller distortion and suggests an advanced TiN-coated LiAl0.1Mn1.9O4 (LAMO) cathode material as an electrode for lithium-ion batteries. TiN coating layers with the same thickness but a different porosity cover the LiAl0.1Mn1.9O4 electrode via reactive magnetron sputtering, and present promising electrochemical behavior. In contrast with the pristine LiAl0.1Mn1.9O4, the dense TiN-coated LiAl0.1Mn1.9O4 electrode demonstrates a remarkable long-term cycling by reducing the contact area of the electrode/electrolyte interface, resulting in structure stabilization. [ABSTRACT FROM AUTHOR]

• Combustion-synthesized Li-Mn spinel-based cathode materials. • Carbon paper substrate promotes the utilization of active material. • Beneficial effect of binder especially at high charge/discharge rates. • Enhanced rechargeability of the high-loaded electrode (8 mg cm−2). LiAl 0.1 Mn 1.9 O 4 spinel oxide was synthesized by combustion method and investigated as cathode material for Li-ion batteries, taking into account the effect of (i) the type of current collector and (ii) the electrode mass loading. Two different substrates were employed as current collectors: Al foil and carbon paper. The materials with higher loading showed an outstanding capacity retention in rate capability test. Although the samples with lower loading started with higher capacities, they showed poor capacity retention. From a practical point of view, the electrode with 4 mg loading per cm2 presented attractive properties with respect to elevated specific capacity and high retention in long-term stability tests. [ABSTRACT FROM AUTHOR]