Hybrid bilayered vanadium oxide electrodes with large and tunable interlayer distances in lithium-ion batteries.

The interlayer distances in layered electrode materials, influenced by the chemical composition of the confined interlayer regions, have a significant impact on their electrochemical performance. Chemical preintercalation of inorganic metal ions affects the interlayer spacing, yet expansion is limited by the hydrated ion radii. Herein, we demonstrate that using varying concentrations of decyltrimethylammonium (DTA) and cetyltrimethylammonium (CTA) cations in chemical preintercalation synthesis followed by hydrothermal treatment, the interlayer distance of hybrid bilayered vanadium oxides (BVOs) can be tuned between 11.

Cation-Driven Assembly of Bilayered Vanadium Oxide and Graphene Oxide Nanoflakes to Form Two-Dimensional Heterostructure Electrodes for Li-Ion Batteries.

Lithium preintercalated bilayered vanadium oxide (LVO or δ-LiVO·HO) and graphene oxide (GO) nanoflakes were assembled using a concentrated lithium chloride solution and annealed under vacuum at 200 °C to form two-dimensional (2D) δ-LiVO·HO and reduced GO (rGO) heterostructures. We found that the Li ions from LiCl enhanced the oxide/carbon heterointerface formation and served as stabilizing ions to improve structural and electrochemical stability. The graphitic content of the heterostructure could be easily controlled by changing the initial GO concentration prior to assembly.

Vanadium and Niobium MXenes-Bilayered V O Asymmetric Supercapacitors.

MXenes offer high metallic conductivity and redox capacitance that are attractive for high-power, high-energy storage devices. However, they operate limitedly under high anodic potentials due to irreversible oxidation. Pairing them with oxides to design asymmetric supercapacitors may expand the voltage window and increase the energy storage capabilities.

The Dopamine Assisted Synthesis of MoO/Carbon Electrodes With Enhanced Capacitance in Aqueous Electrolyte.

A capacitance increase phenomenon is observed for MoO electrodes synthesized a sol-gel process in the presence of dopamine hydrochloride (Dopa HCl) as compared to α-MoO electrodes in 5M ZnCl aqueous electrolyte. The synthesis approach is based on a hydrogen peroxide-initiated sol-gel reaction to which the Dopa HCl is added. The powder precursor (Dopa)MoO, is isolated from the metastable gel using freeze-drying.