Search for: All records

Abstract The development of alternative energy sources is crucial for reducing reliance on fossil fuels, particularly for mobile applications such as personal electronics and transportation. This necessitates the advancement of battery materials based on abundant and inexpensive constituent elements. To achieve this requires investigating materials in a broader compositional and structural design space. Early transition metal oxides, including the intercalation electrode $\alpha -$V₂O₅, however, the performance of V₂O₅is hindered by phase transformations during battery cycling that lead to capacity fade and short device lifetimes. This study investigates the modification of V₂O₅through Mo substitution in a series of the form V ${}_{2-x}$Mo_xO₅forx= 0.05, 0.1, 0.2, 0.4, 0.6, and 0.8. X-ray diffraction data reveal progressive structural changes with increasing Mo content, which in turn change the progression of phase transformations during the first discharge. The different product also results in different cycling profile shapes that indicate differences in the charge storage mechanism as a function of Mo content. As a result, samples with higher Mo-substitution, especially V_1.2Mo_0.8O₅, have narrower hysteresis, higher capacity, and improved capacity retention. While there is a limited solubility of Mo in the V₂O₅structure, with secondary phases and defects at many compositions, we show that Mo substitution alters the cycling behavior of V₂O₅to deep discharge, which can inform the design of intercalation materials for energy storage applications. 

Abstract In alignment with the Materials Genome Initiative and as the product of a workshop sponsored by the US National Science Foundation, we define a vision for materials laboratories of the future in alloys, amorphous materials, and composite materials; chart a roadmap for realizing this vision; identify technical bottlenecks and barriers to access; and propose pathways to equitable and democratic access to integrated toolsets in a manner that addresses urgent societal needs, accelerates technological innovation, and enhances manufacturing competitiveness. Spanning three important materials classes, this article summarizes the areas of alignment and unifying themes, distinctive needs of different materials research communities, key science drivers that cannot be accomplished within the capabilities of current materials laboratories, and open questions that need further community input. Here, we provide a broader context for the workshop, synopsize the salient findings, outline a shared vision for democratizing access and accelerating materials discovery, highlight some case studies across the three different materials classes, and identify significant issues that need further discussion. Graphical abstract