Enhanced Absorption and Diffusion Properties of Lithium on B,N,VC-decorated Graphene

Bioresource-Functionalized Quantum Dots for Energy Generation and Storage: Recent Advances and Feature Perspective

The exponential increase in global energy demand in daily life prompts us to search for a bioresource for energy production and storage. Therefore, in developing countries with large populations, there is a need for alternative energy resources to compensate for the energy deficit in an environmentally friendly way and to be independent in their energy demands. The objective of this review article is to compile and evaluate the progress in the development of quantum dots (QDs) for energy generation and storage. Therefore, this article discusses the energy scenario by presenting the basic concepts and advances of various solar cells, providing an overview of energy storage systems (supercapacitors and batteries), and highlighting the research progress to date and future opportunities. This exploratory study will examine the systematic and sequential advances in all three generations of solar cells, namely perovskite solar cells, dye-sensitized solar cells, Si cells, and thin-film solar cells. The discussion will focus on the development of novel QDs that are economical, efficient, and stable. In addition, the current status of high-performance devices for each technology will be discussed in detail. Finally, the prospects, opportunities for improvement, and future trends in the development of cost-effective and efficient QDs for solar cells and storage from biological resources will be highlighted.

Interfacial Reactions in the Li/Si diffusion couples: Origin of Anisotropic Lithiation of Crystalline Si in Li-Si batteries

As opposed to the common understanding that diffusion into a cubic-structured single crystal is independent of its crystalline orientation, the diffusion of Li to crystalline Si (c-Si) is anisotropic, which acts as the major cause for the fracture of Si anodes in Li-ion batteries. Here, by conducting comprehensive/multi-scale simulation studies based on molecular dynamics and density functional theory, we elucidate how and why Li diffusion in c-Si is anisotropic. We found that Li ions diffuse to c-Si by following a particular atomic-scale space corresponding to the lowest value of the valence orbital in c-Si, causing Li ions to take a tortuous diffusion pathway. The degree of the tortuosity of the pathway differs depending on the crystallographic orientation of Si, and it acts as the major cause for anisotropic lithiation. We also develop a structural parameter that can quantitatively evaluate the orientation dependency of the lithiation of c-Si.