ABSTRACT
This work covers the theoretical calculations and the experimental works on the fundamental properties of certain green energy materials, especially for those of the Li-ion batteries (LIBs), dye-sensitized solar cells (DSSCs), and perovskite solar cells. Furthermore, certain significant issues, which might be closely related to significant mechanisms, are worthy of systematic studies in the near future. As for LIBs, the first-principles method, the combined calculations of the method and the neural network, and the molecular dynamics simulation are verified to be, respectively, useful in understanding the functions of the graphite- and graphene-based anode materials, electrolyte additives, and solid and gel-type electrolytes. The optimal geometries, band structures/discrete electronic states, charge transfers, electron affinities, free carrier densities, energy gaps, spatial charge distributions, spin configurations, densities of states, and pair distribution functions are included in the delicate evaluations. The chemical modifications have drastically/dramatically changed the electronic properties and thus strongly affected the ion transports. And then, the single- or multiorbital hybridizations/the concise chemical and physical pictures are proposed to explain the important results. The similar theoretical framework might be suitable for the generalization to other emergent green energy systems. As to the experimental syntheses and measurements, they have been done for the Li-ion batteries, silicon-nanowire-based hybrid solar cells, DSSCs, and perovskite solar cells, being principally focused on the relation between the Li storage capacity and cycle number. How to design and fabricate the abovementioned systems with safe, cheap, light, high ion transport, and long-lifetime characteristics is the main focus. The working mechanism of the DSSCs based on the interaction of the polymer gel electrolytes (PGEs) with the nanofillers (NFs) is presented. The long-term performance of the quasi-solid-state dye-sensitized solar cells (QS-DSSCs) using PGEs with and without NFs at different temperatures is reviewed. The new components, which serve as anodes, gel and solid electrolytes accompanied by additives, and cathodes, are successfully synthesized in experimental laboratories. Their enhancements on the fundamental functions have been tested in delicate ways. While all the experimental works are explained by the theoretical calculations, they could provide more information/pictures on the critical mechanisms in such energy systems.332
