Introduction

Energy, which is used in everyday living, can be saved in various forms, such as chemical batteries, ¹ solar electromagnetic fields, ² hydrogen, ³ flowing water, ⁴ blowing wind, ⁵ radiative atoms, ⁶ oil mines, ⁶ oil gas, ⁶ and coal mines. ⁷ To greatly reduce the environmental impact, plenty of theoretical and experimental studies have been done for developing the various green energy materials. ^8–10 For example, the up-to-date well-established potential applications cover the battery-driven cell phones ¹¹ and electric vehicles, ¹² the solar-cell factories, ¹³ the hydrogen-based buses, ¹⁴ water-generated electric power, ¹⁵ and the wind turbines. ¹⁶ Specifically, this book is focused on lithium-ion batteries (LIBs), ¹⁷ dye-sensitized solar cells, ¹⁸ and perovskite solar cells. ¹⁹ Furthermore, how to design and fabricate the electronic and optical devices with excellent performance, low cost, light weight, high safety, long lifetime, operating at a controllable temperature, and suitable voltage range are the main issues. ²⁰ The distinct theoretical models are proposed/developed to fully comprehend the diverse physical, chemical, and material phenomena. According to the previous studies, the molecular dynamics simulations, ²¹ the first-principle calculations under the local charge density approximations, ²² and the neutral network methods ²³ are available in thoroughly exploring the fundamental properties and solving the critical issues. As for LIBs, detailed analyses will be conducted on the anode materials accompanied with the chemical modified electrolytes and the significant additives, ²⁴ and the different functional polymer binders. ²⁵ On the experimental side, the successful syntheses of the emergent materials; ²⁶ the high-resolution measurements on geometric, electronic, optical, and transport properties; ²⁷ and the delicate examinations on the battery performance and the photon-to-electron conversion efficiency ²⁸ will be finished under a series of systematic studies. Detailed comparisons between the experimental measurements and the theoretical predictions are also made. Part of the inconsistency arising from them become new and open issues proposed in the contents.