Search

Metal–Organic Polymers (MOPs) have attracted growing attention for lithium-ion battery (LIB) applications due to their merits in orderly ionic transportation and robust structure stability in electrochemical reactions. However, they suffer from poor electronic conductivity. In this work, we apply first-principles density functional theory to explore the potential of three one-dimensional (1D) electrically conductive C6H2S4TM (TM = Fe, Co, and Ni) MOPs with the π–d conjugated coordination as anode materials for Li+ ions storage. Our theoretical results reveal that these 1D MOPs possess a superior theoretical capacity of over 748 mA h g−1. In particular, the 1D C6H2S4Ni MOP shows an exceptional theoretical specific capacity of 1110 mA h g−1 based on the three-electron transferring reaction, which significantly outperforms the traditional graphite-based anode material in LIBs. Moreover, the resonant charge transfer between Ni metal and ligand within the 1D C6H2S4Ni MOP reduces the diffusion energy barrier of the Li atoms when they migrate on the surface of the MOP. The ultrahigh theoretical specific capacity of the C6H2S4Ni MOP predicts that it can be a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Recently, Li4Ti5O12 (LTO) has been experimentally proven as a promising broadband electrochromic material for applications like smart windows, thermal management, and infrared camouflage. However, a detailed understanding of the fundamental mechanism of these phenomena is still lacking, especially how and why the optical spectrum changes with lithiation. We fill this knowledge gap by performing a detailed analysis of LTO's optical properties during charging/discharging via a robust study of the density functional theory (DFT). Our study suggests that the absorption of infrared light is highly sensitive to intercalation of Li in the LTO lattice, in contrast to that of visible wavelengths. This unique characteristic of LTO offers an effective mechanism in controlling infrared radiation intensity with minimal attenuation on the transmission of visible light. Furthermore, the DFT study also reveals that the electrochemical intercalation of Li introduces donor states which will gradually expand and move to deeper levels in the forbidden band. This electronic structure change leads to better conductivity and lower transmittance, which is in line with the experimental observation in the literature. [ABSTRACT FROM AUTHOR]