Tailoring the Electrochemical Properties of Two-Dimensional Bis(diimino)metal Coordination Frameworks by Introducing Co/Ni Heterometallic Structures.
Keisuke WadaHiroaki MaedaTakuya TsujiKen SakaushiSono SasakiHiroshi NishiharaPublished in: Inorganic chemistry (2020)
Bis(diimino)metal coordination frameworks (MDI, M = transition metal), which are a class of metal organic frameworks with two-dimensional anisotropy, high electric conductivity, and redox activity, are attractive platforms for tailoring electrochemical properties by introducing a heterometallic composition. In this study, we synthesized heterometallic CoxNi1-xDI coordination frameworks for electrochemical energy storage applications and investigated their electrochemical properties by experimental and theoretical techniques. Ni atoms were embedded into CoDI, and the crystal structure of CoxNi1-xDI was modified, especially along the interlayer axis, which activated the kinetically impeded redox reactions accompanied by PF6- insertion/extraction. Furthermore, upon charge/discharge with Li+ transport, CoxNi1-xDI with a specific composition exhibited higher specific capacity (248 mAh g-1) than CoDI and NiDI in the potential window of 1.0-3.5 V versus Li+/Li. Density functional theory calculations indicate that the energy levels of the antibonding orbitals around the metals and interlayer spaces are important factors in tailoring the electrochemical properties of CoxNi1-xDI.
Keyphrases
- density functional theory
- ionic liquid
- gold nanoparticles
- metal organic framework
- molecularly imprinted
- transition metal
- label free
- molecular dynamics
- electron transfer
- high resolution
- human health
- risk assessment
- molecular dynamics simulations
- mass spectrometry
- climate change
- high speed
- health risk assessment
- heavy metals