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Chem Sci ; 9(2): 457-462, 2018 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30310560


The core-shell structure of endohedral fullerenes results in good protection of the encapsulated spin carriers from the environment. In this research, the quantum coherence behavior of the endohedral fullerene Sc3C2@C80 in CS2 solution is characterized from 5 K to room temperature. Below the critical temperature of around 140 K, the inner group is hindered, and the EPR spectrum consists of a single broad line. The spin carriers display a maximum phase memory time of 17.2(7) µs at 10 K. In the high temperature region, the inner group is mobile, and the EPR spectrum consists of 22 homogeneously broadened lines due to isotropic hyperfine coupling. The maximum phase memory time for each transition is around 139(1) ns at 200 K which allows arbitrary superposition state manipulations to be performed. This research demonstrates that Sc3C2@C80 displays temperature-crossover behaviour due to weak interaction between the Sc3C2 core and the C80 shell.

ACS Appl Mater Interfaces ; 10(21): 18005-18011, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29717868


The poor contact between the solid-state electrolyte and cathode materials leads to a high interfacial resistance, severely limiting the rate capability of solid Li metal batteries. Herein, an integrative battery design is introduced with a gradiently polymerized solid electrolyte (GPSE), a microchannel current collector array, and nanosized cathode particles. An in situ formed GPSE encapsulates cathode nanoparticles in the microchannel with ductile inclusions to lower the interfacial impedance, and the stiff surface layer of GPSE toward anode suppresses the Li dendrite growth. The Li metal batteries based on GPSE and the Li-free hydrogenated V2O5 (V2O5-H) cathode exhibit an outstanding high rate response of up to 5 C (the capacity ratio of 5 C/1 C is 90.3%) and an ultralow capacity fade rate of 0.07% per cycle over 300 cycles. The other Li-containing cathodes such as LiFePO4 and LiNi0.5Mn0.3Co0.2O2 can also operate effectively at the rates of 5 and 2 C, respectively. Such an ingenious design may provide new insights into other solid metal batteries through an interfacial engineering manipulation at the micro- and nanolevel.

J Nanosci Nanotechnol ; 12(3): 2254-60, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22755045


By means of the density functional theory calculations, two C88(D2:35)-based endohedral fullerenes, Lu3C2@C88(D2:35) and Lu3N@C88(D2:35) which encapsulate tri-lutetium carbide and tri-lutetium nitride cluster were investigated. For the cores in Lu3C2@C88 and Lu3N@C88, the trivalent C2 and N respectively template a butterfly-shaped endohedral moiety and a planar tri-lutetium cluster within the same D2-symmetric C88 cage. Moreover, Lu3N@C88 - D2 has a closed-shell electronic structure but for LuC3C2@C88 - D2, it owns an unpaired electron mainly localized on the internal Lu3C2 cluster. These results clearly showed that the core unit C2(3) as well as N3- play an important role in constructing molecular structures and electronic features of metallofullerenes. Furthermore, the electrochemical redox potentials, and vibrational frequencies of the two endofullerenes agree well with our experimental results. The electronic structures, ionization energies, electron affinities, inner clusters' dynamic motions of them have been predicted to further disclose the characters of these two metallofullerenes.

J Am Chem Soc ; 132(46): 16362-4, 2010 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-21047077


The endohedral fullerene Sc(3)NC@C(80)-I(h) has been synthesized and characterized; it has an unprecedented planar quinary cluster in a fullerene cage. It is also the first chemical compound in which the presence of an unprecedented (NC)(3-) trianion has been disclosed. The fascinating intramolecular dynamics in Sc(3)NC@C(80)-I(h) enables the whole molecule to display high polarity and promising ferroelectricity. This finding inspires the possibility that such a planar quinary cluster may be useful in constructing many other endohedral fullerenes.

J Am Chem Soc ; 131(46): 16646-7, 2009 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-19877678


For the first time, we have produced the stable compound Sc(4)C(2)@C(80)-I(h) and characterized it as a metal carbide endofullerene by FTIR and Raman spectroscopies in combination with DFT calculations. Furthermore, DFT calculations have demonstrated that this molecule has a Russian-doll-type structure, C(2)@Sc(4)@C(80).