Vanadium pentoxide/carbide-derived carbon core–shell hybrid particles for high performance electrochemical energy storage. Issue 48 (23rd November 2016)

• Record Type: Journal Article
• Authors: Zeiger, Marco; Ariyanto, Teguh; Krüner, Benjamin; Peter, Nicolas J.; Fleischmann, Simon; Etzold, Bastian J. M.; Presser, Volker
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 48(2016)
• Page Start: 18899
• Page End: 18909
• Publication Date: 2016-11-23
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6ta08900c
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : V2 O5 /carbide-derived carbon core–shell hybrid electrodes can be synthesized using vanadium carbide as the precursor. The resulting hybrid material shows high energy and power ratings for electrochemical energy storage. Abstract : A novel, two step synthesis is presented combining the formation of carbide-derived carbon (CDC) and redox-active vanadium pentoxide (V2 O5 ) in a core–shell manner using solely vanadium carbide (VC) as the precursor. In a first step, the outer part of VC particles is transformed to nanoporous CDC owing to the in situ formation of chlorine gas from NiCl2 at 700 °C. In a second step, the remaining VC core is calcined in synthetic air to obtain V2 O5 /CDC core–shell particles. Materials characterization by means of electron microscopy, Raman spectroscopy, and X-ray diffraction clearly demonstrates the partial transformation from VC to CDC, as well as the successive oxidation to V2 O5 /CDC core–shell particles. Electrochemical performance was tested in organic 1 M LiClO4 in acetonitrile using half- and asymmetric full-cell configuration. High specific capacities of 420 mA h g −1 (normalized to V2 O5 ) and 310 mA h g −1 (normalized to V2 O5 /CDC) were achieved. The unique nanotextured core–shell architecture enables high power retention with ultrafast charging and discharging, achieving more than 100 mA h g −1 at 5 A g −1 (rate of 12C). Asymmetric cell design with CDC on the positive polarization side leads to a high specific energy of up to 80 W h kg −1 with a superior retention of more than 80% over 10 000 cycles and an overall energy efficiency of up to 80% at low rates.