Tuning the performance of vanadium redox flow batteries by modifying the structural defects of the carbon felt electrode

• Ditty Dixon,
• Deepu Joseph Babu,
• Aiswarya Bhaskar,
• Hans-Michael Bruns,
• Joerg J. Schneider,
• Frieder Scheiba and
• Helmut Ehrenberg

Beilstein J. Nanotechnol. 2019, 10, 1698–1706, doi:10.3762/bjnano.10.165

• )-based carbon felt was subjected to N2-plasma treatment to increase the heteroatom defects and reactive edge sites as a method to increase the performance in vanadium redox flow batteries (VRFBs). N-doping in the felt was mainly in the form of pyrrolic and pyridinic nitrogen. Even though the amount of

• and edge sites. Thus, from the present study, it can be concluded that an alternate way to increase the performance of the VRFBs is to introduce specific defects such as N-doping/substitution or to increase the edge sites. In other words, defects induced in the carbon felt such as heteroatom doping

• are as beneficial as the presence of oxygen functional groups for the improved performance of VRFBs. Therefore, for an optimum performance of VRFBs, defects such as N-substitution as well as oxygen functionality should be tuned. Keywords: carbon felt; defects; nitrogen plasma; vanadium redox flow

Porous N- and S-doped carbon–carbon composite electrodes by soft-templating for redox flow batteries

• Maike Schnucklake,
• László Eifert,
• Jonathan Schneider,
• Roswitha Zeis and
• Christina Roth

Beilstein J. Nanotechnol. 2019, 10, 1131–1139, doi:10.3762/bjnano.10.113

• Technology, Institute of Physical Chemistry, D-76131 Karlsruhe, Germany 10.3762/bjnano.10.113 Abstract Highly porous carbon–carbon composite electrodes for the implementation in redox flow battery systems have been synthesized by a novel soft-templating approach. A PAN-based carbon felt was embedded into a

• obtained inside the macroporous carbon felt. For the investigation of electrode structure and porosity X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen sorption (BET) were used. The electrochemical performance of the carbon felts was evaluated by cyclic voltammetry

• (CV) and electrochemical impedance spectroscopy (EIS). The N- and S-doped carbon electrodes show promising activity for the positive side reaction and could be seen as a significant advance in the design of carbon felt electrodes for use in redox flow batteries. Keywords: N- and S-doped carbon

Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

• Benjamin Baumgärtner,
• Hendrik Möller,
• Thomas Neumann and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2017, 8, 1145–1155, doi:10.3762/bjnano.8.116

• carbon felt, which is intended for adsorption issues, was used as a commercially available test specimen for a LPEI mediated silica coating procedure. The felt can be immersed in the LPEI and TMOS solution and simply separated from the polyamine and the precursor solution resulting in an exhaustive

• surface coating (Figure 10, Supporting Information File 1, Figure S9). The fiber diameter increases from 17 µm, for the neat fibers, to about 35 µm, for the composite fibers including the nanostructured silica shell. Thermogravimetric analysis of the silica coated activated carbon felt shows that the

• 60 °C. Other fibers used for the LPEI mediated silica coating process were anodic oxidized carbon fibers, silicon carbide fibers and an activated carbon felt. The high-tenacity carbon fiber was supplied by SGL Carbon in the process state after anodic oxidation without further sizing (Sigrafil C30

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8