(777a) Comparative Study of the Vanadium Redox Flow Battery Efficient Electrolyte Electro-Catalytic Experiments and Simulation

Comparative
study of the vanadium redox flow battery efficient electrolyte
electro-catalytic experiments and simulation

Chun YANG, Chengming ZHAO, Xiaofeng XIE *, Zongqiang
MAO

Institute
of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084,
China;

All vanadium
redox flow battery (VRB) has been widely used in the large scale wind and
photovoltaic power system for storage of electrical energy ^{[1, 2]}. There
has an excellent solution for back-up rechargeable battery of nuclear energy
plants, which might prevent the disaster like Fukushima nuclear accident.
However, the VRB has a fatal flaw, namely the low energy density. If a catalyst
is added to accelerate the valence change of vanadium ions, to improve the
electrochemical speed, so as to achieve the purpose of improve the efficiency
of the VRB.

In
this study, the different metal catalyses are used for positive vanadium
electrolyte for improving the VRB performance. The electrochemical tests show
the Mn (IV) has particular catalytic properties, which
increase the peak current both anodic and cathodic. The charge/discharge
capacity of single VRFB with Mn (IV) added in positive electrolyte are shown in
Fig1_. When Mn (IV) is added in positive electrolyte, both charge and
discharge capacity increase obviously.

Fig1 charge and
discharge capacity of positive electrolyte added in catalyst

Furthermore,
the catalysis reaction of positive vanadium electrolyte is investigated by density
functional theory (DFT). Geometric structure optimization and spectrum parameters
are calculated by basis set B3LYP with considering the solvent effect. The optimized
geometric structure and thermodynamic parameters have been obtained, and experimental
data and simulation results are in good agreement.

Keywords: All vanadium
redox flow battery; Positive electrolyte; Density functional theory; Electro-catalytic

Acknowledgements:
The work is funded by the National High Technology R&D Program of China
(2012AA051201), Tsinghua University Initiative Scientific Research Program
(201010800623), and the National Natural Science Foundation of China
(21176140).

References:

[1] M.H.
Chakrabarti, R.A.W. Dryfe and E.P.L. Roberts, Electrochim. Acta, 52 (2007)
2189.

[2] M.
Vijayakumar, Sarah D. Burton, Cheng Huang, et al. J. Power Sources, 195 (2010)
7709.