![](bg1.png)
The Effects of Additional Treatment of Activated Coal on the
Increase of Special Characteristics of Gas Diffused Cathods of
Aluminum-air Electrochemical Generator
Elena Alexandrovna Kiseleva
*
, Andrey Zinov’yevich Zhuk, Kleymenov Boris Vladimirovich and
Victor Petrovich Zakharov
Joint Institute for High Temperatures of the Russian Academy of Sciences, Izhorskaya st.13 Bd. 2, Moscow, Russia 125412
Keywords: Carbon materials, iron-cobalt-nitrogen-containing pyrocatalyst
Abstract: The possibility of a significant increase in the specific characteristics due to the treatment of carbon
materials with ammonia is shown in the work. In the course of the work, techniques were developed for
processing a carbon material with aqueous ammonia and pure ammonia, a procedure for the synthesis of an
iron-cobalt-nitrogen-containing catalyst. It has been established that the additional processing of carbon
materials with ammonia improves the characteristics of the experimental samples due to the deposition of
nitrogen-containing functional groups on the surface: for activated carbon from coal raw materials brand
UAF treated at 900 ° C, a current density of 0.041 mA / cm
2
is achieved at a polarization of -0.3 V. It is
shown that the application of iron- cobalt-nitrogen-containing pyrocatalyst synthesized on a activated
carbon brand UAF well catalyzes the oxygen reduction reaction.
1 INTRODUCTION
Currently, much attention is paid to solving the
problems of creating environmentally friendly
autonomous current sources with high energy
intensity for use in various portable electronic
devices, in transport and in electric power industry,
which is caused by environmental pollution by using
hydrocarbon fuels, whose share in large cities is over
90% (Zhuk et al., 2012).
Metal-air energy sources based on aluminum are
promising because they have a high theoretical and
feasible specific energy intensity (250-400 Wh / kg),
low cost, they are environmentally friendly and fire-
proof. Currently, the specific power of air-aluminum
elements is limited by the specific power of the air
electrode (gas diffusion cathode). When discharging
air-aluminum elements with an alkaline electrolyte
at a working temperature of 60 ° C, the current
density at the aluminum anode can reach 1000 mA /
cm
2
, while the current density at the gas diffusion air
cathode is several times lower (150-300 mA / cm
2
).
The most critical and complex component of an Al-
air element is a gas diffusion cathode, which is
responsible for the reduction of air oxygen, and
determines the specific power and working life of
the current source.
The reduction of oxygen can be carried out in
two parallel ways (Bidault et al., 2009; Cheng and
Chen, 2012):
a) by a four-electron reaction to a hydroxide ion:
O
2
+ 2H
2
O + 4e- = 4OH
-
E
0
O
2
/ OH- = + 0.401 V,
b) by a two-electron reaction to hydrogen
peroxide:
O
2
+ H
2
O + 2e- = HO
2
-
+ OH
-
E
0
= -0.076 V
The resulting hydrogen peroxide, depending on
the properties of the catalyst, is then either reduced
to OH
-
or decomposed into oxygen and water.
In order to intensify the process of oxygen
reduction, it is carried out in a porous,
hydrophobized electrode. The efficiency of such an
electrode is determined both by the activity of the
catalyst used and the porous structure formed during
the hydrophobization process, which should have an
optimal ratio of hydrophobic and hydrophilic pores
(Chervin et al., 2012).
In addition to the catalytically active layer, the
GDС, as a rule, contains a hydrophobic layer, the
task of which is to prevent the electrolyte from
getting wet on the back side of the cathode and to
34
Kiseleva, E., Zhuk, A., Vladimirovich, K. and Zakharov, V.
The Effects of Additional Treatment of Activated Coal on the Increase of Special Characteristics of Gas Diffused Cathods of Aluminum-air Electrochemical Generator.
DOI: 10.5220/0008185000340037
In The Second International Conference on Materials Chemistry and Environmental Protection (MEEP 2018), pages 34-37
ISBN: 978-989-758-360-5
Copyright
c
2019 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved