6 Application of Oxygen Reduction Catalysts
245
its research. There are also some controversies on the role of electrocatalysts in the
reaction. For example, the oxygen reduction reaction does not depend on electrocatalysts. However, there are reports that the size, morphology, and composition of
discharge products can be changed by using electrocatalysts.
6.4 Introduction to Oxygen Reduction Electrocatalyst
for Secondary Lithium-Air Battery
In general, the use of electrocatalysts can improve the energy density, capacity,
and cycle performance of batteries. It has also been reported that the performance
of secondary lithium-air batteries is mainly determined by the cathode material.
Although the catalytic mechanism of the electrocatalyst to the electrode reaction is not
clear, there have been many studies on it. Generally speaking, secondary lithium-air
battery electrocatalysts are divided into four categories, as shown in Table 6.4.
Several commonly used electrocatalysts have their own advantages and disadvantages, and their research needs to be deepened, but in general, the requirements for
the electrocatalyst should be that it can discharge the battery (oxygen reduction reaction) and charging process (oxygen evolution reaction) must have catalytic activity,
that is, it can show “dual function” characteristics.
Table 6.4 Classification of electrocatalysts for lithium-air secondary batteries
Electrocatalysts
Pros
Cons
Carbon materials
Show a certain catalytic activity for
the discharge process (oxygen
reduction reaction)
Poor catalytic activity for the
charging process (oxygen
precipitation reaction)
Metal oxides
Inexpensive and stable in nature,
and show excellent catalytic
performance in electrode reactions
Electrical conductivity is generally
low, and it is difficult to make
particles with extremely high
surface area, which greatly reduces
the utilization of active surface area
Precious metals
Has extremely high reversibility to
the electrode reaction, which greatly
improves the energy efficiency and
cycle performance of the battery
Limited resources and high prices
limit its large-scale application
Nonprecious metals Improve the performance of the
battery to a certain extent
The preparation process is
complex, the yield is low, and the
stability needs to be improved
245
its research. There are also some controversies on the role of electrocatalysts in the
reaction. For example, the oxygen reduction reaction does not depend on electrocatalysts. However, there are reports that the size, morphology, and composition of
discharge products can be changed by using electrocatalysts.
6.4 Introduction to Oxygen Reduction Electrocatalyst
for Secondary Lithium-Air Battery
In general, the use of electrocatalysts can improve the energy density, capacity,
and cycle performance of batteries. It has also been reported that the performance
of secondary lithium-air batteries is mainly determined by the cathode material.
Although the catalytic mechanism of the electrocatalyst to the electrode reaction is not
clear, there have been many studies on it. Generally speaking, secondary lithium-air
battery electrocatalysts are divided into four categories, as shown in Table 6.4.
Several commonly used electrocatalysts have their own advantages and disadvantages, and their research needs to be deepened, but in general, the requirements for
the electrocatalyst should be that it can discharge the battery (oxygen reduction reaction) and charging process (oxygen evolution reaction) must have catalytic activity,
that is, it can show “dual function” characteristics.
Table 6.4 Classification of electrocatalysts for lithium-air secondary batteries
Electrocatalysts
Pros
Cons
Carbon materials
Show a certain catalytic activity for
the discharge process (oxygen
reduction reaction)
Poor catalytic activity for the
charging process (oxygen
precipitation reaction)
Metal oxides
Inexpensive and stable in nature,
and show excellent catalytic
performance in electrode reactions
Electrical conductivity is generally
low, and it is difficult to make
particles with extremely high
surface area, which greatly reduces
the utilization of active surface area
Precious metals
Has extremely high reversibility to
the electrode reaction, which greatly
improves the energy efficiency and
cycle performance of the battery
Limited resources and high prices
limit its large-scale application
Nonprecious metals Improve the performance of the
battery to a certain extent
The preparation process is
complex, the yield is low, and the
stability needs to be improved