step to increase the specific capacitance of inorganic pseudocapacitors.
When the working electrodes were measured in 2M potassium hydroxide
electrolyte, electro active ErOOH colloids were in situ formed by
electric-field assisted chemical coprecipitation. At the same time,
pseudocapacitive Faradaic reaction was occurred at the same electrode.
The in situ crystallized ErOOH colloids, which subsequently
integrated into practical electrode structures, can enhance electrochemical
utilization ratio of active Er3+ cations. Therefore, the electrode
can show significantly high electrochemical reactivity and
can deliver ultrahigh specific capacitance of 1811 F/g behaving
the pseudocapacitive mechanism (redox reaction). Furthermore,
in our designed inorganic salt-alkaline electrolyte system, the
highly reactive ErOOH colloids interlaced with carbon spheres
were formed by the coupled in situ chemical/electrochemical crystallizations
and electrochemical Faradaic reactions. The specific
electrode configuration can shorten diffusion length of ion/electron
and can efficiently utilize the active Er cations in salt electrode,
thus high specific capacitance was obtained.
To evaluate the electrochemical performances of ErCl3
electrodes, galvanostatic charge–discharge and CV tests were