metal salt electrode displayed highly electrochemical activity in
KOH electrolyte and showed ultrahigh specific capacitance.
Water-soluble inorganic salts including many free active cations
are promising candidates to study the pseudo capacitance of
cations. Another significant advantage of water-soluble salts
pseudo capacitors is that the use of commercial inorganic salt as
pseudo capacitor does not need complex synthesis procedures
[17–19]. During the study of the inorganic salt pseudo capacitors,
the in situ crystallized colloids during the electrochemical reaction
can deliver high specific capacitance. However, the detailed
mechanism of high capacitance was not fully understood