The invention discloses a method for preparing a
capacitor electrode material non-stoichiometric
lanthanum manganate (LaMnx+ / -1O3). The method comprises the following steps: mixing
nitrate of
manganese and
lanthanum according to a certain ratio, and stirring to obtain
sol;
drying to obtain dried gel; and finally, performing
calcination treatment, thereby obtaining the non-stoichiometric LaMnx+ / -1O3. The product disclosed by the invention is of a porous structure and has a large specific surface area, and
energy density is improved; and the LaMnx+ / -1O3 has relatively
high oxygen vacancy concentration, and the transport speed of ions and electrons is improved, so that the
power density is enhanced. Compared with stoichiometric
lanthanum manganate (LaMnO3), the LaMnx+ / -1O3 has high capacity and
cycling stability when serving as a super-
capacitor electrode material. When the scanning rate is 0.5A / g, the specific
capacitance of LaMn1.1O3 is 508F / g. When the
current density is 3A / g, the capacity is kept at 75% due to 1000-time cycle, and the specific
capacitance is finally stabilized at about 250F / g.