For
the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid
capacitors, potassium
ions are pre-inserted into MnO<sub>2</sub>
tunnel structure, the as-prepared K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16</sub>
materials consist of <a>nanoparticles</a> and nanorods were prepared by facile high-temperature solid-state reaction. <a></a>The
as-prepared materials were
well studied
andthey show outstanding
electrochemical behavior. We
assembled hybrid supercapacitors with commercial activated carbon (YEC-8A) as anode
and K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16 </sub>as cathode. It has high energy densities and
power densities. Li-ion capacitors reach a high energy density of 127.61
Wh kg<sup>-1 </sup>at the power density of 99.86 W kg<sup>-1</sup> and Na-ion capacitor
obtains
170.96 Wh kg<sup>-1 </sup>at 133.79 W kg<sup>-1</sup>. In addition, the <a>hybrid supercapacitor</a>s demonstrate excellent cycling performance which
maintain 97 % capacitance retention for Li-ion capacitor and 85 % for Na-ion capacitor
after 10,000 cycles.
