Preparation of size-selective Mn<inf>3</inf>O<inf>4</inf> hexagonal nanoplates with superior electrochemical properties for pseudocapacitors

Porous Mn<inf>3</inf>O<inf>4</inf> hexagonal nanoplates were synthesized through annealing the hydrohausmannite precursor obtained by a one-pot hydrothermal process and by precisely controlling the concentrations of potassium hydroxide and glucose. The effect of potassium hydroxide and glucose on the growth of hexagonal nanoplates was investigated, and a growth mechanism was also proposed. Due to its abundant pores, the pure Mn<inf>3</inf>O<inf>4</inf>-based electrode exhibits excellent cycling stability with 100% capacity retention after 5000 cycles. The asymmetric supercapacitor exhibited high performance with an energy density of 17.276 W h kg^-1 at a power density of 207.3 W kg^-1 in a wide potential window of 1.5 V.