Synthesis and electrochemical properties of multilayered porous hexagonal Mn(OH)2 nanoplates as supercapacitor electrode material

Hexagonal Mn(OH)2 nanoplates with thickness of about 20 nm were synthesized by a simple hydrothermal method. Each nanoplate consists of several porous nanosheets and the pores in nanosheets are of about 10 nm. Electrochemical tests reveal that the as-prepared multilayered porous Mn(OH)2 nanoplate has a capacitance of 147.4 F/g at 0.1 A/g, good rate capability of 21.6 F/g even at a high current density of 10 A/g. These porous nanoplates also show excellent cycle stability with capacitance retention of 86.3% after 5000 cycles at a relative high current density of 5 A/g. The excellent performance of the sample can be attributed to its multilayered porous structure. This material has great potential application in supercapacitor electrode material, especially where long cycle life and excellent cycle stability are required.