Diaminohexane-assisted preparation of coral-like, poly(benzoxazine)-based porous carbons for electrochemical energy storage.

The assembly of commercial silica colloids in the presence of 1,6-diaminohexane and their subsequent encapsulation by poly(benzoxazine) have been used to produce coral-like porous carbons. The pyrolysis of the polymer followed by the removal of the silica produces a carbon with a continuous skeleton that contains spherical medium-size pores as "reservoirs" with a structure similar to a bunch of grapes. The total volume and the diameter of the "reservoir" pores are tunable. The coral-like morphology and the pore structure of the carbons make them suitable for use as electrode materials for supercapacitors and lithium-ion batteries. As supercapacitor electrodes, they exhibit excellent long-term cycle stability (almost no capacitance fading after 20,000 cycles at a current density of 1 A g(-1)) and good rate capability with capacitance retention of 88% (from 0.1 A g(-1) to 5 A g(-1)). Meanwhile, as a matrix for the encapsulation of SnO2 nanoparticles for Li-ion storage, the electrodes also show a high specific capacity and good cycling stability, i.e., 900 mA h g(-1) after 50 charge-discharge cycles. The good electrochemical performance of such carbons shows that they are promising candidate electrode materials for electrochemical energy storage.