Precipitated synthesis of Al2O3-ZnO nanorod for high-performance symmetrical supercapacitors

Composite materials based on zinc oxide have been made more and more attention because of their excellent capacitance performance and high efficiency ion/electron transmission ability. The Al2O3-ZnO metal oxide composite was used for high-performance supercapacitor materials by the solvent precipitation method. The electrochemical theoretical calculation shows that the surface capacitive (Q(c)) plays a leading role in total charge contribution. The Al2O3-ZnO nanorod displays a high specific capacity (C-s) (463.7 F g(-1)) and the favorable cyclic stability (96.9%), which is higher than the Al2O3 and the ZnO. The number of ion transferred (sigma) is 6.3 and the ion diffusion coefficient (D) is 7.6 x 10(-13) cm(2) s(-1). The symmetrical supercapacitor (SSC) was assembled with Al2O3-ZnO, and the energy density can reach 10.3 Wh kg(-1) with 1360.9 W kg(-1). This study demonstrates that Al2O3-ZnO nanorods can be used as electrodes for high performance supercapacitor devices, which provide a novel idea of the synthesis of electrode materials.