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A novel ZnO/ZnO-Bi2O3 nanocomposite was prepared by a homogeneous precipitation method. The nucleation sites, namely ZnO-Bi2O3 particles with nominal chemical composition of (ZnO)0.94(Bi2O3)0.06, were prepared by ball milling and subsequent annealing treatment. The as-synthesized materials were characterized by XRD, SEM and electrochemical measurements. Compared with single ZnO, the ZnO/ZnO-Bi2O3 nanocomposite show better cycling stability and higher discharge capacity. When the content of ZnO-Bi2O3 was 15 wt.%, the discharge capacity of ZnO/ZnO-Bi2O3 nanocomposite hardly declined over 60 cycling test, the average discharge capacity reached 590.2 mAh g−1. Cyclic voltammograms clearly illuminated that the added ZnO-Bi2O3 particles could decrease electrode polarization, maintain the electrochemical activity, and enhance the discharge capacity of ZnO.

Nanosized ZnO particles were prepared by a facile homogeneous precipitation method. Resorcinol-formaldehyde sol with addition of the ZnO particles was carbonized at 700 °C for 1.5 h to prepare ZnO/carbon-aerogel composite. TEM investigation shows that ZnO particles were em-bedded in 3-dimensional net-like carbon and covered uniformly by amorphous carbon coating. Compared with ZnO, the ZnO/carbon-aerogel composite showed better cycling stability, higher discharge capacity and lower charge-transfer resistance. The discharge capacity delivered by the ZnO/carbon-aerogel composite remained above 550 mAh g-1during 40 cycles with little capacity loss. The enhanced electrochemical performances were mainly ascribed to the effects of the net-like structure of amorphous carbon, which uniformly surrounded the ZnO particles to guarantee good contact and acted as a skeleton to alleviate the shape change and dendrite growth of zinc electrode.