a Hefei National Laboratory for Physical Science at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, PR China
b School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China
Received 5 January 2012. Accepted 11 May 2012. Available online 19 May 2012.
Ca9Co12O28 nanoparticles with size of about 25 nm were prepared by Pechini process at 850 °C for 4 h. The as-obtained nanoparticles demonstrated initial charge/discharge capacities of 908 and 816 mAh/g and a stable discharge capacity of 210 mAh/g after 50 cycles. Different morphologies of Ca9Co12O28 as multilayer structure and micro-plates were also obtained by solid-state reaction and coprecipitation-precursor technique at 850 °C for 20 h. When they were studied in the charge/discharge experiments of lithium ion batteries, the initial discharge capacities reached values of 762 and 790 mAh/g, together with stable discharge capacities of 141 and 151 mAh/g after 50 cycles, respectively, which were both lower than those of nanoparticles.
