中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 23 No. 7 July 2013 |
（1. College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009, China;
2. State Key Laboratory of Materials-Oriented Chemical Engineering,
Nanjing University of Technology, Nanjing 210009, China）
Abstract:Co-P (4.9% P) powders with a chain-like morphology were prepared by a novel chemical reduction method. The Co-P and germanium powders were mixed at various mass ratios to form Co-P composite electrodes. Charge and discharge test and electrochemical impedance spectroscopy (EIS) were carried out to investigate the electrochemical performance, which can be significantly improved by the addition of germanium. For instance, when the mass ratio of Co-P powders to germanium is 5:1, the sample electrode shows a reversible discharge capacity of 350.3 mA·h/g and a high capacity retention rate of 95.9% after 50 cycles. The results of cyclic voltammmetry (CV) show the reaction mechanism of Co/Co(OH)2 within Co-P composite electrodes and EIS indicates that this electrode shows a low charge-transfer resistance, facilitating the oxidation of Co to Co(OH)2.
Key words: Co-P alloy; germanium; anode material; electrochemical performance
