Monodisperse Antimony Nanocrystals for High-Rate Li-ion\nand Na-ion Battery Anodes: Nano versus Bulk

Abstract

We report colloidal synthesis of\nantimony (Sb) nanocrystals with\nmean size tunable in the 10–20 nm range and with narrow size\ndistributions of 7–11%. In comparison to microcrystalline Sb,\n10 and 20 nm Sb nanocrystals exhibit enhanced rate-capability and\nhigher cycling stability as anode materials in rechargeable Li-ion\nand Na-ion batteries. All three particle sizes of Sb possess high\nand similar Li-ion and Na-ion charge storage capacities of 580–640\nmAh g^–1 at moderate charging/discharging current\ndensities of 0.5–1C (1C-rate is 660 mA g^–1). At all C-rates (0.5–20C, e.g. current densities of 0.33–13.2\nAg^1–), capacities of 20 nm Sb particles are systematically\nbetter than for both 10 nm and bulk Sb. At 20C-rates, retention of\ncharge storage capacities by 10 and 20 nm Sb nanocrystals can reach\n78–85% of the low-rate value, indicating that rate capability\nof Sb nanostructures can be comparable to the best Li-ion intercalation\nanodes and is so far unprecedented for Na-ion storage.