화학공학소재연구정보센터
Electrochimica Acta, Vol.55, No.8, 2951-2957, 2010
Microwave solid-state synthesis and electrochemical properties of carbon-free Li3V2(PO4)(3) as cathode materials for lithium batteries
Monoclinic Li3V2(PO4)(3) can be rapidly synthesized at 750 degrees C for 5 min (MW5m) by using microwave solid-state synthesis method. The refined cell parameters and atomic coordination of the sample MW5m show some deviations compared with those of the sample synthesized in conventional solid-state synthesis method, especially the coordinate of Li atoms. Compared with the electrochemical properties of the carbon-coating sample Li3V2(PO4)(3), the carbon-free sample MW5m presents well electrochemical properties. In the cut-off voltage of 3.0-4.3 V. MW5m sample presents a specific charge capacity of 132 mAh g(-1), almost equivalent to the reversible cycling of two lithium ions per Li3V2(PO4)(3) formula unit (133 mAh g(-1)), and specific discharge capacity of 126.4 mAh g(-1). In the cut-off voltage of 3.0-4.8 V. MW5m shows an initial specific discharge capacity of 183.4 mAh g(-1) at 0.1 C, near the theoretical discharge capacity. In the cycle performance, the capacity fade of Li3V2(PO4)(3) is dependent on the cut-off voltage and the preparation method, more capacity lost at relatively higher charge/discharge voltage. The reasons for the excellent electrochemical properties of Li(3)V2(PO4)(3) rapidly synthesized in microwave field are discussed in detail. (C) 2009 Elsevier Ltd. All rights reserved.