화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.30, 13549-13555, 2020
Toward Uniform In Situ Carbon Coating on Nano-LiFePO4 via a Solid-State Reaction
In this work, toward uniform in situ carbon coating on nano-LiFePO4 (nano-LFP) via a solid-state reaction, we systematically investigated the effects of the heating rate on the characteristics of the product and process with nano-FePO4 as the template and iron source. It was found that the high reactivity of nano-FePO4 almost eliminated the effect of the heating rate on the phase transformation of LiFePO4 (LFP) but aggravated the impacts on the morphology and the distribution of the carbon layer of the final product. The uniform carbon coating on nano-LFP was found to correspond to a moderate diffusion rate of gas molecules containing carbon, as determined by the thermal decomposition characteristics of the carbon source and the heating rate together. This strategy showed promise in the accelerated synthesis of nano-LFP/carbon composites with high electrochemical performance and was verified to be effective when using different carbon sources, sucrose and polyvinyl alcohol, which had distinct differences in thermal decomposition characteristics. As a result, we achieved the preparation of nano-LFP with an excellent rate performance (140 mA.h.g(-1) @10 C) using a high heating rate (I5 degrees C/min), low calcination temperature (650 degrees C), and short calcination time (4 h).