Manzi Jessica, Curcio Mariangela, Brutti Sergio
Department of Science, University of Basilicata, V.le Ateneo Lucano 10, Potenza 85100, Italy.
CNR-ISC, U. O. S. La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy.
Nanomaterials (Basel). 2015 Dec 10;5(4):2212-2230. doi: 10.3390/nano5042212.
Olivine-type lithium metal phosphates (LiMPO₄) are promising cathode materials for lithium-ion batteries. LiFePO₄ (LFP) is commonly used in commercial Li-ion cells but the Fe/Fe couple can be usefully substituted with Mn/Mn, Co/Co, or Ni/Ni, in order to obtain higher redox potentials. In this communication we report a systematic analysis of the synthesis condition of LiCoPO₄ (LCP) using a solvo-thermal route at low temperature, the latter being a valuable candidate to overcome the theoretical performances of LFP. In fact, LCP shows higher working potential (4.8 V 3.6 V) compared to LFP and similar theoretical capacity (167 mAh·g). Our goal is to show the effect of the synthesis condition of the ability of LCP to reversibly cycle lithium in electrochemical cells. LCP samples have been prepared through a solvo-thermal method in aqueous-non aqueous solvent blends. Different Co salts have been used to study the effect of the anion on the crystal growth as well as the effect of solution acidity, temperature and reaction time. Materials properties have been characterized by Fast-Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopies. The correlation between structure/morphology and electrochemical performances has been investigated by galvanostatic charge-discharge cycles.
橄榄石型锂金属磷酸盐（LiMPO₄）是很有前景的锂离子电池正极材料。磷酸铁锂（LFP）常用于商用锂离子电池，但Fe/Fe电对可用Mn/Mn、Co/Co或Ni/Ni进行有效替代，以获得更高的氧化还原电位。在本通讯中，我们报告了采用低温溶剂热法对磷酸钴锂（LCP）合成条件的系统分析，低温溶剂热法是克服LFP理论性能的一个有价值的候选方法。事实上，与LFP相比，LCP显示出更高的工作电位（4.8 V对3.6 V）和相似的理论容量（167 mAh·g）。我们的目标是展示合成条件对LCP在电化学电池中可逆循环锂能力的影响。LCP样品通过在水-非水溶剂混合物中采用溶剂热法制备。使用了不同的钴盐来研究阴离子对晶体生长的影响以及溶液酸度、温度和反应时间的影响。通过快速傅里叶变换红外光谱、X射线衍射和扫描电子显微镜对材料性能进行了表征。通过恒电流充放电循环研究了结构/形态与电化学性能之间的相关性。
