Progress in Synthesis and Performance of active materials for Lithium-ion Batteries

VISINTIN A.

la Paz

Workshop; 6th IWLiME; 2019

6th IWLiME

In the last years, new lithium-ion intercalation materials have been studied at INIFTA (National University of La Plata) as a result of the Argentine government?s interest in exploiting large lithium deposits in the north of the country. We are working on the development of techniques for building electrodes with a good response to high discharge currents. Lithium iron phosphates with olivine structures would meet the requirement of energy drain at high current values. The specific power of the cells is also important and it is possible to grow up this value, changing the cathodes to materials with higher redox potential. The spinels of LiMn2-xNixO4 are the more promising systems in this particular field. A clear comprehension of the processes that occurs during the use of Lithium based batteries is indispensable to improve the performance and efficiency of these systems. Sometimes, it is not possible to detect all the physicochemical processes only using electrochemical measurements, and in the case of lithium-ion batteries, the possibility to make electrochemical experiments in a classical tree electrodes cell joined to other chemical or physical techniques is very hard. Typical impediments to this type of experiment are, for example, the nature of the electrodes, electrolytes and working conditions of these types of batteries. For this reason we develop an in-operando lithium ion battery cell system capable to work in typical current/potentials experiments for these kinds of batteries and at the same time allow performing X-Ray absorption or diffraction experiments over the active materials.Whit this setup it is now possible to characterize different anodic and cathodic active materials by X-ray spectroscopy techniques like XANES and EXAF at different working conditions i.e. different states of charge (SOC) or during a potentiodynamic running and also under normal operation conditions like charge-discharge cycles. The aim of this work is focused the use of the same electrochemical cell not only to XAFS but also to other types of techniques (XRD, XRF, etc) working at faster potentiodynamic experiments or higher current conditions. In our laboratories we are focused on the synthesis and the physical and electrochemical characterization of these materials using different techniques like cyclic voltammetry, charge-discharge cycling, electrochemical impedance spectroscopy, SEM, TEM, XRD, and EDS. Also we are working on the production of lithium-ionThis presentation summarizes all the results and progress made in recent years in our different lines of materials and prototypes development.