Abstract
New actors have emerged in the aerospace sector recently, renewing the interest in space exploration and bringing growth to space activities. As such, to rise to the challenges that will come in the future, developing adequate technologies is needed. Energy storage systems for Space missions are widely dominated by the Li-ion technology, which has not evolved much in the past years. This work, co-financed by CNES and Région Occitanie, is aimed at developing a material able to raise significantly the specific capacity of Li-ion batteries.Silicon have been studied for several decades as replacement for graphite at the negative electrodes of such systems. Its low potential and impressive specific capacity, more than ten times that of graphite, make silicon one of the most promising material. However, the volumetric expansion linked to the alloying reaction with Lithium, and the different issues related, strictly limit the use of silicon in commercial electrodes. In fact, silicon is currently only used as an additive to boost carbon capacity. In this work, the use of a natural compound, dopamine, is suggested as a solution to restrain the impact of the expansion on the electrode life expectancy. Dopamine is able to self-polymerize in easy-to-obtain condition, covering nearly any substrate. Three types of core-shell particles have been realized: Si@C, Si@C@Li3PO4 and Si@C-Metal. In each cases, the structure was studied by several methods (XRD, Raman, TEM,…), before the effects of the shell on the electrochemical properties were evaluated in half-cell versus lithium. The particles studied in this work show the versatility of poly-dopamine and the core-shell structure, hinting at a bright future.