Among the many industrial and research level applications of fluorides like microelectronics, polymers, agronomy, imaging, dental composites, uranium enrichment processes or catalysis, there is a recent and growing interest for these ionic compounds in the field of energy storage and conversion. Li-ion technology in particular, has been attracted to fluorides due to the possibility of more-than-one electrode reaction. In fact, these reactions can potentially enhance the energy stored in commercial cells (conversion reactions). By reaction with lithium, transition metal fluorides such as MnF 3 , FeF 3 , CoF 3 or CuF 2 , can be reduced to the respective zero valent metal/LiF mixture with resulting high theoretical capacities ranging from 3 to 4.2 times the amount currently delivered by commercial LiFePO 4 (170 mAh g-1). Since, in practice, the most of the research efforts are being put into iron trifluoride due to chemical (relatively mild synthesis conditions), electro-chemical (lower polarization than MnF 3 for example) and environmental (Fe is more environmentally friendly than Co) reasons, in this review we will focus on the electro-chemistry, synthesis strategies and amelioration techniques for the high oxidation state ferric fluoride and its derivatives.