Assessment of sulfate-based compounds for Li-ion batteries
In 2013, Chemistry of Materials is celebrating its 25th anniversary by publishing a special issue. In this context, Dr. Gwenaëlle Rousse and Pr. Jean-M. Tarascon were both contacted to participate to the special issue with a study entitled Sulfate-Based Polyanionic Compounds for Li-Ion Batteries: Synthesis, Crystal Chemistry, and Electrochemistry Aspects. Their researches took place in the framework of ALISTORE-ERI (European) and RS2E (French) research networks.
In the study, authors describe how this new family of materials was able to see the light of day as well as the strategy they use to develop new and more eco-efficient synthesis pathways. They also exposed the scientific approach allowing to obtain fluor-free materials (useful for safety reasons), such as hydroxysulfates or sulfates.
Following this work, a material of LiFeSO4F was created. This material is most notably remarkable for its electrochemical performances similar (in terms of energy densities) to those of LiFePO4, the most prized material for EV applications.
However, despite such performances the two scientists remain cautious due to the smaller thermic stability of LiFeSO4F toward the electrolyte compared to that of LiFePO4. The researchers also tried to correlate magnetic (TN) and electrochemical properties of both compounds due to both both properties depending on the iono-covalent nature of the chemical bond.
Finally, the researchers concluded by listing new and potentially attractive polyanionic materials and shared their personal view on the future of polyanionic compounds versus layered compounds (known for their greater energy density but also for their elevated cost).
Sulfate-Based Polyanionic Compounds for Li-Ion Batteries: Synthesis, Crystal Chemistry, and Electrochemistry Aspects. G. Rousse and J. M. Tarascon
Chemistry of Materials, Just Accepted Manuscript, 20 August 2013, DOI : 10.1021/cm4022358.