Aerosol-assisted synthesis of colloidal aggregates with different morphology: toward the electrochemical optimization of Li3VO4 battery anodes using scalable routes

Abstract

The improvement of properties through strict morphology control often requires the use of difficult to scale up synthesis routes. Thus, a compromise between scalability and morphology control is required to partially exploit the advantages of this control in materials functionality. Here, we show that a scalable and continuous route (aerosol route) is able to produce Li3VO4 colloidal aggregates with different morphology (spherical and platelet-like) using easy to handle economic precursors (V2O5, LiOH, and LiNO3 in stoichiometric amounts). The key for these differences in morphology resides on controlling the nature of the intermediate stages that can occur during particle formation in aerosol synthesis. We also show that the electrochemical response of Li3VO4 is strongly dependent on morphology. Thus, optimization of morphology allows building anodes that to our knowledge outperform other reported Li3VO4 anodes and even compete with most of the reported Li3VO4/C composites at adequate high rates (2–8 A/g). Finally, we have developed a simple and scalable coating protocol (suspensions with solid concentrations of 100 g/L are used) that additionally improves the long-term stability of the optimized anodes. Combination of the two scalable methods leads to Li3VO4 anodes that operating at a safe cutoff voltage of 0.2 V can retain a high capacity (280 mAh/g) with excellent coulumbic efficiency (>99.9%), even after 500 cycles at a competitive rate (2 A/g discharge–charge).