Aerosol-Assisted Synthesis of Colloidal Aggregates
with Different Morphology: Toward the Electrochemical Optimization
of Li3VO4 Battery Anodes Using Scalable Routes
posted on 2016-02-09, 00:00authored byPedro Tartaj, Jose M. Amarilla, Maria B. Vazquez-Santos
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).