Composite Lithium-Conductive LATP+PVdF Membranes: Development, Optimization, and Applicability for Li-TEMPO Hybrid Redox Flow Batteries

Lithium metal hybrid flow batteries (Li-HFBs) represent a very promising type of RFBs distinguished by improved energy and power density and simplified set-up. Unfortunately, the absence of a highly conductive and stable membrane hinders Li-HFBs evolution. This talk will describe the development of Li1.3Al0.3Ti1.7(PO4)3-poly(vinylidene fluoride) composite membranes and will demonstrate their applicability for Li-HFBs. The easily fabricated membranes demonstrate high ionic conductivity of 3.4 ∙ 10-4 S cm-1 (in contrast with 0.74 and 0.16 ∙ 10-4 S cm-1 of commercially available Nafion and Neosepta, correspondingly) and improved stability towards metallic lithium. The hybrid Li-TEMPO cell with composite membrane shows stable coulombic and energy efficiency (over 95 and 73%, respectively), moderate capacity decay from 2.5 to 1.4 Ah L-1 (preliminarily associated with membrane’s permeability), and no membrane degradation after 100 charge/discharge cycles. The combination of functional features established for the proposed composite membranes makes them promising for Li-HFBs, as well as for other energy storage devices, and can potentially accelerate their introduction to the energy storage market.