Synthesis of mixed ionic–electronic Li+–NASICON glass-ceramic nanocomposites for cathode applications

Abstract

A novel route for preparation of mixed ionic–electronic (MIE) glass-ceramics is proposed. Glass-ceramic nanocomposites are prepared by externally dispersing MIE glass viz. [Li2O]x-[V2O5-P2O5]100 − x (where x = 10 and 20 wt% with and the ratio of V2O5 and P2O5 has been kept to 9:1 and 3:1) in the NASICON-structured LiTi2(PO4)3 (LTP) matrix using mechanical milling-assisted synthesis route. After subjecting these glass-ceramic composites to suitable sintering temperature, the samples are structurally and electrically characterized using XRD, FESEM, and impedance spectroscopy. The maximum conductivity (100 °C) is found to be 5 × 10−5 Ω−1 cm−1 for an LTP-glass-ceramic composite, which is significantly higher than that of LTP. Impedance spectroscopy, electronic conductivity, and cyclic voltammetry scans strongly suggest simultaneous transport of ions and electrons. These composites exhibit thermal stability up to ~250 °C. These mixed conductors are found to be potential candidates as electrode/cathode materials in all-solid-state Li+ ion batteries.