LiTi2(PO4)3/reduced graphene oxide nanocomposite with enhanced electrochemical performance for lithium-ion batteries

Abstract

An LiTi₂(PO₄)₃/reduced graphene oxide (rGO) nanocomposite with a NASICON-type structure was synthesized using a simple microwave-assisted one-pot method followed by calcination. The LiTi₂(PO₄)₃ nanoparticles were uniformly deposited on rGO substrates, and the size of LiTi₂(PO₄)₃ particles in the composite was 30–40 nm. Electrodes prepared from the nanocomposite delivered a reversible capacity of 138 mA h g⁻¹ at a 0.1 C-rate and the apparent diffusion coefficient of Li⁺ in the anode, as calculated from the cyclic voltammetry curves, is 1.55 × 10⁻¹⁴ cm² s⁻¹. The electrode exhibited good charge/discharge cycling stability, retaining over 93.2% of its initial capacity after 100 cycles at 1 C-rate and reaching a coulombic efficiency of approximately 99.8%. This excellent cycle stability is further confirmed by TEM analysis, which reveals that almost all of the LiTi₂(PO₄)₃ nanoparticles remain unchanged after 200 cycles.