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.