Li1.3Al0.3Ti1.7(PO4)3 Behaving as a Fast Ionic Conductor and Bridge to Boost the Electrochemical Performance of Li4Ti5O12

Li1.3Al0.3Ti1.7(PO4)3 (LATP) is a Li-ion conductive solid electrolyte with high ionic conductivity; meanwhile, it also possesses relatively high electronic conductivity compared to those of the other fast ionic conductors. In this work, LATP was composited with Li4Ti5O12 (LTO) at a mass ratio of 0.026 and calcined at 700 °C for 5 h. The composite delivers reversible capacities of 164.8, 156.3, 152.4, 146.5, 130.5, and 158.6 mAh g–1 at the current densities of 100, 200, 400, 800, 1600, and 100 mA g–1, respectively, as well as a capacity of 112 mAh g–1 after cycling at 500 mA g–1 for 1200 cycles. The appreciable performance is attributable to the three-dimensional Li-ion diffusion channels in LATP to facilitate Li-ion migration, and the local charge imbalance resulted from the substitution of Al3+ for Ti4+ to promote charge transfer in LTO, thus the LATP-composited LTO exhibits enhanced ionic and electronic conductivities, as well as the markedly boosted electrochemical performance.