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

Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 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 Li 4 Ti 5 O 12 (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 Al 3+ for Ti 4+ 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.