Construction of core-shell TiNb2O7/Li4Ti5O12 composites with improved lithium storage for lithium-ion batteries

Abstract

In this study, the (TiNb2O7) TNO and modified (Li4Ti5O12) LTO composites with the core–shell (CS) structures have been designed and prepared by the spry-dried method. In the structural composite, the modified LTO core can stabilize the dimensional stability with excellent rate capability, and the TNO shell can offer a larger capacity, leading to high-performance anode materials. Our results indicate that the CS composites without the TNO nanoparticles (NPs) aggregation reveal a more negligible electrochemical polarization (EP) with improved kinetics than traditional composites. The optimal TNO content in the CS composite is 30 wt%, which can show a larger capacity than that of bare LTO, with the C-rate ranging between 17.5 and 3500 mA g−1. It delivers a capacity of 164.9 mA h g−1 at 1050 mA g−1, higher than bare LTO (157.6 mA h g−1) and traditional composite (154.6 mA h g−1). Furthermore, the full lithium-ion battery (LIB) is fabricated using the CS composite as the anode and LiNi0.5Mn1.5O4 (LNMO) as the cathode. The designed LIB shows an improved energy density of 122.0 W h kg−1 with remarkable cycling stability.