Crystallized lithium titanate nanosheets prepared via spark plasma sintering for ultra-high rate lithium ion batteries

Abstract

This paper shows that a lithium titanate (LTO) nanosheet material is successfully prepared by the spark plasma sintering (SPS) method at 500 °C within only 5 minutes, using its nanosheet precursor synthesized by hydrothermal reaction. The pulsed electric field induces the phase transition of the precursor at much lower temperature and in a much shorter time during the SPS process. Moreover, the thin layer morphology of the LTO precursor can be well maintained after SPS treatment, which has been changed into nanoparticles during the conventional solid state calcination. The crystalline LTO nanosheets prepared by SPS deliver high specific capacities of 151.2 mA h g⁻¹ and 147.2 mA h g⁻¹ at high current densities of 8 A g⁻¹ (45.7C) and 10 A g⁻¹ (57.1C), respectively. Moreover, the LTO nanosheets display stable capacity retentions of 73.9% and 75.6% after 1000 cycles at 1 A g⁻¹ and 2 A g⁻¹, respectively.