Publication

Abstract : The single-pot synthesis of dual-phase spinel-LiTiO and anatase-TiO (LTO-TiO) nanoparticles over all the phase fractions ranging from pure LTO to pure TiO is conducted. Carrying out the process over the complete range enabled the identification of a unique weight ratio of 85:15 (LTO:TiO), providing the best combination of capacity, rate capability and cycling stability. We show that for this composition dual-phase nanoparticles have a predominant interfacial orientation of (111)∣∣(004) , while it is (111)∣∣(101) for other compositions. This study therefore shows that the dual-phase interface with these specific orientations gives the best performance. The synergistic combination of dual-phase nanoparticles with multi-wall carbon nanotubes improves the performance further. This results in an electrode with supercapacitor-like rate capability delivering high discharge capacities of 174, 127, 119, 110, 101 and 91 mAh g at specific currents of 2000, 6000, 12 000, 18 000, 24 000 and 30 000 mA g, respectively. A discharge capacity of 174 mAh g at a specific current of 2000 mA g with only 0.005% capacity loss per cycle over 3000 cycles is demonstrated. At current densities of 6000, 12 000 and 24 000 mA g, stable cycling is obtained for 1500 cycles. The present work enables nano-engineered interfaces in LTO-TiO dual-phase nanoparticles with an electrochemical performance that is better than its individual components, opening up the potential for high-power Li-ion battery applications.