The in Operando/Situ Analytical Techniques Assisted Study of Pre-Lithiated MoOx @ TiO2 As the Anode Material of Lithium Ion Batteries

Abstract

Nowadays, as more environmental-friendly and safe energy storage, Lithium-ion Batteries (LIBs) is being pursued, TiO2 is suggested as the anode material, having desirable performance in stability and cycle, but there is the main challenge of low specific capacity (330mAh/g theoretically). To overcome, modifying molybdenum (Mo) into TiO2 reduces the impedance and increases the Li ion diffusion rate. The MoOx@TiO2 is synthesized by the by reacting (NH4)2MoO4 and TiO2 (rutile and anatase phase mixed) followed by annealing at elevated temperature (700°C). From the TEM and XRD results, we had synthesized MoOx@TiO2 shell-core structure. With the modifying of Mo, the specific capacity had reached 1273mAh/g and 995mAh/g in the first cycle under 0.1C and 0.2C current respectively. The fading of the capacity in different current showed the similar tendency, having the irreversible capacity of 36% and 29% after the first cycle. The loss of capacity during cycling is inevitable, thus the electrochemical pre-lithiation method was used by applying various constant voltage for certain duration to force the forming of solid electrolyte interphase (SEI) layer and the diffusion of lithium ion into the electrode. Pre-lithiated MoOx@TiO2 has better Coulombic efficiency (CE) and reversible capacity. The complex mechanism of pre-lithiation is studied by the assistance of In Operando/Situ techniques (In Operando XRD and Raman). The In Operando experiments would be done on the single holed coin cell (CR2030). With the dealt challenge, MoOx@TiO2 would be the potential dominant material for the anode material of LIBs. Figure 1