A Novel Strategy toward High-Performance Lithium Storage of Li4Ti5O12 Using Cu2V2O7 as Additive

Cu2V2O7 is an important material to improve low conductivity of Li4Ti5O12. Herein, Li4Ti5O12/Cu2V2O7 with different Cu2V2O7 ratios is successfully prepared by a liquid phase-assisted dispersion method. The results show that the electrochemical properties of Li4Ti5O12 are affected by the Cu2V2O7 content incorporated in the composites. Among all obtained samples, Li4Ti5O12/0.05 Cu2V2O7 reveals the best electrochemical performance and capacity retention rate, and its first cycle specific capacity is 246.3/197.2 mAh g(-1) when the current density is 30 mA g(-1) and it maintains values of 175.8/175 mAh g(-1) for 200 cycles between 1.0 and 3.0 V. The resulting Li4Ti5O12/0.05 Cu2V2O7 composite also displays higher capacities at elevated current densities of 120 and 1200 mA g(-1), with values always superior to those of the original Li4Ti5O12. The detailed electrode dynamics analysis illustrates that the introduced Cu2V2O7 phase in the composites improves the cycle stability and lithium-ion transfer rate of Li4Ti5O12. Through in situ X-ray diffractometry (XRD) test analysis of the Li4Ti5O12/0.05 Cu2V2O7 composite material, it is confirmed that the lithium storage mechanism is improved, where metallic Cu is formed in situ during each charge and discharge reaction process; thereby, the electronic conductivity of the composite material is improved and charge transfer resistance of the bulk material is reduced.