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

Cu 2 V 2 O 7 is an important material to improve low conductivity of Li 4 Ti 5 O 12 . Herein, Li 4 Ti 5 O 12 /Cu 2 V 2 O 7 with different Cu 2 V 2 O 7 ratios is successfully prepared by a liquid phase‐assisted dispersion method. The results show that the electrochemical properties of Li 4 Ti 5 O 12 are affected by the Cu 2 V 2 O 7 content incorporated in the composites. Among all obtained samples, Li 4 Ti 5 O 12 /0.05 Cu 2 V 2 O 7 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 Li 4 Ti 5 O 12 /0.05 Cu 2 V 2 O 7 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 Li 4 Ti 5 O 12 . The detailed electrode dynamics analysis illustrates that the introduced Cu 2 V 2 O 7 phase in the composites improves the cycle stability and lithium‐ion transfer rate of Li 4 Ti 5 O 12 . Through in situ X‐ray diffractometry (XRD) test analysis of the Li 4 Ti 5 O 12 /0.05 Cu 2 V 2 O 7 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.