Nanostructured Nb2O5 cathode for high-performance lithium-ion battery with Super-P and graphene compound conductive agents

摘要

Nb2O5 nanostructures were produced by a rational hydrothermal method, which were used as the cathode material in lithium-ion batteries. The Super-P and graphene compounds were used as the conductive agents. Owing to the excellent conductivity of graphene, it is favorable for the contacting area between electrolyte and the electrode material. The results showed that adding graphene can increase the conductivity of the entire electrode system. The specific capacity of Nb2O5 with 4 wt% graphene is 180 mAh g(-1), meanwhile the capacity retention rate is more than 85% after 100 charge and discharge cycles under a current rate of 5 C. Adding an appropriate amount of graphene as the conductive agent can greatly improve the conductivity of the electrode system, reduce the charge transfer resistance during the charge-discharge process to increase the specific capacity, and enable the battery to keep excellent cycle stability. This work demonstrates that the obtained Nb2O5, with Super-P and graphene compound conductive agents can greatly increase performances of lithium ion battery such as capacity, rate performance, and cycle performance and conductivity.