摘要
The unsatisfactory rate capability and poor cycling stability at high rate of sodium-ion batteries(SIBs) have impeded their practical applications. Herein, a Na_(3)V_(2)(PO_(4))_(3)/Na_(3)V_(3)(PO_(4))_(4) multiphase cathode materials for high-rate and long cycling SIBs was successfully synthesized by regulation the stoichiometric ratio of raw materials. The combined experiment and simulation results show that the multiphase materials consisted of NASICON structural phase Na3V2(PO4)3 and layered structure phase Na_(3)V_(3)(PO_(4))_(4), possess abundant phase boundaries. Electrochemical experiments demonstrate that the multiphase materials maintain a remarkable reversible capacity of 69.0 mA h g^(-1) even at an ultrahigh current density of 100 C with a high capacity retention of 81.25 % even after 10,000 cycles. Na_(3)V_(2)(PO_(4))_(3)/Na_(3)V_(3)(PO_(4))_(4) electrode exhibits a higher working voltage, superior rate capability and better cycling stability than Na_(3)V_(2)(PO_(4))_(3) electrode, which indicates that the introduction of second phase can be an effective strategy for the development of novel cathode materials for SIBs.
基金
the financial support of this work by the Science, Technology, and Innovation Commission of Shenzhen Municipality (JCYJ20180508151856806 and JCYJ20180306171121424)
the Key R&D Program of Shanxi (No. 2019ZDLGY04-05)
the National Natural Science Foundation of Shaanxi (No.2019JLZ-01
No.2019JLM-29 and No.2020JQ-189)
the Research Fund of the State Key Laboratory of Solidification Processing (NPU), China (No.2019-TS-06)
China Postdoctoral Science Foundation (No.2018M641015)。
