Synthesis, Structure, Electronic, Ionic, and Magnetic Properties of Li9V3(P2O7)3(PO4)2 Cathode Material for Li-Ion Batterie
详细信息 查看全文
- 作者：Quan Kuang ; Yanming Zhao ; Jiantie Xu
- 刊名：Journal of Physical Chemistry C
- 出版年：2011
- 出版时间：April 28, 2011
- 年：2011
- 卷：115
- 期：16
- 页码：8422-8429
- 全文大小：1025K
- 年卷期：v.115,no.16(April 28, 2011)
- ISSN：1932-7455
文摘
Layered monodiphosphate Li9V3(P2O7)3(PO4)2 can be synthesized by direct solid-state reaction using either hydrogen or carbon as the reducing agent at the sintered temperature of 750 掳C. When the temperature is higher than 800 掳C, Li9V3(P2O7)3(PO4)2 begins to decompose into Li3V2(PO4)3 and Li4P2O7. The measurement results of electronic conductivity, magnetization, and electrochemical impedance spectroscopy are reported for the first time. After carbon coating, the electronic conductivity comes to 2.07 脳 10鈭? S cm鈭?, which is the same order of magnitude as that of carbon-coated LiFePO4 and Li3V2(PO3)4. Li-ion diffusion coefficient (4.19 脳 10鈭?0 cm2 s鈭?) for carbon-uncoated Li9V3(P2O7)3(PO4)2 is close to that of LiCoO2 and much higher than that of LiFePO4. Li9V3(P2O7)3(PO4)2 exhibits a paramagnetic behavior in the temperature range of 5鈭?00 K, which is consistent with the result from our X-ray photoelectron spectroscopy analysis where the oxidation state of vanadium is +3 in the Li9V3(P2O7)3(PO4)2 compound. The favorable electronic and ionic properties suggest that Li9V3(P2O7)3(PO4)2 can be a potential cathode material for Li-ion batteries.