Li3V2(PO4)3 Addition to the Olivine Phase: Understanding the Effect in Electrochemical Performance
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- 作者：Sudeep Sarkar ; Sagar Mitra
- 刊名：Journal of Physical Chemistry C
- 出版年：2014
- 出版时间：June 5, 2014
- 年：2014
- 卷：118
- 期：22
- 页码：11512-11525
- 全文大小：868K
- 年卷期：v.118,no.22(June 5, 2014)
- ISSN：1932-7455
文摘
Several chemical compositions of (1 鈥?x)LiFePO4鈥?i>xLi3V3(PO4)3 with Li3V2(PO4)3 decorated LiFePO4 morphology are synthesized via modified solid-state synthesis. The current study is undertaken to establish a relation between composite formation and their electrochemistry as an excellent cathode material. A detailed physical and structural investigation revealed the formation of a Li3V2(PO4)3 decorated LiFePO4 composite. To investigate the electrochemical performance of LiFePO4鈥揕i3V2(PO4)3 composites, a series of compositions are prepared with end member of LiFePO4 and Li3V2(PO4)3. A specific composition of 0.97LiFePO4鈥?.03Li3V3(PO4)3 shows a high reversible capacity of 163.8 mAh g鈥? at 1 C current rate in the potential window of 2鈥?.5 V. The present study could provide a great physical insight into the stability of solid electrolyte interface and subsequent decrease in charge transfer resistance of composite materials and exhibits an excellent electrode kinetics and electrochemical stability compared to pristine LiFePO4. Electrode kinetics is studied at 100% depth of discharge at open circuit potential and continuous charge鈥揹ischarge cycle by the electrochemical impedance spectroscopy technique. It is observed that the improvement of electrochemical performance is mainly controlled by the Li3V2(PO4)3 phase because of its unique three-dimensional open structure. Finally, understanding the physical and electrochemical behavior of the (1 鈥?x)LiFePO4鈥?i>xLi3V3(PO4)3 composite electrode is studied that could be useful to design new cathode materials further for lithium ion batteries.