The Structure–Property Investigation of Bi1–xCexFeO3 (x = 0, 0.05)–Li Battery: In Situ XRD and XANES Studies
The Structure–Property Investigation of Bi1–xCexFeO3 (x = 0, 0.05)–Li Battery: In Situ XRD and XANES Studies
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DOI：
10.1021/jp3065745
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发表时间：
2012-09
影响因子：
3.7
通讯作者：
Xingmin Zhang;M. Gao;Yueliang Gu;Hong-liang Bao;Xiaolong Li;Xingtai Zhou;W. Wen
中科院分区：
文献类型：
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作者：
Xingmin Zhang;M. Gao;Yueliang Gu;Hong-liang Bao;Xiaolong Li;Xingtai Zhou;W. Wen
采用共沉淀法合成了BiFeO 3和Bi0.95Ce0.05FeO3。在合成过程中，通过同步辐射X射线衍射（XRD）原位监测相变。Ce的加入提高了BiFeO 3相的形成温度，同时大大抑制了颗粒尺寸的增长。Ce0.05Bi0.95FeO3被进一步用于锂电池应用，并且在1.15和3.0V之间观察到良好的电化学循环性能。与BiFeO 3相比，Ce的添加不仅增加了放电容量，而且显示出高0.15V的放电电压（在第二次循环中）。在2个Li离子插入之后，Bi离子被还原成金属Bi并从钙钛矿晶格中分离出来。在随后的充电过程中，金属Bi可以被氧化回其离子状态。在第二次放电过程中观察到放电电压升高。a/b轴晶格参数主要受Li嵌入/脱嵌的影响，c轴晶格参数主要受c轴离子种类的影响。存在两种不同的传导途径：一种是沿着a/b平面的离子传导，另一种是沿沿着c轴的电子传导。
BiFeO3 and Bi0.95Ce0.05FeO3 were synthesized via a coprecipitation technique. During the synthesis process, the phase transitions were monitored via in situ synchrotron X-ray diffraction (XRD). The Ce addition increased the formation temperature of BiFeO3 phase, while greatly suppressed the particle size growth. Ce0.05Bi0.95FeO3 was further employed for lithium battery application, and good electrochemical cycling performance was observed between 1.15 and 3.0 V. Ce addition not only increased the discharge capacity but also displayed 0.15 V higher discharge voltage (in the second cycle), compared with BiFeO3. After 2 Li ions insertion, Bi ions are reduced to metallic Bi and separated out of the perovskite lattice. In the following charge process, metallic Bi can be oxidized back to its ionic state. Elevated discharge voltage was observed in the second discharge process. a/b-axis lattice parameters are mainly changed by Li intercalation/deintercalation, and c-axis lattice parameters are heavily affected by the ionic species in the c-axis. There are two distinct conduction pathways: one is the ionic conduction along the a/b-plane, and the other is the electronic conduction along the c-axis.