Cobalt-doped todorokites prepared by refluxing at atmospheric pressure as cathode materials for Li batteries
Cobalt-doped todorokites prepared by refluxing at atmospheric pressure as cathode materials for Li batteries
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常压回流制备钴掺杂钙钛矿作为锂电池正极材料
DOI：
10.1016/j.electacta.2010.09.003
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发表时间：
2010-12
影响因子：
6.6
通讯作者：
刘凡
中科院分区：
文献类型：
--
作者：
刘凡
以水钠锰矿为原料，采用常压水热法合成了掺钴钙钛矿。采用X射线衍射（XRD）、X射线光电子能谱（XPS）、热重分析（TGA）、扫描电子显微镜（SEM）和化学成分分析等手段对合成产物的晶体结构、表面形貌和化学成分进行了表征。结果表明，所有产物均为3×3隧道结构的钙钛矿，化学组成为MgxCoyMnOz·nH 2 O，其中0.18≤x≤0.22，0≤y≤0.31，2.01≤z≤2.52，0.35≤n≤ 0.73。研究了掺钴钙钛矿作为锂二次电池正极材料的充放电性能。未掺杂的钙镁石的放电容量在第一次循环时约为211 mAhg-1，30次循环后下降至37 mAhg-1。钴取代锰可显著提高钙镁锰矿的循环容量。钴含量为10-15%的钙钛矿具有较好的放电性能。Mg0.18Co0.12MnO2.19·Co含量约为10%的0.45H2O显示出219 mAhg − 1的高初始放电容量和100次循环后102 mAhg − 1的循环容量。采用粉末微电极循环伏安法进一步验证了钴掺杂对钙钛矿电化学性能的影响。
Cobalt-doped todorokites were synthesized by refluxing process at atmospheric pressure from the transformation of birnessites. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), scanning electron microscope (SEM) and chemical composition analysis were used to characterize the crystal structures, surface morphologies and chemical compositions of synthesized products. Results showed that all refluxing products were todorokites with 3×3 tunnel structure and the chemical compositions were denoted as MgxCoyMnOz·nH2O, where 0.18≤x≤0.22, 0≤y≤0.31, 2.01≤z≤2.52 and 0.35≤n≤ 0.73. Cobalt-doped todorokites were investigated as cathode materials of lithium rechargeable batteries for charge/discharge characteristics. Discharge capacity of the undoped todorokite was about 211mAhg−1at first cycle, and then decreased to 37mAhg−1after 30 cycles. The cyclic capacities of todorokite could be improved remarkably by substitution of cobalt for manganese. Todorokites with Co content of 10–15% displayed better discharge performance. Mg0.18Co0.12MnO2.19·0.45H2O with Co content about 10% showed a high initial discharge capacity of 219mAhg−1and cycling capacity of 102mAhg−1after 100 cycles. The effect of doping cobalt on electrochemical performance of todorokite was further proved with cyclic voltammetry by using powder microelectrode.
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影响因子：
3.9
作者：
Q. Feng;H. Kanoh;K. Ooi;M. Tani;Y. Nakacho
通讯作者：
Q. Feng;H. Kanoh;K. Ooi;M. Tani;Y. Nakacho
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
S. Oh;S. Park;E. Jung;Y. Bae;Yangfang Sun
通讯作者：
S. Oh;S. Park;E. Jung;Y. Bae;Yangfang Sun
影响因子：
6.6
作者：
Y. Kadoma;Satoru Oshitari;K. Ui;N. Kumagai
通讯作者：
Y. Kadoma;Satoru Oshitari;K. Ui;N. Kumagai
影响因子：
9.2
作者：
Yong Yang;D. Shu;You Jinkua;Z. G. Lin
通讯作者：
Yong Yang;D. Shu;You Jinkua;Z. G. Lin
影响因子：
9.2
作者：
Christopher S. Johnson;M. Thackeray
通讯作者：
Christopher S. Johnson;M. Thackeray