Hydrothermal synthesis of Co3O4 microspheres as anode material for lithium-ion batteries
Hydrothermal synthesis of Co3O4 microspheres as anode material for lithium-ion batteries
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DOI：
10.1016/j.electacta.2007.10.020
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发表时间：
2008-01-01
影响因子：
6.6
通讯作者：
Zhang, Xiaogang
中科院分区：
文献类型：
--
作者：
Liu, Yan;Mi, Changhuan;Zhang, Xiaogang
采用简单的水热法制备了Co 3 O 5微球。通过XRD和SEM分析，可以得到粒径为1 μ m的球形颗粒，且结晶良好。通过BET测量，更高的比表面积（93.4 m2 g-1）和更大的孔体积（78.4 cm 3 g-1）为额外的Li+插入位点提供了更多的界面键合，这导致由于SEI膜形成而导致的异常大的初始不可逆容量和容量循环损失。首次成型的Co 3 O 4微球作为锂离子负极材料，从第12次循环开始，容量保持率几乎在90%以上，经过25次循环后，其储锂容量仍保持在550.2mAh g（-1），表现出良好的长寿命稳定性。进行了循环伏安测试和充放电实验前后的电化学阻抗谱（EIS）测试，并计算了相应的D-i、D-j值。讨论了交流阻抗谱与循环性能的关系。结果表明，Co_3O_4电极容量的降低主要是由于Li ~* 的电荷转移阻抗增大和循环过程中锂的扩散过程减少所致，这与Co_3O_4电极的电化学行为相一致。(c)2007爱思唯尔有限公司版权所有。
Co3O5 microspheres were synthesized in mass production by a simple hydrothermal treatment. One micrometer-sized spherical particles with well-crystallization could be obtained by XRD and SEM. Higher specific surface area (93.4 m(2) g(-1)) and larger pore volume (78.4 cm(3) g(-1)) by BET measurements offered more interfacial bondings for extra sites of Li+ insertion, which resulted in the anomalous large initial irreversible capacity and capacity cycling loss due to SEI film formation. The capacity retention of Co3O4 microspheres involved first forming acted as Li-ion anode material is almost above 90% from 12th cycle and it retain lithium storage capacity of 550.2 mAh g(-1) after 25 cycles, which show good long-life stability. The electrochemical impedance spectroscopy (EIS) tests before and after cyclic voltammetry measurements and charge-discharge experiments were carried out and the corresponding D-i,D-j values were also calculated. The relationship of the ac impedance spectra and the cycling behaviors was discussed. It is found that the decrease of capacity results from the larger Li-* charge-transfer impedance and the lower lithium-diffusion processes on cycling, which is in very good agreement with the electrochemical behaviors of Co3O4 electrode. (c) 2007 Elsevier Ltd. All rights reserved.