Characterization of Li2MnSiO4 and Li2eSiO4 cathode materials synthesized via a citric acid assisted sol-gel method
Characterization of Li2MnSiO4 and Li2eSiO4 cathode materials synthesized via a citric acid assisted sol-gel method
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DOI：
10.1016/j.matchemphys.2009.11.027
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发表时间：
2010-03-15
影响因子：
4.6
通讯作者：
Ma, L.
中科院分区：
文献类型：
--
作者：
Deng, C.;Zhang, S.;Ma, L.
采用柠檬酸辅助溶胶-凝胶法制备了正硅酸盐家族的两个成员Li2FeSiO4和Li2MnSiO4。作为锂离子电池的正极材料，对它们的结构、形态和电化学特性进行了研究和比较。两种正极材料的纳米粒子具有相似的晶格参数。Li2FeSiO4的最大放电容量为152.8 ma hg(-1)，经过50次循环后，其最大放电容量的98.3%仍保持不变。然而，锂锰sio4的放电容量衰减迅速，在20次循环后稳定在70 mAh g（-1）左右。电化学阻抗和差分容量分析表明，Li2MnSiO4比Li2FeSiO4具有更大的电荷转移阻抗和更高的电化学不可逆性，这使得其电化学行为严重恶化，导致两种硅酸盐材料之间存在差异。(C) 2009 Elsevier B.V.版权所有
Two members of the family of orthosilicate, Li2FeSiO4 and Li2MnSiO4, are prepared by a citric acid assisted sol-gel method. As cathode materials for lithium-ion batteries, their structural, morphological and electrochemical characteristics are investigated and compared. Both cathode materials have nanoparticles with similar lattice parameters. Li2FeSiO4 has a maximum discharge capacity of 152.8 m A hg(-1), and 98.3% of its maximum discharge capacity is retained after fifty cycles. However, the discharge capacity of Li2MnSiO4 fades rapidly and stabilized at about 70 mAh g(-1) after twenty cycles. The electrochemical impedance and differential capacity analysis indicate that Li2MnSiO4 has larger charge transfer impedance and higher electrochemical irreversibility than Li2FeSiO4, which makes its electrochemical behaviors seriously deteriorate and leads to difference between two silicate materials. (C) 2009 Elsevier B.V. All rights reserved.