A three-dimensional LiFePO4/carbon nanotubes/graphene composite as a cathode material for lithium-ion batteries with superior high-rate performance
A three-dimensional LiFePO4/carbon nanotubes/graphene composite as a cathode material for lithium-ion batteries with superior high-rate performance
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DOI：
10.1016/j.jallcom.2014.09.169
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发表时间：
2015-03
影响因子：
6.2
通讯作者：
Xingling Lei;Haiyan Zhang;Yiming Chen;Wenguang Wang;Yipeng Ye;Chuchun Zheng;Peng Deng;Zhicong Shi-Zhi
中科院分区：
文献类型：
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作者：
Xingling Lei;Haiyan Zhang;Yiming Chen;Wenguang Wang;Yipeng Ye;Chuchun Zheng;Peng Deng;Zhicong Shi-Zhi
通过固相反应成功合成了三维磷酸铁锂（LiFePO4）/碳纳米管（CNT）/石墨烯复合材料。与LiFePO4/碳纳米管(LFP-CNT)复合材料和LiFePO4/石墨烯(LFP-G)复合材料相比，LiFePO4/碳纳米管/石墨烯(LFP-CNT-G)复合材料用作锂离子电池正极材料，在相对高电流密度下表现出优异的高倍率性能和良好的充放电循环性能。石墨烯纳米片和碳纳米管构建的3D导电网络有利于锂离子可逆反应过程中更快的电子转移、更高的锂离子扩散系数和更低的电阻。石墨烯纳米片和碳纳米管的协同效应提高了LiFePO4基正极的倍率性能和循环稳定性。 LFP-CNT-G 电极在 0.2 C 时显示出 168.9 mA h g−1 的可逆容量，在 20 C 时显示出 115.8 mA h g−1 的可逆容量。电化学阻抗谱表明 LFP-CNT-G 电极具有最小的电荷转移电阻，表明在锂离子嵌入/脱嵌反应中，电子从电解质到 LFP-CNT-G 活性材料的快速转移是由于石墨烯和碳纳米管的三维网络。
A three-dimensional lithium iron phosphate (LiFePO4)/carbon nanotubes (CNTs)/graphene composite was successfully synthesized via solid-state reaction. The LiFePO4/carbon nanotubes/graphene (LFP–CNT–G) composite used as Li-ions battery cathode material exhibits superior high-rate capability and favorable charge–discharge cycle performance under relative high current density compared with that of LiFePO4/carbon nanotubes (LFP–CNT) composite and LiFePO4/graphene (LFP–G) composite. Graphene nanosheets and CNTs construct 3D conducting networks are favor for faster electron transfer, higher Li-ions diffusion coefficient and lower resistance during the Li-ions reversible reaction. The synergistic effect of graphene nanosheets and CNTs improves the rate capability and cycling stability of LiFePO4-based cathodes. The LFP–CNT–G electrode shows reversible capacity of 168.9 mA h g−1at 0.2 C and 115.8 mA h g−1at 20 C. The electrochemical impedance spectroscopy demonstrate that the LFP–CNT–G electrode has the smallest charge-transfer resistance, indicating that the fast electron transfer from the electrolyte to the LFP–CNT–G active materials in the Li-ions intercalation/deintercalation reactions owing to the three-dimensional networks of graphene and carbon nanotubes.