Alloyed Cu/Si core-shell nanoflowers on the three-dimensional graphene foam as an anode for lithium-ion batteries
Alloyed Cu/Si core-shell nanoflowers on the three-dimensional graphene foam as an anode for lithium-ion batteries
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DOI：
10.1016/j.electacta.2019.03.071
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发表时间：
2019-05
影响因子：
6.6
通讯作者：
Chenguang Liu;Yinchao Zhao;Ruowei Yi;Yi Sun;Yinqing Li;Li Yang;I. Mitrovic;Stephen Taylor;P. Chalker;Cezhou Zhao
中科院分区：
文献类型：
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作者：
Chenguang Liu;Yinchao Zhao;Ruowei Yi;Yi Sun;Yinqing Li;Li Yang;I. Mitrovic;Stephen Taylor;P. Chalker;Cezhou Zhao
在这项研究中，我们展示了一种简单的方法来制造一个灵活的合金铜/硅核壳纳米花结构锚定在三维石墨烯泡沫作为集流体。这种组合提供了灵活和独立的结构和三维导电网络，允许电流收集和传输的独特性能。通过简单的电沉积和蚀刻在三维石墨烯泡沫上合成氧化铜纳米花，其用作出色的模板以延缓硅的锂化/脱锂化期间的应力效应。在铜氧化物纳米花上均匀沉积硅涂层后，采用简单的氢气退火还原铜氧化物纳米花，形成铜/硅合金，显著提高了硅的导电性。此外，该结构可以在没有任何导电添加剂或粘合剂的情况下直接组装。在电化学测试中，所得的铜/硅核壳纳米花电极在1.6 A g−1下表现出1869 mAh g− 1的高初始容量，在500次循环后具有66.6%的高留存率。更重要的是，在10 A g−1的高电流密度下，这种阳极仍然保持了>63%的高容量保持率（与最高容量679 mAh g−1相比），为储能应用提供了巨大的潜力。
In this study, we demonstrate a facile method to fabricate a flexible alloyed copper/silicon core-shell nanoflowers structure anchored on the three-dimensional graphene foam as a current collector. This combination provides flexible and free-standing structure and three-dimensional conductive network, allowing unique properties for current collection and transmission. The copper oxide nanoflowers are synthesized on the three-dimensional graphene foam by a simple electrodeposition and etching, which serves as an outstanding template to retard the stress effects during the lithiation/delithiation of silicon. After the silicon coating uniformly deposited on the copper oxide nanoflowers, a simple hydrogen annealing was applied to reduce copper oxide nanoflowers and form the copper/silicon alloy, remarkably enhancing the conductivity of silicon. Moreover, this structure can be directly assembled without any conductive additive or binder. In electrochemical testing, the resulting copper/silicon core-shell nanoflowered electrode demonstrates a high initial capacity of 1869 mAh g−1at 1.6 A g−1, with a high retention rate of 66.6% after 500 cycles. More importantly, at a high current density of 10 A g−1, this anode still remains a high capacity retention >63% (compared with the highest capacity 679 mAh g−1), offering enormous potential for energy storage applications.