Ultrasmall Fe2GeO4 nanodots anchored on interconnected carbon nanosheets as high-performance anode materials for lithium and sodium ion batteries
Ultrasmall Fe2GeO4 nanodots anchored on interconnected carbon nanosheets as high-performance anode materials for lithium and sodium ion batteries
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DOI：
10.1016/j.apsusc.2017.08.026
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发表时间：
2018-01-01
影响因子：
6.7
通讯作者：
He, Chunnian
中科院分区：
文献类型：
--
作者：
Han, Jinzhi;Qin, Jian;He, Chunnian
其固有电导率差，充放电过程中体积膨胀大，极大地限制了锗基三元氧化物作为锂离子电池和钠离子电池正极材料的发展。为了缓解这些问题，我们提出了一种理想的策略，即同时实现活性颗粒纳米化和与导电碳材料的复合。因此，通过一步高温煅烧工艺，在三维互连的n掺杂超薄碳纳米片（3D Fe2GeO4/N-CNSs）上构建了均匀且紧密锚定的超小Fe2GeO4纳米点（约4.6 nm）。这种独特的杂化纳米结构不仅可以有效地提高电子导电性，而且可以限制Fe2GeO4在充放电过程中的聚集和体积波动。结果表明，三维Fe2GeO4/N-CNSs电极在锂离子和钠离子电池阳极上均表现出优异的电化学性能。当用于锂离子电池负极时，电极提供了高度可逆的比容量(在0.4 a g（-1) 180次循环后1280 mA h g(-1)）。这是Fe2GeO4首次应用于钠离子电池负极，表现出卓越的倍率性能(0.1 a g（-1）时350 mA h g（-1), 22.8 a g（-1）时180 mA h g(-1)）和超长循环稳定性（6000次循环后可保持86%的可逆容量）。(C) 2017 Elsevier B.V.版权所有
Poor intrinsic conductivity and huge volume expansion during charge/discharge process greatly limit the development of Ge-based ternary oxide as anode material for both lithium-ion batteries and sodium-ion batteries. To alleviate these issues, an ideal strategy is developed to achieve active particle nanocrystallization and composite with conductive carbon materials, simultaneously. Therefore, ultrasmall Fe2GeO4 nanodots (similar to 4.6 nm) uniformly and tightly anchored on 3D interconnected N-doped ultrathin carbon nanosheets (3D Fe2GeO4/N-CNSs) were constructed via one-step high temperature calcination process. This unique hybrid nanostructure can not only effectively enhance electron conductivity but also restrict the aggregation and volume fluctuation of Fe2GeO4 during the charge/discharge process. As a result, the 3D Fe2GeO4/N-CNSs electrode exhibited excellent electrochemical performances for both lithium-ion and sodium-ion battery anodes. When utilized for lithium-ion battery anode, the electrode delivered a highly reversible specific capacity (1280 mA h g(-1) at 0.4 A g(-1) after 180 cycles). It is the first time that Fe2GeO4 was applied for sodium-ion battery anode, which showed a remarkable rate capability (350 mA h g(-1) at 0.1 A g(-1) and 180 mA h g(-1) at 22.8 A g(-1)), and ultralong cycling stability (similar to 86% reversible capacity retention after 6000 cycles). (C) 2017 Elsevier B.V. All rights reserved.