Key Laboratory for Green Chemical Technology of MOE, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , P. R. China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin University , Tianjin 300072 , P. R. China.
ACS Appl Mater Interfaces. 2018 Apr 25;10(16):13470-13478. doi: 10.1021/acsami.8b00353. Epub 2018 Apr 12.
To address the issues of low electrical conductivity, sluggish lithiation kinetics and dramatic volume variation in FeO anodes of lithium ion battery, herein, a double carbon-confined three-dimensional (3D) nanocomposite architecture was synthesized by an electrostatically assisted self-assembly strategy. In the constructed architecture, the ultrafine FeO subunits (∼10 nm) self-organize to form nanospheres (NSs) that are fully coated by amorphous carbon (AC), formatting core-shell structural FeO/AC NSs. By further encapsulation by reduced graphene oxide (rGO) layers, a constructed 3D architecture was built as dual carbon-confined rGO/FeO/AC. Such structure restrains the adverse reaction of the electrolyte, improves the electronic conductivity and buffers the mechanical stress of the entire electrode, thus performing excellent long-term cycling stability (99.4% capacity retention after 465 cycles relevant to the second cycle at 5 A g). Kinetic analysis reveals that a dual lithium storage mechanism including a diffusion reaction mechanism and a surface capacitive behavior mechanism coexists in the composites. Consequently, the resulting rGO/FeO/AC nanocomposite delivers a high reversible capacity (835.8 mA h g for 300 cycles at 1 A g), as well as remarkable rate capability (436.7 mA h g at 10 A g).
为了解决锂离子电池 FeO 阳极电导率低、嵌锂动力学缓慢和体积变化剧烈的问题，本文采用静电辅助自组装策略合成了一种双重碳限制的三维（3D）纳米复合材料结构。在构建的结构中，超细微的 FeO 亚单位（约 10nm）自组装形成纳米球（NSs），完全被无定形碳（AC）包覆，形成核壳结构的 FeO/AC NSs。通过进一步被还原氧化石墨烯（rGO）层包裹，构建了一种双重碳限制的 3D 结构 rGO/FeO/AC。这种结构抑制了电解质的不良反应，提高了电子电导率，并缓冲了整个电极的机械应力，从而表现出优异的长期循环稳定性（与第 2 个循环相比，在 5A g 下经过 465 个循环后容量保持率为 99.4%）。动力学分析表明，复合材料中存在双锂存储机制，包括扩散反应机制和表面电容行为机制。因此，所得的 rGO/FeO/AC 纳米复合材料具有高可逆容量（在 1A g 下 300 个循环为 835.8mAh g）和出色的倍率性能（在 10A g 下为 436.7mAh g）。
