Xia Yuan, Zhao Tiancong, Zhu Xiaohang, Zhao Yujuan, He Haili, Hung Chin-Te, Zhang Xingmiao, Chen Yan, Tang Xinlei, Wang Jinxiu, Li Wei, Zhao Dongyuan
Department of Chemistry, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, and Laboratory of Advanced Materials, Fudan University, Shanghai, P. R. China.
Nat Commun. 2021 May 20;12(1):2973. doi: 10.1038/s41467-021-23150-8.
The gradient-structure is ideal nanostructure for conversion-type anodes with drastic volume change. Here, we demonstrate an inorganic-organic competitive coating strategy for constructing gradient-structured ferroferric oxide-carbon nanospheres, in which the deposition of ferroferric oxide nanoparticles and polymerization of carbonaceous species are competitive and well controlled by the reaction thermodynamics. The synthesized gradient-structure with a uniform size of 420 nm consists of the ferroferric oxide nanoparticles (4-8 nm) in carbon matrix, which are aggregated into the inner layer (15 nm) with high-to-low component distribution from inside to out, and an amorphous carbon layer (~20 nm). As an anode material, the volume change of the gradient-structured ferroferric oxide-carbon nanospheres can be limited to ~22% with ~7% radial expansion, thus resulting in stable reversible specific capacities of ~750 mAh g after ultra-long cycling of 10,000 cycles under ultra-fast rate of 10 A g. This unique inorganic-organic competitive coating strategy bring inspiration for nanostructure design of functional materials in energy storage.
对于具有剧烈体积变化的转换型阳极而言，梯度结构是理想的纳米结构。在此，我们展示了一种用于构建梯度结构的四氧化三铁-碳纳米球的无机-有机竞争包覆策略，其中四氧化三铁纳米颗粒的沉积和含碳物质的聚合是竞争性的，并且通过反应热力学得到了很好的控制。合成的尺寸均匀约为420 nm的梯度结构由碳基质中的四氧化三铁纳米颗粒（4-8 nm）组成，这些纳米颗粒聚集在内层（约15 nm），其成分从内到外呈高到低分布，还有一层非晶碳层（约20 nm）。作为阳极材料，梯度结构的四氧化三铁-碳纳米球的体积变化可限制在约22%，径向膨胀约7%，因此在10 A g的超快速率下进行10000次超长循环后，可实现约750 mAh g的稳定可逆比容量。这种独特的无机-有机竞争包覆策略为储能功能材料的纳米结构设计带来了启发。
