The yolk-shell structure of Si@void@C anode for lithium ion batteries with Chito-oligosaccharide (COS) as carbon and nitrogen source was successfully prepared by using a newly designed method. As a low-molecular-weight precursor, COS is completely soluble in an aqueous solution to make the composite more homogeneous. The COS derived carbon has a higher porosity than macromolecules derived carbon, providing reliable channels for ions to shuttle. In addition, amino groups from COS effectually promote the wettability of electrode interface. For the yolk-shell structure of Si@void@C composite, the outer carbon shell is not only conducive to the rapid transmission of electrons and lithium ions, but also to the reduction of charge transfer resistance and effective protection of the silicon core ball from electrolyte corrosion. Furthermore, the void layer between silicon core and carbon shell can adapt to huge volume expansion of Si and stabilize the electrode structure. Therefore, Si@void@C exhibits superior cycle stability and high rate performance. At a current density of 420 mA g⁻¹, after 200 cycles, the Si@void@C maintains a high capacity of 1038.5 mAh g⁻¹. In this experiment, the innovative synthesis of a unique yolk-shell structure of Si@C composites is an effective way to obtain high-performance anode materials.

采用一种新设计的方法，成功制备了以壳寡糖（COS）为碳氮源的锂离子电池Si @ void @ C阳极的卵黄结构。作为低分子量的前体，COS完全溶于水溶液，使复合材料更均匀。COS衍生的碳比大分子衍生的碳具有更高的孔隙率，为离子穿梭提供了可靠的通道。另外，来自COS的氨基有效地促进了电极界面的润湿性。对于Si @ void @ C复合材料的卵黄壳结构，碳壳的外层不仅有利于电子和锂离子的快速传输，而且有助于降低电荷转移阻力并有效保护硅核球免受电解液腐蚀。此外，硅核和碳壳之间的空隙层可以适应硅的巨大体积膨胀并稳定电极结构。因此，Si @ void @ C具有优异的循环稳定性和高倍率性能。在420 mA g的电流密度下^-1，经过200次循环后，Si @ void @ C保持1038.5 mAh g ^-1的高容量。在该实验中，创新的Si @ C复合材料独特的卵黄壳结构合成是获得高性能阳极材料的有效方法。