Si@C Core-Shell Nanostructure-Based Anode for Li-Ion Transport

Silicon-based anode materials are gaining popularityin lithium-ionbattery research due to their high theoretical specific capacity comparedto the conventional graphite anode. However, the commercializationof silicon-based anode materials has been hampered by their limitedelectronic conductivity and significant volume expansion. To addressthese challenges, our strategy was conducted to prepare porous silicon@carbon(p-Si@C) nanocomposites as an anode material using a simple aqueoussolution method. In this work, nitrogen-containing p-phenylenediamine was chosen as the carbon source for synthesizingthe nanostructured p-Si@C composites. The excellent electrochemicalperformance can be achieved, with over 100 cycles, a specific capacityof 624 mAh g(-1), and a high Coulombic efficiencyof 97.2%. These promising results were attributed to efficient Li-iontransport and low volume expansion, which are confirmed by the distributionfunction of relaxation time plots coupled with impedance spectroscopytechnique, followed by the calculation of the expansion rate obtainedfrom the SEM cross-sectional image. Hence, our work not only clearlyprovides a simple yet valuable method for the preparation of nanostructuredsilicon-based anode material with good electrochemical performancebut also demonstrates its potential for industrial battery-grade development.