Sub‐nanometer structured silicon‐carbon composite nanolayers armoring on graphite for fast‐charging and high‐energy‐density lithium‐ion batteries

Abstract Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithium‐ion batteries (LIBs) because of their high capacity and excellent safety. Nevertheless, the unsatisfactory fast‐charging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development. Here, a novel Si/C anode was fabricated by homogeneously depositing amorphous C‐Si nanolayers on graphite (C‐Si@graphite). C‐Si nanolayers with uniformly dispersed sub‐nanometer Si particles in 3D carbon skeleton significantly boost electron and Li‐ion transport and efficiently relieve Si's agglomeration and volume change. As a result, the tailored C‐Si@graphite electrodes show an excellent rate capacity (760.3 mAh·g −1 at 5.0C) and long cycle life of over 1000 cycles at 1.0C and 800 cycles at 2.0C under industrial electrode conditions. In addition, the assembled full cells (C‐Si@graphite, anode; LiNi 0.8 Co 0.1 Mn 0.1 O 2 , cathode) present superior fast‐charging capability (240.4 Wh·kg −1 , charging for 16.2 min, 3.0C) and long cycle life (80.7% capacity retention after 500 cycles at 1.0C), demonstrating the massive potential of C‐Si@graphite for practical application.