Macroporous Directed and Interconnected Carbon Architectures Endow Amorphous Silicon Nanodots as Low-Strain and Fast-Charging Anode for Lithium-Ion Batteries

Abstract Fabricating low-strain and fast-charging silicon-carbon composite anodes is highly desired but remains a huge challenge for lithium-ion batteries. Herein, we report a unique silicon-carbon composite fabricated by uniformly dispersing amorphous Si nanodots (SiNDs) in carbon nanospheres (SiNDs/C) that are welded on the wall of the macroporous carbon framework (MPCF) by vertical graphene (VG), labeled as MPCF@VG@SiNDs/C. The high dispersity and amorphous features of ultrasmall SiNDs (~ 0.7 nm), the flexible and directed electron/Li + transport channels of VG, and the MPCF impart the MPCF@VG@SiNDs/C more lithium storage sites, rapid Li + transport path, and unique low-strain property during Li + storage. Consequently, the MPCF@VG@SiNDs/C exhibits high cycle stability (1301.4 mAh g −1 at 1 A g −1 after 1000 cycles without apparent decay) and high rate capacity (910.3 mAh g −1 , 20 A g −1 ) in half cells based on industrial electrode standards. The assembled pouch full cell delivers a high energy density (1694.0 Wh L −1 ; 602.8 Wh kg −1 ) and an excellent fast-charging capability (498.5 Wh kg −1 , charging for 16.8 min at 3 C). This study opens new possibilities for preparing advanced silicon-carbon composite anodes for practical applications.