Crystalline/Non-Crystalline Carbon Co-Modified Strategy to Construct N, S Co-Doped Carbon Layer Wrapped Fe0.95S1.05/Carbon Nanotubes for Enhanced Lithium Storage Property

Due to their high theoretical capacity and abundant resources, transition metal sulfides are regarded as a prospering alternative to replace the commercial graphite anode in lithium-ion batteries (LIBs), particularly for large-scale energy storage and conversion applications. Nonetheless, low conductivity, easy agglomeration and obvious volume change greatly impede their practical application. In this work, a novel crystalline/non-crystalline carbon co-modified strategy is proposed to fabricate N, S co-doped carbon (NSC) layer wrapped Fe0.95S1.05/carbon nanotubes (CNTs) composite (Fe0.95S1.05/CNTs@NSC) through a simple Fenton reaction followed by a sulfurization process. Systematical characterizations and analyses reveal that this strategy well combines the advantages of crystalline CNTs and non-crystalline NSC, ensuring good conductivity and a high contribution to capacity from the carbon matrix. Meanwhile, the joint encapsulation of Fe0.95S1.05 by both CNTs and NSC can significantly mitigate the agglomeration and volume change of Fe0.95S1.05 during the continuous charge/discharge process. Benefiting from these advantageous features, the resultant Fe0.95S1.05/CNTs@NSC composite displays much improved cycling stability and rate capability when compared to the counterparts. Clearly, our research offers a distinct and innovative approach to design and construct advanced transition metal sulfides/carbon composite anodes for LIBs.