Abstract
We present a strategic approach to improve the cycle performance of a polymeric binder-free anode based on nano-Si@C microspheres by incorporating a multiwalled carbon nanotubes (MW-CNTs) network and performing carbodiimide-based condensation coupling to form a robust molecular-junction between MW-CNTs and nano-Si@C microspheres. Field-emission scanning electron microscopy reveals that one-dimensional MW-CNTs homogeneously wrapped the individual Si@C microspheres and they interwove through the intergranular nanospace. The incorporation of amide bonds at the junction primarily contributes to the stabilization and reinforcement of the hybrid electrodes. Their reversible capacity after 50 cycles with 0.5 A g−1 was significantly improved from 81 mAh·g−1 to 520 mAh·g−1. Such robustness associated with the supramolecularly assembled MW-CNTs is expected to facilitate electron conductivity and mass transfer kinetics, leading to enhanced electrochemical performance of the Si@C anode.
Highlights
We present a strategic approach to improve the cycle performance of a polymeric binder-free anode based on nano-Si crystals embedded in a carbon microsphere (Si@C) microspheres by incorporating a multiwalled carbon nanotubes (MW-CNTs) network and performing carbodiimide-based condensation coupling to form a robust molecularjunction between MW-CNTs and nano-Si@C microspheres
We proposed a new strategic approach based on a supramolecularly assembled cathode composed of multiwalled carbon nanotubes (MW-CNTs) and LiNi0.5Co0.2Mn0.3O2 (NCM523) for achieving both high rate capability and stable cycling characteristics at a high tapped density of 3.8 g cm−3 21,22
The hybrid of MW-CNTs and Si@C microspheres was prepared in three steps by solution processes, as shown in Scheme 1
Summary
We present a strategic approach to improve the cycle performance of a polymeric binder-free anode based on nano-Si@C microspheres by incorporating a multiwalled carbon nanotubes (MW-CNTs) network and performing carbodiimide-based condensation coupling to form a robust molecularjunction between MW-CNTs and nano-Si@C microspheres. The incorporation of amide bonds at the junction primarily contributes to the stabilization and reinforcement of the hybrid electrodes Their reversible capacity after 50 cycles with 0.5 A g−1 was significantly improved from 81 mAh·g−1 to 520 mAh·g−1. Si anode suffers from massive volume changes during cycling, which results in the pulverization of the active materials of the anode and loss of electrical components Such a huge volume change of the anode causes breakdown and subsequent reformation of the solid electrolyte interface (SEI) layer. Composites of Si with carbonaceous materials (e.g., graphene, graphite, and carbon nanotubes etc.) have attracted much attention, because the carbon materials contribute the physical constrain for volume expansion via covering the silicon crystals It delivers the decreasing an internal resistance in the electrode via large area direct contact with Si crystal surface[17,18,19]. The adhesion between the Si particles and polymeric binders is not still sufficiently strong for the fixation of Si particles via physisorption, leading to the detachment of the coating and capacity fading upon cycling
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
