A chain-like compound of Si@CNT nanostructures and MOF-derived porous carbon as an anode for Li-ion batteries

Abstract

Silicon anodes are considered to have great prospects for use in batteries; however, many of their defects still need to be improved. The preparation of hybrid materials based on porous carbon is one of the effective ways to alleviate the adverse impact resulting from the volume change and the inferior electronic conductivity of a silicon electrode. Herein, a chain-like carbon cluster structure is prepared, in which MOF-derived porous carbon acts as a shell structure to integrally encapsulate Si nanoparticles, and CNTs play a role in connecting carbon shells. Based on the exclusive structure, the carbon shell can accommodate the volume expansion more effectively, and CNTs can improve the overall stability and conductivity. The resulting composite reveals excellent rate capacity and enhanced cycling stability; in particular, a capacity of 732 mA•h•g −1 at 2 A•g −1 is achieved with a reservation rate of 72.3% after cycling 100 times at 1 A•g −1 .

Review of silicon-based alloys for lithium-ion battery anodes

“…(4) Using coating layer materials with enhanced mechanical properties and high electronic and ionic conduct-ivity. The aim of this approach is to maintain the morphology and avoid the fracture of the active material [40][41][42]. The protective coating layer can not only prevent direct contact between the electrolyte and Si but also function as a conductive material to provide channels for the rapid transport of electrons and ions, thereby improving the structural stability of SEI films and the rate property of the battery.…”

“…The protective coating layer can not only prevent direct contact between the electrolyte and Si but also function as a conductive material to provide channels for the rapid transport of electrons and ions, thereby improving the structural stability of SEI films and the rate property of the battery. ( 5) Translating bulk Si into nanoscale materials [41,[43][44][45][46], including Si nanoparticles (NPs), nanowires and nanoarrays, and nanotubes. Previous papers showed that nanomaterials have "size-dependent" effects and that different dimensional materials have different critical diameters [7,[47][48][49].…”

Carbon-based materials and their composites as anodes: A review on lithium-ion batteries

“…To prepare Si/CNT composite, the in-situ growth of CNTs via the CVD method has mostly been used [122][123][124]. In one research, CNTs were directly grown onto the surface of fine Si nanoparticles using the CVD method [125].…”

Recent Applications of Molecular Structures at Silicon Anode Interfaces

“…The resin and the MOF formed double carbon coating, which helped to deliver reversible capacities of 1107 mAh g −1 at 0.5 A g −1 after 100 cycles and 852 mAh g −1 at 1 A g −1 over 300 cycles. Qiao et al reported the decoration of Si nanoparticles with CNTs, which assisted their subsequent encapsulation in ZIF-67 [55,56]. After pyrolysis, the obtained Si@CNTs@c-ZIF composite delivered a capacity of 568.8 mAh g −1 at 1 A g −1 after 200 cycles (60.1% retention) [55].…”