Deposition of silver nanoparticles into silicon/carbon composite as a high-performance anode material for Li-ion batteries

Abstract

A silicon/silver/carbon (Si/Ag/C) composite with a core-core-shell structure has been synthesized via a simple method based on pyrolysis of an organic carbon source and silver mirror reaction. The Si and Ag nanoparticles are served as cores, while the porous amorphous carbon layer formed from pyrolysis of citric acid is served as shell. The porous amorphous carbon layer and highly conductive Ag nanoparticles can effectively alleviate the volume change of Si nanoparticles during lithiation/delithiation process and provide sufficient electrical conductivity for Si nanoparticles. As an anode material, the obtained Si/Ag/C composite exhibits excellent electrochemical performances, including high initial coulombic efficiency (85.6 % at 200 mA g −1 ), stable cycling performance (a discharge capacity of 2006.3 mA g −1 at 200 mA g −1 after 100 cycles), and excellent rate performance (a discharge capacity of 826.4 mA h g −1 at 3 A g −1 ). This simple method may open up an effective way to make other anode and cathode materials for commercial lithium-ion battery.

Si/Ag/C Nanohybrids with in Situ Incorporation of Super-Small Silver Nanoparticles: Tiny Amount, Huge Impact

“…43,46 Here, the average size of the as-synthesized silver nanoparticles in this work is significantly reduced to well below 5 nm, which has been rarely used to modify the silicon anode. 29,49,50 By combing the simultaneous in situ synthesis of silver and composition with a carbon matrix, it is possible to incorporate the super-small silver nanoparticles into the Si/C composite homogeneously. 51 The super-small size feature and homogeneous dispersion of the silver nanoparticles significantly improve the performance of Si-based anodes with a tiny amount of silver.…”

“…Besides the poor cyclic stability, the rate performance of Si anodes also needs to be improved. , Si possesses rather low intrinsic electron conductivity because of its semiconductor nature. Various strategies have been developed to resolve these problems including particle size reduction to the nanoscale level, ,, compositing Si with conductive buffer media such as Cu, Ag, and carbonaceous material, ,,− and constructing hierarchical architectures. , Despite of the success of the performance improvement based on the strategies addressed above, the issue of mass loading density of Si has been largely ignored, which is vital for practical applications regarding total energy/power density output. , …”

Improved performances of lithium-ion batteries using intercalated a-Si–Ag thin film layers as electrodes

“…51,52 However, there is no such peak observed during the rst discharge curve corresponding to the potential of SEI layer formation, which is consistent with the results of previous reports. 50,53,54 Although SEI formation may occur, the capacity involved in SEI formation would be very small compared to the high discharge capacity we observed. Therefore, the initial irreversible capacity is not mainly caused by the formation of the SEI layer but possibly by the fracture of the Si lm, and it becomes relatively stable in the subsequent cycles until larger areas of the structures collapse.…”

“…49 The intensities of both cathodic and anodic peaks gradually increase with increased cycling due to the activation processes at the electrodes. 11,50 The formation of a solid electrolyte interface (SEI) layer should occur between 0.5 and 1 V, and it is usually indicated by a peak in the CV data around 0.8 V due to the dissociation of electrolyte. 51,52 However, there is no such peak observed during the rst discharge curve corresponding to the potential of SEI layer formation, which is consistent with the results of previous reports.…”

Si/CNTs@melamine‐formaldehyde resin‐based carbon composites and its improved energy storage performances

“…For the anodic process, two broad peaks at 0.36 and 0.54 V stand for the de‐lithiation reaction of Li x Si to Si. The intensities of all cathodic and anodic peaks increase continuously with cycling which reveals an activation process of Si 40,41 …”