Highly stable multi-layered silicon-intercalated graphene anodes for lithium-ion batteries

Abstract

Abstract

Hierarchically structured silicon/graphene composites wrapped by interconnected carbon nanotube branches for lithium‐ion battery anodes

“…This is further verified by the decrease in the intensities of OC=O and C=O peaks (Figure 3E), indicating the reduction of GO into rGO after CVD process. In particular, a clear peak at 282.4 eV confirms the formation of CSi bond which is further supported by the peak of Si 2p spectrum at 100.6 eV 29,37,38 . This chemical bond of CNT@NiNP@Si/rGO allows Si particles to be tightly interconnected with CNT and rGO conducting networks for the improved electronic conduction and buffering to sustain volume expansion/contraction.…”

“…The characteristic Si peak is shown at 520 cm −1 , which indicates that crystalline Si remains intact after the synthesis process. Another peak, which is not visible in Si, is captured at 969.8 cm −1 for CNT@NiNP@Si/rGO indicating the SiC bond 29‐31 . Furthermore, the two prominent peaks at 1,345 and 1,595 cm −1 are associated with the defect induced D band and the sp 2 hybridized G band of carbon, respectively.…”

“…Another peak, which is not visible in Si, is captured at 969.8 cm À1 for CNT@NiNP@Si/rGO indicating the Si C bond. [29][30][31] Furthermore, the two prominent peaks at 1,345 and 1,595 cm À1 are associated with the defect induced D band and the sp 2 hybridized G band of carbon, respectively. Considering that the intensity ratio of D to G band (I d /I g ) is an indicator of determining the degree of disorderness of the carbon, 32,33 the higher I d /I g value of CNT@NiNP@Si/rGO (1.07) compared to those of GO (0.99), and CNT@NiNP@rGO (0.98) indicates the increase in the disorderness during the CVD process due to the incorporation of Si microparticles.…”

Nanostructured Graphene Oxide-Based Hybrids as Anodes for Lithium-Ion Batteries

“…It was shown that the particle morphology, specific surface area, and architecture of hybrids are the key issues optimizing the electrochemical performance. For example, Kim et al have recently prepared a 2D multi-layered Si/rGO hybrid anode by direct growth of Si intercalated into a porous multi-layered rGO film, in which the porous rGO network acts as a cushion against the expansion of the Si layer during lithiation [101]. The templated self-assembly (TSA) strategy seems to be another efficient way for the preparation of Si/rGO composite [102][103][104][105].…”

Ultrathin 5 μm Thick Silicon Nanowires Intercalated with Reduced Graphene Oxide Binderless Anode for Lithium-Ion Batteries

“…Si undergoes a 300% volume change when lithiated, causing significant stress on the surrounding media that may produce fracturing after delithiation if not properly contained. , A common solution to the volume expansion of Si is to use graphite (Grt), which has a low volume expansion, with a binder to increase the intermolecular entanglement, resulting in good mechanical and electrochemical stability in the LIBs. , Without a binder to increase the internal adhesion of the anode, the damage from Si volume expansion severely cripples the cycle lifetime. , This can be attributed to the starting materials used to create binderless anodes. The use of graphene oxide flakes (GOFs) and reduced graphene oxide flakes (rGOFs) limits the anode’s structural adhesion and increases the thickness due to the inefficient packing, irreversible staking, and agglomeration caused by π–π stacking interactions and van der Waals forces. − The aggregation of flakes limits the minimum usable thickness and the relative amount of Si loading to synthesize their anodes, resulting in anodes of thicknesses from tens to hundreds of microns and reduced conductivities. ,− …”