Nanostructured Silicon Anodes for High‐Performance Lithium‐Ion Batteries

Abstract

Despite the high theoretical capacity of Si anodes, the electrochemical performance of Si anodes is hampered by severe volume changes during lithiation and delithiation, leading to poor cyclability and eventual electrode failure. Nanostructured silicon and its nanocomposite electrodes could overcome this problem holding back the deployment of Si anodes in lithium‐ion batteries (LIBs) by providing facile strain relaxation, short lithium diffusion distances, enhanced mass transport, and effective electrical contact. Here, the recent progress in nanostructured Si‐based anode materials such as nanoparticles, nanotubes, nanowires, porous Si, and their respective composite materials and fabrication processes in the application of LIBs have been reviewed. The ability of nanostructured Si materials in addressing the above mentioned challenges have been highlighted. Future research directions in the field of nanostructured Si anode materials for LIBs are summarized.

Review—Promises and Challenges of In Situ Transmission Electron Microscopy Electrochemical Techniques in the Studies of Lithium Ion Batteries

“…24,25,41,130,149 Moreover, Si NWs in physical contact can weld together at their junctions by generating strong interfacial bonding after lithiation and delithiation. 41 The fusion at the Si NWs interfaces provides facile Li diffusion between surfacecontacted NWs, and may enable the self-assembly and self-healing of an interconnected network of Si NWs, because the detached NWs can still participate in Li storage after they form a robust interconnected network.…”

“…The detrimental effect of the swelling may be mediated by formation of a coating like nickel (Ni) on silicon nanotubes (SiNTs), Si nanopillars, or yolk-shell-structured Si NPs. 24,51,68,162,163 Using functional Ni coatings or SiO x layers on the outer surface or both inside and outside of the SiNTs, with large hoop stress, the Si expanded inward toward the hollow inner core, instead of expansion outward or much less outward expansion. 162,164 However, Karki, et al, found that electrodes with negligible SiO x layer and significantly higher mass loading exhibit relatively low capacity-retention and faded quickly after early cycles.…”

“…151,157 Intriguingly, incorporation of highly conductive graphene sheets in crystalline Si NPs improved the efficiency of the external voltage/work voltage applied to the electrode, maintaining the integrity of the crystalline Si NPs and the storage capacity even in the process of electrochemical sintering. 24,158 In addition, amorphous Si is an advisable active material, and more favorable in kinetics and in suppressing fracture behavior during lithiation as compared to that of crystalline Si in LIBs. 27,159,160 Crystallization and fracture in lithiated NWs was found to be mitigated by the use of amorphous Si as an anode material.…”

“…Typical reviews recently regarding in situ TEM in electrochemistry primarily focus on imaging of materials evolution in gas-and liquidphase chemical reactions, 22 economic production of graphene and two-dimensional (2D) transition of metal dichalcogenides (TMDCs) as well as their composites, 23 introduction of the advances and challenges of the device itself, 2,7,19 individual anode materials of LIBs such as nanoscale silicon, [24][25][26][27] tin nanoneedles, 21 Si/C hybrid nanostructures, 28 and germanium. 17 Here, we will first introduce the fundamental structure of LIBs and compare them with traditional electrochemical measurements for LIBs, especially in the aspect of quantitatively determining lithium diffusion coefficient (D Li ) on the electrode.…”

Si@SiOx/Graphene Nanosheets Composite: Ball Milling Synthesis and Enhanced Lithium Storage Performance

“…inTrODUcTiOn Lithium-ion batteries have been widely used in consumer electronics, electrical vehicles, and energy storage market (Tarascon and Armand, 2001;Chan et al, 2008;Li et al, 2009;Huang et al, 2013;Rahman et al, 2016). In recent years, lots of efforts have been put in exploring anode materials with higher specific capacities over graphite.…”