Silicon-based nanomaterials for lithium-ion batteries

Abstract

Silicon-based nanomaterials have been of scientific and commercial interest in lithium-ion batteries due to the low cost, low toxicity, and high specific capacity with an order of magnitude beyond that of conventional graphite. The poor capacity retention, caused by pulverization of Si during cycling, triggers researchers and engineers to explore better battery materials. This review summarizes recent work in improving Si-based anode materials via different approaches from diverse Si nanostructures, Si/metal nanocomposites, to Si/C nanocomposites, and also offers perspectives of the Si-based anode materials. Lithium ion batteries (LIBs) as attractive energy storage devices have become ubiquitous power sources for mobile electronics. Increasing power and energy requirements for applications such as electric and hybrid electric vehicles, have spurred intense interest in developing high capacity electrode materials to surpass the capacities of electrode materials used in current LIBs [17]. To achieve the requirements, much research work has been performed on new anode materials with high specific capacities. Silicon has attracted increasing attention as a potential high-capacity anode material because of numerous appealing features such as high theoretical specific capacity of 4212 mAh g -1 , higher safety and stability than graphite (lithiated silicon is more stable in typical electrolytes than lithiated graphite). Si anode materials, however, suffer from some drawbacks involving the drastic volume change (larger than 300%) during the alloying/de-alloying reactions with Li [8], the intrinsic low electrical conductivity, and the unstable solid electrolyte interphase (SEI) formed in the common electrolyte of LiPF 6 . These limitations still challenge the investigation and development on identification of higher capacity for the next generation LIBs. Various advances in Si morphology have been achieved in the past years, demonstrating that nanostructured Si-based materials particularly offer superior properties in LIBs.In this review, we address the recent developments in optimizing Si-based materials via diverse Si nanostructures, Si/metal nanocomposites, and Si/C nanocomposites. In addition, we offer some perspectives for the design of better Si nanomaterials.

Nanostructured Silicon Anodes for High‐Performance Lithium‐Ion Batteries

“…Moreover, the discharge potential of Si anode is about 0.2 V with respect to Li/Li + , which is lower than most of the other alloy‐type and metal oxides anodes . Furthermore, lithiated Si is claimed to have higher safety compared to graphite and greater chemical stability in a wide range of electrolytes when compared to graphite …”

Nanoparticles Engineering for Lithium‐Ion Batteries

“…The impressive electrochemical performance can be attributed to the self‐assembling system of HF‐etched Si nanoparticles, GO, and ethanol solution. The resultant binder‐free electrode of Si/GNSs has the following merits: i) The Si nanoparticles are well dispersed in the GNS’ networks (Figure b), which can prevent the Si nanoparticles from agglomerating into larger particles vulnerable to fracture and pulverization during cycling . ii) The GNSs can enhance the electronic conductivity of the composite electrode.…”

“…The resultant binder-free electrode of Si/GNSs has the following merits: i) The Si nanoparticles are well dispersed in the GNS' networks (Figure 4 b), which can prevent the Si nanoparticles from agglomerating into larger particles vulnerable to fracture and pulverization during cycling. [ 52 ] ii) The GNSs can enhance the electronic conductivity of the composite electrode. iii) The void spaces between Si nanoparticles can facilitate the Li ion diffusion (Figure 4 c).…”

Employing MXene as a matrix for loading amorphous Si generated upon lithiation towards enhanced lithium-ion storage

“…Significant progresses have been made to addressing the issues mentioned above. For instance, Si materials are designed with nanostructures [9,10] , porous structures [11] , or nanocomposites [12] , Si electrodes are designed via combining nano/micro particles or with 3D microchannels [13] , addition of electrolyte additives, and utilizing 2D materials constructs an electrode structure [14,15] . Facile ion transport, superior electrical conductivity, and sustained structural integrity were achieved to some extent [16] .…”