Revisiting the Preparation Progress of Nano‐Structured Si Anodes toward Industrial Application from the Perspective of Cost and Scalability

Abstract

The urgent demand for lithium ion batteries with high energy density is driving the increasing research interest in Si, which possesses an ultrahigh theoretical capacity. Though various modification strategies have been proposed from the aspects of electrolytes, binders, Si‐M alloys, and Si/C composites, the preparation of nano‐structured Si is the first step for industrial application, since it has the potential solve the intrinsic problem of severe volume change during the lithiation/delithiation process. A series of Si nanostructures including 0D (nanoparticles), 1D (nanowires, nanotubes), 2D (thin film), and 3D (porous structure) have been developed and displayed encouraging results. However, it remains a great challenge to realize industrial production with acceptable cost and batch stability. In this review, the preparation development of nano‐structured Si is revisited. After briefly introducing the market situation for nanostructured Si, the fabrication of various kinds of nanostructure Si are introduced, and the corresponding progress including ball milling, magnesium thermal reduction, temple method, chemical vapor deposition, and chemical etching are comprehensively reexamined and compared from the perspective of mechanism, cost, technical maturity, and recent development. Finally, the further directions of nano‐structured Si preparation toward industrial production are deeply discussed. This review of preparation of nanostructured Si helps to pave the way toward commercial application of high energy density Si‐anodes.

Revisit the Progress of Binders for a Silicon-Based Anode from the Perspective of Designed Binder Structure and Special Sized Silicon Nanoparticles

“…7−9 Therefore, silicon has been widely considered as an alternative to graphite for next-generation LIBs. 10,11 When silicon is used as the anode of LIBs, one silicon atom can be alloyed with 4.4 lithium atoms, which shows a capacity 10 times higher than that of graphite in theoretical capacity. 12 Besides, the low operating potential of about 0.2 V vs Li/Li + is also a significant advantage.…”

“…Graphite is the mainstream anode material in the market, and its energy density potential has been fully exploited to about 360 mA h g –1 (372 mA h g –1 for the theoretical specific capacity), which could not meet the demand of a power battery. Plenty of elements, alloys, and oxides were found to be applied as anode materials to replace graphite to give a higher capacity. − Compared with Sn, Ge, and Ga, silicon-based anode material is outstanding in energy density. − Therefore, silicon has been widely considered as an alternative to graphite for next-generation LIBs. , When silicon is used as the anode of LIBs, one silicon atom can be alloyed with 4.4 lithium atoms, which shows a capacity 10 times higher than that of graphite in theoretical capacity . Besides, the low operating potential of about 0.2 V vs Li/Li + is also a significant advantage .…”

“…A number of efforts have been devoted to settle the critical issues mentioned above. The developed strategies include utilizing nanoscale morphologies, compositing with a stress-relief buffer matrix, and constructing a physical compartment to minimize electrode pulverization and capacity loss in silicon anodes. ,− In addition, modifying silicon from the perspective of inactive materials is also an effective way to improve the performance of a battery. Binders have been proven to be a component of a battery which could bring significant improvement in battery performance with low cost over the past decades.…”

Advances of Synthesis Methods for Porous Silicon-Based Anode Materials

“…To address the issues associated with Si, especially volume expansion, massive efforts have been made, including: avoiding materials pulverization via the design of silicon nanostructures, ( An et al, 2020 ; Qi et al, 2020 ; Sun et al, 2022a ; Sun et al, 2022b ; Li et al, 2022 ) improving cycling stability through SiO/SiO x -based anode materials, ( Wang et al, 2020a ; Tian et al, 2022 ) and increasing electronic/ionic conductivities through utilizing advanced electrolyte additives and novel binders. ( Huang et al, 2019 ; Zhao et al, 2021 ; Zhou et al, 2021 ; Zhu et al, 2021 ) The 3D porous Si-based materials have enough internal voids to accommodate volume expansion due to the existence of their large pores, so that their structures can maintain their integrity during the processes of lithiation/delithiation, avoiding pulverization of silicon-based materials.…”

Three-Dimensional Monolithically Self-Grown Metal Oxide Highly Dense Nanonetworks as Free-Standing High-Capacity Anodes for Lithium-Ion Batteries

“…Furthermore, most reported strategies are based on complex, costly, and low-content active material composite anodes, thus limiting their real-world applicability. − As such, attempts at commercializing pristine silicon anodes were unsuccessful thus far, which is only possible by embedding silicon into carbon-based matrices. Several C@Si anode materials are already in circulation; however, the low amount of silicon has greatly affected their capacities, which range between 400 and 1000 mA h/g …”