Silicon-Containing Anodes for High-Energy Density Lithium-Ion Batteries
Authors: Eshetu Gebrekidan Gebresilassie , Zhang Heng , Judez Xabier , Adenusi Henry , Armand Michel , Passerini Stefano , Figgemeier Egbert 
Published: September 2023

Next- Generation Lithium(Li)-based rechargeable battery technologies utilising silicon (Si) and Si-containing (Si/Gr, SiOx/Gr, SiNx etc.) anodes coupled with high-capacity/high-voltage insertion-type cathodes (IC) have gained significant attention from both academic and industrial sectors.1 This originates from their practically achievable high energy density, offering a new possibility towards the large-scale espousal of electric vehicles and effective integration of renewable energy sources. In pursuit of designing such high-energy-density electrical energy storage devices, the anode compartment plays huge role and has accordingly reaped increasing interest. In this regards, Si and Si-containing materials are considered to be the most promising choices to replace state-of-the-art graphite in the construction of Lithium-ion batteries (LIBs). This is attributed to their unparalleled high theoretical capacity, suitable operating voltage, natural abundance, environmental benignity, nontoxicity, high safety, and so forth.

However, Si and Si-containing materials are endowed with their own advantages and inherent shortcomings. Colossal volume change, much lower diffusivity (σe-+ and DLi+), unstable and fragile solid electrolyte interphase (SEI) formation, electrode swelling, and electrolyte drying are among the most impending intrinsic challenges that hider the large-scale commercialization of such innovative materials. Moreover, the detailed storage mechanism, electrochemistry, failure mechanism and impact of each component in case of blended/composite anode materials (e.g., Si/Gr and SiOX/Gr) etc. remain to be key loopholes to fully understand and thus enable the systems.

In this paper, accounts on the various Si-containing active materials (Si, SiOx, Si/Gr blend/composite, SiOx/Gr blend/composite, SiNx etc) including their pros and cons, recent progresses, detailed storage chemistries and mechanisms, characteristics, possible tailored remedies to evade their challenges and thus improving performances - in hope of facilitating their large-scale deployment in the market, and future prospects and research directions will be presented. Impact of atomic level peculiar properties on the material and battery cells level key performance matrices are thoroughly examined. Moreover, the specific energy (Eg) and energy (Ev) density of various insertion-type cathode materials as a function of a) the weight fraction of Si at a fixed areal capacity, b) areal capacity at various Si contents, c) various kinds of electrolytes (liquid, polymer, glass and ceramic) at a fixed areal capacity, and d) electrolyte thickness are evaluated and analyzed.

The approach presented in this paper will spur new concepts and perspectives into the best use of Silicon (Si) and Si-containing anode materials for the development Next-Generation high-energy density LIBs.

1Eshetu, G. G.; Zhang, H.; Judez, X.; Adenusi, H.; Armand, M.; Passerini, S.; Figgemeier, E, “Gebrekidan Gebresilassie Eshetu, Heng Zhang, Xabier Judez, Henry Adenusi, Michel Armand, Stefano Passerini, & Egbert Figgemeier, “Production of high-energy Li-ion batteries comprising silicon-containing anodes and insertion-type cathodes.” Nat. Commun. 2021, 12 (1), 1–14.