Chemical Preinsertion of Lithium: An Approach to Improve the Intrinsic Capacity Retention of Bulk Si Anodes for Li-ion Batteries

Abstract

Silicon represents one of the most promising anodes for next-generation Li-ion batteries due to its very high capacity and low electrochemical potential. However, the extremely poor cycling stability caused by the huge volume change during charge/discharge prevents it from the commercial use. In this work, we propose a strategy to decrease the intrinsic volume change of bulk Si-based anodes by preinsertion Li into Si with a chemical reaction. Amorphous Li12Si7 was successfully synthesized by a hydrogen-driven reaction between LiH and Si associated with subsequent energetic ball milling. The as-prepared amorphous Li12Si7 anode exhibits significantly improved lithium storage ability as ∼70.7% of the initial charge capacity is retained after 20 cycles. This finding opens up the possibility to develop bulk Si-based anodes with high capacity, long cycling life and low fabrication cost for Li-ion batteries.

Electrochemical properties of the ternary alloy Li5AlSi2 synthesized by reacting LiH, Al and Si as an anodic material for lithium-ion batteries

“…This fact indicates that the chemically pre-inserted Li in the sample-preparation process were capable of being electrochemically extracted completely. A similar phenomenon was also observed in the LieSi and LieMgeSi systems, as reported previously [27,31]. In addition, it should be mentioned that the first Liextraction capacity delivered by the Li 5 AlSi 2 prepared by the Fig.…”

Nanostructured magnesium silicide Mg2Si and its electrochemical performance as an anode of a lithium ion battery

“…This additional peak is related to the dealloying of the Li-Si alloys [9,35] allowing to reach higher capacities for the eutectic alloy in the VC / FEC containing electrolyte. Cyclic voltammetry response of the as-cast Mg 2 Si and the Si-rich eutectic alloys was measured in the 1M LiPF 6 containing EC/PC/DMC (1:1:3), and is shown in Figure S8 for the first 5 cycles of charge/discharge between 0.02 and 2.00 V versus Li, respectively, at a scan rate of 0.10 mV/s.…”

“…Several studies has been conducted to improve the cyclic stability of Mg-Si system via different methods such as various synthesis techniques which further to the HDR and ball milling also included sputtering [5,8], variations in the Mg-Si composition ratio [8], pre-insertion of Li [9,10], and use of carbon composites/carbon coating [11][12][13].…”

Synthesis temperature dependence of the structural and electrochemical properties of Mg2Si anodic materials prepared via a hydrogen-driven chemical reaction

“…With the ever-increasing energy and environmental problems, Li-ion secondary batteries have a large potential for applications in electric vehicles and intelligent energy storage sectors [1][2][3][4][5][6]. In recent years, magnesium silicide (Mg 2 Si), a promising anodic material, has attracted significant attention due to its favorable voltage profile, high specific capacity, natural abundance, low cost, and environmental compatibility [7][8][9][10][11].…”

“…To solve these problems, we recently demonstrated a facile hydrogen-driven chemical reaction (HDCR) technique for preparing alkali/alkaline earth metal silicides by reacting the corresponding hydrides with silicon [6,17,18]. Such technique effectively avoids the large difference in the melting points of alkali/alkaline earth metals and Si, and achieves the high purities of the resultant products.…”