Silicon (Si) has gained huge attention as an anode material for next-generation high-capacity lithium-ion batteries (LIBs). However, despite its overwhelming beneficial features, its large-scale commercialization is hampered due to unavoidable challenges such as colossal volume change during (de)­alloying, inherent low electronic and ionic conductivities, low Coulombic efficiency, unstable/dynamic solid electrolyte interphase (SEI), electrolyte drying and so forth. Among other strategies, the use of a fraction dose of chemical additives is hailed as the most effective, economic and scalable approach to realize Si-anode-based LIBs. Functional additives can modify the nature and chemical composition of the SEI, which in turn dictates the obtainable capacity, rate capability, Coulombic/energy efficiency, safety, and so forth of the battery system. Thus, we report a systematic and comparative investigation of various electrolyte additives, namely tetraethoxysilane (TEOS), (2-cyanoethyl)­triethoxysilane (TEOSCN), vinylene carbonate (VC), fluoroethylene carbonate (FEC), and a blend of TEOSCN, VC, and FEC (i.e., VC/FEC/TEOSCN) using electrochemical analysis, X-ray photoelectron spectroscopy, density functional theory calculation, and differential scanning calorimetry. The ternary mixture (FEC/VC/TEOSCN) results in a thinner SEI layer consisting of high shear modulus SEI-building species (mainly LiF). It also provides much improved thermal stability amid all tested additives, showing its potentiality to enable high capacity and safer Si-based anode LIBs. Thus, nitrile-functionalized silanes are highly promising electrolyte additives to boost the electrochemical performance and safety-induced risks of Si-based anode LIBs, emanating from the formation of a robust SEI layer.

The dosage of (2-cyanoethyl)triethoxysilane (TEOSCN) is investigated as the electrode/electrolyte interface modulating electrolyte additive to improve the performance of LiN0.6Mn0.2Co0.2O2/silicon–graphite batteries at a high temperature (45 °C).

The composition of the liquid electrolyte is a key factor in lifetime performance of lithium-ion batteries. The selection and quantification of additives to the electrolyte is an active field of research. This study focuses on finding the optimal additive combination of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) for NMC622-Graphite cells. The central goal of this work is to accelerate the experimental search in a large search area by using a Bayesian-optimization algorithm to guide the search. Different measurements are used as target variable such as open-circuit voltage gradient and coulombic efficiency. Consequentially, the capability of these measurements for accelerated lifetime prediction compared to conventional ageing tests by cycling is investigated. The search gathered and confirmed additive combinations with excellent performance after four iterations with a total of 15 additive combinations analyzed. The results of this study give insights into the interaction of VC and FEC with regard to ageing.