The development of lithium metal anodes for next-generation batteries hinges on overcoming two critical challenges: the instability of the solid electrolyte interphase (SEI) during dynamic plating/stripping cycles and susceptibility to environmental degradation. Conventional SEI layers are inherently brittle, leading to crack formation under mechanical stress from volume changes, which triggers continuous electrolyte decomposition and irreversible lithium consumption. Furthermore, lithium metal rapidly deteriorates upon exposure to air, forming electrically insulating byproducts that hinder ion transport and render the electrode inactive.
To address these issues, this study presents a novel interfacial engineering strategy based on silane coupling agent modification using 3-methacryloxypropyltrimethoxysilane (MPS). The process begins with immersing commercial lithium foil in a 5% MPS solution in tetrahydrofuran (THF) for 30 minutes. During this step, the alkoxy groups of MPS react spontaneously with surface LiOH—naturally present due to air exposure—to form covalent LiOSi bonds.SPIB Antibody References Subsequent thermal treatment at 100 °C promotes condensation of silanol groups, creating a cross-linked, dense, and stable organic-inorganic hybrid layer approximately 320 nm thick.
Comprehensive characterization confirms the structural integrity and chemical bonding of the modified layer. X-ray photoelectron spectroscopy (XPS) reveals distinct Si 2p peaks at 101.6 eV (LiOSi), 102.6 eV (OSiC), and 103.8 eV (OSiO), indicating successful grafting. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) detects characteristic ions such as LiOSi⁺ (m/z = 51), (LiO)₂Si⁺ (m/z = 74), and (LiO)₃Si⁺ (m/z = 97), providing direct evidence of strong chemical bonding between the MPS layer and the lithium substrate. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) show a uniform, crack-free morphology without aggregation, confirming the homogeneity of the coating.Phospho-Chk1 Antibody Autophagy
Electrochemical evaluation demonstrates exceptional performance. Symmetric MPS-Li||MPS-Li cells exhibit stable cycling for over 1400 h at 1 mA cm⁻² and 600 h at 3 mA cm⁻², with minimal voltage fluctuation and no micro-short circuiting. In contrast, pristine Li||Li cells fail within 70 hours at 3 mA cm⁻² due to dendrite-induced internal shorting.PMID:34802048 Morphological analysis after 100 cycles shows that cycled MPS-Li maintains a smooth, compact surface with closely packed grains, while unmodified Li develops porous, fragmented structures indicative of severe SEI fracture and dead lithium accumulation.
Full-cell testing further validates the approach. The MPS-Li||LiFePO₄ cell delivers 122 mAh g⁻¹ after 300 cycles at 1 C under high cathode loading (12 mg cm⁻²) and limited electrolyte (3 μL mg⁻¹), significantly outperforming the reference cell. Similarly, the MPS-Li||S cell retains 652 mAh g⁻¹ after 300 cycles at 0.2 C, compared to 482 mAh g⁻¹ for the control. These results underscore the effectiveness of the MPS layer in suppressing side reactions and stabilizing the interface.
Notably, the modified electrode exhibits superior air stability. After 2 hours of exposure to ambient air (30% humidity), MPS-Li retains 88.1% of its theoretical capacity, whereas untreated lithium becomes electrochemically inert. EIS data reveal only a modest increase in charge transfer resistance for air-exposed MPS-Li, while the resistance of unmodified lithium skyrockets, rendering it unusable in full cells. Even when used directly in batteries after air exposure, MPS-Li-based cells maintain excellent cycling performance.
This work highlights the dual functionality of silane coupling agents: they not only reinforce the SEI layer through strong interfacial adhesion but also act as a physical barrier against environmental attack. By integrating chemical bonding and physical entanglement mechanisms, the MPS layer enables uniform lithium deposition, suppresses dendrites, and extends cycle life. The simplicity, low cost, and compatibility with industrial processes make this approach highly promising for practical deployment in advanced lithium metal batteries.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com