Silicon monoxide (SiO), with its high specific capacity and low discharge voltage plateau, stands out as a promising anode material for high-energy lithium-ion batteries. However, the application of SiO anodes suffers from an inferior initial Coulombic efficiency (ICE), the instability of the solid electrolyte interface (SEI) layer, and inferior Li+ transport kinetics, leading to unsatisfactory cycling stability and rate capability. Herein, a LiF/Sn–Li hybrid SEI layer is in situ constructed on chemically prelithiated SiO by spontaneous reaction with SnF2 (SnF2–SiO), driven by the redox potential difference between SnF2 and Li, which induces the reductive decomposition of SnF2 and interfacial chemical transformation. Chemical prelithiation compensates for irreversible lithium loss by introducing additional active lithium, thereby enhancing the ICE of the SiO anodes. Notably, the cooperative effect of LiF and Sn–Li alloy stabilizes the electrochemical interface, enhances Li+ diffusion kinetics, and reduces charge transfer resistance. As expected, the SnF2–SiO delivers a remarkable ICE (99.7%) and cycling stability (1126.0 mAh g–1 after 200 cycles), together with superior overall performance for lithium-ion full batteries (SnF2–SiO//LiFePO4). This work confirms the significance of chemical prelithiation and regulation of the hybrid SEI layer for advancing silicon-based anodes in high-performance lithium batteries.
Hao Liu,Yaji Huang,Huikang Song,Tianhang Tang,Hao Shi,Lang Kai,Chenlu Yang
A novel pathway for the co-disposal of municipal solid waste incineration fly ash (MFA) and bottom slag (BS) with waste glass (WG) was proposed. Combined melting experiments and theoretical calculation were employed, which revealed the structural evolution of the CaO-Fe₂O₃-SiO₂ system and the underlying mechanisms of heavy metal immobilization. It was demonstrated that stable glassy products were obtained within a CaO/(Fe₂O₃+SiO₂) mass ratio ( M C / ( SF ) ) range of 0.13~0.41. The leaching concentrations of heavy metals in these vitrified products were suppressed to the relevant regulatory standards. With an increasing M C / ( SF ) , the glass network became more depolymerized, as evidenced by a higher population of low-connectivity Qⁿ units in the structure. However, under Fe₂O₃-enriched system, the Fe coordination shifted from solely tetrahedral [FeO₄] towards a mixed tetrahedral/octahedral environment. Moreover, Pb and Cd were incorporated into the glass matrix via interstitial doping. The depolymerized network dominated by CaO favored the Pb enrichment. Cd tended to be stabilized in the Fe-rich structure, facilitated by the formation of highly localized Cd-O bonds. This study elucidated the coupling effects of oxide composition on glass structure and heavy metal immobilization behavior, providing a fundamental theoretical basis for understanding and optimizing the vitrification process for solid waste treatment.
For Bi x Sb 2− x Te 3 (BST) in thermoelectric field, the element ratio is easily influenced by the chemical environment, deviating from the stoichiometric ratio and giving rise to various intrinsic defects. In P-type polycrystalline BST, Sb Te and Bi Te are the primary forms of defects. Defect engineering is a crucial strategy for optimizing the electrical transport performance of Bi 2 Te 3 -based materials, but achieving synchronous improvement of thermal performance is challenging. In this study, mesoporous SiO 2 is utilized to successfully mitigate the adverse impacts of vacancy defects, resulting in an enhancement of the electrical transport performance and a pronounced reduction in thermal conductivity. Crystal and the microstructure of the continuous modulation contribute to the effective phonon–electronic decoupling. Ultimately, the peak zT of Bi 0.4 Sb 1.6 Te 3 /0.8 wt% SiO 2 (with a pore size of 4 nm) nanocomposites reaches as high as 1.5 at 348 K, and a thermoelectric conversion efficiency of 6.6% is achieved at Δ T = 222.7 K. These results present exciting possibilities for the realization of defect regulation in porous materials and hold reference significance for other material systems.
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