Constructing LiF-Dominated Interphases with Polymer Interwoven Outer Layer Enables Long-Term Cycling of Si Anodes.

Constructing a robust solid electrolyte interphase (SEI) is extremely critical to developing high-energy-density silicon (Si)-based lithium-ion batteries. However, it is still elusive how to accurately manipulate the chemical composition and structure of the SEI layer. Herein, a LiF-dominated SEI film intertwined by a highly elastic polymer is achieved by regulating the defluorination mechanism of the fluorinated carbonate additive on the Si electrode surface. The experimental and computational results confirm that the decomposition route of trans-difluoroethylene carbonate (DFEC) molecules can be significantly altered in the presence of lithium difluoro(oxalato)borate (LiDFOB) additive. The induction of direct defluorination of DFEC step by LiDFOB, as opposed to the breaking of C-O bonds without LiDFOB addition, is crucial in ensuring the exclusive formation of LiF-dominated SEI and maintaining the cyclic structure of DFEC. The defluorinated DFEC easily polymerizes to form poly(vinylene carbonate), enhancing the elasticity of the SEI. The resulting LiF-dominated SEI film with a polymer interwoven outer layer shows enhanced ionic conductivity and mechanical stability, which can effectively accelerate electrode reaction kinetics and maintain the structural stability of the Si electrode. As a result, the Si electrode with the electrolyte containing the designed dual-additive exhibits superior cycling stability and excellent rate performance, delivering a high reversible capacity of 1487.3 mAh g-1 after 1000 cycles at 2 A g-1.

Well-Dispersed Fe Nanoclusters for Effectively Increasing the Initial Coulombic Efficiency of the SiO Anode.

An efficient surface modification strategy is proposed to significantly increase the initial Coulombic efficiency (ICE) of SiO anode material. The SiO@Fe material with the Fe nanocluster homogeneously decorating on the SiO surface is successfully prepared by a chemical vapor deposition process. The well-dispersed Fe nanoclusters realize an Ohmic contact with lithium silicates, the commonly regarded irreversible lithiation product, which effectively lowers the electron conduction barriers and promotes the concomitant lithium-ion release of the lithium silicates upon the delithiation process, increasing the ICE of the SiO anode. The prepared SiO@Fe exhibits a much higher ICE of 87.2% compared to 64.4% of pristine SiO, with the largest increment (23%) never reported, except for the prelithiation, and delivers significantly enhanced cycling and rate performance. These findings provide an effective way to convert the "inert" phase to "active" which essentially increases the ICE of the electrode.

Intron polymorphisms of MAGI-1 and ACSF2 and effects on their expression in different goose breeds.

The goose is one of the most important waterfowl, having lowing laying rate. Previous studies have shown the SNPs in the introns of MAGI-1 (Record-106975) and ACSF2 (Record-106582) significantly associated with egg production in geese. However, the mechanism of those SNPs influencing egg production remains unclear. In this study, the three goose breeds (Yangzhou geese, Zhedong white geese, and Carlos geese) with obviously different egg production were selected, and the allele frequency distribution and functions of those SNPs were investigated. The results suggested that the allele frequency distribution of ACSF2 was significantly different among the three goose breeds (χc2 = 92.377, Pc = 2.29 × 10-22), with the C allele appearing at frequencies of 0.29 in the Yangzhou geese and 0.94 in the Carlos geese. In contrast, the allele frequencies of MAGI-1 were not significantly different among the different goose breeds. Quantitative Reverse Transcription PCR (qRT-PCR) showed that the expression of MAGI-1 with the AG genotype individuals was significantly higher than those of the AA and GG genotype. For ACSF2, the CC genotype had significantly higher expression than both the AC genotype and the AA genotype. The luciferase reporter analysis revealed that the site-directed mutation ACSF2 (A>C) significantly drove the expression activity. Further analysis suggested that the mutation altered the binding site of the transcription factor BARHL2. Binding of BARHL2 to the ACSF2 intron was confirmed by electrophoretic mobility shift assay (EMSA) analysis. Thus, our findings revealed the A>C mutation of ACSF2 (Record-106582) could promote the expression by regulating the binding of BARHL2, resulting in differences in egg performance, which provided molecular insights into the effect of the polymorphism in ACSF2 on egg performance in geese.