RESUMO
Lithium (Li) metal is considered as a promising anode candidate for high-energy-density batteries. However, the high reactivity of Li metal leads to poor air stability, limiting its practical application. Additionally, the interfacial instability, such as dendrite growth and an unstable solid electrolyte interphase layer, further complicates its utilization. Herein, a dense lithium fluoride (LiF)-rich interfacial protective layer is constructed on the Li surface through a simple reaction between Li and fluoroethylene carbonate (denoted as LiF@Li). The LiF-rich interfacial protective layer consists of both organic (ROCO2Li and C-F-containing species, which only exist on the outer layer) and inorganic (LiF and Li2CO3, distribute throughout the layer) components with a thickness of â¼120 nm. Specifically, chemically stable LiF and Li2CO3 play an important role in blocking air and hence improve the air durability of LiF@Li anodes. Notably, LiF with high Li+ diffusivity facilitates uniform Li+ deposition, while organic components with high flexibility relieve volume change upon cycling, thereby enhancing the dendrite inhibition capacity of LiF@Li. Consequently, LiF@Li exhibits remarkable stability and excellent electrochemical performance in both symmetric cells and LiFePO4 full cells. Moreover, LiF@Li maintains its initial color and morphology even after air exposure for 30 min, and the air-exposed LiF@Li anode still retains its superior electrochemical performance, further establishing its outstanding air-defendable capability. This work proposes a facile approach in constructing air-stable and dendrite-free Li metal anodes toward reliable Li metal batteries.
RESUMO
BACKGROUND: The article aims to study the results of EB virus nucleic acid quantification (EBV-DNA) in whole blood lymphocytes to examine whether serum can diagnose EB virus infection in children. Group A consisted of 65 children admitted to the hospital with a probable EB virus infection between February 2017 and February 2018. In the same period of health check-ups, 65 children were randomly selected as Group B. METHODS: To find out the differences between Group A and Group B, EBV-DNAs in whole blood lymphocyte and serum were detected by quantitative fluorescence assay, and EBV-CA-IgM antibody was detected by enzyme-linked immunosorbent assay. RESULTS: The results demonstrate that Group A had a greater rate of positive EBV-DNAs in whole blood lymphocytes and serum than Group B. EBV-DNA positivity was greater in whole blood lymphocytes of Group A and Group B than in serum. In whole blood lymphocytes from Group A, the positive rate of EBV-DNA and EBV-CA-IgM antibodies was statistically significant. CONCLUSION: The positive rate of EBV-DNA in whole blood lymphocytes of EBV-infected children is higher than in serum, the suitable specimens for diagnosis should be chosen based on the individual condition of children patients.