Insight into the Contribution of the Electrolyte Additive LiBF4 in High-Voltage LiCoO2||SiO/C Pouch Cells.

High-voltage pouch cells using an LiCoO2 cathode and SiO/C anode are regarded as promising energy storage devices due to their high energy densities. However, their failure is associated with the unstable, high-impedance cathode electrolyte interphase (CEI) film on the cathode and the solid electrolyte interphase (SEI) film on the anode surface, which hinder their practical use. Here, we report a novel approach to ameliorate the above challenges through the rational construction of a stable, low-impedance cathode and anode interface film. Such films are simultaneously formed on both electrodes via the participation of the traditional salt, lithium tetrafluoroborate (LiBF4), as electrolyte additive. The application of 1.0% LiBF4 enhances the capacity retention of the cell from 26.1 to 82.2% after 150 cycles between 3.0 and 4.4 V at 1 C. Besides, the low-temperature discharge performance is also improved by LiBF4 application: the discharge capacity of the cell with LiBF4 is 794 mAh compared with 637 mAh without LiBF4 at 1 C and -20 °C. The excellent electrochemical performance of pouch cells is ascribed to the contribution of LiBF4. Especially, the low binding energy of LiBF4 with the oxygen on the LiCoO2 surface leads to the enrichment of LiBF4 that forms the protective cathode interface, which fills the blanks of previous research.

Residual behavior and risk assessment of prochloraz in bayberries and bayberry wine for the Chinese population.

The bayberry is an important economic fruit as well as a minor crop in China, and few pesticide products are registered for bayberry. Prochloraz is a widely used fungicide with a high detection rate on bayberry. This study evaluated the potential dietary risk of prochloraz for different populations in China based on field trial data and market surveillance. The results indicate that one-time applications at dosages of 1000 and 1500 mg/kg with a recommended preharvest interval of 20 days do not pose a chronic or acute dietary risk. However, applying the above dosages twice will cause a potential short-term dietary risk. Risk assessment results conducted on surveillance samples indicated acceptable long-term risks for the general population, with a hazard quotient < 0.82. Furthermore, simulated washing and wine production processes were performed to mimic household practices to investigate residue transfer and distribution. We found that rinsing with tap water for 1 min was an effective way to remove residue, and the processing factors of prochloraz for both bayberry and wine were < 1, indicating that wine production could reduce residue levels. Prochloraz had a strong capacity to transfer to wine due to its high log Kow value, with transfer percentages up to 43%. This study supports the recommendation on good agricultural practices for prochloraz application and provides a guide for safe consumption.