RESUMEN
Accurate quantitative elemental and isotope analysis of nanoparticles at the single-particle level is crucial for better understanding their origin, properties and behaviors. Single particle inductively coupled plasma-mass spectrometry (spICP-MS) has emerged as a promising technique for nanoparticle analysis. However, challenges persist in obtaining accurate and consistent element profiles and ratios for small-sized nanoparticles by conventional quadrupole (QMS) or time-of-flight mass analyzers (TOF-MS) due to their low level and transient nature. In this paper, we present a novel analytical method for single nanoparticle analysis using multiple collector ICP-MS (MC-ICP-MS) combined with a modern high-speed digital oscilloscope. The single particle events are acquired using an "event-triggered signal capture" (ETSC) technique, which enables the simultaneously capture and visualization of multiple isotopes of transient individual particle profiles with nanosecond time resolution. This greatly facilitates precise and efficient analysis of nanoparticles. The minimum detectable particle size is calculated to be as small as 8 nm (â¼1 ag 109Ag) for AgNPs. Based on the 109/107Ag ratios obtained from 2000 particles, the precisions of 109/107Ag ratio measurements on 20 nm, 40 nm, 60 nm, 80 nm and 100 nm were approximately 0.086 (SD), 0.063 (SD), 0.051 (SD), 0.040 (SD), and 0.029 (SD), which is limited by counting statistics of the isotopic signals. Furthermore, the achieved standard error of 109/107Ag can be reduced to sub-permil level (0.7 ) even for the measurement of 20 nm AgNPs (N = 17,000). These results demonstrate that the ETSC provides a unique method for isotope analysis of single particles, holding great potential for enhancing our understanding of nanoparticles.
RESUMEN
Ether-based electrolyte is beneficial to obtaining good low-temperature performance and high ionic conductivity in potassium ion batteries. However, the dilute ether-based electrolytes usually result in ion-solvent co-intercalation of graphite, poor cycling stability, and hard to withstand high voltage cathodes above 4.0â V. To address the aforementioned issues, an electron-withdrawing group (chloro-substitution) was introduced to regulate the solid-electrolyte interphase (SEI) and enhance the oxidative stability of ether-based electrolytes. The dilute (~0.91â M) chloro-functionalized ether-based electrolyte not only facilitates the formation of homogeneous dual halides-based SEI, but also effectively suppress aluminum corrosion at high voltage. Using this functionalized electrolyte, the K||graphite cell exhibits a stability of 700â cycles, the K||Prussian blue (PB) cell (4.3â V) delivers a stability of 500â cycles, and the PB||graphite full-cell reveals a long stability of 6000â cycles with a high average Coulombic efficiency of 99.98 %. Additionally, the PB||graphite full-cell can operate under a wide temperature range from -5 °C to 45 °C. This work highlights the positive impact of electrolyte functionalization on the electrochemical performance, providing a bright future of ether-based electrolytes application for long-lasting, wide-temperature, and high Coulombic efficiency PIBs and beyond.