PDF Publication Title:
Text from PDF Page: 049
interface while integrating corroborating analytical characterization of the same. Simplified experiments with individual in situ tools could help bridge the existing knowledge gap (see, for example, Figure 2.3.7).29-31 Li dendrite growth t = 0s Charging of Li battery Discharge of Li battery 2 μm Figure 2.3.7. Example of high-angle annular dark-field imaging during Li dendrite growth. From Ref. 31. To advance current understanding of composition, evolution, transport processes, and reactivity at electrochemical interfaces, empirical approaches are required that simultaneously enable visual observation and identification of interfacial phenomena. Significant relevant advances have been made in electron microscopy and X-ray spectroscopy. Multiple studies have appeared recently that combine theoretical simulations with fundamental ex situ and in situ characterization techniques. Figures 2.3.8, for example, combines X-ray spectroscopy and electron microscopy in a multi-modal effort for operando nanoscale characterization in batteries.32 These studies provide a tantalizing glimpse of functional heterogeneity within a microscopic cathode particle, highlighting the importance of buried interfaces with respect to composition, structure, and depth of charge or discharge. Spatial resolution and data collection rates are still limiting factors that restrict how these processes might be manipulated/regulated to enhance capacity, ionic conductivity, or mechanical stability. Complementary information from electron energy loss spectroscopy, for example, may soon become possible using direct electron detectors,33 while increased coherence in synchrotron light sources enabled by upgrades of the Advanced Light Source is expected to provide improved spatial resolution for scanning transmission X-ray microscopy by exploiting ptychography34 or coherent diffractive imaging.35 Current knowledge of the heterogeneous ionic interfaces extant in operational electrochemical cells is even more limited, largely because of the complexity of the interfacial structure and chemistry in such systems. Not only can chemical inter-diffusion, lattice strain, defects, and chemical reactions occur, but space charge effects near the electrodes also complicate detailed analysis. As these phenomena are correlated, all associated microscopic factors (i.e., lattice, electrons, and ions) must be simultaneously considered when studying the effects of spatial, temporal, and space charge. New characterization techniques, which could analyze all these factors simultaneously under relevant and simulated operating environments, are an aspirational goal. Few studies have probed interfacial mechanical properties in situ in the context of ionic transport. For solid-liquid interfaces, a proof of concept was provided by using contact resonance scanning probe microscopy to image the ion insertion pathways through changes in Young’s modulus when Li+ ions are electrochemically driven into layered Ti3C2 (a member of the 2D-layered transition metal carbide family known as MXenes), as shown in Figure 2.3.9. This study provides evidence that the ionic transport across the interface is heterogeneous, resulting in strongly heterogeneous mechanical properties and stresses. Addressing these scientific challenges would provide the community with access to a live visual record of interfacial behaviors, such as SEI formation from infancy through its development, SEI aging and failure processes, and the nucleation and growth processes important in deposition at metal electrodes. Comparative studies between various metal anodes in terms of propensity to form dendrites and its effect on the physical and mechanical properties of the interface and interphase (porosity, crystallinity, and thickness) would also become possible. Availability of such live records would aid the development of theory, electrode designs, and artificial interface synthesis able to bypass the current trial-and-error paradigm for evolving electrode and electrolyte designs for enhancing cell lifetime. NEXT GENERATION ELECTRICAL ENERGY STORAGE PRIORITY RESEARCH DIRECTION – 3 43PDF Image | Next Generation Electrical Energy Storage
PDF Search Title:
Next Generation Electrical Energy StorageOriginal File Name Searched:
BRN-NGEES_rpt-low-res.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)