Publications

Abstract Low active material loading in the composite electrode of all‐solid‐state batteries (SSBs) is one of the main reasons for the low energy density in current SSBs. In this work, it is demonstrated with both modeling and experiments that in the regime of high cathode loading, the utilization of cathode material in the solid‐state composite is highly dependent on the particle size ratio of the cathode to the solid‐state conductor. The modeling, confirmed by experimental data, shows that higher cathode loading and therefore an increased energy density can be achieved by increasing the ratio of the cathode to conductor particle size. These results are consistent with ionic percolation being the limiting factor in cold‐pressed solid‐state cathode materials and provide specific guidelines on how to improve the energy density of composite cathodes for solid‐state batteries. By reducing solid electrolyte particle size and increasing the cathode active material particle size, over 50 vol% cathode active material loading with high cathode utilization is able to be experimentally achieved, demonstrating that a commercially‐relevant, energy‐dense cathode composite is achievable through simple mixing and pressing method.

Roughened copper electrodes, including those derived from cuprous oxide, have long been known to exhibit an enhanced Faradaic efficiency to C2+ products during CO2 electroreduction. However, the source of this enhancement has not been rationalized mechanistically. In this work, we present a theoretical study of roughened copper electrodes derived from cuprous oxide, phosphide, nitride, and sulfide. We utilize a carefully benchmarked effective medium theory potential to develop geometric models of the roughened electrodes on an unprecedented scale. Using density functional theory with an implicit electrolyte, we determine applied bias dependent binding energy distributions for critical reaction intermediates. We apply simple thermodynamic models to evaluate the role of surface roughening on selectivity during CO2 electroreduction. We find that the manner of roughening (i.e., starting from oxide, phosphide, sulfide, or nitride) does not significantly affect the binding energy distributions found, and we suggest design rules to maximize selectivity to C2+ products on copper.

Experimental' measurements of the rate coefficient (k(app)) and apparent enthalpies and entropies of activation (Delta H-app arid Delta S-app) for alkane cracking catalyzed by acidic zeolites can be used to characterize the effects of zeolite structure and alkane size On the intrinsic enthalpy and entropy of activation, Delta H-int(double dagger) and Delta S-int(double dagger). To determine Delta H-int(double dagger) and Delta S-int(double dagger), enthalpies and entropies of adsorption, Delta Hads-H+ and Delta Sads-H+, must be determined for alkane molecules moving from the gas phase to Bronsted add sites at reaction temperatures (>673 K). Experimental values of Delta H-app and Delta S-app must also be properly defined in terms of Delta Hads-H+ and Delta Hads-H+. We report here a method for determining Delta Hads-H+ and Delta Sads-H+ in which the adsorption site is represented by a fixed volume that includes the proton. Values of Delta Hads-H+ and Delta Sads-H+ obtained from Monte Carlo simulations are in good agreement with values obtained from experimental data measured at 300-400 K. An important feature of the simulations, however, is their ability to account for the redistribution of alkane adsorbed at protons in different locations with ineteasing temperature. Values of Delta H-int(double dagger) and Delta S-int(double dagger), for the cracking of propane through n-hexane, determined from measured values of k(app) and Delta H-app and simulated: values of Delta Hads-H+ and Delta Sads-H+, agree well with values obtained independently from quantum mechanics/molecular mechanics calculations. Application of our method of analysis reveals that the observed increase in kapp with increasing n-alkane size is due primarily to a decrease in Delta H-int(double dagger) with increasing chain length and that Delta S-int(double dagger) is independent of chain length.

Abstract Li‐excess disordered rocksalts (DRXs) hold promise as next‐generation cathodes for Li‐ion batteries due to their high capacity and energy density, along with the potential to eliminate the need for Co and Ni. However, due to their low Li + diffusivity, DRXs need to be pulverized into nanoparticles to achieve high performance. Herein, a new strategy for overcoming this limitation is demonstrated, involving the design of as‐synthesized partially disordered oxides with a structure that lies between ordered layered and fully disordered, exhibiting a varying degree of local (dis)order. This unique structure activates new Li + diffusion channels, improving percolation and transport properties. This strategy allows a large content of Li + to be accessed in material with large, micron‐sized particles through highly reversible Cr 3+/6+ and O redox, yielding a first discharge capacity of 286 mAh g −1 (881 Wh kg −1 ). The Li + percolation network is further improved by substituting Ti with a mixture of multiple metals, which appears to locally decrease the migration barrier through lattice distortion. Proper tuning of the chemical composition, especially the content of metals with empty d orbitals, is established as a crucial factor for controlling the degree of disorder and mitigating voltage fade and hysteresis growth upon cycling.

The complexity, pace, and volatility of present-day work demands more dynamic organizational management systems. More recent management systems, e.g., agile or design thinking, have not proven to be the “silver bullet” to improved dynamic capabilities in part due to the paradoxical nature of multi-faceted organizational outcomes (e.g., people v. profit, quality v. innovation). Thus, scholars seek to examine the underlying principles and theories of management approaches, regardless of origin or age. Our proposed presentation symposium combines historical and futuristic perspective to examine 21st century lean practices through the lenses of temporality, centrality of work teams, and problem solving. The use of lean management approaches shifted significantly since 2000, from primary use in manufacturing settings to achieve efficiency, to extensive use knowledge-based settings, including hospitals and R&D, to achieve improved efficiency, quality, and innovation. This symposium includes three presentations and a discussion from internationally renowned scholars that collectively highlight temporality, centrality of work teams, and problem solving as critical lenses through which to study and improve management systems. Building upon a pluralistic approach, this symposium will take a significant step in advancing knowledge and provoking new directions for future research on team-oriented management systems. Managing Through a Pandemic: A Daily Management System for COVID-19 Response and Recovery Author: Dorothy Hung; U. of California, Berkeley Author: Thomas Rundall; U. of California, Berkeley Author: Justin Lee; U. of California, Berkeley Author: Negeen Khandel; U. of California, Berkeley Author: Stephen M. Shortell; U. of California, Berkeley Factors for Kaizen Event Success in Hospitals Author: Kimberly Harry; Virginia Tech Author: Wiljeana Jackson Glover; Babson College The paradox of Lean Management and Innovation climates: Problem-Solving as a potential moderator Author: Tal Katz-Navon; Arison School of Business, Reichman U. (IDC), Israel Author: Eitan Naveh; Technion Israel Institute of Technology Author: Noa Ebenstein-Ziv; Technion – Israel Institute of Technology

No abstract is provided for this article.

In this paper, we investigate via physical experiments and computer simulations the response of Chua's circuit under periodic external forcing. The amplitude and frequency of the external forcing form two additional control parameters, and we present bifurcation diagrams on the plane of these two parameters. We investigate the behavior of Chua's circuit due to external forcing when the unforced circuit is in various dynamical regimes. We finally compare our results with those obtained from a nonautonomous oscillator with an inertial nonlinearity.