This paper presents in situ characterization of lithium-ion diffusion at nano- to micro-meter scales in a Li-rich layered oxide thin film cathode under external bias by using Electrochemical Strain Microscopy (ESM) and Atomic Force Microscopy (AFM) techniques. The local variations of the diffusion coefficient are calculated and visualized from the ESM images. The results indicate that the Li-io...

Vacuum arc ion sources, commonly also known as "Mevva" ion sources, are used to generate intense pulsed metal ion beams. It is known that the mean charge state of the ion beam lies between 1 and 4, depending on cathode material, arc current, arc pulse duration, presence or absence of magnetic field at the cathode, as well as background gas pressure. A characteristic of the vacuum arc ion beam i...

A high-power, rectangular discharge chamber is being investigated by the University of Michigan for operation with multiple discharge cathode assemblies (DCAs). The multiple cathode approach attempts to increase thruster lifetime by operating three DCAs sequentially, possibly providing a threefold increase in discharge life. Previous multiplecathode electric propulsion devices, such as the SPT-...

Undesired electrode-electrolyte interactions prevent the use of many high-energy-density cathode materials in practical lithium-ion batteries. Efforts to address their limited service life have predominantly focused on the active electrode materials and electrolytes. Here an advanced three-dimensional chemical and imaging analysis on a model material, the nickel-rich layered lithium transition-...

Extensive resources have been allocated to diagnose and minimize lifetime-limiting factors in gridded ion thrusters. While most of this effort has focused on grid erosion, results from wear tests indicate that discharge cathode erosion may also play an important role in limiting the lifetime of ring-cusp ion thrusters proposed for future large flagship missions. The detailed characterization of...

A model for negative glow metal-vapor ion lasers that self-consistently describes the dynamics of the negative glow and the cathode sheath regions of the discharge has been developed. The model computes the electron energy distribution and the population of relevant excited states in the negative glow self-consistently with the charged particle fluxes and electric field distribution in the cath...

We report Co-free, Li-rich Li1+x Ni0.5 Mn1.5 O4 (0<x<1) compounds as high-voltage and high-capacity cathode materials for Li-ion cells. Their tailored morphology allows high density and facile processability for electrode development. In the potential range 2.4-4.9 V, the cathode material of composition Li1.5 Ni0.5 Mn1.5 O4 shows excellent performance in terms of capacity and cycling stability ...

Abstract The thick-target ISOL (Isotope mass Separation OnLine) method provides beams of more than 1000 radionuclides 74 elements. is well established for elements with sufficiently high volatility at ca. 2000 °C. To extract non-volatile the formation a volatile molecule required. While successful in some cases ( e.g. carbon or boron), most these are not yet available as beam. A variety carrier...

Swelling of a commercial 5 Ah lithium-ion cell with a nickel/manganese/cobalt-oxide cathode is investigated as a function of the charge state and the charge/discharge rate. In combination with sensitive displacement measurements, knowledge of the electrode configuration within this prismatic cell's interior allows macroscopic deformations of the casing to be correlated to electrochemical and me...