Li-ion batteries are used in many applications in everyday life: cell phones, laser pointers, laptops, cordless drillers or saws, bikes and even cars. Yet, there is room for improvement in order to make the batteries smaller and last longer. The Fromm group contributes to this research focusing mainly on nanoscale lithium ion cathode materials. This contribution gives an overview over our curre...

Lithium-ion batteries are commonly used as energy storage devices in a variety of applications. The cathode architectures and materials have a large influence on the performance of lithium-ion batteries, namely power and energy densities. Three-dimensional bicontinuous cathode structures should help improve the charge and discharge rate performances, while maintaining a high energy capacity. By...

Field emission is one of the principal phenomena limiting the operating voltage of practical electron guns. There is interest in developing photoemission cathode based DC electron guns employing cathode field strengths and cathode-anode voltages well above the present stateof-the-art. Such electron sources could provide high brightness, high average current beams for energy recovered supercondu...

An electrochemically-active high-temperature form of LiCoO2 (HT-LiCoO2) is prepared by thermally decomposing its constituent metal-nitrates at 700 oC. The synthetic conditions have been optimized to achieve improved performance with the HT-LiCoO2 cathode in Li-ion batteries. For this purpose, the synthesized materials have been characterized by powder X-ray diffraction, scanning electron micros...

A new vacuum arc type ion source (VARIS) has been developed and tested for high current uranium operation. Figure 1 shows a cross sectional view of the ion source. The discharge arrangement has a tubular anode opposite to the cathode mount carrying 17 cathodes (each one is 5.7mm in diameter and 17mm in length). The anode, made of stainless steel, is placed 15mm apart from the cathode. Its apert...

A multiwall carbon nanotube (MWCNT) sponge network, coated by ALD V(2)O(5), presents the key characteristics needed to serve as a high-performance cathode in Li-ion batteries, exploiting (1) the highly electron-conductive nature of MWCNT, (2) unprecedented uniformity of ALD thin film coatings, and (3) high surface area and porosity of the MWCNT sponge material for ion transport. The core/shell ...

In fusion negative ion sources, the negative ions are formed on the caesiated plasma grid predominantly by hydrogen atoms from the plasma. The space charge of the negative ions leaving the wall is not fully compensated by incoming positive ions and at high enough emission a virtual cathode is formed. This virtual cathode limits the flux of negative ions transported across the sheath to the plas...

nt matter & 2013 0.1016/j.nanoen.2 thor. uthor. Tel.: +1 216 . : [email protected] (L. Dai). Abstract The recent progress and future development of cathode materials for lithium ion batteries have been critically reviewed in this article. We have given some critical opinions and rational ideas regarding the development of cathode materials to dramatically reduce the cost and increase the efficienc...