Layered lithium transition metal oxides are one of the most important types of cathode materials in lithium-ion batteries (LIBs) that possess high capacity and relatively low cost. Nevertheless, these layered cathode materials suffer structural changes during electrochemical cycling that could adversely affect the battery performance. Clear explanations of the cathode degradation process and it...

www.tubecad.com Copyright © 2003 GlassWare All Rights NEXT > < PREVIOUS 1 Pg. Mechanical engineers must know the basics of their practice — lever, wedge, wheel and axle, pulley, and screw — as these five simple machines form the basis of all other more complex machines. Likewise, vacuum tube circuit designers must know the inner workings of the grounded-cathode amplifier, the cathode follower, ...

in this paper, using a one-dimensional simulation model, the reforming process of sour gas, i.e. ch4, co2, and h2s, to the various charged particles and syngas in a dielectric barrier discharge (dbd) reactor is studied. an electric field is applied across the reactor radius, and thus a non-thermal plasma discharge is formed within the reactor. based on the space-time coupled finite element meth...

in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

Rechargeable batteries with high energy and power density are in great demand as energy sources for various purposes; e.g., portable telecommunication, computer equipment, hybrid electric vehicles, etc. Lithiumion batteries are the most promising candidates to fulfill such needs due to their intrinsic high discharge voltage and relatively light weight. The current commercial lithium-ion battery...

Photon-enhanced thermionic emission (PETE)[1] appears as a promising technology for electric power generation from renewable resources. Its combination of photovoltaic and thermionic effects leads to devices which can operate at high temperature through thermionic emission still exploiting efficient electrons promotion through a semiconductor band gap when it is chosen as a cathode. However, th...

During Phase I, the following goals were achieved: (1) design and fabrication of a novel, nano-dimensional CNT field emitter assembly for high current density application, with high durability; (2) fabrication of a ceramic based micro channel plate (MCP) and characterization of its secondary electron emission; and (3) characterizing the CNT/MCP cathode for high field emission and durability. As...

Sulfur is an exciting cathode material with high specific capacity of 1,673 mAh/g, more than five times the theoretical limits of its transition metal oxides counterpart. However, successful applications of sulfur cathode have been impeded by rapid capacity fading caused by multiple mechanisms, including large volume expansion during lithiation, dissolution of intermediate polysulfides, and low...

Sensing and responding to endogenous electrical fields are important abilities for cells engaged in processes such as embryogenesis, regeneration and wound healing. Many types of cultured cells have been induced to migrate directionally within electrical fields in vitro using a process known as galvanotaxis. The underlying mechanism by which cells sense electrical fields is unknown. In this stu...