A review of the catalytic oxidation of carbon-carbon composite aircraft brakes

This document is the Accepted Manuscript version, made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/. The final, definitive version of this paper is available online at doi: https://doi.org/10.1016/j.carbon.2015.08.100.The use of de-icing chemicals at airport runways has been shown to produce oxides and carbonates of sodium, potassium and calcium which catalyse the oxidation of carbon-carbon composite aircraft brakes leading to an increase of the oxidation rate by an order of magnitude. This review reports on studies that have characterised the catalytic oxidation and discusses the mechanism of the catalytic reaction based on investigations that were carried out with both C-C composites and carbon as a fossil fuel. The alkali metal oxides/carbonates are more active catalysts and in their case, the redox reaction between the monoxides and the peroxides has been identified as the most likely catalysis mechanism. In order to reduce or eliminate the problem of catalysis, doping with boron or phosphorus compounds has been investigated by a number of researchers. The effect of these along with the use of protective coatings is also reviewed.Peer reviewe

Solid state generators and energy harvesters for waste heat recovery and thermal energy harvesting

This review covers solid state thermal to electrical energy converters capable of transforming low grade heat directly into electricity for waste heat recovery and thermal energy harvesting. Direct solid state heat engines, such as thermoelectric modules and thermionic converters for spatial temperature gradients, are compared with pyroelectric energy harvesters and thermomagnetic generators for transient changes in temperature. Temperature and size limitations along with the maturity of the technologies are discussed based on energy density and temperature range for the different generator technologies. Despite the low energy conversion efficiency with solid state generators, electric power density ranges from 4 nW/mm2 to 324 mW/mm2. The most promising sector to implement changes while reducing the primary energy consumption and saving resources, is the processing industry along with stationary and mobile electronics

Performance Analysis of Battery/Supercapacitor Hybrid Energy Source for the City Electric Buses and Electric Cars

This paper discusses the benefits of using supercapacitors (SCs) when combined with a parallel battery in electric vehicles (EVs), and also demonstrates its feasibility by means of dynamic simulation. A semi-active architecture using a DC/DC converter was chosen, and the implementation of the hybrid energy source was assessed for potential decrease in strain and prolonged battery lifecycle. Data from the literature validated the hybrid energy storage system model and indicated a good agreement. Dynamic simulations were performed using generic models in Matlab-Simulink and ADVISOR, the NYC driving cycle for two types of EVs, that is, for a public transit city electric bus and for an electric car. The outcomes involving the hybridization revealed a substantial decrease in battery charge. The SC power aid and the distance increase in the hybrid system were assessed to be around 26.75% and 87 km, respectively. The results showed corroborated advantages accredited to the hybridization. This later could likewise enable a decrease in the size of the EV battery's main energy source

Dynamic simulation of battery/supercapacitor hybrid energy storage system for the electric vehicles

One of the most efficient options for enhancing energy use by electric vehicles is through hybridization using supercapacitors (SCs). A supercapacitor has many beneficial features especially its high efficiency, capacity to store large amounts of energy, a simpler charging system and quick delivery of charge. The objective of this paper was to highlight the benefits and demonstrate the feasibility of using SCs in combination with parallel battery in EVs by employing a modelling and simulation method. A semi-active topology which employed a single DC/DC converter was selected, and the performance of the battery/SC hybrid energy storage system (HESS) was evaluated for possible reduction in stress and extended battery life. The HESS was modelled based on generic battery, SC and converter models within Simscape Power Systems in Matlab-Simulink and ADVISOR. The HESS model was validated by data from the literature and showed a good compatibility. This implies that the model used in the present study is reliable and have a high probability of deriving an accurate prediction of the HESS performance. Dynamic simulations were performed for Tesla S70 electric car. The results relating to hybridization showed a significant reduction in battery charge. The SC power contribution and the range extension in the HESS was estimated to be in average 21.5% and 80 km for the USC06 driving cycle, respectively. The simulation results presented a range of verified benefits attributed to the HESS: by deploying transient currents during acceleration and deceleration which greatly reduces battery stress, there is significant enhancement of system performance; an appreciable reduction in the number of cycles/year has a direct positive impact on battery aging process; there is a striking increase in vehicle range; and finally, it provides insulation for the battery pack at very cold ambient air temperatures. Moreover, the hybridization could allow reducing the size of the primary power source or the EV battery

A Carbon-Air Battery for High Power Generation

We report a carbon–air battery for power generation based on a solid-oxide fuel cell (SOFC) integrated with a ceramic CO2-permeable membrane. An anode-supported tubular SOFC functioned as a carbon fuel container as well as an electrochemical device for power generation, while a high-temperature CO2-permeable membrane composed of a CO32− mixture and an O2− conducting phase (Sm0.2Ce0.8O1.9) was integrated for in situ separation of CO2 (electrochemical product) from the anode chamber, delivering high fuel-utilization efficiency. After modifying the carbon fuel with a reverse Boudouard reaction catalyst to promote the in situ gasification of carbon to CO, an attractive peak power density of 279.3 mW cm−2 was achieved for the battery at 850 °C, and a small stack composed of two batteries can be operated continuously for 200 min. This work provides a novel type of electrochemical energy device that has a wide range of application potentials