This paper presents a phase-zero evaluation case of installing on-off-board hybrid powered Electric Motor Vehicle (EMV) in existing and new local line and reports development of a model fuel cell powered locomotive. EMV such as electric car and locomotive are a new conceptual EMV using hybrid power between off-board substation and on-board Regenerative Fuel Cell (RFC) power system with Metal Hydride (MH) stored hydrogen generated with water electrolyzer by off-board surplus power. In this study, it is estimated a possibility to close power gap over 30 % in placing the new conceptual vehicle. The Locomotive is a 110 cm long locomotive powered by a 20 W PEMFC configured with 20 cells and supplied with about 2 g hydrogen, from a cylinder of 100 g metal hydride, and natural convection air (02). Measuring 50 cm (W), 50 cm (H), and weighting 25.9 kgf, the locomotive has a permanent magnet motor with a rated power 38 W (12 V, 3 A) and ran on railway that has a gauge of 126 mm (3'6“/8.5=4.94”), a length of 100 m. The performance of this train was acceleration of 0.5 m/s, cruising speed of 4.1 m/s at traction force of 15.8 N (1.6 kgf), average rolling friction of 5 N (460 gf).

Bipolar plates for proton exchange membrane (PEM) fuel cells are currently under development. These plates separate individual cells of the fuel cell stack, and thus must be sufficiently strong to support clamping forces, be electrically conducting, be fitted with flow channels for stack thermal control, be of a low permeability material to separate safely hydrogen and oxygen feed streams, be corrosion resistant, and be fitted with distribution channels to transfer the feed streams over the plate surface. To date, bipolar plate costs dominate stack costs, and therefore future materials need to meet strict cost targets.

A first step in the bipolar plate development program is an assessment of design constraints. Such constraints have been estimated and evaluated and are discussed here. Conclusions point to promising advanced materials, such as conductive, corrosion resistant coatings on metal substrates, as candidates for mass production of fuel cell bipolar plates. Possible candidate materials are identified, and testing procedures developed to determine suitability of various materials.

Water uptake and resistivity have been determined for Dupont's Nafion-115®and Dow membrane 800 EW while in contact with a water-saturated nitrogen atmosphere using Fourier transform near-infrared (NIR), and AC impedance four point techniques in the temperature range of 23°C to 100°C. Results show that at room temperature there is a significant increase in water content and a corresponding decrease in the electrical resistivity as the relative humidity increases from 0% to 100%. Results also indicate that there is a substantial decrease in water uptake from water vapor at 100°C relative to that at 23°C. The water content of Dow membrane is higher than Nafion-115 under all conditions tested. The water contents of Dow PFSA 800 EW and Nafion-115 membranes at about 92% R.H. and 23°C are approximately 25 wt% and 18 wt%, respectively. The corresponding water content values at 100°C are 10 wt% and 8 wt%, respectively. The resistivity of the membranes decreases sharply with the temperature up to 60°C, reaches a minimum near 80°C then increases up to 100°C. The Dow membrane has lower resistivity than Nafion-115 over the entire range.

Measurements of PEM fuel cell device performance were made with different gas inlet temperatures and relative humidity using a newly-designed test fixture. Significant improvement in device performance was observed when the fuel inlet temperature was increased above the operating temperature of the cell. These measurements were then correlated to a model to describe energy and mass transport processes.

The electronic conductivity and redox behavior of conjugated polymers make them suitable for charge storage applications. We present preliminary results for an all polymer system consisting of a p-doped polypyrrole cathode and pseudo n-doped polypyrrole/polystyrenesulfonate anode. Using a thin film construction technique, electrodes were assembled into cells using a polymer gel electrolyte based on polyacrylonitrile, which has a high room temperature conductivity. Charge capacities of 13 mAh g−1 based on the mass of the electroactive polymer in the cathode have been obtained for over 100 cycles.

The electropolymerized polypyrrole films formed from micellar solution of anionic surfactants, viz., Dodecylbenzene sulfonate(DBS), showed potential-dependent anion and cation ion switching behavior and the peculiar columnar structure. The formation process and the redox of the polypyrrole was studied with the in situ atomic force microscopy (AFM) and electrochemical quartz crystal microbalance(EQCM) methods. In-situ AFM observation clearly indicated that such a columnar structure started to form around critical charge densities of 60-100 mC cm−2. The cyclic voltammogram for the PPy doped with DBS− film showed two redox couples, each of which corresponds to a cation and an anion exchange process. Thus, the film behaves as a dual-mode ion doping/undoping exchanger. As the PPy film was prepared in higher concentration of the surfactant dopant, where the micelles are formed in solution, the resulting film showed a considerably higher(ca. three orders of magnitude) diffusion coefficient compared to ordinary PPy films so far reported. Such an enhanced diffusivity of ions could be attributed to a peculiar structure of the polymer formed. The feasibility of such polypyrrole in use of supercapacitor material was discussed.

We have synthesized and characterized a range of novel polyelectrolytes containing weakly basic aluminosilicate anions in the polymer backbone in order to achieve t+ = 1 and high ionic mobility. Room-temperature conductivity is observed to increase in the series: [NaAl(OEOMe)2 ((OE)xO)2/2]n < [NaAl(OR)2(OSiMe2(CH2)3(OE)xO(CH2)3SiMe2O)2/2]n < [NaAl(OSiR3)(OSiMe2(CH2)3(OE)xO (CH2)3SiMe2O)3/2]n. This trend is ascribed to reduced ion pairing due to decreasing anion basicity, and lowered Tg resulting from increasing siloxy character. The addition of cryptand [2.2.2] increases conductivities by 1 -1.5 orders of magnitude. A maximum room-temperature conductivity is observed at a ratio of ≈10 etheric oxygens/cation. Related lithium polymer electrolytes were evaluated in mechanically joined solid state Li |PE |[LixMn2O4-C-PE] cells.

A variety of organic solvent-based electrolytes have been studied for ambient temperature, rechargeable lithium (ion) batteries. The ionic behavior of the electrolyte system was investigated through conductivity measurements. The electrochemical characteristics of carbon-based materials (carbon fiber and graphite) as the negative electrode were examined in different compositions of the organic electrolytes. The electrolyte composition as well as the structure of the electrode material greatly influenced the charge/discharge profiles of the electrode.

Dual Intercalating Molten Electrolyte (DIME) electrodes and cells have been examined using a number of low-melting and room-temperature molten salts. A cell with a chloroaluminate melt achieved a cycling efficiency of 85% with a discharge voltage of 2.92 V. Coke-elastomer composite electrodes underwent cation reductive intercalation without experiencing the exfoliation and degradation seen for graphite rods. Theoretical studies for an imidazolium-graphite intercalate predict the graphite layer spacing expands between 5.18 and 8.01 Å upon insertion of the imidazolium molecule into the graphite lattice.

This paper presents and discusses fundamental processes taking place at the lithium and LixC6 electrode/electrolyte interphases and models for these interphases. We deal with both nonaqueous and polymer (dry and gel) electrolytes, graphitized and nongraphitized carbonaceous materials as anodes for Li-ion batteries. Each electrode/electrolyte combination has its own unique features and problems but there are some general phenomena common to all of them. Issues to be reviewed include SEI composition, morphology and formation reactions, graphite surface modifications including chemical bonded SEI and micro channels formation, electrode degradation processes, lithium deposition-dissolution and intercalation-deintercalation mechanisms, rate-determining steps (RDS), electrolyte and electrode parameters and conditions affecting the above mentioned processes. Technologyrelated issues are emphasized.

The lithium metal anode electrodeposited on nickel was studied by charge-discharge test coupled with in-situ ac impedance measurement. The test gives information about lithium anode interface and the modified interface of electrodeposited lithium by CO2 is confirmed to enhance the lithium cycleability. Also the CO2 protects the lithium interface in the presence of H20 impurity during cycling test.

The surface modification of lithium deposited at various current densities in propylene carbonate containing 1.0 ml dm−3 LiCIO4 was performed by addition of various amount of HF into the electrolyte, in order to investigate the effect of the HF addition on the surface reaction of lithium. XPS and SEM analyses showed that the surface state of lithium was influenced by the concentration of HF and the electrodeposition current. These two parameters are related to the chemical reaction rate of the lithium surface with HF and the electrodeposition rate of lithium, respectively. The surface modification was highly effective in suppressing lithium dendrite formation when the chemical reaction rate with HF was greater than the electrochemical deposition rate of lithium.

Our research examines the efficacy of tin additions to LaNi5 in improving the hydrogen storage capacity of the material during charging/discharging. Alloys were prepared using high energy ball milling (mechanical alloying), a technique superior to arc casting for alloying elements with a wide disparity in melting points. Characterization by x-ray diffraction and Rietveld analysis shows that tin preferentially occupies the Ni(3g) sites in the LaNi5 structure, and the unit cell volume increases linearly with tin content to the maximum tin solubility of 7.33 atomic percent (LaNi4.56Sn0.44). We found that powders prepared by mechanical alloying and not exposed to air require no activation to induce hydrogen absorption. The hydrogen storage capacity in the gas and electrochemical phase was measured as a function of tin content. We found that with increasing tin, the plateau pressure decreases logarithmically, whereas the hydrogen storage capacity decreases linearly.

Proprietary, multicomponent hydrogen storage materials have been developed making use of the principles of disorder by atomic engineering of the short-range and intermediate -range order. These materials form the basis for Ovonic Nickel-Metal Hydride batteries which have emerged as the leading battery technology for electric vehicle applications. Ovonic Batteries have the highest volumetric energy density available extending the practical range of electric vehicles from under 100 miles to over 200 miles.

Low catalyst loading gas diffusion membrane electrodes have been developed for spaceflight qualified nickel-hydrogen (NiH2) batteries. These electrodes involve the use of new electrode designs and innovative manufacturing methods. Supported catalysts, mixed catalysts and alternative catalyst systems have been developed to decrease catalyst loading levels, and therefore reduce electrode cost, without reducing performance or reliability. This advanced electrode technology has currently accumulated more than 13,000 charge/discharge cycles in real-time, low-earth-orbit (LEO) testing. The technology has been incorporated into several nickel-hydrogen spaceflight programs including the TUBSAT B spacecraft, built by the Technical University of Berlin and launched in January of 1994 aboard a Russian Cyclone rocket.

Recent advances in high surface area (HSA) electrode materials have played an important role in the development of high-performance batteries and fuel cells. HSA electrodes can significantly increase the power-density of batteries and fuel cells by enhancing the heterogeneous electrochemical reaction rate and concurrently reducing battery and fuel cell size and weight. The compactness of HSA electrodes can also reduce the ohmic potential drop, which has the clear advantage of reducing power losses. This paper reports results on utilizing direct metallization of porous substrates to prepare new HSA electrode materials. Specifically, Nickel HSA electrode materials, relevant to the Ni-Cd and metal-hydride rechargeable batteries, were prepared on porous carbon substrates by direct thermolysis of organometallic precursors and/or electroless Ni plating. SEM and XPS characterization results indicate a Ni metallic film was conformally coated over the porous carbon skeleton. The real electroactive areas were determined electrochemically in NaOH solution and results will be discussed in correlation with the metallization conditions.

The nickel-hydrogen (Ni-H2) cell is rapidly replacing nickel-cadmium (Ni-Cd) cell as the system of choice for aerospace applications where weight is crucial. The heavy-sintered nickel electrode used in this cell accounts for about 38% of the cell weight. The use of small diameter fiber nickel electrodes will reduce the weight and improve the specific energy of the state-of-the-art Ni-H2 cell by about 50%. One advantage of this small diameter nickel fiber material is the increase in the surface area available for the deposition of active material. Initial testing of this type of electrode is very promising. This electrode is also applicable to other nickel-based batteries, such as nickel-zinc, nickel-iron, and nickel-metalhydride, both for space and commercial applications.

Appropriate selection of long endurance materials is critical to the cost effective use of fuel cell technology for near-term commercial and defense applications. To effectively transition this technology from laboratory prototype to fielded system, the durability of all fuel cell subsystems must be addressed. Material selection based upon a thorough understanding of system performance requirements, operational environments, and user interfaces not only provides high reliability and enhanced safety, but also lowers life cycle costs.

This paper discusses the development of an Aluminum Fuel Cell Power System (FCPS) for the Advanced Research Projects Agency (ARPA) Unmanned Underwater Vehicle (UUV) program, focusing on the operational endurance testing that was conducted to evaluate candidate materials for cell stack, electrolyte, and coolant subsystems.

The FCPS is a 15 kW closed aluminum-oxygen fuel cell system that provides up to 1.1 MWh energy. Loral has completed small-scale bench tests and is currently fabricating a full-scale system to be demonstrated in 1995. Requirements that strongly influenced material selection included: chemical compatibility - 4M KOH electrolyte pumped at 50°C, with dissolved aluminum and hydrargillite; system operational objectives - time between refueling and maintenance ranging from daily startup / shutdown to three weeks continuous; ARPA program objectives - commercial components, rapid prototyping, low life cycle costs.

A materials / component endurance test program was established and conducted early in the design phase of the FCPS program. To date, Loral has completed over 3000 operational test hours, with nearly 8000 hours of accumulated exposure to KOH. Results of these tests have been incorporated into the FCPS detailed design, and are expected to significantly enhance the performance of the fielded system. This program is sponsored by ARPA Maritime Systems Technology Office under NASA contract NAS3-26715.

Lithium-ion (or ‘rocking-chair’) batteries with lithiated oxide cathodes and carbon anodes are finding increasing acceptance in many electronic applications including low rates (e.g., memory backup, real time clock, bridge function) and high rates (e.g., laptop computers, cellular phones, camcorders, etc.). This technology offers significant improvements in safety relative to cells using lithium metal anodes, with only a modest reduction in energy density. In general, materials for lithium-ion cells are chosen to minimize the energy density penalties associated with replacing the lithium electrode with an intercalation electrode. In this review paper, we describe the properties of the cathode, anode and electrolyte, and discuss requirements for improved materials for advanced lithium-ion systems. Consideration is given to energy density, rate capability, cycleability and thermal stability.