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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 199 records · Page 11

Experimental investigation and model development of the Skylab ATM secondary nickel-cadmium batteries

The performance of a Ni-Cd battery was evaluated and the cyclic battery controls to be used on the ATM batteries were determined. Cell and battery performance models were developed which to predict the performance of the secondary Ni-Cd batteries on the ATM. Capacity degradation and charge acceptance characteristics were considered. Mathematical models for each of these operating areas were developed based on data from two separate test programs. The capacity degradation model describes the expected usable battery capacity as a function of time, temperature, and depth-of-discharge. The charge acceptance model describes the cell charge acceptance as a function of charge rate, temperature, and state of charge. The models were designed for computer use and to facilitate possible battery modification. They can be used to predict expected performance or to compare real time performance during flight.

Kirsch, W. W.↗

The Research and Development of a Soluble Reactants and Products Secondary Battery System

A redox battery system which employs an aqueous dectrolyte is developed. Results are presented of the following experimental studies (1) measurement of the essential physical and chemical properties of the reactants and products; (2) evaluation of commerically available anion membranes as the cell separator, (3) determination of the composition and degradation mechanism of the anion membrane, and/or developing an anion membrane separator; and (4) evaluation of the performance of prototype secondary battery systems.

Liu, C. C.↗

Battery Fault Detection with Saturating Transformers

A battery monitoring system utilizes a plurality of transformers interconnected with a battery having a plurality of battery cells. Windings of the transformers are driven with an excitation waveform whereupon signals are responsively detected, which indicate a health of the battery. In one embodiment, excitation windings and sense windings are separately provided for the plurality of transformers such that the excitation waveform is applied to the excitation windings and the signals are detected on the sense windings. In one embodiment, the number of sense windings and/or excitation windings is varied to permit location of underperforming battery cells utilizing a peak voltage detector.

Davies, Francis J.↗

Long Life, High Energy Silver-Zinc Batteries

This viewgraph presentation includes: 1) an introduction to RBC Technologies; 2) Rechargeable Zinc Alkaline (RZA(tm)) Systems which include MnO2/Zn, Ni/Zn, Ag/Zn, and Zn/Air; and 3) RZA Silver/Zinc Battery Developments. Conclusions include the following: 1)Issues with long term wet life and cycle life of the silver/zinc battery system are being overcome through the use of new anode formulations and separator designs; 2) Performance may exceed 200 cycles to 80% of initial capacity and ultimate wet-life of > 36 months; and 3) Rechargeable silver/zinc batteries available in prismatic and cylindrical formats may provide a high energy, high power alternative to lithium-ion in military/aerospace applications.

Kainthla, Ramesh↗

Electrical characterization of the Magellan batteries after storage

Two 22 cell batteries designed by Martin Marietta were tested. The batteries were rated at 26.5 Amp-Hr. The battery design is characterized by the following: Gates Aerospace 42B030AB15, 11 pos/12 neg, Pellon 2536 separator, passivated pos/teflonated neg. The tests can be summarized as follows: (1) no noticeable capacity loss after storage period; and (2) batteries exhibited larger non-uniformity of cell voltages during constant current charge.

Deligiannis, Frank↗

Fabrication and testing of silver-hydrogen cells

The development and life testing of single electrode and multi electrode stacks to optimize the individual components and characterize the performance of a silver hydrogen battery system are described. A NASA-developed inorganic separator material was used as the main separator within the cells. Single electrode test cells were cycled at 75% of nominal capacity out through approximately 1,000 cycles in a number of cases where deterioration in performance was observed. This deterioration appears to be a decay in usable capacity of the silver electrode; but the exact mechanism is still unidentified. Twenty ampere-hour boilerplate test cells consisting of a stack of ten silver electrodes and twenty hydrogen electrodes were cycled also at 75% depth of discharge. The oldest stack achieved 522 stable cycles to the end of the program. Weight analysis of light-weight cells showed that 50 ampere-hour cells with improved components could be capable of as much as 40 watt hours per pound.

Klein, M. G.↗

Aqueous alkali metal hydroxide insoluble cellulose ether membrane

A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

Hoyt, H. E.↗

Copper chloride cathode for a secondary battery

Higher energy and power densities are achieved in a secondary battery based on molten sodium and a solid, ceramic separator such as a beta alumina and a molten catholyte such as sodium tetrachloroaluminate and a copper chloride cathode. The higher cell voltage of copper chloride provides higher energy densities and the higher power density results from increased conductivity resulting from formation of copper as discharge proceeds.

Bugga, Ratnakumar V.↗

Flasher Powered by Photovoltaic Cells and Ultracapacitors

A unique safety flasher powered by photovoltaic cells and ultracapacitors has been developed. Safety flashers are used wherever there are needs to mark actually or potentially hazardous locations. Examples of such locations include construction sites, highway work sites, and locations of hazardous operations. Heretofore, safety flashers have been powered by batteries, the use of which entails several disadvantages: Batteries must be kept adequately charged, and must not be allowed to become completely discharged. Batteries have rather short cycle lives, and their internal constituents that react chemically to generate electricity deteriorate (and hence power-generating capacities decrease) over time. The performances of batteries are very poor at low temperatures, which often occur in the circumstances in which safety flashers are most needed. The disposal of batteries poses a threat to the environment. The development of the present photovoltaic/ultracapacitor- powered safety flasher, in which the ultracapacitors are used to store energy, overcomes the aforementioned disadvantages of using batteries to store energy. The ultracapacitors in this flasher are electrochemical units that have extremely high volumetric capacitances because they contain large-surface-area electrodes separated by very small gaps. Ultracapacitors have extremely long cycle lives, as compared to batteries; consequently, it will never be necessary to replace the ultracapacitors in the safety flasher. The reliability of the flasher is correspondingly increased, and the life-of-system cost and the adverse environmental effects of the flasher are correspondingly reduced. Moreover, ultracapacitors have excellent low-temperature characteristics, are maintenance-free, and provide consistent performance over time.

Eichenberg, Dennis J.↗

Automating the Transition Between Sensorless Motor Control Methods for the NASA Glenn Research Center Flywheel Energy Storage System

The NASA Glenn Research Center (GRC) has been working to advance the technology necessary for a flywheel energy storage system for the past several years. Flywheels offer high efficiency, durability, and near-complete discharge capabilities not produced by typical chemical batteries. These characteristics show flywheels to be an attractive alternative to the more typical energy storage solutions. Flywheels also offer the possibility of combining what are now two separate systems in space applications into one: energy storage, which is currently provided by batteries, and attitude control, which is currently provided by control moment gyroscopes (CMGs) or reaction wheels. To date, NASA Glenn research effort has produced the control algorithms necessary to demonstrate flywheel operation up to a rated speed of 60,000 RPM and the combined operation of two flywheel machines to simultaneously provide energy storage and single axis attitude control. Two position-sensorless algorithms are used to control the motor/generator, one for low (0 to 1200 RPM) speeds and one for high speeds. The algorithm allows the transition from the low speed method to the high speed method, but the transition from the high to low speed method was not originally included. This leads to a limitation in the existing motor/generator control code that does not allow the flywheels to be commanded to zero speed (and back in the negative speed direction) after the initial startup. In a multi-flywheel system providing both energy storage and attitude control to a spacecraft, speed reversal may be necessary.

Fehrmann, Elizabeth A.↗

An explosion-proof battery case

Battery case, equipped with relief valve, connector, and two covers, separates the explosive mixture from all potential spark sources. Bottom ends of vent tubes are cemented into cell vents and upper ends fit through the gas barrier cover. This arrangement isolates generated gases from the electric power.

Keathley, W. H.↗

Heat sterilizable separators

Heat sterilizable separator material for development of heat sterilizable Ag-Zn batteries meeting contamination requirements in interplanetary exploration

Lutwack, R.↗

LILI (Long-term Ice-field Levitating Investigator): Mars Aerial and Ground Explorer for Martian Polar Regions

Exploration of Mars is currently underway by use of a rover and helicopter team. A hybrid ground/aerial vehicle concept that marries the respective strengths of rovers and rotorcraft for Mars exploration is presented in this paper. LILI (Long-term Ice-field Levitating Investigator) is a novel hybrid ground- and aerial-mobility concept vehicle proposed for exploration of the Martian polar regions. LILI combines episodic rotary-wing flight with primary ground-mobility-mode of a propeller-driven sled via an arrangement of three skis/runners and tilting proprotors. In this manner, the best of both worlds can be achieved for Mars polar exploration: rapid, obstacle-bypassing flight with low-power, efficient, longer duration -- and range -- sledding. LILI’s propulsion system is based on solar-electric recharging of batteries. Consequently, periods of its air or ground movement are separated by periods of recharging. The overall project goal is to refine the vehicle and mission concept, while constrained within the current technology state of the art, and, leveraging the design heritage of the Ingenuity Mars Helicopter technology demonstrator. LILI’s aerodynamic performance, flow interactions, and design characteristics, as well as potential mission profiles are suggested.

LILI↗

The electrical performance of Ag Zn batteries for the Venus multi-probe mission

An evaluation of 5 Ah and 21 Ah Silver-Zinc batteries was made to determine their suitability to meet the energy storage requirements of the bus vehicle, 3 small probes and large probe for the Venus multi-probe mission. The evaluation included a 4 Ah battery for the small probe, a 21 Ah battery for the large probe, one battery of each size for the bus vehicle power, a periodic cycling test on each size battery and a wet stand test of charged and discharged cells of both cell designs. The study on the probe batteries and bus vehicle batteries included both electrical and thermal simulation for the entire mission. The effects on silver migration and zinc penetration of the cellophane separators caused by the various test parameters were determined by visual and X-ray fluorescence analysis. The 5 Ah batteries supported the power requirements for the bus vehicle and small probe. The 21 Ah large probe battery supplied the required mission power. Both probe batteries delivered in excess of 132 percent of rated capacity at the completion of the mission simulation.

Palandati, C.↗