Engineering topics
Surampudi, S.
Publications and source records attributed to Surampudi, S..
Low Crossover Polymer Electrolyte Membranes for Direct Methanol Fuel Cells
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Storage Characteristics of Lithium Ion Cells
Prototype aerospace lithium ion cells have shown impressive performance in several categories, such as specific energy, energy density and low-temperature performance.
Performance Characteristics of Lithium-Ion Cells for Mars Sample Return Athena Rover
In contrast to the primary batteries (lithium thionyl chloride) on the Sojourner Mars Rover and the upcoming 2001 Mars Rover, the Mars Sample Return (MSR) Athena Rover will utilize rechargeable lithium ion batteries, following the footsteps of MSP 2001 Lander.
Performance Characteristics of Lithium-Ion Cells for NASA's Mars 2001 Lander Application
NASA requires lightweight rechargable batteries for future missions to Mars and the outer planets that are capable of operating over a wide range of temperatures, with high specific energy and energy densities.
Irreversible Capacities of Graphite in Low Temperature Electrolytes for Lithium-Ion Batteries
Carbonaceous anode materials in lithium ion rechargeable cells experience irreversible capacity, mainly due to a consumption of lithium in the formation of surface passive films. The stability and kinetics of lithium intercalation into the carbon anodes are dictated by these films.
DS-2 Mars Microprobe Battery
In January of 1999 the NM DS-2 Mars microprobe will be launched to impact on Mars in December. The technical objectives of the missions are to demonstrate: key technologies, a passive atmospheric entry, highly integrated microelectronics which can withstand both low temperatures and high decelerations, and the capability to conduct in-situ, surface and subsurface science data acquisition. The scientific objectives are to determine if ice is present below the Martian surface, measure the local atmospheric pressure, characterize the thermal properties of the martian subsurface soil, and to estimate the vertical temperature gradient of the Martian soil. The battery requirements are 2-4 cell batteries, with voltage of 6-14 volts, capacity of 550 mAh at 80C, and 2Ah at 25C, shelf life of 2.5 years, an operating temperature of 60C and below, and the ability to withstand shock impact of 80,000 g's. The technical challenges and the approach is reviewed. The Li-SOCL2 system is reviewed, and graphs showing the current and voltage is displayed, along with the voltage over discharge time. The problems encountered during the testing were: (1) impact sensitivity, (2) cracking of the seals, and (3) delay in voltage. A new design resulted in no problems in the impact testing phase. The corrective actions for the seal problems involved: (1) pre weld fill tube, (2) an improved heat sink during case to cover weld and (3) change the seal dimensions to reduce stress. To correct the voltage delay problem the solutions involved: (1) drying the electrodes to reduce contamination by water, (2) assemblage of the cells within a week of electrode manufacture, (3) ensure electrolyte purity, and (4) provide second depassivation pulse after landing. The conclusions on further testing were that the battery can: (1) withstand anticipated shock of up to 80,000 g, (2) meet the discharge profile post shock at Mars temperatures, (3) meet the required self discharge rate and (4) meet environmental requirements.
Lithium-Ion Batteries for Aerospace Applications
This presentation reviews: (1) the goals and objectives, (2) the NASA and Airforce requirements, (3) the potential near term missions, (4) management approach, (5) the technical approach and (6) the program road map. The objectives of the program include: (1) develop high specific energy and long life lithium ion cells and smart batteries for aerospace and defense applications, (2) establish domestic production sources, and to demonstrate technological readiness for various missions. The management approach is to encourage the teaming of universities, R&D organizations, and battery manufacturing companies, to build on existing commercial and government technology, and to develop two sources for manufacturing cells and batteries. The technological approach includes: (1) develop advanced electrode materials and electrolytes to achieve improved low temperature performance and long cycle life, (2) optimize cell design to improve specific energy, cycle life and safety, (3) establish manufacturing processes to ensure predictable performance, (4) establish manufacturing processes to ensure predictable performance, (5) develop aerospace lithium ion cells in various AH sizes and voltages, (6) develop electronics for smart battery management, (7) develop a performance database required for various applications, and (8) demonstrate technology readiness for the various missions. Charts which review the requirements for the Li-ion battery development program are presented.
Electrolytes for Li-Ion Cells in Low Temperature Applications
A number of upcoming NASA missions require energy storage devices which display high energy density and can effectively operate at low temperature. Lithium-ion batteries have been identified as the most promising technology which can meet these stringent requirements.
Lithium Ion Batteries for Mars Exploration Missions
The upcoming NASA's missions aimed at exploring our Planetary system require batteries that can operate at extreme operating temperatures, with high specific energy and energy densities. Conventional aerospace rechargeable battery systems are inadequate to meet the demands.
Performance Characteristics of Lithium-Ion Cells for Mars Sample Return Athena Rover
In contrast to the primary batteries (lithium thionyl chloride) on the Sojourner Mars Rover and the upcoming 2001 Mars Rover, the Mars Sample Return (MSR) Athena Rover will utilize rechargeable lithium ion batteries, following the footsteps of MSP 2001 Lander. The MSR Athena Rover will contain a rechargeable lithium ion battery of 16 V and a total energy of 150 Wh. The mass and volume of the projected power system will be a maximum of 3 kg and 2 liters, respectively. Each battery consists of twelve cells (6-7 Ah), combined in three parallel strings of four cells (16 V) each, such that the capability of the Rover shall be maintained even in the event of one string failure. In addition to the usual requirements of high specific energy and energy density and long cycle life (100 cycles), the battery is required to operate at wide range of temperatures, especially at sub-zero temperatures down to -20 C. In this paper, we report various performance characterization tests carried out on lithium ion cells, fabricated by different manufacturers under a NASA/DoD lithium ion battery consortium.
Thin Film Li Ion Microbatteries for NASA Applications
Rechargeable thin film microbatteries have recently become the topic of widespread research for use in low power applications such as battery-backed CMOS memory, miniaturized implantable medical devices and smart cards. In particular, the Center for Integrated Space Microsystems (CISM) at NASA's Jet Propulsion Laboratory has interest in applying this technology for secondary power systems in miniaturized satellites, microsensors, microactuators and other remote MEMS applications. The general requirements of the microbatteries for these applications are high specific energy, wide range of temperature stability. low self-discharge rate, and flexibility of cell design. The thin film Li ion materials system using LiCoO2(LiPO(x)N(1-x))SnO is expected to fulfill these requirements.
Batteries and Fuel Cells in Space
The year 2000 will mark the 44th anniversary of the space program that started with the launch of the first Sputnik on October 4, 1956.
Lithium Ion Batteries for Mars Exploration Missions
The desired performance characteristics and physical requirements of spacecraft batteries for planetary exploration are reviewed, particularly with respect to surface landers and rovers intended for near-future Mars missions.
Development of Ultra Low Temperature, Impact Resistant Lithium Battery for the Mars Microprobe
The requirements of the power source for the Mars Microprobe, to be backpacked on the Mars 98 Spacecraft, are fairly demanding, with survivability to a shock of the order of 80,000 g combined with an operational requirement at -80 degrees Celcius.
The Role of Electrolyte Upon the SEI Formation Characteristics and Low Temperature Performance of Lithium-Ion Cells With Graphite Anodes
Quarternary lithium-ion battery electrolyte solutions containing ester co-solvents in mixtures of carbonates have been demonstrated to have high conductivity at low temperatures (<-20 degrees Celcius).
Lithium Battery Requirements for Planetary Exploration
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Inter-Agency Lithium-Ion Program
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