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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Solid-state Architecture Batteries for Enhanced Rechargeability and Safety (SABERS) Beyond Li-Ion: Technology to Enable Sustainable Electric Aviation

All-electric vertical take-off and landing vehicles (eVTOL) for urban air mobility (UAM) concepts face numerous challenging technical barriers before their introduction into the consumer marketplace. The primary barrier to overcome is developing an energy storage system capable of meeting the rigorous aerospace safety and performance criteria. The performance metrics for eVTOL vehicles are at least two times greater than those of electric ground vehicles. Furthermore, inherently non-flammable batteries are essential for safe operation of commercial electric aerovehicles. The SABERS concept proposes a battery that meets the key performance criteria through development of a solid-state architecture battery utilizing high-capacity sulfur-selenium cathode and lithium metal anode. The combination of sulfur and selenium offers a balanced energy-to-power density ratio, which can be tailored to the specific application by altering the stoichiometric ratios of sulfur to selenium. This hybrid cathode will be developed by implementing NASA patented holey graphene technology as a highly conductive, ultra-lightweight electrode scaffold. A solid-state electrolyte will be used as a safe, non-flammable replacement to the highly flammable liquid organic electrolytes currently used in SOA lithium-ion batteries. This solid-state lithium-sulfur/selenium cell will be designed into a serial stacking configuration to enable dense packaging of the battery cells. The serial stacking configuration is termed a bipolar stack, which has the advantages of reducing overall cell weight, simplifying the interfaced connections for the cell, and minimizing the cooling requirements. Lastly, optimization of battery components will occur through a robust and rigorous combination of various computational modeling techniques covering multiple length scales. The expected result will be a fully solid-state battery with operational temperatures up to 150 °C which provides the required energy density, discharge rates, and inherent safety to meet the strict aerospace mission performance criteria. This presentation will demonstrate a feasible path for solid-state cells that possess a specific energy of greater than 400 Wh/kg to enable electric aircraft.

Urban Air Mobility (UAM) Vehicles↗
NASA NTRS2006

The 2004 NASA Aerospace Battery Workshop

Topics covered include: Super NiCd(TradeMark) Energy Storage for Gravity Probe-B Relativity Mission; Hubble Space Telescope 2004 Battery Update; The Development of Hermetically Sealed Aerospace Nickel-Metal Hydride Cell; Serial Charging Test on High Capacity Li-Ion Cells for the Orbiter Advanced Hydraulic Power System; Cell Equalization of Lithium-Ion Cells; The Long-Term Performance of Small-Cell Batteries Without Cell-Balancing Electronics; Identification and Treatment of Lithium Battery Cell Imbalance under Flight Conditions; Battery Control Boards for Li-Ion Batteries on Mars Exploration Rovers; Cell Over Voltage Protection and Balancing Circuit of the Lithium-Ion Battery; Lithium-Ion Battery Electronics for Aerospace Applications; Lithium-Ion Cell Charge Control Unit; Lithium Ion Battery Cell Bypass Circuit Test Results at the U.S. Naval Research Laboratory; High Capacity Battery Cell By-Pass Switches: High Current Pulse Testing of Lithium-Ion; Battery By-Pass Switches to Verify Their Ability to Withstand Short-Circuits; Incorporation of Physics-Based, Spatially-Resolved Battery Models into System Simulations; A Monte Carlo Model for Li-Ion Battery Life Projections; Thermal Behavior of Large Lithium-Ion Cells; Thermal Imaging of Aerospace Battery Cells; High Rate Designed 50 Ah Li-Ion Cell for LEO Applications; Evaluation of Corrosion Behavior in Aerospace Lithium-Ion Cells; Performance of AEA 80 Ah Battery Under GEO Profile; LEO Li-Ion Battery Testing; A Review of the Feasibility Investigation of Commercial Laminated Lithium-Ion Polymer Cells for Space Applications; Lithium-Ion Verification Test Program; Panasonic Small Cell Testing for AHPS; Lithium-Ion Small Cell Battery Shorting Study; Low-Earth-Orbit and Geosynchronous-Earth-Orbit Testing of 80 Ah Batteries under Real-Time Profiles; Update on Development of Lithium-Ion Cells for Space Applications at JAXA; Foreign Comparative Technology: Launch Vehicle Battery Cell Testing; 20V, 40 Ah Lithium Ion Polymer Battery for the Spacesuit; Low Temperature Life-Cycle Testing of a Lithium-Ion Battery for Low-Earth-Orbiting Spacecraft; and Evaluation of the Effects of DoD and Charge Rate on a LEO Optimized 50 Ah Li-Ion Aerospace Cell.

Source record↗
NASA NTRS2019

Physics-Based Modeling and Simulation of Emerging Battery Technologies for Aerospace

Recently there is a growing interest in the aviation sector to reduce air and noise pollution. Electrochemical energy storage devices such as batteries coupled with a distributed electric propulsion system can reduce noise concerns as well as emissions and allow the concept of Urban Air Mobility to come to fruition. The battery performance needs to improve considerably compared from current state-of-art Li-ion battery (about 200Wh/Kg) to realize all-electric passenger jet for short flights (up to 690 miles). NASA is exploring lithium-oxygen battery chemistry to power hybrid (battery powered electrical system) and all-electric aircraft for short distance and long-distance flights. Li-O2 is one of the advanced Li-ion technologies that promise to provide specific energy of more than 750Wh/Kg. For this presentation, we present our work on improving power density of Li-O2 batteries through the use of multiphysics simulations. Next, a path is outlined to port these model to simulate performance for a new battery chemistry for space application, Li-CO2. Li-CO2 uses carbon dioxide as the active material instead of oxygen. Although this technology is in its early development, the offers two benefits: it can be used as a CO2 scrubber, as oxygen is one of the by-products on charging, and as a backup or a standalone battery for various Mars or Venus missions, where the carbon dioxide content in the atmosphere is high and need battery to operate at higher temperatures.

Mehta, Mohit↗
NASA NTRS2017

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar ar-rays meet their sunlit power demands and supply excess power to battery packs for power de-livery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are ex-posed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

Miller, J. E.↗
NASA NTRS2017

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar arrays meet their sunlit power demands and supply excess power to battery packs for power delivery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are exposed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

Miller, J. E.↗
NASA NTRS2011

Li-Ion Cells Employing Electrolytes With Methyl Propionate and Ethyl Butyrate Co-Solvents

Future NASA missions aimed at exploring Mars and the outer planets require rechargeable batteries that can operate at low temperatures to satisfy the requirements of such applications as landers, rovers, and penetrators. A number of terrestrial applications, such as hybrid electric vehicles (HEVs) and electric vehicles (EVs) also require energy storage devices that can operate over a wide temperature range (i.e., -40 to +70 C), while still providing high power capability and long life. Currently, the state-of-the-art lithium-ion system has been demonstrated to operate over a wide range of temperatures (-30 to +40 C); however, the rate capability at the lower temperatures is very poor. These limitations at very low temperatures are due to poor electrolyte conductivity, poor lithium intercalation kinetics over the electrode surface layers, and poor ionic diffusion in the electrode bulk. Two wide-operating-temperature-range electrolytes have been developed based on advances involving lithium hexafluorophosphate-based solutions in carbonate and carbonate + ester solvent blends, which have been further optimized in the context of the technology and targeted applications. The approaches employed include further optimization of electrolytes containing methyl propionate (MP) and ethyl butyrate (EB), which are effective co-solvents, to widen the operating temperature range beyond the baseline systems. Attention was focused on further optimizing ester-based electrolyte formulations that have exhibited the best performance at temperatures ranging from -60 to +60 C, with an emphasis upon improving the rate capability at -20 to -40 C. This was accomplished by increasing electrolyte salt concentration to 1.20M and increasing the ester content to 60 percent by volume to increase the ionic conductivity at low temperatures. Two JPL-developed electrolytes 1.20M LiPF6 in EC+EMC+MP (20:20:60 v/v %) and 1.20M LiPF6 in EC+EMC+EB (20:20:60 v/v %) operate effectively over a wide temperature range in MCMB-LiNiCoAlO2 and Li4Ti5O12-LiNi-CoAlO2 prototype cells. These electrolytes have enabled high rate performance at low temperature (i.e., up to 2.0C rates at -50 C and 5.0C rates at -40 C), and good cycling performance over a wide temperature range (i.e., from -40 to +70 C). Current efforts are focused upon improving the high temperature resilience of the methyl propionatebased system through the use of electrolyte additives, which are envisioned to improve the nature of the solid electrolyte interphase (SEI) layers.

Smart, Marshall C.↗
NASA NTRS2004

Lithium-Ion rechargeable batteries on Mars Rover

NASA's Mars Rovers, Spirit and Opportunity, have been roving on the surface of Mars, capturing impressive images of its terrain and analyzing the drillings from Martian rocks, to answer the ever -puzzling questions of life beyond Earth and origin of our planets. These rovers are being enabled by an advanced rechargeable battery system, lithium-ion, for the first time on a space mission of this scale, for keeping the rover electronics warm, and for supporting nighttime experimentation and communications. These rover Li-ion batteries are characterized by their unique low temperature capability, in addition to the usual advantages associated with Li-ion chemistry in terms of mass, volume and energy efficiency. To enable a rapid insertion of this advanced Li-ion chemistry into flight missions, we have performed several performance assessment studies on several prototype cells over the last few years. These tests mainly focused primarily on the long-term performance characteristics, such as cycling and storage, as described in our companion paper. In addition, various tests have been performed on MER cells and engineering and proto flight batteries; under conditions relevant to these missions. For example, we have examined the performance of the cells in: a) an inverted orientation, as during integration and launch, and b) conditions of low rate discharge, between 3.0-2.5 V to support the mission clock. Likewise, we have determined the impedance of the proto-flight Rover battery assembly unit in detail, with a view to asses whether a current-limiting resistor would be unduly stressed, in the event of a shorting induced by a failed pyro. In this paper we will describe these studies in detail, as well as the performance of Li-ion batteries in Spirit and Opportunity rovers, during cruise and on Mars.

2003 Mars Exploration Rover (MER)↗
NASA NTRS2006

An Update on the Performance of Li-Ion Rechargeable Batteries on Mars Rovers

NASA's Mars Rovers, Spirit and Opportunity have been exploring the surface of Mars for the last thirty months, far exceeding the primary mission life of three months, performing astounding geological studies to examine the habitability of Mars. Such an extended mission life may be attributed to impressive performances of several subsystems, including power subsystem components, i.e., solar array and batteries. The novelty and challenge for this mission in terms of energy storage is the use of lithium-ion batteries, for the first time in a major NASA mission, for keeping the rover electronics warm, and supporting nighttime experimentation and communications. The use of Li-ion batteries has considerably enhanced or even enabled these rovers, by providing greater mass and volume allocations for the payload and wider range of operating temperatures for the power subsystem and thus reduced thermal management. After about 800 days of exploration, there is only marginal change in the end-of discharge (EOD) voltages of the batteries or in their capacities, as estimated from in-flight voltage data and corroborated by ground testing of prototype batteries. Enabled by such impressive durability from the Li-ion batteries, both from a cycling and calendar life stand point, these rovers are poised to extend their exploration well beyond 1000 sols, though other components have started showing signs of decay. In this paper, we will update the performance characteristics of these batteries on both Spirit and Opportunity.

low temperatures↗
NASA NTRS2009

Performance Testing of Yardney Li-Ion Cells and Batteries in Support of Future NASA Missions

NASA requires lightweight rechargeable 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. Due to the attractive performance characteristics, Li-ion batteries have been identified as the battery chemistry of choice for a number of future applications. For example, JPL is planning to launch another unmanned rover mission to the planet Mars. This mission, referred to as the Mars Science Laboratory (MSL), will involve the use of a rover that is much larger than the previously developed Spirit and Opportunity Rovers for the 2003 Mars Exploration Rover (MER) mission, that are currently still in operation on the surface of the planet after more than five years. Part of the reason that the MER rovers have operated so successfully, far exceeding the required mission duration of 90 sols, is that they possess robust Li-ion batteries, manufactured by Yardney Technical Products, which have demonstrated excellent life characteristics. Given the excellent performance characteristics displayed, similar Li-ion batteries have been projected to successfully meet the mission requirements of the up-coming MSL mission. In addition to future missions to Mars, Li-ion technology is attractive for a number of other future NASA applications which require high specific energy, rechargeable batteries. To ascertain the viability of using Li-ion batteries for these applications, a number of performance validation tests have been performed on both Yardney cells and batteries of various sizes. These tests include mission simulation tests, charge and discharge rate characterization testing, cycle life testing under various conditions, and storage testing.

Smart, M. C.↗
NASA NTRS2010

NASA Glenn Research Center Electrochemistry Branch Battery Overview

This presentation covers an overview of NASA Glenn s history and heritage in the development of electrochemical systems for aerospace applications. Specific areas of focus are Li-ion batteries and their development for future Exploration missions. Current component development efforts for high energy and ultra high energy Li-ion batteries are addressed. Electrochemical systems are critical to the success of Exploration, Science and Space Operations missions. NASA Glenn has a long, successful heritage with batteries and fuel cells for aerospace applications. GRC Battery capabilities and expertise span basic research through flight hardware development and implementation. There is a great deal of synergy between energy storage system needs for aerospace and terrestrial applications.

Manzo, Michelle A.↗
NASA NTRSDate not supplied

Computational Tools to Design Molten Salt Electrolytes for High-Temperature Environments

Current Li-ion batteries are designed for a small operating window of 5 °C to 55 °C. Modifications to the electrolyte for operation in Mars atmosphere extended this range on the lower bound to ~ -40 °C. These operating-temperature ranges are far from those presented in high-temperature environments, such as the Venus surface, where temperatures are around 450 °C. Protecting the state-of-the-art Li-ion batteries require insulations that decreases the volumetric capacity and limiting the operational time-window. These unique challenges require a paradigm shift in materials used for designing high-temperature batteries. Molten salt electrolyte-based batteries offer a plausible route to designing high-temperature batteries. ZEBRA batteries are known to be one of the safest energy storage devices operating at 270-350 °C. Nitrate based eutectics, operating at 150 °C have also been used in Li-O2 batteries. In this study, we will examine molten-salt electrolyte transport and electrochemical properties using first-principles computations and benchmark against experiments. Further, we will present thermodynamics-based models for designing and predicting melting point of molten salt mixtures. Based on these computational tools, new molten salt mixtures designed with desired operating temperatures and electrochemical windows will be presented. Implications of these new eutectics in the context of high-temperature environment exploration will also be discussed.

Balachandran Radhakrishnan↗
NASA NTRS2003

NASA Tech Briefs, January 2003

Topics covered include: Optoelectronic Tool Adds Scale Marks to Photographic Images; Compact Interconnection Networks Based on Quantum Dots; Laterally Coupled Quantum-Dot Distributed-Feedback Lasers; Bit-Serial Adder Based on Quantum Dots; Stabilized Fiber-Optic Distribution of Reference Frequency; Delay/Doppler-Mapping GPS-Reflection Remote-Sensing System; Ladar System Identifies Obstacles Partly Hidden by Grass; Survivable Failure Data Recorders for Spacecraft; Fiber-Optic Ammonia Sensors; Silicon Membrane Mirrors with Electrostatic Shape Actuators; Nanoscale Hot-Wire Probes for Boundary-Layer Flows; Theodolite with CCD Camera for Safe Measurement of Laser-Beam Pointing; Efficient Coupling of Lasers to Telescopes with Obscuration; Aligning Three Off-Axis Mirrors with Help of a DOE; Calibrating Laser Gas Measurements by Use of Natural CO2; Laser Ranging Simulation Program; Micro-Ball-Lens Optical Switch Driven by SMA Actuator; Evaluation of Charge Storage and Decay in Spacecraft Insulators; Alkaline Capacitors Based on Nitride Nanoparticles; Low-EC-Content Electrolytes for Low-Temperature Li-Ion Cells; Software for a GPS-Reflection Remote-Sensing System; Software for Building Models of 3D Objects via the Internet; "Virtual Cockpit Window" for a Windowless Aerospacecraft; CLARAty Functional-Layer Software; Java Library for Input and Output of Image Data and Metadata; Software for Estimating Costs of Testing Rocket Engines; Energy-Absorbing, Lightweight Wheels; Viscoelastic Vibration Dampers for Turbomachine Blades; Soft Landing of Spacecraft on Energy-Absorbing Self-Deployable Cushions; Pneumatically Actuated Miniature Peristaltic Vacuum Pumps; Miniature Gas-Turbine Power Generator; Pressure-Sensor Assembly Technique; Wafer-Level Membrane-Transfer Process for Fabricating MEMS; A Reactive-Ion Etch for Patterning Piezoelectric Thin Film; Wavelet-Based Real-Time Diagnosis of Complex Systems; Quantum Search in Hilbert Space; Analytic Method for Computing Instrument Pointing Jitter; and Semiselective Optoelectronic Sensors for Monitoring Microbes.

Source record↗
NASA NTRS2006

Li-Ion Batteries for Space Applications: High Specific Energy and Wide-Operating Temperature

Compared to the conventional Ni-Co oxides (with or without AI additions), the NMC (1/3:1/3:1/3) cathode provides marginal improvement in specific capacity. However, some of the formulations based on the solid solutions of layered Li2Mn03 and LiM02 (M = Mn0.5Ni0.5} have shown capacities as high as 250 mAh/g, combined with high cell voltages (4.5 V) and with the likelihood of enhanced thermal stability. Multi-component electrolytes with low EC-proportions and selected co-solvents provide significant improvement in the low temperature performance, down to -60 C, combined with the non-flammable attribute from the co-solvents. The NMC cathode shows good compatibility with the carbonate-based low temperature electrolytes. Impressive performances have been realized at low temperatures of <= 30 C. Electrolytes with high salt concentration and high EC content fare well at room temperatures, while the formulations with low EC content and low salt concentration are preferred at low temperatures. DPA studies reveal increased SEI growth on the electrodes, especially anode, upon irradiation. Performance of low temperature electrolytes in prototype cells corroborate the findings from laboratory cells.

storage↗
NASA NTRS2013

NASA Tech Briefs, April 2013

Topics covered include: Fully Integrated, Miniature, High-Frequency Flow Probe Utilizing MEMS Leadless SOI Technology; Nanoscale Surface Plasmonics Sensor With Nanofluidic Control; Advanced Dispersed Fringe Sensing Algorithm for Coarse Phasing Segmented Mirror Telescopes; Neural Network Back-Propagation Algorithm for Sensing Hypergols; Bulk Moisture and Salinity Sensor; Change-Based Satellite Monitoring Using Broad Coverage and Targetable Sensing; Circularly Polarized Microwave Antenna Element with Very Low Off-Axis Cross-Polarization; Ultra-Low Heat-Leak, High-Temperature Superconducting Current Leads for Space Applications; Flash Cracking Reactor for Waste Plastic Processing; An Automated Safe-to-Mate (ASTM) Tester; Wireless Chalcogenide Nanoionic-Based Radio-Frequency Switch; Compute Element and Interface Box for the Hazard Detection System; DOT Transmit Module; Composite Aerogel Multifoil Protective Shielding; Li-Ion Electrolytes with Improved Safety and Tolerance to High-Voltage Systems; Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation; Controlled, Site-Specific Functionalization of Carbon Nanotubes with Diazonium Salts; Regenerable Sorbent for CO2 Removal; Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value; Lexan Linear Shaped Charge Holder with Magnets and Backing Plate; Robotic Ankle for Omnidirectional Rock Anchors; Wind, Wave, and Tidal Energy Without Power Conditioning; An Active Heater Control Concept to Meet IXO Type Mirror Module Thermal-Structural Distortion Requirement; Waterless Clothes-Cleaning Machine; Integrated Electrical Wire Insulation Repair System; LVGEMS Time-of-Flight Mass Spectrometry on Satellites; Surface Inspection Tool for Optical Detection of Surface Defects; Per-Pixel, Dual-Counter Scheme for Optical Communications; Certification-Based Process Analysis; Surface Navigation Using Optimized Waypoints and Particle Swarm Optimization; Smart-Divert Powered Descent Guidance to Avoid the Backshell Landing Dispersion Ellipse; Estimating Foreign-Object-Debris Density from Photogrammetry Data; Adaptive Sampling of Spatiotemporal Phenomena with Optimization Criteria; Building a 2.5D Digital Elevation Model From 2D Imagery; Eyes on the Earth 3D; Target Trailing With Safe Navigation for Maritime Autonomous Surface Vehicles; Adams-Based Rover Terramechanics and Mobility Simulator - ARTEMIS; ISTP CDF Skeleton Editor; Uplink Summary Generator (ULSGEN) Version 1.0; Robotics On-Board Trainer (ROBoT); Software Engineering Tools for Scientific Models; Automatic Data Filter Customization Using a Genetic Algorithm; Tracker Toolkit; Towards Efficient Scientific Data Management Using Cloud Storage; On a Formal Tool for Reasoning About Flight Software Cost Analysis; A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries; Spacecraft Crew Cabin Condensation Control; and Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex.

Source record↗
NASA NTRS2004

High power, gel polymer lithium-ion cells with improved low temperature performance for NASA and DoD applications

Both NASA and the U.S. Army have interest in developing secondary energy storage devices that are capable of meeting the demanding performance requirements of aerospace and man-portable applications. In order to meet these demanding requirements, gel-polymer electrolyte-based lithium-ion cells are being actively considered, due to their promise of providing high specific energy and enhanced safety aspects.

high power li-ion batteries↗
NASA NTRS2011

A Summary on Progress in Materials Development for Advanced Lithium-ion Cells for NASA's Exploration Missions

Vehicles and stand-alone power systems that enable the next generation of human missions to the moon will require energy storage systems that are safer, lighter, and more compact than current state-of-the-art (SOA) aerospace quality lithium-ion (Li-ion) batteries. NASA is developing advanced Li-ion cells to enable or enhance future human missions to Near Earth Objects, such as asteroids, planets, moons, libration points, and orbiting structures. Advanced, high-performing materials are required to provide component-level performance that can offer the required gains at the integrated cell level. Although there is still a significant amount of work yet to be done, the present state of development activities has resulted in the synthesis of promising materials that approach the ultimate performance goals. This paper on interim progress of the development efforts will present performance of materials and cell components and will elaborate on the challenges of the development activities and proposed strategies to overcome technical issues.

Reid, Concha M.↗
NASA NTRS2011

Progress in Materials and Component Development for Advanced Lithium-ion Cells for NASA's Exploration Missions

Vehicles and stand-alone power systems that enable the next generation of human missions to the Moon will require energy storage systems that are safer, lighter, and more compact than current state-of-the- art (SOA) aerospace quality lithium-ion (Li-ion) batteries. NASA is developing advanced Li-ion cells to enable or enhance the power systems for the Altair Lunar Lander, Extravehicular Activities spacesuit, and rovers and portable utility pallets for Lunar Surface Systems. Advanced, high-performing materials are required to provide component-level performance that can offer the required gains at the integrated cell level. Although there is still a significant amount of work yet to be done, the present state of development activities has resulted in the synthesis of promising materials that approach the ultimate performance goals. This report on interim progress of the development efforts will elaborate on the challenges of the development activities, proposed strategies to overcome technical issues, and present performance of materials and cell components.

Reid, Concha, M.↗
NASA NTRS2012

Safety and Long-Term Performance of Lithium-ion Pouch Cells

Lithium-ion batteries have the highest energy density of the batteries available in the commercial market today. Although most lithium-ion cell designs use a metal can design, this has changed significantly in recent years. Cell designs are offered in the pouch format as they offer better volumetric and gravimetric energy densities and in some cases, higher tolerance to abuse or off-nominal conditions. In the past decade, several state-of-the-art lithium-ion pouch cell designs have been tested. The pouch cell designs have become more robust in the past two years but there are still a few issues that need to be looked into for optimization. The pouch cells seem to have a tendency to swell when left in storage under ambient conditions. The cells also swell under overvoltage and undervoltage conditions. A significant issue that has been observed is the swelling of the cells under a vacuum condition which could lead to deformation of the cell pouch after this exposure. This last factor would be very critical in the use of these cell designs for space applications as vacuum exposure is used to check for cell and battery leaks before it is flown into space. In rare cases, corrosion of the aluminum layer of the pouches has been observed in stored cells. Pouch material analysis has been carried out in an effort to understand the strength of the pouches and determine if this is a factor in the corrosion as well as unsafe condition of the cells as deformation of the inner layers of the pouch could occur when the cells swell under the various conditions described above. Pouch materials are typically aluminized plastic, made up of a layer of Al sandwiched between one or more layers of polymeric material. Deformations or cell manufacturing processes could lead to a compromise of the inner polymeric layer/s of the pouch leading to the corrosion of the Al layer in the aluminized pouch material. The safety of the pouch cell designs has been determined for cells from various manufacturers. The results are varied and in some cases, unexpected. This paper presents a summary of the tests carried out on a few li-ion pouch cell designs from various cell manufacturers. The data will include performance under different conditions specifically cycling under vacuum conditions with and without restraints as well as safety test data. The presentation will also include detailed analysis of the pouch material for the cells studied.

Jeevarajan, Judith↗