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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

Li-Ion Battery and Supercapacitor Hybrid Design for Long Extravehicular Activities

With the need for long periods of extravehicular activities (EVAs) on the Moon or Mars or a near-asteroid, the need for long-performance batteries has increased significantly. The energy requirements for the EVA suit, as well as surface systems such as rovers, have increased significantly due to the number of applications they need to power at the same time. However, even with the best state-of-the-art Li-ion batteries, it is not possible to power the suit or the rovers for the extended period of performance. Carrying a charging system along with the batteries makes it cumbersome and requires a self-contained power source for the charging system that is usually not possible. An innovative method to charge and use the Li-ion batteries for long periods seems to be necessary and hence, with the advent of the Li-ion supercapacitors, a method has been developed to extend the performance period of the Li-ion power system for future exploration applications. The Li-ion supercapacitors have a working voltage range of 3.8 to 2.5 V, and are different from a traditional supercapacitor that typically has a working voltage of 1 V. The innovation is to use this Li-ion supercapacitor to charge Liion battery systems on an as-needed basis. The supercapacitors are charged using solar arrays and have battery systems of low capacity in parallel to be able to charge any one battery system while they provide power to the application. Supercapacitors can safely take up fast charge since the electrochemical process involved is still based on charge separation rather than the intercalation process seen in Li-ion batteries, thus preventing lithium metal deposition on the anodes. The lack of intercalation and eliminating wear of the supercapacitors allows for them to be charged and discharged safely for a few tens of thousands of cycles. The Li-ion supercapacitors can be charged from the solar cells during the day during an extended EVA. The Liion battery used can be half the capacity required for a nominal EVA. The small Li-ion battery can be divided into two parallel modules with independent charging ports that would allow the supercapacitors to charge one battery while the other is providing power to the rover or suit.

Jeevarajan, Judith↗
DOE OSTI2025

Biomass-Derived Carbon and Their Composites for Supercapacitor Applications: Sources, Functions, and Mechanisms

Biomass-derived carbons are eco-friendly and sustainable materials, making them ideal for supercapacitors due to their high surface area, excellent conductivity, cost-effectiveness, and environmental benefits. This review provides valuable insights into biomass-derived carbon and modified carbon for supercapacitors, integrating both experimental results and theoretical calculations. This review begins by discussing the origins of biomass-derived carbon in supercapacitors, including plant-based, food waste-derived, animal-origin, and microorganism-generated sources. Then, this review presents strategies to improve the performance of biomass-derived carbon in supercapacitors, including heteroatom doping, surface functionalization, and hybrid composite construction. Furthermore, this review analyzes the functions of biomass-derived carbon in supercapacitors both in its pure form and as modified materials. The review also explores composites derived from biomass-based carbon, including carbon/MXenes, carbon/MOFs, carbon/graphene, carbon/conductive polymers, carbon/transition metal oxides, and carbon/hydroxides, providing a thorough investigation. Most importantly, this review offers an innovative summary and analysis of the role of biomass-derived carbon in supercapacitors through theoretical calculations, concentrating on four key aspects: energy band structure, density of states, electron cloud density, and adsorption energy. Finally, the review concludes the future research directions for biomass carbon-based supercapacitors, including the discovery of novel biomass materials, tailoring surface functional groups, fabricating high-performance composite materials, exploring ion transfer mechanisms, and enhancing practical applications. In summary, this review offers a thorough exploration of the sources, functions, and mechanisms of biomass-derived carbon in supercapacitors, providing valuable insights for future research.

biomass-derived carbon↗
NASA NTRS2016

Mechanical Model Development for Composite Structural Supercapacitors

Novel composite structural supercapacitor concepts have recently been developed as a means both to store electrical charge and to provide modest mechanical load carrying capability. Double-layer composite supercapacitors are often fabricated by impregnating a woven carbon fiber fabric, which serves as the electrodes, with a structural polymer electrolyte. Polypropylene or a glass fabric is often used as the separator material. Recent research has been primarily limited to evaluating these composites experimentally. In this study, mechanical models based on the Multiscale Generalized Method of Cells (MSGMC) were developed and used to calculate the shear and tensile properties and response of two composite structural supercapacitors from the literature. The modeling approach was first validated against traditional composite laminate data. MSGMC models for composite supercapacitors were developed, and accurate elastic shear/tensile properties were obtained. It is envisioned that further development of the models presented in this work will facilitate the design of composite components for aerospace and automotive applications and can be used to screen candidate constituent materials for inclusion in future composite structural supercapacitor concepts.

Micromechanics↗
DOE OSTI2026

Reducing Internal Resistance in Activated Carbon Supercapacitors via Exfoliated Coal-Derived Graphene Additive

Low equivalent series resistance (ESR) is critical for high-rate energy storage devices (e.g., supercapacitors), and graphene is a promising additive for reducing ESR in carbon-based supercapacitor electrodes. However, graphene can be costly and difficult to produce at scale. This study investigates the addition of graphene, produced through electrochemical exfoliation of domestic coal-derived graphite, in activated carbon-based supercapacitors. The coal-derived graphene was incorporated at varying weight loadings and tested in symmetric supercapacitors with aqueous electrolytes. ESR was evaluated using both direct current internal resistance (DCIR) and electrochemical impedance spectroscopy (EIS) measurements. DCIR measurements revealed ESR reductions of ∼34%, ∼18%, and ∼21% at 3, 5, and 10 wt % loadings, respectively, compared to the baseline (0 wt %) of ∼0.54 Ω. These results were further confirmed by EIS measurements. Correspondingly, power density increased by ∼52%, ∼27%, and ∼35% at 3, 5, and 10 wt % loadings relative to the baseline (∼29 kW/kg). Additionally, the electrodes exhibited moderate increases in specific capacitance and energy density, along with stable cycling performance (capacitance retention above 85% after 100,000 cycles) and capacitive behavior (α = 0.95−0.97), suggesting favorable charge transfer kinetics. These findings highlight the potential of exfoliated coal-derived graphene as an effective additive for supercapacitor electrodes.

capacitors↗
NASA NTRS2008

Low-Temperature Supercapacitors

An effort to extend the low-temperature operational limit of supercapacitors is currently underway. At present, commercially available non-aqueous supercapacitors are rated for a minimum operating temperature of -40 C. A capability to operate at lower temperatures would be desirable for delivering power to systems that must operate in outer space or in the Polar Regions on Earth. Supercapacitors (also known as double-layer or electrochemical capacitors) offer a high power density (>1,000 W/kg) and moderate energy density (about 5 to 10 Wh/kg) technology for storing energy and delivering power. This combination of properties enables delivery of large currents for pulsed applications, or alternatively, smaller currents for low duty cycle applications. The mechanism of storage of electric charge in a supercapacitor -- at the electrical double-layer formed at a solid-electrode/liquid-electrolyte interface -- differs from that of a primary or secondary electrochemical cell (i.e., a battery) in such a manner as to impart a long cycle life (typically >10(exp 6) charge/discharge cycles).

Brandon, Erik J.↗
NASA NTRS2010

Supercapacitor Electrolyte Solvents with Liquid Range Below -80 C

A previous NASA Tech Brief ["Low-Temperature Supercapacitors" (NPO-44386) NASA Tech Briefs, Vol. 32, No 7 (July 2008), page 32] detailed ongoing efforts to develop non-aqueous supercapacitor electrolytes capable of supporting operation at temperatures below commercially available cells (which are typically limited to charging and discharging at > or equal to -40 C). These electrolyte systems may enable energy storage and power delivery for systems operating in extreme environments, such as those encountered in the Polar regions on Earth or in the exploration of space. Supercapacitors using these electrolytes may also offer improved power delivery performance at moderately low temperatures (e.g. -40 to 0 C) relative to currently available cells, offering improved cold-cranking and cold-weather acceleration capabilities for electrical or hybrid vehicles. Supercapacitors store charge at the electrochemical double-layer, formed at the interface between a high surface area electrode material and a liquid electrolyte. The current approach to extending the low-temperature limit of the electrolyte focuses on using binary solvent systems comprising a high-dielectric-constant component (such as acetonitrile) in conjunction with a low-melting-point co-solvent (such as organic formates, esters, and ethers) to depress the freezing point of the system, while maintaining sufficient solubility of the salt. Recent efforts in this area have led to the identification of an electrolyte solvent formulation with a freezing point of -85.7 C, which is achieved by using a 1:1 by volume ratio of acetonitrile to 1,3-dioxolane

Brandon, Erik↗
DOE OSTI2026

(CrMnCoNiTi) 3 O 4 high-entropy spinel oxide as a high-performance electrode for supercapacitors

In this study, spinel-structured (CrMnCoNiTi)₃O₄ high-entropy oxides (HEOs) have been successfully synthesized using the solution combustion method, and their performance as supercapacitor electrode materials was investigated. These HEOs exhibit excellent performance, stemming from the unique high-entropy effect and lattice distortion. This structure effectively buffers volumetric strain during cycling, conferring the material with extremely high structural stability and specific capacity. The material demonstrates a high specific capacity of 491.5 C∙g⁻¹ at a current density of 0.5 A∙g⁻¹. Furthermore, it shows extraordinary cycling stability: after 10,000 charge/discharge cycles at 5 A∙g⁻¹, the capacity retention rate is 99%, and the Coulombic efficiency consistently remains close to 100%. Ex-situ structural characterizations further reveal that this excellent cycling durability originates from a cooperative multination valence reconstruction mechanism within an entropy-stabilized spinel framework. Additionally, a symmetric supercapacitor assembled using this material and 1 M KOH electrolyte successfully extended the working voltage to 1.2 V. This research highlights the great potential of high-entropy oxides in synergizing high energy density and ultra-long cycling life, laying a solid foundation for the development of next-generation high-performance supercapacitor electrode materials.

High entropy oxides↗
DOE OSTI2025

Facile synthesis of co-doped Carbon nanofibers for supercapacitor applications

Here, in this study, the synthesis and electrochemical performance of carbon nanofibers (CNFs) co-doped with aluminum (Al) and nitrogen (N) and decorated with zinc oxide (ZnO) nanoparticles are investigated. After electrospinning polyacrylonitrile (PAN) nanofibers, the nanofiber mats are coated with Al and ZnO precursors by the dip coating method and converted into carbon nanofibers by thermal treatments at 850 °C. Co-doping and nanoparticle decoration affect the efficacy of carbon nanofibers as supercapacitors. With a maximal specific capacitance of 206.28 Fg -1 , it is believed that our produced carbon nanofibers, which can effectively store the renewable energy resources required to meet the rising energy demand, offer superior electrochemical properties compared to traditional supercapacitor materials. The effective incorporation of Al, N, and ZnO into the CNF structure, in conjunction with enhanced electrochemical performance, represents a significant advancement in the development of functional carbon nanofibers.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

MXene/graphitic carbon nitride-supported metal selenide for all-solid-state flexible supercapacitor and oxygen evolution reaction

We report a new type of combination of rare earth metal selenides (Ce 2 Se 3 and Er 2 Se 3 ) with a Ti 3 C 2 T x /S-doped graphitic carbon nitride heterostructure for bifunctional application in flexible supercapacitors and oxygen evolution reactions. The incorporation of S-doped graphitic carbon nitride in MXenes reduced the layer stacking tendency of both two-dimensional sheets and eliminated volume expansion by forming a heterostructure. Cerium and erbium rare earth metal centers induce reactive surface sites, whereas binary layers of Ti 3 C 2 T x /S-doped graphitic carbon nitride provide a conducting matrix for the homogeneous growth of the metal selenides. The assembled all-solid-state flexible asymmetric supercapacitor exhibited a high specific capacitance of 60 F g –1 , an energy density of 10.1 W h kg –1 (volumetric energy density: 0.9 mW h cm –3 ) at 2 A g –1 , and 100% capacitance retention after 10 000 charge–discharge cycles with good flexibility for real-time applications. Furthermore, the optimum nanohybrid showed a low overpotential of 280 mV and a Tafel slope of 99 mV dec –1 with durable electrocatalytic performance. Furthermore, this work is the first to investigate the bifunctional energy efficiency of rare earth metal selenides grown over MXene materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Microscopic 3D Graphene for High-Performance Supercapacitors with Ultra-High Areal Capacitance

Despite graphene being considered as an ideal supercapacitor electrode material, its use in commercial devices is limited because few methods exist to produce high-quality graphene at large scale and low-cost. We report a simple method to synthesize 3D graphene by graphenization of coal tar pitch with a K2CO3 catalyst. This produces 3D graphenes with high specific surface areas up to 2113 m2 g-1 and exceptional crystallinity (Raman ID/IG as low as ~ 0.15). The material has an outstanding specific capacitance of 182.6 F g-1 at a current density of 1.0 A g-1. This occurs at mass loading of 30 mg cm-2 which is 3 times higher than commercial requirements, yielding an ultra-high areal capacitance of 5.48 F cm-2. Moreover, the K2CO3 is recycled and reused over 10 cycles. The synthesis method and resulting electrocapacitive performance properties create new opportunities for using 3D graphene more broadly in practical supercapacitor devices.

Pham, Viet Hung↗
DOE OSTI2026

Supercapacitor-Based Power Resilience Solutions for Modern Grids, Microgrids, and Facilities

This report summarizes the tests and results of a supercapacitor based energy storage system demonstration project performed in collaboration with Capacitech Energy, Orlando Utilities Commission and Sandia National Labs. This project evaluated a 3.6 farad (F), 720 V rated supercapacitor system in a microgrid environment to study three primary use cases: black start, voltage regulation, and load leveling, and successfully demonstrated the performance for the use cases.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS2015

Graphene-Based Electrode for a Supercapacitor

A supercapacitor electrode mechanism comprising an electrically conductive, porous substrate, having one or more metallic oxides deposited on a first surface and a chemically reduced graphene oxide deposited on a second surface, to thereby provide an electrical double layer associated with the substrate. The substrate may be carbon paper or a similar substance. The layers of the supercapacitor are optionally rolled into an approximately cylindrical structure.

Chen, Bin↗
NASA NTRS2018

Metal Oxide Vertical Graphene Hybrid Supercapacitors

A metal oxide vertical graphene hybrid supercapacitor is provided. The supercapacitor includes a pair of collectors facing each other, and vertical graphene electrode material grown directly on each of the pair of collectors without catalyst or binders. A separator may separate the vertical graphene electrode materials.

Meyya Meyyappan↗
DOE OSTI2024

Upcycling linear low-density polyethylene waste to turbostratic graphene for high mass loading supercapacitors

Linear low-density polyethylene (LLDPE) waste is difficult to upcycle into more valuable carbon materials because it tends to completely decompose into small molecules during thermal processing. In this work, LLDPE is upcycled into a high quality turbostratic graphene using a pre-treatment step to oxidatively crosslink the polymer with the assistance of solid additives (KCl and K 2 CO 3 ) that improve crosslinking by increasing the effective surface area of the polymer melt during processing. After this pretreatment step, the crosslinked polymer could then be carbonized and catalytically graphenized between 400–950°C without decomposition of the polymer feedstock. The LLDPE derived graphene (LLDPE-G) obtained from this process has a Brunauer–Emmett–Teller (BET) specific surface area, up to 1800m 2 g -1 and average Raman I D /I G and I 2D /I G ratios of 0.85 and 0.57, respectively, indicating high quality graphene. When used as an electrode material in symmetric supercapacitors, LLDPE-G possesses a specific capacitance up to 175Fg -1 at a mass loading of 20mgcm -2 , which is two times the commercial requirement, yielding an areal capacitance of 3.5 Fcm -2 . Moreover, LLDPE-G exhibits exceptional cycling stability with a capacitance retention of 95.8 % after 100,000 cycles at a current density of 4.0 Ag -1 . Additionally, the KCl and K 2 CO 3 solids are recycled and reused over 3 complete reaction cycles to make new LLDPE-G with the material quality and electrocapacitive performance retained and verified after each cycle. Our approach creates new opportunities for upcycling waste LLDPE and other varieties of polyethylene into a higher value graphene used for electrochemical energy storage applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Dual-Functional Thermocapacitive Heat Pump with Electrochemical Supercapacitors for Building Thermal Management and Energy Storage

Efficient heating and cooling technologies can help reduce the energy consumption and carbon emissions of buildings. This work explores the use of supercapacitive cells in a multifunctional, liquid-regenerated thermocapacitive heat pump that can provide electrical energy storage in addition to heating and cooling. A proof-of-concept prototype based on eight commercial supercapacitors and using deionized water as a liquid regenerator demonstrated cooling and energy storage capabilities. A peak cooling coefficient of performance (COPc) of 0.27 was achieved at a temperature drop of 0.24 K. The highest measured electrical energy storage density of the cells was 5.93 J cm-3, and the highest cooling power delivered relative to the volume of the cells was 0.58 mW cm-3. This work demonstrates the use of electrochemical energy storage devices in multifunctional equipment for thermal management in buildings.

25 ENERGY STORAGE↗
DOE OSTI2026

Investigation of a thermocapacitive cycle by aqueous supercapacitors for multifunctional heat pump and energy storage

Thermocapacitive cycles are promising thermal and energy storage cycles using supercapacitors, which can achieve thermal efficiencies over 50% of the Carnot limit. There is a lack of work investigating the use of thermocapacitive effects in practical heat pumps. Here, this paper explores the design of thermocapacitive cells with higher temperature changes to be better suited for heat pumping applications. To evaluate the cell designs on temperature changes, pouch type cells are prototyped and modeled, and tested using a micro-calorimeter. A peak adiabatic temperature span of a LiCl aqueous cell is 2.7 °C. By arranging the cells in a cascade manner, the projected adiabatic temperature span can reach up to 12 °C with a heating density of 15 kW m −3 and an energy storage density of 0.83 kWh m −3 . Models predict that this could be increased to 30 °C and 1.65 kWh m −3 through improvements to cell capacitance and thermopower. Incorporating the energy storage capabilities into heating and cooling devices can be beneficial to building thermal management as energy storage becomes increasingly important for energy system integration.

25 ENERGY STORAGE↗
DOE OSTI2025

Wastepaper-derived porous carbon supported cobalt nanocomposites for all solid-state flexible supercapacitor

The conversion of wastepaper into high-value carbon materials has gained significant attention as a sustainable strategy for energy storage applications. Owing to its low cost, abundance, and intrinsic fibrous structure, wastepaper serves as an attractive precursor for carbon-based electrode materials. In this work, a novel electrode comprising cobalt nanoparticles and Co 3 O 4 embedded in wastepaper-derived porous carbon has been developed for use in a flexible all-solid-state asymmetric supercapacitor. The integration of cobalt nanoparticles and Co 3 O 4 introduces redox-active centres, which enhance the electrochemical activity of the carbon framework. Mean while, the interconnected porous and conductive carbon network enables rapid ion diffusion and efficient electron transport, synergistically improving the overall electrochemical performance. It delivers a high specific capacitance of 61.5 Fg -1 , a power density of 5143 W kg -1 , and an energy density of 9 Wh kg -1 at a current density of 2.5 A/ g. Furthermore, the device maintains outstanding cycling stability, retaining 82.86 % of its capacitance after 10,000 charge-discharge cycles. Practical applicability is confirmed through its ability to power

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Pseudocapacitive Titanium Oxynitride Nanowires for Ultrahigh Capacitance Supercapacitors

High-quality, multifunctional two-dimensional (2D) titanium oxynitide (TiNO) thin films and one-dimensional (1D) TiNO nanowires have been synthesized using a pulsed laser deposition, a simple, fast, and congruent evaporation method. First-principles calculations as a function of surface orientation and termination indicate that surface oxidation of TiNO nanowires can stabilize the (110) orientation observed experimentally. The specific capacitance value for the TiNO nanowire samples (2725 mF/cm 2 ) has been found to be nearly six times more than that of the TiNO thin film samples (400 mF/cm 2 ), which is attributed to the high packing density of TiNO nanowires over a given area. The nanowire samples have also been found to exhibit a significantly higher energy density (1.35 μWh/cm 2 ) than the TiNO thin-film samples (0.33 μWh/cm 2 ). Thus, the TiNO material system in thin-film and nanowire forms has been demonstrated to be a promising candidate for use as an electrode material in supercapacitors and other charge-storage applications.

capacitors↗