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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

A comprehensive study on two types of supercapacitor composite electrodes comprising MnO 2 and activated carbon nanofibers: Self-supporting membrane and ground powder

Manganese dioxide (MnO 2 )@carbon composites have been attractively considered as electrode materials for supercapacitors (SCs) due to synergistic effects. This work systematically investigated the structure of MnO 2 @carbon nanofiber (CNF) composite electrodes with the different forms of CNFs and the corresponding electrochemical performance of SCs. In brief, novel activated carbon nanofibers were first fabricated by electrospinning the hydroxyl-containing poly(amic acid) solution, and then the preferred CNF material was decorated by MnO 2 crystals in the form of self-supporting membrane and ground powders, respectively. Additionally, the synthesis parameters were investigated and optimized based on the electrochemical performance of SCs. The results reveal that the powdered composite electrode exhibits a higher specific surface area of 501 m 2 g –1 compared to the self-supporting membrane composite electrode under the same conditions, resulting in a promising specific capacity of 214.1 mAh g –1 (770.8 Fg –1 ) in 6M KOH solution at 0.5 A g –1 . In addition, the capacitance of the symmetrical SC device assembled by G-HMC-1:3–80 reaches 179.8 Fg –1 , coupled with an energy density of 24.86 Whkg –1 at 230 Wkg –1 power density. This work provides valuable hints for designing SC composite electrode materials with outstanding performance.

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↗
DOE OSTI2025

Confinement of Ti 3 C 2 T x MXene Nanosheets within a Polymer Matrix via In-situ Polymerization and Deposition on Carbon Cloth for Supercapacitors

Here, with the promising preliminary electrochemical performance, further investigation into polymer-filler interfacial regulation and confined ion transport in the CC/polymer/MXene system could provide deeper insights, paving the way for its application in flexible supercapacitors and other energy storage devices requiring highly adaptable electrodes.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Upcycling Linear Low-Density Polyethylene Waste into Graphene for High Mass Loading Supercapacitors

Polyethylene is notoriously difficult to upcycle because it decomposes into light gases at approximately 350-400 °C which prevents processing it at higher temperatures to convert it into electrode materials. We address this challenge by using an air-based, thermos-oxidative process, which heats linear low-density polyethylene (LLDPE) just below the decomposition point to initiate oxidation and cross-linking of LLDPE alkyl chains. These molecular transformations allow LLDPE to be graphenized at 950 °C without decomposing. The LLDPE-derived graphene (LLDPE-G) has a BET specific surface area up to 1,800 m2/g and Raman ID/IG ratio of 0.85. When used as electrode material for a symmetric supercapacitor with the 1 M H2SO4 electrolyte, LLDPE-G possesses an specific capacitance up to 175 F/g at mass loading of 20 mg/cm2, yielding an areal capacitance of 3.5 F/cm2. The cycling stability with capacitance demonstrates a retention of 95.8% after 100,000 cycles at high current density of 4.0 A/g.

Gao, Yuan↗
DOE OSTI2024

Upcycling Linear Low-Density Polyethylene Waste into Graphene for High Mass Loading Supercapacitors

Upcycling plastic into advanced carbons, such as graphene and porous carbon, offers attractive options to manage waste streams by converting the plastic into carbon electrode materials for energy storage devices. Linear low density polyethylene (LLDPE) is firstly bulk-oxidized with a facile and scalable method and then carbonized and catalyticlly graphenized into porous graphene materials. The LLDPE derived graphene (LLDPE-G) has a BET specific surface area up to 1800 m2/g and Raman ID/IG ratio of 0.85. When used as electrode material for symmetric supercapacitor, LLDPE-G possesses outstanding specific capacitance and excellent areal capacitance. Moreover, LLDPE-G exhibits exceptional cycling stability with capacitance retention of 95.8% after 100,000 cycles. Last but not least, KCl is recycled and reused over 3 cycles with material quality and electrocapacitive performance of LLDPE-G retained and verified after each cycle.

Gao, Yuan↗
DOE OSTI2024

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

This presentation was given at the 2024 AIChE Annual Meeting, San Diego, CA, October 27-31, 2024. This presentation describes a low-cost and scalable method to convert coal tar pitch into high-quality 3D graphene with high surface area, hierarchical pore size distribution, and high electrical conductivity which allows for the creation of supercapacitor electrodes with ultra-high mass loading (30 mg/cm2), leading to ultra-high areal capacitance.

Pham, Viet Hung↗
DOE OSTI2024

Upcycling Low Linear Density Polyethylene Waste into Turbostratic Graphene for High Mass Loading Supercapacitors

In this work, LLDPE was 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 K2CO3) 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 complete decomposition of the material. The LLDPE derived graphene (LLDPE-G) obtained from this process has a Brunauer–Emmett–Teller (BET) specific surface area, up to 1800 m2g-1 and average Raman ID/IG and I2D/IG ratios of 0.85 and 0.57, respectively, indicating high quality graphene. When used as an electrode material in symmetric supercapacitors, LLDPE-G possesses an outstanding specific capacitance up to 175 Fg-1 at a mass loading of 20 mgcm-2, which is two times the commercial requirement, yielding an excellent 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 K2CO3 were recycled and reused over 3 complete 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 not only waste LLDPE but also other varieties of PE to high value graphene materials.

Gao, Yuan [NETL Site Support Contractor, National ↗
NASA NTRS2012

Asymmetric Supercapacitor for Long-Duration Power Storage

A document discusses a project in which a series of novel hybrid positive electrode materials was developed and tested in asymmetric capacitors with carbon negative electrodes. The electrochemical performance of the hybrid capacitors was characterized by cyclic voltammetry and a DC charge/discharge test. The hybrid capacitor exhibited ideal capacitor behavior with an extended operating voltage of 1.6 V in aqueous electrolyte, and energy density higher than activated carbon-based supercapacitors. Nanostructured MnO2 is a promising material for electrochemical capacitors (ECS) because of its low cost, environmentally friendly nature, and reasonably high specific capacitance. The charge capacity of the capacitors can be further improved by increasing the specific surface area of the MnO2 electrode material. The power density and space radiation stability of the capacitors can be enhanced by coating the MnO2 nanoparticles with conducting polymers. The conducting polymer coating also helps in radiation-hardening the ECS.

Rangan, Krishnaswamy K.↗
NASA NTRS2012

Carbon Nanotube Tower-Based Supercapacitor

A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

Meyyappan, Meyya↗
NASA NTRS2016

Systems and Methods for Implementing High-Temperature Tolerant Supercapacitors

Systems and methods in accordance with embodiments of the invention implement high-temperature tolerant supercapacitors. In one embodiment, a high-temperature tolerant super capacitor includes a first electrode that is thermally stable between at least approximately 80C and approximately 300C; a second electrode that is thermally stable between at least approximately 80C and approximately 300C; an ionically conductive separator that is thermally stable between at least approximately 80C and 300C; an electrolyte that is thermally stable between approximately at least 80C and approximately 300C; where the first electrode and second electrode are separated by the separator such that the first electrode and second electrode are not in physical contact; and where each of the first electrode and second electrode is at least partially immersed in the electrolyte solution.

Brandon, Erik J.↗
NASA NTRS2023

Emperor's new clothes: Novel textile-based supercapacitors using sheep wool fiber as electrode substrate

Textile-based supercapacitors (TSCs) are being used to meet the ever-increasing demand for mobile, safe, and convenient energy sources to power personal electronic devices. To that end, the smart textiles used in wearable technology need to be made from highly conductive yarns that are easily manufacturable. To date, synthetic- and cellulosic-based yarns have been exclusively used for the fabrication of TSCs, while other yarns have not been explored. Here, we used conductive protein-based yarns for TSCs and report on the use of wool coated with Ti 3 C 2 T x MXene as a potential electrode material. To knit TSCs, wool and cotton yarns were coated with MXene flakes and their surfaces were characterized using Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS). The electrochemical characterization was conducted to examine the performance of wool- and cotton-based MXene electrodes as substrates and determine charge storage and resistive behavior. These tests showed that wool TSCs exhibited more pseudocapacitive behavior, while cotton TSCs exhibited a wider current range. At a scan rate of 5 mV/s, cotton TSCs presented an areal capacitance of 823.9 mF/cm 2 while this value for the wool TSCs was 284 mF/cm 2 . The performance of yarns was also tested under various mechanical deformation conditions and after washing in order to assess the stability of TSCs. This study indicates the potential of protein-based yarns as electrode substrates for integration of MXene to fabricate smart textile-based devices.

Alyssa Grube↗
NASA NTRS2012

Lithium Batteries and Supercapacitors Capable of Operating at Low Temperatures for Planetary Exploration

Demonstrated improved performance with wide operating temperature electrolytes containing ester co - solvents (i.e., methyl propionate and ethyl butyrate) in a number of prototype cells: center dot Successfully scaled up low temperature technology to 12 Ah size prismatic Li - ion cells (Quallion, LCC), and demonstrated good performance down to - 60 o C. center dot Demonstrated wide operating temperature range performance ( - 60 o to +60 o C) in A123 Systems LiFePO 4 - based lithium - ion cells containing methyl butyrate - based low temperature electrolytes. These systems were also demonstrated to have excellent cycle life performance at ambient temperatures, as well as the ability to be cycled up to high temperatures.

Li-ion Batteries↗
DOE OSTI2026

A Quinoidal Two‐Dimensional Metal–Organic Framework for High‐Performance Micro‐Supercapacitors and Solid‐State Lithium Batteries

Two-dimensional (2D) metal-organic frameworks (MOFs) integrating redox-active linkers enable dense charge sites and open ion pathways for microscale energy storage. We report a quinoidal dicarboxylate ligand, AQM-H2L, derived from p-azaquinodimethane, forming crystalline frameworks with Cu2+ and Zn2+ nodes. The Cu-based MOF (AQM-AQM-H2L-Cu) exhibits layered sheets (>14 Å spacing) constructed from dinuclear Cu-carboxylate units and conjugated AQM linkers, which narrow the bandgap and introduce Cu2+/Cu+ pseudocapacitance. Exfoliated nanosheets (∼5 nm) retain crystallinity and excellent processability. Integrated into graphene films, they deliver areal and volumetric capacitances of 29.6 mF cm-2 and 18.1 F cm-3, achieving 2.6 mWh cm-3 energy density at 160 mW cm-3. As ionic fillers (1 wt%) in PEO solid polymer electrolytes, the nanosheets markedly enhance LiFePO4 cell performance, affording 169.8 mAh g-1 at 0.2 C and 93% retention after 400 cycles. This work establishes quinoidal linkers as a compact and robust design motif for ionically active 2D frameworks toward high-performance miniature and solid-state energy devices.

Chen, Ziman↗
DOE OSTI2024

The Polarity of Co-solvents Regulates the Charge Storage Mechanisms in Supercapacitors with Concentrated Electrolytes

Developing better energy storage devices depends on comprehending the underlying mechanisms involved in charge storage. With the continuous conception of new electrolytes, this task becomes progressively more urgent and complex. An example is the utilization of co-solvated concentrated solutions. While these show promising electrochemical responses, their dynamic properties (especially under confinement) and their relationships with performance are not fully understood. Here, we combined modified step potential electrochemical spectroscopy and quasielastic neutron scattering to investigate systems composed of activated mesoporous carbon (AMC) and concentrated solutions of lithium bis(trifluoromethanesulfonyl)imide in acetonitrile co-solvated with either toluene or acetone. Further, we report that acetone does not impair surface-controlled mechanisms, contrary to the case with toluene, which competes with charged species to populate the AMC’s pores without contributing to charge storage. In turn, toluene promotes a greater overall capacitance owing to Faradaic processes, which may be related to changes in the solvation structures under confinement.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗