Search

power generation and storage
Carbon Nanotube
Carbon Nanotube Tower-Based Supercapacitor
This invention provides a four-part system that includes: (1) first and second, spaced-apart planar collectors; (2) first and second arrays of Multi-Wall Carbon Nanotube (MWCNT) towers, serving as electrodes, that extend between the first and second collectors, where the MWCNT towers are grown directly on the collector surfaces without deposition of a catalyst or a binder material on the collectors surface; (3) a separator module having a transverse area that is substantially the same as the transverse area of either electrode; and (4) at least one MWCNT tower that acts as a hydrophilic structure with improved surface wettability. The growth of MWCNT and/or Single Wall Carbon Nanotube (SWCNT) towers is done directly on polished, ultra-smooth alloy substrates containing iron and or nickel, such as nichrome, kanthal and stainless steel. The growth process for generating an MWCNT tower array requires heating the collector metal substrate in an inert argon gas atmosphere to 750 C. After thermal equilibration, 1000 sccm of 8/20 ethylene/Hs gas flow results in the growth of carbon nanotube towers.
materials and coatings
Examples of anticipated applications of holey nanocarbons: sensors, energy storage, water separation, etc.
Holey Carbon Allotropes
This invention is for scalable methods that allows preparation of bulk quantities of holey nanocarbons with holes ranging from a few to over 100 nm in diameter. The first method uses metal particles as a catalyst (silver, copper, e.g.) and offers a wider range of hole diameter. The second method is free of catalysts altogether and offers more rapid processing in a single step with minimal product work-up requirements and does not require solvents, catalysts, flammable gases, additional chemical agents, or electrolysis. The process requires only commercially available materials and standard laboratory equipment; and, it is scalable. Properties that can be controlled include: surface area, pore volume, mechanical properties, electrical conductivity, and thermal conductivity.
electrical and electronics
Supercapacitors
Metal Oxide-Vertical Graphene Hybrid Supercapacitors
The electrodes are soaked in electrolyte, separated by a separator membrane and packaged into a cell assembly to form an electrochemical double layer supercapacitor. Its capacitance can be enhanced by a redox capacitance contribution through additional metal oxide to the porous structure of vertical graphene or coating the vertical graphene with an electrically conducting polymer. Vertical graphene offers high surface area and porosity and does not necessarily have to be grown in a single layer and can consist of two to ten layers. A variety of collector metals can be used, such as silicon, nickel, titanium, copper, germanium, tungsten, tantalum, molybdenum, & stainless steel. Supercapacitors are superior to batteries in that they can provide high power density (in units of kw/kg) and the ability to charge and discharge in a matter of seconds. Aside from its excellent power density, a supercapacitor also has a longer life cycle and can undergo many more charging sequences in its lifespan than batteries. This long life cycle means that supercapacitors last for longer periods of times, which alleviates environmental concerns associated with the disposal of batteries.
sensors
A wide variety of applications
Fluid Measurement Sensor
The fluid measurement sensor is configured with a spiral electrical trace on flexible substrate. The sensor receives a signal from the accompanying magnetic field data acquisition system. Once electrically active, the sensor produces its own harmonic magnetic field as the inductor stores and releases magnetic energy. The antenna of the measurement acquisition system is switched from transmitting to receiving mode to acquire the magnetic-field response of the sensor. The magnetic-field response attributes of frequency, amplitude, and bandwidth of the inductor correspond to the physical property states measured by the sensor. The received response is correlated to calibrated data to determine the physical property measurement. When multiple sensors are inductively coupled, the data acquisition system only needs to activate and read one sensor to obtain measurement data from all of them. Fluid level measurement occurs in several ways. In the immersion method, the capacitance of the sensor circuit changes as it is immersed in fluid, thus changing the frequency response as the fluid level rises or falls. Fluid level can also be measured from the outside of a non-conductive container. The response frequency from the sensor is dependent upon the inductance of the container plus the combination of fluid and air inside it, which corresponds to the level of liquid inside the container. Roll and pitch are measured by using three or more sensors in a container. With any given orientation, each sensor will detect a different fluid level, thus providing the basis for calculating the fluid angle. Volume can be measured in the same way, using the angle levels detected by the sensors and the geometric characteristics of the container to perform the volume calculation.
Power Generation and Storage
front
Novel, Solid-State Hybrid Ultracapacitor Battery
The subject technology is an extension of closely related, solid-state ultracapacitor innovations by the same team of inventors. The primary distinction for this specific technology is the addition of co-dopants to affect the dielectric behavior of the barium titanatebased perovskite materials. These co-dopants include lanthanum and other rare earths as well as hydroxyl ions. The materials are processed at the nano scale, and are subjected to carefully designed thermal treatments as well. The presence of the hydroxyl ions has been shown to provide several orders of magnitude increase in the capacitance of the dielectric material. Additionally, these high capacitance values are obtained at relatively low voltages found in current consumer and industrial electronics. The capacitors tested to date are simple, single-layer devices. Ultimately, a range of manufacturing methods are possible for making commercial devices. Features of the technology enable manufacturing via traditional thick-film processing methods widely used in the capacitor industry, or via advanced printing methods for state-of-the-art printed electronics. Future efforts will be made to advance the manufacturing and packaging processes to increase device energy density, including multilayer devices and packages
Power Generation and Storage
front
Solid-State Ultracapacitor for Improved Energy Storage
NASAs solid-state ultracapacitor technology is based on the novel materials design and processes used to make the IBLC-type ultracapacitor. The IBLC concept is known to provide outstanding capacitance behavior but has been difficult to reproduce. NASA has developed a careful process to produce dielectric materials to be used in printed electronic applications with reproducibility. An individual cell is created by building electrodes on each side of the dielectric layer, and complete modules can be constructed by stacking multiple cells. Closely related NASA innovations on dielectric and conductive ink (electrode) formulations are key to the ultracapacitor construct, and are included in the technology package. Target performance criteria of this technology include the following: &#8226 Use of standard materials and processing methods &#8226 Robust, solid-state device with no liquid electrolytes &#8226 High-energy densitytarget energy densities of 60 J/cc at a minimum operating voltage of 50 V &#8226 High dielectric breakdown strength (> 25 MV/m) &#8226 Excellent pulse-power performance; rapid discharge and charge &#8226 Reliable performance under repeated cycling (> 500,000 cycles) Additional development work is underway to build and test complete capacitor modules and further improve material properties and performance.
Materials and Coatings
front
New Dielectric Material for High-Performance, Solid-State Ultracapacitors
NASA&#8217s technology is a dielectric materials formulation comprising polymers, organic binders, solvents, and surfactants, formulated together with a ceramic perovskite nanopowder. The ceramic nanopowder can be optimized for the required dielectric properties of capacitance, voltage breakdown, and leakage. This involves the addition of dopants or the use of advanced coatings on the powder particulates, and subsequent thermal treatments. The rheology of the formulation can be adjusted to work with a variety of coating or printing methods, from conventional thick-film methods to advanced inkjet or direct-write 3D printing methods used for printed electronics. 3D printing provides the ease of printed manufacturing along with the deposition of thinner layers (e.g., 5 microns in thickness vs. 50-100 micron layer via thick-film methods). Individual devices can then be formed in multilayer arrangements, or stacked and packaged as required for the given device application. The ink composition is a careful blend of polyimide or polyvinylidene fluoride (PVDF) polymers, solvents, surfactants, and barium titanate nanopowders. Proper ratios are needed for viscosity and processability (e.g., nanopowder wetting and dispersion), along with the optimal ultracapacitor device performance.
Stay up to date, follow NASA's Technology Transfer Program on:
facebook twitter linkedin youtube
Facebook Logo Twitter Logo Linkedin Logo Youtube Logo