24M Technologies will lead a team to develop low cost, durable, enhanced separators/solid state electrolytes to build batteries using a lithium metal anode. Using a polymer/solid electrolyte ceramic blend, 24M will be able to make a protective layer that will help eliminate side reactions that have previously contributed to performance degradation and provide a robust mechanical barrier to branchlike metal fibers called dendrites. Unimpeded, dendrites can grow to span the space between the negative and positive electrodes, causing a short-circuit. The resulting, large-area lithium electrode sub-assemblies, or LESAs, will be cost-effective solutions that are scalable to high-volume manufacturing while providing a toolbox to further tailor electrode performance.

The team led by Accio Energy will develop an ElectroHydroDynamic (EHD) system that harvests energy from the wind through physical separation of charge rather than through rotation of an electric machine. The EHD technology entrains a mist of positively charged water droplets into the wind, which pulls the charge away from the electrically-grounded tower, thereby directly converting wind energy into a mounting voltage. The resulting High-Voltage Direct Current (HVDC) can then be transferred across higher efficiency power lines without the need for a generator, a gearbox, or costly high power AC-DC conversion required by traditional wind energy systems. The simple design of the EHD wind system is highly modular, and can be built with low-cost, mass manufacturing approaches. EHD systems also have minimal moving parts, and can be "containerized" for easy transport and installation at offshore sites. In contrast to the current trend for larger (and relatively expensive) turbines with increased power-per-tower, the EHD approach would utilize low-cost hardware with simple transport and installation, and native HVDC operation to reduce the cost of electricity from offshore wind. EHD technology can also operate at lower wind velocities than traditional turbines, and can thus increase the capacity factor at locations with highly variable winds. If successful, this project will demonstrate EHD technology as an entirely new option for offshore wind that offers a different path to cost effective utilization of a large renewable resource.

Aeris Technologies will partner with Rice University and Los Alamos National Laboratory to develop a complete methane leak detection system that allows for highly sensitive, accurate methane detection at natural gas systems. The team will combine its novel compact spectrometer based on a mid-infrared laser, its patent-pending multi-port sampling system, and an advanced computational approach to leak quantification and localization. Their approach will use artificial neural networks and dispersion models to quantify and locate leaks with increased accuracy and reduced computational time for use in a diverse range of meteorological conditions and wellpad configurations. At each wellpad, a control unit will house the core sensor, a computing unit to process data, and wireless capability to transmit leak information to an operator, while the multi-port gas-sampling system will be distributed across the wellpad. Aeris' goal is to be able to detect and measure methane leaks smaller than 1 ton per year from a 10 meter by 10 meter site. At this level of sensitivity, which is in the ppb range, Aeris estimates that its system can facilitate a 90% reduction in fugitive methane emissions. Compared to current monitoring systems that can cost $25,000 annually, Aeris' goal is a cost of $3,000 or less a year to operate.

Enzymes are required to break plant biomass down into the fermentable sugars that are used to create biofuel. Currently, costly enzymes must be added to the biofuel production process. Engineering crops to already contain these enzymes will reduce costs and produce biomass that is more easily digested. In fact, enzyme costs alone account for $0.50-$0.75/gallon of the cost of a biomass-derived biofuel like ethanol. Agrivida is genetically engineering plants to contain high concentrations of enzymes that break down cell walls. These enzymes can be "switched on" after harvest so they won't damage the plant while it's growing.

Alcoa is designing a new, electrolytic cell that could significantly improve the efficiency and price point of aluminum production. Conventional cells reject a great deal of waste heat, have difficulty adjusting to electricity price changes, and emit significant levels of CO₂. Alcoa is addressing these problems by improving electrode design and integrating a heat exchanger into the wall of the cell. Typically, the positive and negative electrodes--or anode and cathode, respectively--within a smelting cell are horizontal. Alcoa will angle their cathode, increasing the surface area of the cell and shortening the distance between anode and cathode. Further, the cathode will be protected by ceramic plates, which are highly conductive and durable. Together, these changes will increase the output from a particular cell and enable reduced energy usage. Alcoa's design also integrates a molten glass (or salt) heat exchanger to capture and reuse waste heat within the cell walls when needed and reduce global peak energy demand. Alcoa's new cell design could consume less energy, significantly reducing the CO₂ emissions and costs associated with current primary aluminum production.

Researchers at Alliant Techsystems (ATK) and ACENT Laboratories are developing a device that relies on aerospace wind-tunnel technologies to turn CO₂ into a condensed solid for collection and capture. ATK's design incorporates a special nozzle that converges and diverges to expand flue gas, thereby cooling it off and turning the CO₂ into solid particles which are removed from the system by a cyclonic separator. This technology is mechanically simple, contains no moving parts and generates no chemical waste, making it inexpensive to construct and operate, readily scalable, and easily integrated into existing facilities. The increase in the cost to coal-fired power plants associated with introduction of this system would be 50% less than current technologies.

Alveo Energy is developing a grid-scale storage battery using Prussian Blue dye as the active material within the battery. Prussian Blue is most commonly known for its application in blueprint documents, but it can also hold electric charge. Though it provides only modest energy density, Prussian Blue is so readily available and inexpensive that it could provide a cost-effective and sustainable storage solution for years to come. Alveo will repurpose this inexpensive dye for a new battery that is far cheaper and less sensitive to temperature, air, and other external factors than comparable systems. This will help to facilitate the adoption and deployment of renewable energy technology. Alveo's Prussian Blue dye-based grid-scale storage batteries would be safe and reliable, have long operational lifetime, and be cheaper to produce than any existing battery technology.

American Superconductor (AMSC) is developing a freezer that does not rely on harmful refrigerants and is more energy efficient than conventional systems. Many freezers are based on vapor compression, in which a liquid refrigerant circulates within the freezer, absorbs heat, and then pumps it out into the external environment. Unfortunately, these systems can be expensive and inefficient. ITC's freezer uses helium gas as its refrigerant, representing a safe, affordable, and environmentally friendly approach to cooling. ITC's improvements to the Stirling cycle system could enable the cost-effective mass production of high-efficiency freezers without the use of polluting refrigerants. ITC received a separate award of up to $1,766,702 from the Department of the Navy to help decrease military fuel use.

Ames Laboratory is developing a new class of permanent magnets based on the more commonly available element cerium for use in both EVs and renewable power generators. Cerium is 4 times more abundant and significantly less expensive than the rare earth element neodymium, which is frequently used in today's most powerful magnets. Ames Laboratory will combine other metal elements with cerium to create a new magnet that can remain stable at the high temperatures typically found in electric motors. This new magnetic material will ultimately be demonstrated in a prototype electric motor, representing a cost-effective and efficient alternative to neodymium-based motors.

Applied Materials is working with ARPA-E and the Office of Energy Efficiency and Renewable Energy (EERE) to build a reactor that produces the silicon wafers used in solar panels at a dramatically lower cost than existing technologies. Current wafer production processes are time consuming and expensive, requiring the use of high temperatures to produce ingots from molten silicon that can be sliced into wafers for use in solar cells. This slicing process results in significant silicon waste--or "kerf loss"--much like how sawdust is created when sawing wood. With funding from ARPA-E, Applied Materials is developing a reactor where ultra-thin silicon wafers are created by depositing silicon directly from vapor onto specialized reusable surfaces, allowing a significant reduction in the amount of silicon used in the process. Since high purity silicon is one of the most significant costs in producing solar cells, this kerf-less approach could significantly reduce the overall cost of producing solar panels. Applied Materials is partnering with Suniva, who will use funds from EERE to integrate these low-cost wafers into solar cells and modules that generate low-cost electricity, and with Arizona State University, who will develop high-efficiency devices on ultra-thin kerfless substrates. This partnership could enable low-cost, domestic manufacturing of solar modules, allowing the U.S. to reduce the amount of equipment we import from other countries.

Argonne National Laboratory (ANL) with its partners will develop a transparent nanofoam polymer that can be incorporated into a window film/coating for single-pane windows. The transparent polymer-nanoparticle composite will be applied to glass, and will improve the thermal insulation and the soundproofing of a window. Key to this technology is the generation of small and hollow nanometer-sized particles with thin shells. These will be embedded in a polymer with a carefully controlled structure and uniform dispersal of nanoshells in the polymer matrix. Competing approaches such as those used for silica aerogels have limited ability to fine tune the material's structure, resulting in materials with weaker mechanical strength, difficulties with transparency, and high processing costs. ANL will develop materials fabricated with self-assembly and a level of precision that allows careful prediction of how light and heat transmit through the material. The team also plans to introduce ultrasound-enhanced continuous processing techniques to manufacture the nanofoam at low cost and with high transparency without undesired haze and enhanced sound isolation capabilities. ANL predicts that the technology will enable an inexpensive window film that can be installed by the homeowner to upgrade a single-glazed window to double-glazed performance at about 25% of the cost.

Argonne National Laboratory (ANL) is developing a cost-effective exchange-spring magnet to use in the electric motors of wind generators and EVs that uses no rare earth materials. This ANL exchange-spring magnet combines a hard magnetic outer shell with a soft magnetic inner core--coupling these together increases the performance (energy density and operating temperature). The hard and soft magnet composite particles would be created at the molecular level, followed by consolidation in a magnetic field. This process allows the particles to be oriented to maximize the magnetic properties of low-cost and abundant metals, eliminating the need for expensive imported rare earths. The ultimate goal of this project is to demonstrate this new type of magnet in a prototype electric motor.

Arizona State University (ASU) and its partners will develop new windowpanes for single-pane windows to minimize heat losses and improve soundproofing without sacrificing durability or transparency. The team from ASU will produce a thermal barrier composed of silicon dioxide nanoparticles deposited on glass by supersonic aerosol spraying. The layer will minimize heat losses and be transparent at a substantially lower cost than can be done presently with silica aerogels, for example. A second layer deposited using the same method will reflect thermal radiation. The windowpanes will also incorporate layers of dense polymers to control condensation and adhesion, while improving strength. The coating is designed to last more than 20 years and be resistant to damage from scratching, peeling, or freezing of water vapor within the pores of the silica layer.

Arizona State University (ASU) will develop a stochastic optimal power flow (SOPF) framework, which would integrate uncertainty from renewable resources, load, distributed storage, and demand response technologies into bulk power system management in a holistic manner. The team will develop SOPF algorithms for the security-constrained economic dispatch (SCED) problem used to manage variability in the electric grid. The algorithms will be implemented in a software tool to provide system operators with real-time guidance to help coordinate between bulk generation and large numbers of DERs and demand response. ASU's project features unique data-analytics based short-term forecast for bulk and distributed wind and solar generation utilized by the advisory tool that generates real-time recommendations for market operators based on the SOPF algorithm outputs.

Arizona State University (ASU) is developing a solar cell that can maintain efficient operation at temperatures above 400°C. Like many other electronics, solar panels work best in cooler environments. As the temperature of traditional solar cells increases beyond 100°C, the energy output decreases markedly and components are more prone to failure. ASU's technology adapts semiconducting materials used in today's light-emitting diode (LED) industry to enable efficient, long-term high-temperature operation. These materials could allow the cells to maintain operation at much higher temperatures than today's solar cells, so they can be integrated as the sunlight-absorbing surface of a thermal receiver in the next generation of hybrid solar collectors. The solar cell would provide electricity using a portion of the incoming sunlight, while the receiver collects usable heat at high temperature that can be stored and dispatched to generate electricity as needed.

Baldor Electric Company is developing a new type of traction motor with the potential to efficiently power future generations of EVs. Unlike today's large, bulky EV motors which use expensive, imported rare-earth-based magnets, Baldor's motor could be light, compact, contain no rare earth materials, and have the potential to deliver more torque at a substantially lower cost. Key innovations in this project include the use of a unique motor design, incorporation of an improved cooling system, and the development of advanced materials manufacturing techniques. These innovations could significantly reduce the cost of an electric motor.

Battelle Memorial Institute is developing an optical sensor to monitor the internal environment of lithium-ion (Li-Ion) batteries in real-time. Over time, crystalline structures known as dendrites can form within batteries and cause a short circuiting of the battery's electrodes. Because faults can originate in even the tiniest places within a battery, they are hard to detect with traditional sensors. Battelle is exploring a new, transformational method for continuous monitoring of operating Li-Ion batteries. Their optical sensors detect internal faults well before they can lead to battery failures or safety problems. The Battelle team will modify a conventional battery component to scan the cell's interior, watching for internal faults to develop and alerting the battery management system to take corrective action before a hazardous condition occurs.

E. I. du Pont de Nemours & Company (DuPont) and Bio Architecture Lab are exploring the commercial viability of producing fuel-grade isobutanol from macroalgae (seaweed). Making macroalgae an attractive substrate for biofuel applications however, will require continued technology development. Assuming these developments are successful, initial assessments suggest macroalgae aquafarming in our oceans has the potential to produce a feedstock with cost in the same range as terrestrial-based substrates (crop residuals, energy crops) and may be the feedstock of choice in some locations. The use of macroalgae also diversifies the sources of U.S. biomass in order to provide more options in meeting demand for biofuels. The process being developed will use a robust industrial biocatalyst (microorganism) capable of converting macroalgal-derived sugars directly into isobutanol. Biobutanol is an advanced biofuel with significant advantages over ethanol, including higher energy content, lower greenhouse gas emissions, and the ability to be blended in gasoline at higher levels than ethanol without changes to existing automobiles or the fuel industry infrastructure. Butamax is currently commercializing DuPont's biobutanol fermentation technology that uses sugar and starch feedstocks.

Boston Electrometallurgical Corporation will develop and scale a one step molten oxide electrolysis process for producing Ti metal directly from the oxide. Titanium oxide is dissolved in a molten oxide, where it is directly and efficiently extracted as molten titanium metal. In this process, electrolysis is used to separate the product from the solution as a bottom layer that can then be removed from the reactor in its molten state. If successful, it could replace the multistep Kroll process with a one-step process that resembles today's aluminum production techniques. If successful, Ti ingots could be produced at cost parity with stainless steel, opening the doorway to industrial waste heat recovery applications and increasing its adoption in commercial aircraft.

The Boston University (BU) team is developing control technology to help grid operators more actively manage power flows and integrate renewables by optimally turning entire power lines on and off in coordination with traditional control of generation and load resources. The control technology being developed would provide grid operators with tools to help manage transmission congestion by identifying the facilities whose on/off status must change to lower generation costs, increase utilization of renewable resources and improve system reliability. The technology is based on fast optimization algorithms for the near to real-time change in the on/off status of transmission facilities and their software implementation.

Bridger Photonics plans to build a mobile methane sensing system capable of surveying a 10 meter by 10 meter well platform in just over five minutes with precision that exceeds existing technologies used for large-scale monitoring. Bridger's complete light-detection and ranging (LiDAR) remote sensing system will use a novel, near-infrared fiber laser amplifier in a system mounted on a ground vehicle or an unmanned aerial vehicle (UAV), which can be programmed to survey multiple wellpads a day. Data captured by the LiDAR system will provide 3-D topographic and methane absorption imagery using integrated inertial navigation and global positioning system data to show precisely where a methane leak may be occurring and at what rate. This approach will also be used to identify objects on the wellsite to better inform the search optimization. Bridger's goal is for its devices to be able to service up to 85 sites, and thus cost $1,400 to $2,220 a year to operate per wellsite. By advancing an affordable methane detection system that can both pinpoint and assess leakage quickly, Bridger's system could help companies repair methane leaks and catalyze an overall reduction in methane emissions from natural gas development.

Brown University is developing a power conversion device to maximize power production and reduce costs to capture energy from flowing water in rivers and tidal basins. Conventional methods to harness energy from these water resources face a number of challenges, including the costs associated with developing customized turbine technology to a specific site. Additionally, sites with sufficient energy exist near coastal habitats which depend on the natural water flow to transport nutrients. Brown University's tidal power conversion devices can continuously customize themselves by using an onboard computer and control software to respond to real-time measurements, which will increase tidal power conversion efficiency. Brown University's technology will allow for inexpensive installation and software upgrades and optimized layout of tidal power generators to maximize power generation and mitigate environmental impacts.

Cadenza Innovation is developing an innovative system to join and package batteries using a wide range of battery chemistries. Today's battery packs require heavy and bulky packaging that limits where they can be positioned within a vehicle. By contrast, Cadenza's design enables flexible placement of battery packs to absorb and manage impact energy in the event of a collision. Cadenza's battery will use a novel configuration that allows for double the energy density through the use of a multifunctional pack design.

The team at the California Institute of Technology (Caltech) has developed a method to determine the mechanical properties of lithium as a function of size, temperature, and microstructure. The body of scientific knowledge on these properties and the way dendrites form and grow is very limited, in part due to the reactivity of metallic lithium with components of air such as water and carbon dioxide. The team proposes to conduct a targeted investigation on the properties of electrodeposited lithium metal in commercial thin-film solid-state batteries. As part of the effort, the team will perform structural and mechanical testing on electrodeposited lithium, at dendrite-relevant dimensions. Their investigation will provide new information on the microstructure, strength, and stiffness of electrodeposited lithium. Finally, they will conduct cycling experiments on the commercial cells to observe lithium transport and dendrite nucleation and growth. If successful, the project will result in new knowledge about the microstructure and properties of lithium, and may further our understanding of dendrite nucleation and growth mechanisms - a starting point to developing higher energy battery technologies.

Caltech, in coordination with Los Alamos National Laboratory (LANL), will investigate the scaling of adiabatic heating of plasma by propelling magnetized plasma jets into stationary heavy gases and/or metal walls. This is the reverse of the process that would occur in an actual fusion reactor - where a gas or metal liner would compress the plasma - but will provide experimental data to assess the magneto-inertial fusion approach. By using this alternative frame of reference, the researchers will be able to conduct experiments more frequently and at a lower cost because the experimental setup is non-destructive. The team will investigate the jet-target collision using many experiments with a wide range of parameters to determine the actual equation of state relating compression, change in magnetic field, and temperature increase. The experimental work will be supplemented with advanced 3D computer models. If successful, these results will show that compressional heating by a liner is a viable method for increasing temperatures to the levels required for magneto-inertial fusion. The study will also provide critical information on the interactions and limitations for a variety of possible driver and plasma target combinations being developed across the ALPHA program portfolio.

Case Western Reserve University will develop a data analytics approach to building-efficiency diagnosis and prognostics. Their tool, called EDIFES (Energy Diagnostics Investigator for Efficiency Savings), will not require complex or expensive computational simulation, physical audits, or building automation systems. Instead, the tool will map a building's energy signature through a rigorous analysis of multiple datastreams. Combining knowledge of specific climatic, weather, solar insolation, and utility meter data through data assembly, the team will analyze these time-series datastreams to reveal patterns and relationships that were previously ignored or neglected. EDIFES will provide a virtual energy audit combined with a predictive energy usage calculator for efficiency solutions without setting foot in a building. The team's goal is to design EDIFES in such a way that beyond time-series, whole building utility data, only minimal information will be required from the building owner for accurate virtual energy audits that identify efficiency problems and solutions and provide continuous efficiency monitoring. EDIFES will be a resource for equipment providers and contractors to illustrate replacement equipment value, a mechanism for utilities to measure the impact of energy efficiency programs, and a tool for financiers to evaluate the potential risk and opportunity of efficiency investments. EDIFES will target the light commercial building space where minimal tools are available and a high potential for savings exists.

Case Western Reserve University is developing a highly magnetic iron-nitride alloy to use in the magnets that power electric motors found in EVs and renewable power generators. This would reduce the overall price of the motor by eliminating the expensive imported rare earth minerals typically found in today's best commercial magnets. The iron-nitride powder is sourced from abundant and inexpensive materials found in the U.S. The ultimate goal of this project is to demonstrate this new magnet system, which contains no rare earths, in a prototype electric motor. This could significantly reduce the amount of greenhouse gases emitted in the U.S. each year by encouraging the use of clean alternatives to oil and coal.

Case Western Reserve University is developing a water-based, all-iron flow battery for grid-scale energy storage at low cost. Flow batteries store chemical energy in external tanks instead of within the battery container. Using iron provides a low-cost, safe solution for energy storage because iron is both abundant and non-toxic. This design could drastically improve the energy storage capacity of stationary batteries at 10-20% of today's cost. Ultimately, this technology could help reduce the cost of stationary energy storage enough to facilitate the adoption and deployment of renewable energy technology.

Chemtronergy will develop an advanced solid oxide fuel cell (SOFC) system to electrochemically convert ammonia into electricity. Conventional SOFC systems are manufactured using ceramic fabrication techniques that are time-consuming, energy-intensive, and have high material costs. SOFCs also typically operate at 700-900°C to chemically activate the fuel feedstock and ensure that it is sufficiently cracked or reformed for electrochemical use. This high temperature, however, imposes harsh operating conditions and stresses on the materials, which further increases costs. To address these challenges, the team proposes to lower the operating temperature below 650°C and to develop anode, cathode, and electrolyte materials using a combination of advanced materials discovery, reaction kinetics modeling, and 3D printing technology for large-scale rapid prototyping. The team hopes to greatly reduce the cost of SOFC systems while providing a distributed power-generating option with high efficiency, long life, and a reduced carbon footprint.

The Citrine Informatics team is demonstrating a proof-of-concept for a system that would use experimental work to intelligently guide the investigation of new solid ionic conductor materials. If successful, the project will create a new approach to material discovery generally and new direction for developing promising ionic conductors specifically. The project will aggregate data (both quantitative and meta-data related to experimental conditions) relevant to ionic conductors from the published literature and build advanced, machine learning models for prediction based upon the resulting large database. The team's system will also experimentally explore the new materials space identified and suggested by the models. The Citrine project could provide researchers near-real-time feedback as they perform experiments, allowing them to dynamically select the most promising research pathways. This would in turn unlock more rapid ionic conductor identification and development, and transform the fields of theoretical and experimental materials science at-large.

City University of New York (CUNY) Energy Institute is working to tame dendrite formation and to enhance the lifetime of Manganese in order to create a long-lasting, fully rechargeable battery for grid-scale energy storage. Traditional consumer-grade disposable batteries are made of Zinc and Manganese, two inexpensive, abundant, and non-toxic metals, but these disposable batteries can only be used once. If they are recharged, the Zinc in the battery develops filaments called dendrites that grow haphazardly and disrupt battery performance, while the Manganese quickly loses its ability to store energy. CUNY Energy Institute is also working to reduce dendrite formation by pumping fluid through the battery, enabling researchers to fix the dendrites as they form. The team has already tested its Zinc battery through 3,000 recharge cycles (and counting). CUNY Energy Institute aims to demonstrate a better cycle life than lithium-ion batteries, which can be up to 20 times more expensive than Zinc-based batteries.

The Colorado School of Mines will develop a new membrane for redox flow battery systems based on novel, low-cost materials. The membrane is a hybrid polymer that includes heteropoly acid molecules and a special purpose fluorocarbon-based synthetic rubber called a fluoroelastomer. The team will enhance the membrane's selectivity by refining the polymer structure, employing crosslinking techniques, and also through doping the polymer with cesium. The fluoroelastmer is commercially available, thereby contributing to a superior performance-to-cost ratio for the membrane. Flow battery experts at Lawrence Berkeley Laboratory will extensively test the selectivity, conductivity, and stability of the membranes developed in this project, and 3M will apply its decades of membrane fabrication experience to scale-up the new technology. If successfully developed, the separator in this project will increase efficiency and reduce cost in existing flow battery systems such as the all-iron redox flow battery.

Colorado State University (CSU) will develop a high-throughput ground-based robotic platform that will characterize a plant's root system and the surrounding soil chemistry to better understand how plants cycle carbon and nitrogen in soil. CSU's robotic platform will use a suite of sensor technologies to investigate crop genetic-environment interaction and generate data to improve models of chemical cycling of soil carbon and nitrogen in agricultural environments. The platform will collect information on root structure and depth, and deploy a novel spectroscopic technology to quantify levels of carbon and other key elements in the soil. The technology proposed by the Colorado State team aims to speed the application of genetic and genomic tools for the discovery and deployment of root traits that control plant growth and soil carbon cycling. Crops will be studied at two field sites in Colorado and Arizona with diverse advantages and challenges to crop productivity, and the data collected will be used to develop a sophisticated carbon flux model. The sensing platform will allow characterization of the root systems in the ground and lead to improved quantification of soil health. The collected data will be managed and analyzed through the CyVerse "big data" computational analytics platform, enabling public access to data connecting aboveground plant traits with belowground soil carbon accumulation.

The innovation lies in the exploitation of novel natural energy source: reduced metal deposits. The energy released during oxidation of these metals could be used to reduce CO₂ into fuels and chemicals reducing petroleum usage.This proposed project fits within the Chemical-Chemical Area of Interest, as it involves the coupling of the oxidation of reduced minerals in the Earth's crust to the production of reduced carbon chemicals for fuel utilization. This addresses both of Mission Areas of ARPA-E as the co-generation of fuels during copper bioleaching will potentially reduce the import of energy from foreign sources, reduce greenhouse gas emissions, improve energy efficiency in the mining industry, and ensure that the U.S. maintains a lead in the development of this disruptive new technology.

Columbia University will develop a new platform for generating multiple simultaneous optical channels (wavelengths) with low power dissipation, thereby enabling optical interconnects for low power computing. Optical interconnect links communicate using optical fibers that carry light. Wavelength-division multiplexing (WDM) is a technology that combines a number of optical carrier signals on a single optical fiber by using different wavelengths. This technique enables bidirectional communications over strands of fiber, dramatically increasing capacity. Low-power lasers generate the wavelengths used in a WDM system, but it is important to stabilize the wavelength for each channel to allow for precise separation and filtering. The importance of stabilization increases when the number and density of wavelength channels increases. Energy use also increases because each of the laser sources must be individually stabilized. In contrast, the Columbia team proposes using a single high-powered stabilized laser to generate greater than 50 wavelength sources with high efficiency using an on-chip comb. This approach can improve laser energy efficiency from 0.01% to 10%.

Cornell University will develop a new type of rechargeable lithium metal battery that provides superior performance over existing lithium-ion batteries. The anode, or negative side of a lithium-ion battery, is usually composed of a carbon-based material. In lithium metal batteries, the anode is made of metallic lithium. While using metallic lithium could result in double the storage capacity, lithium metal batteries have unreliable performance, safety issues, and premature cell failure. There are two major causes for this performance degradation. First, side reactions can occur between the lithium metal and the liquid or solid electrolyte placed between the positive and negative electrodes. Second, when recharged, branchlike metal fibers called dendrites can grow on the negative electrode. These dendrites can grow to span the space between the negative and positive electrodes, causing short-circuiting. To overcome these challenges, Cornell proposes research to pair a variety of cathodes with a lithium metal anode. The work builds upon recent theoretical and experimental discoveries by the team, which show that a class of structured electrolytes can provide multiple mechanisms for stabilizing lithium metal anodes and suppress dendrite growth. The team will also develop structured electrolyte coatings that provide barriers to oxygen and moisture, but do not impede lithium-ion transport across the electrolyte/electrode interface. Such coatings will suppress the unwelcome lithium metal/electrolyte reactions and will also enable manufacturing of lithium metal batteries under standard dry room conditions. The structures developed could also be used in batteries based on other metals, such as sodium and aluminum that are more abundant and less expensive than lithium, but also affected by dendrite formation.

Cornell University is developing a new photobioreactor that is more efficient than conventional bioreactors at producing algae-based fuels. Traditional photobioreactors suffer from several limitations, particularly poor light distribution, inefficient fuel extraction, and the consumption of large amounts of water and energy. Cornell's bioreactor is compact, making it more economical to grow engineered algae and collect the fuel the algae produces. Cornell's bioreactor also delivers sunlight efficiently through low-cost, plastic, light-guiding sheets. By distributing optimal amounts of sunlight, Cornell's design would increase efficiency and decrease water use compared to conventional algae reactors.

Cornell University will develop an innovative, high-efficiency, gallium nitride (GaN) power switch. Cornell's design is significantly smaller and operates at much higher performance levels than conventional silicon power switches, making it ideal for use in a variety of power electronics applications. Cornell will also reuse expensive GaN materials and utilize conventional low-cost production methods to keep costs down.