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Lemmon, John P.

Publications and source records attributed to Lemmon, John P..

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Multi-functional anodes boost the transient power and durability of proton exchange membrane fuel cells

Abstract Proton exchange membrane fuel cells have been regarded as the most promising candidate for fuel cell vehicles and tools. Their broader adaption, however, has been impeded by cost and lifetime. By integrating a thin layer of tungsten oxide within the anode, which serves as a rapid-response hydrogen reservoir, oxygen scavenger, sensor for power demand, and regulator for hydrogen-disassociation reaction, we herein report proton exchange membrane fuel cells with significantly enhanced power performance for transient operation and low humidified conditions, as well as improved durability against adverse operating conditions. Meanwhile, the enhanced power performance minimizes the use of auxiliary energy-storage systems and reduces costs. Scale fabrication of such devices can be readily achieved based on the current fabrication techniques with negligible extra expense. This work provides proton exchange membrane fuel cells with enhanced power performance, improved durability, prolonged lifetime, and reduced cost for automotive and other applications.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2020

High-Throughput Exploration of Lithium-Alloy Protection Layers for High-Performance Lithium-Metal Batteries

To realize high specific capacity Li-metal batteries, a protection layer for the Li-metal anode is needed. We are carrying out combinatorial screening of Li-alloy thin films as the protection layer which can undergo significant lithiation with minimum change in volume and crystal structure. In this paper, we have fabricated lithium-free binary alloy thin film composition spreads of Co 1–x Sn x on Cu layers on Si substrates. The crystallinity of the thin films was tuned by varying the deposition temperature followed by electrochemical lithiation to form Li-alloy ternary thin films. Synchrotron diffraction is used as the main tool to investigate the crystallinity of the films before and after lithiation. Co 3 Sn 2 alloy thin films are found to exhibit significant lithium uptake capacity while maintaining its structural integrity, and are thus a good candidate of the Li-metal protection layer.

25 ENERGY STORAGE↗
DOE OSTI2016

Organometallic-inorganic hybrid electrodes for lithium-ion batteries

Disclosed are embodiments of active materials for organometallic and organometallic-inorganic hybrid electrodes and particularly active materials for organometallic and organometallic-inorganic hybrid cathodes for lithium-ion batteries. In certain embodiments the organometallic material comprises a ferrocene polymer.

25 ENERGY STORAGE↗
DOE OSTI2016

Metallization pattern on solid electrolyte or porous support of sodium battery process

A new battery configuration and process are detailed. The battery cell includes a solid electrolyte configured with an engineered metallization layer that distributes sodium across the surface of the electrolyte extending the active area of the cathode in contact with the anode during operation. The metallization layer enhances performance, efficiency, and capacity of sodium batteries at intermediate temperatures at or below about 200.degree. C.

25 ENERGY STORAGE↗
DOE OSTI2016

Planar high density sodium battery

A method of making a molten sodium battery is disclosed. A first metallic interconnect frame having a first interconnect vent hole is provided. A second metallic interconnect frame having a second interconnect vent hole is also provided. An electrolyte plate having a cathode vent hole and an anode vent hole is interposed between the metallic interconnect frames. The metallic interconnect frames and the electrolyte plate are sealed thereby forming gaseous communication between an anode chamber through the anode vent hole and gaseous communication between a cathode chamber through the cathode vent hole.

25 ENERGY STORAGE↗
DOE OSTI2016

In situ electrochemical-electron spin resonance investigations of multi-electron redox reaction for organic radical cathodes

Organic radical batteries (ORBs) bearing robust radical polymers as energy storage species, are emerging promisingly with durable high energy and power characteristics by unique tunable redox properties. Here we report the development and application of in situ electrochemical-electron spin resonance (ESR) methodologies to identify the charge transfer mechanism of Poly(2,2,6,6- tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) based organic radical composite cathodes in the charge-discharge process of lithium half cells. The in situ experiments allow each electrochemical state to be associated with the chemical state (or environment) of the radical species upon the cell cycling. In situ ESR spectra of the composite cathode demonstrate a two-electron redox reaction of PTMA. Moreover, two different local environments of radical species are found in the composite electrode that includes both concentrated and isolated radicals. These two types of radicals show similarities during the redox reaction process while behave quite differently in the non-faradic reaction of ion sorption/desorption on the electrode surface.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2015

Energy: Reimagine Fuel Cells

New types of fuel cell on the horizon could eliminate the need for such trade-offs and ease the integration of renewables into the grid. Currently, fuel cells are used to generate only electricity and heat. They can be modified to store energy and produce liquid fuels such as methanol, thanks to breakthroughs in materials and designs. Developing fuel cells with a battery mode is one focus of the programme I direct at the US Advanced Research Projects Agency–Energy (ARPA-E). I lead 13 projects across academia, industry and national laboratories.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Controlling porosity in lignin-derived nanoporous carbon for supercapacitor applications

Low-cost renewable lignin has been used as a precursor to produce porous carbons. However, to date, it has not been easy to obtain high surface area porous carbon without activation processes or templating agents. Here, we demonstrate that low molecular weight lignin yields highly porous carbon (1092 m² g⁻¹) with more graphitization through direct carbonization without additional activation processes or templating agents. We found that molecular weight and oxygen consumption during carbonization are critical factors to obtain high surface area, graphitized porous carbons. This highly porous carbon from low-cost renewable lignin sources is a good candidate for supercapacitor electrode materials.

25 ENERGY STORAGE↗
DOE OSTI2014

The Role of FeS in Initial Activation and Performance Degradation of Na-NiCl 2 Batteries

The role of iron sulfide (FeS) in initial cell activation and degradation in the Na-NiCl 2 battery was investigated in this work. The research focused on identifying the effects of the FeS level on the electrochemical performance and morphological changes in the cathode. The x-ray photoelectron spectroscopy study along with battery tests revealed that FeS plays a critical role in initial battery activation by removing passivation layers on Ni particles. It was also found that the optimum level of FeS in the cathode resulted in minimum Ni particle growth and improved battery cycling performance. The results of electrochemical characterization indicated that sulfur species generated in situ during initial charging, such as polysulfide and sulfur, are responsible for removing the passivation layer. Consequently, the cells containing elemental sulfur in the cathode exhibited similar electrochemical behavior during initial charging compared to that of the cells containing FeS.

25 ENERGY STORAGE↗
DOE OSTI2014

Liquid-Metal Electrode to Enable Ultra-Low Temperature Sodium-Beta Alumina Batteries for Renewable Energy Storage

Metal electrodes have a high capacity for energy storage but have found limited applications in batteries because of dendrite formation and other problems. In this paper, we report a new alloying strategy that can significantly reduce the melting temperature and improve wetting with the electrolyte to allow the use of liquid metal as anode in sodium-beta alumina batteries (NBBs) at much lower temperatures (e.g., 95 to 175°C). Commercial NBBs such as sodium-sulfur (Na-S) battery and sodium-metal halide (ZEBRA) batteries typically operate at relatively high temperatures (e.g., 300-350°C) due to poor wettability of sodium on the surface of β"-Al2O3. Our combined experimental and computational studies suggest that Na-Cs alloy can replace pure sodium as the anode material, which provides a significant improvement in wettability, particularly at lower temperatures (i.e., <200°C). Single cells with the Na-Cs alloy anode exhibit excellent cycling life over those with pure sodium anode at 175 and 150°C. The cells can even operate at 95°C, which is below the melting temperature of pure sodium. These results demonstrate that NBB can be operated at ultra lower temperatures with successfully solving the wetting issue. This work also suggests a new strategy to use liquid metal as the electrode materials for advanced batteries that can avoid the intrinsic safety issues associated with dendrite formation on the anode.

Lu, Xiaochuan↗
DOE OSTI2014

In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High Performance Supercapacitors

Electrochemical performance of the existing state-of-the art capacitors is not very high, key scientific barrier is that its charge storage mechanism wholly depends on adsorption of electrolyte on electrode. We present a novel method for the synthesis of nitrogen -doped porous carbons and address the drawback by precisely controlling composition and surface area. Nitrogen-doped porous carbon was synthesized using a self-sacrificial template technique without any additional nitrogen and carbon sources. They exhibited exceptionally high capacitance (239 Fg-1) due to additional pseudocapacitance originating from doped nitrogen. Cycling tests showed no obvious capacitance decay even after 10,000 cycles, which meets the requirement of commercial supercapacitors. Our method is simple and highly efficient for the production of large quantities of nitrogen-doped porous carbons.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175°C

Operation of sodium-nickel chloride battery at temperatures lower than 200°C reduces cell degradation and improves the cyclability. One of the main technical issues in terms of operating this battery at intermediate temperatures such as 175°C is the poor wettability of molten sodium on β”-alumina solid electrolyte (BASE) causing reduced active area and limited charging . In order to overcome the problem related to poor wettability of Na melt on BASE at 175°C, Pt grid was applied on the anode side of BASE using a screen printing technique. Deeper charging and improved cycling behavior was observed on the cells with metalized BASEs due to extended active area.

intermediate temperature↗
DOE OSTI2014

X-ray Absorption Measurements on Nickel Cathode of Sodium-beta Alumina batteries: Fe-Ni-CI Chemical Associations

Sections of Na-Al-NiCl2 cathodes from sodium-beta alumina ZEBRA batteries have been characterized with X-ray fluorescence mapping, and XANES measurements to probe the microstructure, elemental correlation, and chemical speciation after voltage cycling. Cycling was performed under identical load conditions at either 240 or 280 °C operating temperature and subsequently quenched in either the charged or discharged state. X-ray fluorescence mapping and XANES measurements were made adjacent to the current collector and β"-Al2O3 solid electrolyte interfaces to detect possible gradients in chemical properties across the cathode. An FeS additive, introduced during battery synthesis, was found to be present as either Fe metal or an Fe(II) chloride in all cathode samples. X-ray fluorescence mapping reveals an operating temperature and charge-state dependent spatial correlation between Fe, Ni, and Cl concentration. XANES measurements indicate that both Ni and Fe are chemically reactive and shift between metallic and chloride phases in the charged and discharged states, respectively. However the percentage of chemically active Ni and Fe is significantly less in the cell operated at lower temperature. Additionally, the cathode appeared chemically homogeneous at the scale of our X-ray measurements.

Bowden, Mark E.↗
DOE OSTI2013

Cell degradation of a Na–NiCl 2 (ZEBRA) battery

In this work, the parameters influencing the degradation of a Na-NiCl 2 (ZEBRA) battery were investigated. Planar Na-NiCl 2 cells using β”-alumina solid electrolyte (BASE) were tested with different C-rates, Ni/NaCl ratios, and capacity windows, in order to identify the key parameters for the degradation of Na-NiCl 2 battery. The morphology of NaCl and Ni particles were extensively investigated after 60 cycles under various test conditions using a scanning electron microscope. A strong correlation between the particle size (NaCl and Ni) and battery degradation was observed in this work. Even though the growth of both Ni and NaCl can influence the cell degradation, our results indicate that the growth of NaCl is a dominant factor in cell degradation. The use of excess Ni seems to play a role in tolerating the negative effects of particle growth on degradation since the available active surface area of Ni particles can be still sufficient even after particle growth. For NaCl, a large cycling window was the most significant factor, of which effects were amplified with decrease in Ni/NaCl ratio.

25 ENERGY STORAGE↗