Molten Air Research Articles

Molten air—A new class of high capacity batteries

The present invention relates to rechargeable electrochemical battery cells (molten air batteries). The cells use air and a molten electrolyte, are quasi-reversible (rechargeable) and have the capacity for multiple electrons stored per molecule, have high intrinsic electric energy storage capacities. The present disclosure also relates to the use of such in a range of electronic, transportation and power generation devices, including as greenhouse gas reduction applications, electric car batteries and increased capacity energy storage systems for the electric grid. US patent 10637115 is for the invention of air and carbon or CO2 Molten Air batteries, while US patent 11094980 is for the invention of air and metal, boron and a variety of salt/Molten Air batteries.

An ultra stable and efficient bifunctional cathode catalyst for iron molten air batteries

Iron molten air battery possesses cost-efficiency and high theoretical specific energy density merits, and is one of the promising battery systems for future application in energy storage. Although substantial efforts and significant progress have been made in recent years, it is still one of the major challenges to explore a stable and efficient bifunctional catalyst in high-temperature molten salt environments. Herein, the NiMnO3–La2O3 composite is synthesized on porous nickel foam substrates by a hydrothermal method and used as a cathode catalyst for the iron molten air battery. The results show that the NiMnO3–La2O3 composite has excellent stability and durability. After 250 cycles in a 500 °C molten salt electrolyte, the microscopic morphology of the catalyst is almost the same as that before using. Moreover, the NiMnO3–La2O3 composite exhibits excellent oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) activity, less discharge polarization, and excellent rate performance. The iron molten air battery with NiMnO3–La2O3 composite cycles stably over 250 cycles with the highest Coulombic efficiency of 99.8% and the average discharge potential of 1.14 V at 500 °C in the air. This work opens a new avenue toward developing a stable and efficient bifunctional cathode catalyst for the iron molten air batteries.

Mathematical modelling of slag–metal reactions and desulphurization behaviour in gas-stirred ladle based on the DPM-VOF coupled model

ABSTRACT A 3D transient CFD–reaction coupled model is developed to predict the slag–metal reaction and desulphurization kinetics in ladle furnace with both molten slag and air layers considered. The coupled model is able to predict the circulating flow field, capture the transient fluctuation characteristics of slag–air and steel–slag phase interfaces as well as the reaction area. Results also indicate that the distribution and evolution of the steel composition under gas stirring is predicted well. The influence of the chemical compositions of molten steel and slag on sulphur removal efficiency is studied. It is displayed that the Al addition into liquid steel or CaO addition into slag would increase the sulphur distribution ratio, resulting in the improvement of desulphurization efficiency.

An Amorphous MnO2/Lithiated NiO Nanosheet Array as an Efficient Bifunctional Electrocatalyst for Iron Molten Air Batteries

Iron molten air battery is considered one of the promising batteries in next‐generation energy storage due to high theoretical specific energy density, cost efficiency, and environment‐friendly merits. Herein, an amorphous MnO2/lithiated NiO nanosheet array is grown directly on a highly conductive nickel foam substrate to use as a bifunctional electrocatalyst in iron molten air batteries. The advantages of the nanosheet array structure are having more highly exposed active sites for electrochemical reactions, as well as a conductive stable 3D framework for allowing barrier‐free diffusion and transport of ions and oxygen gas. As a result, the amorphous MnO2/lithiated NiO nanosheet array exhibits a promising catalytic activity for oxygen evolution reaction and oxygen reduction reaction with a voltage gap of only 0.29 V. The as‐assembled iron molten air battery shows an impressive rechargeability with the highest coulombic efficiency of nearly 100% through 200 cycles with an average discharge potential of ≈1.14 V at 500 °C. Moreover, the cell has a high rate response up to 6.7 C with a discharge voltage of above 0.9 V. The study achieves critical advances for iron molten air batteries without the use of precious metals in contrast with previous results using the Pd‐based catalyst.

Comparative RANS turbulence modelling of lost salt core viability in high pressure die casting

In this work, the implementation of three turbulence models inside the open source C++ computational fluid dynamics (CFD) library OpenFOAM were tested in 2D and 3D to determine the viability of salt cores in high pressure die casting. A finite-volume and volume of fluid approach was used to model the two-phase flow of molten metal and air, with the latter being treated as compressible. Encouragingly, it is found that, although the choice of turbulence model seems to affect the dispersion of the two-phase interface, the force acting at the surface of the salt core depends only very weakly on the turbulence model used. The results were also compared against those obtained using the commercially available and widely-used casting software MAGMA5.

Nano PdO Activated Iron Molten Air Battery

Iron molten air is a new battery class that combines multielectron cathodic storage, high capacity air electrodes with the high redox activity of a molten electrolyte. The need for a bifunctional a...

Enhanced Iron Molten Air Battery Cycle Life and the Chemistry of the Nickel Oxide/Air Interface

Iron molten air batteries are a promising technology for clean and efficient electrical power generation, but their durability is a key challenge to commercialization. Here, we replaced LiCl in the KCl-LiCl-LiOH system with Li2SO4 or Li0.87Na0.63K0.50CO3 to investigate electrode corrosion and improve cycle life. The nickel air electrode exhibited low corrosion rate in KCl-Li2SO4-LiOH, but the kinetics of the air electrode reactions was impaired. Electrolyte composition influences pitting corrosion of the Ni air electrode in KCl-LiCl-LiOH and intercrystalline corrosion in KCl-Li2SO4-LiOH. KCl-LiNaKCO3-LiOH is a superior electrolyte for these iron air batteries with nickel air electrode. A tenacious, compact Li nickel oxide nano-scale particle layer on the nickel air surface in KCl-LiNaKCO3-LiOH retards nickel fin matrix (current collector) corrosion allowing long-term use. The air electrode surface is an electrocatalytic layer of uniform nano-particles. The iron molten air battery cycled for 850 cycles with an average coulombic efficiency of 88.6% and average discharge potential of ∼1.04 V, achieving a ten-fold increase in cycle life in contrast with the previous result using KCl-LiCl-LiOH. This study explores key factors improving the Ni air electrode and cycle life without interfering with the cycling performance of the iron molten air battery.

(Invited) The Molten Air Battery and the Multiple Electron Storage Advantage

We’ve demonstrated multiple electron per molecule processes yield higher battery storage capacity, introducing a variety of novel storage chemistries including high efficiency in-situ photoelectrochemical solar cells,1,2 aluminum sulfur battery,3 super-iron battery,4 ammonia useful for fuel cells,5 and zirconia on VB2 batteries.6 Unusual multiple electron opportunities abound. For example, not only redox active oxygen from air, but also redox active carbon dioxide from air can be utilized for charge storage.7,8 The Licht group has recently introduced a new class of multiple electrons per molecule battery: Molten Air Batteries.9-14 These new batteries use multi-electron charge storage, a molten electrolyte, are quasi-reversible (rechargeable), and have amongst the highest intrinsic battery storage capacities. This talk will focus on advances in the molten air class of rechargeable batteries including carbon (4 electron storage), iron (3 electron storage) and VB2 (11 electron storage). For example, uncommonly, the carbon molten air battery can utilize carbon dioxide directly from the air or from industrial smoke stacks: charging: CO2(g) -> C(solid) + O2(g) (1) discharging: C(solid) + O2(g) -> CO2(g) (2) 1) S. Licht, G. Hodes, R. Tenne, J. Manassen, A Light Variation Insensitive High Efficiency Solar Cell" Nature , 326, 863-864 (1987). 2) S. Licht, "A Description of Energy Conversion in Photoelectrochemical Solar Cells" Nature , 330, 148-151 (1987). 3) D. Peramunage, S. Licht, "A Novel Solid Sulfur Cathode for Aqueous Batteries" Science , 261, 1029-1032 (1993). 4) S. Licht, B. Wang, S. Ghosh, "Energetic Iron(VI) Chemistry: The Super-Iron Battery," Science , 285, 1039-1042 (1999). 5) S. Licht, B. Cui, B, Wang, F.-F. Li, J. Lau, S, Liu, "Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3," Science, 345 , 637-640, (2014). 6) S. Licht, H. Wu, X. Yu, Y. Wang, "Renewable Highest Capacity VB2/Air Energy Storage," Chemical Communication , 2008, 3257-3259 (2008). 7) S. Licht, A. Douglas, R. Carter, M. Lefler, C. L. Pint, C. “Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes,” ACS Central Science , 2, 162-168 (2015). 8)J. Ren, S. Licht, “Tracking airborne CO2 mitigation and low cost transormation into valuable carbon nanotubes,” Scientific Reports, 6, 27760-1-11 (2016). 9) S. Licht, B. Cui, J. Stuart, B. Wang, J. Lau, "Molten Air Batteries - A new, highest energy class of rechargeable batteries," Energy & Environmental Science ,6, 3646-3657, with 2 pages supplementary information (2013). 10) B. Cui, S. Licht, "A Low Temperature Iron Molten Air Battery," Journal of Materials Chemistry A , 2, 10577-10580, with 3 pages supplementary (2014). 11) S. Liu, X. Li, B. Cui, X. Liu , Y. Hao, Q. Guo, P. Xu, S. Licht, "Critical advances for the iron molten air battery: A new lowest temperature, rechargeable, ternary electrolyte domain," Journal of Materials Chemistry A, 3, 21039-21043, with 2 page Supplementary Info (2015). 12) B. Cui, X. Xiang, S. Liu, H. Xin, X. Liu, and Stuart Licht, "A novel rechargeable zinc-air battery with molten salt electrolyte," Journal of Power Sources, 342, 435-441. (2017). 13) B. Cui, H. Xin, S. Liu, Xianjun Liu, Y. Hao, Q. Guo, and S. Licht, "Improved cycle iron molten air battery performance using a robust fin air electrode," Journal of the Electrochemical Society , 164, A88-A92 (2017). 14) Baochen Cui, Wei , Xiang, Shuzhi Liu, Hongyu Xin, Xianjun Liu, and Stuart Licht, "A long cycle life, high coulombic iron molten air battery," Sustainable Energy & Fuels , cover article, in press (2017).

A New Approach to Carbon Dioxide Utilization: The Carbon Molten Air Battery

As the levels of carbon dioxide (CO2) increase in the Earth’s atmosphere, the effects on climate change become increasingly apparent. With the demand to reduce our dependence on fossils fuels and lower our carbon emissions, a transition to renewable energy sources is necessary. Cost effective large-scale electrical energy storage must be established for renewable energy to become a sustainable option for the future. We've previously shown that carbon dioxide can be captured directly from the air at solar efficiencies as high as 50%, and that carbon dioxide associated with cement formation and the production of other commodities, such as ammonia and iron, can be electrochemically avoided in the STEP process.1-6 The carbon molten air battery, presented by our group in late 2013,7 as one of a new class of rechargeable “molten air” batteries that utilize a molten electrolyte and a quasi-reversible air electrode,7-10 is attractive due to its scalability, location flexibility, and construction from readily available resources, providing a battery that can be useful for large scale applications, such as the storage of renewable electricity. Uncommonly, the carbon molten air battery can utilize carbon dioxide directly from the air:7,11-18 charging: CO2(g) → C(solid) + O2(g) (1) discharging: C(solid) + O2(g) → CO2(g) (2) More specifically, in a molten carbonate electrolyte containing added oxide, such as lithium carbonate with lithium oxide, the 4 electron charging reaction eq. 1 approaches 100% faradic efficiency and can be described as the following two equations: O2- (dissolved) + CO2(g) → CO3 2- (molten) (1a) CO3 2- (molten) → C(solid) + O2(g) + O2- (dissolved) (1b) Using carbon formed directly from the CO2in our earth’s atmosphere, the carbon molten air battery is a viable system to provide large-scale energy storage. References 1Licht, STEP generation of energetic molecules: A solar chemical process to end anthropogenic global warming, J. Phys. Chem., C, 113, 16283 (2009). 2Licht, Efficient Solar-Driven Synthesis, Carbon Capture, and Desalinization, STEP: Solar Thermal Electrochemical Production of Fuels, Metals, Bleach Advanced Materials ,47, 5592 (2011). 3Licht, Wu, Hettige, Wang, Lau, Asercion, Stuart, STEP Cement: Solar Thermal Electrochemical Production of CaO without CO2emission, Chemical Communications , 48, 6019 (2012). 4Licht, Cui, Wang, Li, Lau, Liu, Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3, Science, 345, 637 (2014). 5Cui, Zhang, Liu, Liu, Xiang, Liu, Xin, Lefler, Licht, Electrochemical synthesis of ammonia directly from N2 and water over iron-based catalysts supported on activated carbons, Green Chemistry ,2 DOI: 10.1039/C6GC02386J (2016). 6Li, Wang, Licht, Sustainable Electrochemical Synthesis of large grain or catalyst sized iron , J. Sustainable Metallurgy ,2, 405 (2016). 7Licht, Cui, Stuart, Wang, Lau, Molten Air Batteries - A new, highest energy class of rechargeable batteries, Energy & Environmental Science ,6, 3646 (2013). 8Liu, Li, Cui, Liu , Hao, Guo, Pe. Xu, Licht, Critical advances for the iron molten air battery: A new lowest temperature, rechargeable, ternary electrolyte domain, J. Materials Chemistry, A ,3, 21039 (2015); ibid, 2, 10577 (2014). 9Cui, Xin, Liu, Liu, Hao, Guo, Licht, Improved cycle iron molten air battery performance using a robust fin air electrode,” J. Electrochem. Soc. ,in press (2016). 10Cui, Xiang, Liu, Xin, Liu Licht, A novel rechargeable zinc-air battery with molten salt electrolyte, J. Power. Sources ,in press (2017). 11Licht, Cui, Wang, STEP Carbon Capture: the barium advantage, J. CO2 Utilization ,1, 58 (2013). 12Ren, Li, Lau, Gonzalez-Urbina, Licht, One-pot synthesis of carbon nanofibers from CO2, Nano Letters , 15, 6142 (2015). 13Ren, Lau, Lefler, S. Licht, The minimum electrolytic energy needed to convert carbon dioxide by electrolysis in carbonate melts, J. Phys. Chem. , C, 119, 23342 (2015). 14Licht, Douglas, Ren, Carter, Lefler, Pint, Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes, ACS Central Science , 2, 162 (2015). 15Ren, Lau, Lefler, Licht, The minimum electrolytic energy needed to convert carbon dioxide by electrolysis in carbonate melts, J. Phys. Chem. , C, 119, 23342 (2015). 16Lau, Dey, Licht, Thermodynamic assessment of CO2to carbon nanofiber transformation for carbon sequestration in a combined cycle gas or a coal power plant, Energy Conservation and Management , 122, 400 (2016). 17Wu, Li, Ji, Liu, Li, Yuan, Zhang, Ren, Lefler, Wang, Licht, One-Pot Synthesis of Nanostructured Carbon Material from Carbon Dioxide via Electrolysis in Molten Carbonate Salts, Carbon , 6, 27760 (2016). 18Ren, Licht, Tracking airborne CO2mitigation and low cost transformation into valuable carbon nanotubes, Scientific Reports , 106, 208 (2016). Figure: Variations of the Molten Battery. Figure 1

A long cycle life, high coulombic efficiency iron molten air battery

Despite the recent advancements in iron molten air batteries, great challenges still remain to realize cycling stability, high energy efficiency and a long-term cycling life.

Improved Cycle Iron Molten Air Battery Performance Using a Robust Fin Air Electrode

Iron molten air batteries are an attractive technology for electrical energy storage because of advantages of higher capacity, low cost, sustainability, and environmental friendliness compared to existing secondary batteries; however, battery applications still suffer from low coulombic efficiency and poor cycle stability. Here we report design of a robust fin air electrode for the iron molten air battery. The battery cycled stably at 500°C for 80 cycles with an average discharge potential of ∼1.04 V and average charging potential of ∼1.20 V. The highest coulombic efficiency reaches 93.4% to a 0.7 V discharge cutoff. The encouraging performance offers hope to design more advanced air electrodes for iron molten air batteries.

Correction: Critical advances for the iron molten air battery: a new lowest temperature, rechargeable, ternary electrolyte domain

Correction for ‘Critical advances for the iron molten air battery: a new lowest temperature, rechargeable, ternary electrolyte domain’ by Shuzhi Liu et al., J. Mater. Chem. A, 2015, 3, 21039–21043.

Critical advances for the iron molten air battery: a new lowest temperature, rechargeable, ternary electrolyte domain

The iron molten air battery cycled stably at 500 °C for 60 cycles using cost effective nickel and steel electrodes and KCl–LiCl–LiOH eutectic electrolyte with added NaOH.

Molten Air - a New Class of Rechargeable Batteries

A new class of high-energy batteries, the molten air battery, is presented. These batteries use a molten electrolyte, are quasi-reversible (rechargeable), and have amongst the highest intrinsic battery storage capacities available.In today’s society there exists a need for higher energy capacity, cost effective batteries for a range of electronic, transportation and large-scale power storage devices. The molten air battery overcomes these problems. For example, these batteries address the “range anxiety” of electric vehicles as a result of energy density limitations, and offer increased energy storage capacity for the electric grid.The electron charge transfer chemistry of the molten air battery is demonstrated through three examples. These examples utilize metal, carbon and vanadium diboride as reactive material each containing the respective intrinsic volumetric energy capacities of 10,000 Wh liter-1 for Fe to Fe(III), 19,000 Wh liter-1 for C to CO2 - and 27,000 Wh liter-1 for VB2 to B2O3 + V2O5, compared to 6,200 Wh liter-1 for the lithium air battery.

A low temperature iron molten air battery

Molten air battery, a new class of rechargeable battery with the highest storage density, is demonstrated to work at temperatures more compatible with EV applications.

Research and Application of Heat Transfer Fluids in Solar Thermal Power

mproving the thermophysical properties of heat transfer fluid is always a research hotspot and difficult subject in the application of solar energy for medium and high temperature. The research and application of these heat transfer fluid, including steam, heat transfer oil, molten salt, air, liquid alloy and nanofluids, were summarized in this paper. After comparing their characteristics, it is found that molten salt, air and liquid alloy have greater application and development prospects. Future research directions include extending the temperature span of operating condition, enhancing the efficiency of heat transfer and storage, lengthening service life and finding out the correlation between microstructure and related performance.

Molten air – a new, highest energy class of rechargeable batteries

This study introduces the principles of a new class of high-energy batteries and their fundamental chemistry is demonstrated. These molten air batteries use air, a molten electrolyte, are quasi-reversible (rechargeable), have the capability for multiple electrons stored per molecule, and have the highest intrinsic electric energy storage capacities. Here we show three examples of the new battery's electron transfer chemistry. These are the metal, carbon and VB2 molten air batteries with respective intrinsic volumetric energy capacities of 10 000 (for Fe to Fe(III)), 19 000 (C to CO32−) and 27 000 W h l−1 (VB2 to B2O3 + V2O5), compared to 6200 W h l−1 for the lithium air battery. Higher energy capacity, cost effective batteries are needed for a range of electronic, transportation and greenhouse gas reduction power generation devices. Needed greenhouse gas battery reduction applications include overcoming the battery driven “range anxiety” of electric vehicles, and increased capacity energy storage for the electric grid.

Shape and stability computations of electromagnetically confined liquid metal boundaries

High-frequency electromagnetic shaping of liquid metal boundaries involves a coupling between the molten metal interface and the magnetic fields. Modeling a stable molten metal and air interface requires a self-consistent solution. Previous work by the authors describes a two-part iterative free boundary solution procedure applied to liquid metal column cross sections. This article describes the extension of this methodology to axisymmetric systems and, in addition, shows that the method predicts Rayleigh-Taylor type instabilities. Thus, the equilibrium free boundaries calculated using this method are statically stable equilibria.