High Energy Density Systems Research Articles

Effects of mosaic crystal instrument functions on x-ray Thomson scattering diagnostics

Mosaic crystals, with their high integrated reflectivities, are widely employed in spectrometers used to diagnose high energy density systems. X-ray Thomson scattering (XRTS) has emerged as a powerful diagnostic tool of these systems, providing in principle direct access to important properties such as the temperature via detailed balance. However, the measured XRTS spectrum is broadened by the spectrometer instrument function (IF), and without careful consideration of the IF one risks misdiagnosing system conditions. Here, we consider in detail the IF of 40 and 100 μm mosaic Highly Annealed Pyrolytic Graphite crystals, and how the broadening varies across the spectrometer in an energy range of 6.7–8.6 keV. Notably, we find a strong asymmetry in the shape of the IF toward higher energies. As an example, we consider the effect of the asymmetry in the IF on the temperature inferred via XRTS for simulated 80 eV CH plasmas and find that the temperature can be overestimated if an approximate symmetric IF is used. We, therefore, expect a detailed consideration of the full IF will have an important impact on system properties inferred via XRTS in both forward modeling and model-free approaches.

Resonant inelastic x-ray scattering in warm-dense Fe compounds beyond the SASE FEL resolution limit

Resonant inelastic x-ray scattering (RIXS) is a widely used spectroscopic technique, providing access to the electronic structure and dynamics of atoms, molecules, and solids. However, RIXS requires a narrow bandwidth x-ray probe to achieve high spectral resolution. The challenges in delivering an energetic monochromated beam from an x-ray free electron laser (XFEL) thus limit its use in few-shot experiments, including for the study of high energy density systems. Here we demonstrate that by correlating the measurements of the self-amplified spontaneous emission (SASE) spectrum of an XFEL with the RIXS signal, using a dynamic kernel deconvolution with a neural surrogate, we can achieve electronic structure resolutions substantially higher than those normally afforded by the bandwidth of the incoming x-ray beam. We further show how this technique allows us to discriminate between the valence structures of Fe and Fe2O3, and provides access to temperature measurements as well as M-shell binding energies estimates in warm-dense Fe compounds.

Ocean wave energy harvesting with high energy density and self-powered monitoring system

Constructing a ocean Internet of Things requires an essential ocean environment monitoring system. However, the widely distributed existing ocean monitoring sensors make it impractical to provide power and transmit monitored information through cables. Therefore, ocean environment monitoring systems particularly need a continuous power supply and wireless transmission capability for monitoring information. Consequently, a high-strength, environmentally multi-compatible, floatable metamaterial energy harvesting device has been designed through integrated dynamic matching optimization of materials, structures, and signal transmission. The self-powered monitoring system breaks through the limitations of cables and batteries in the ultra-low-frequency wave environment (1 to 2 Hz), enabling real-time monitoring of various ocean parameters and wirelessly transmitting the data to the cloud for post-processing. Compared with solar and wind energy in the ocean environment, the energy harvesting device based on the defective state characteristics of metamaterials achieves a high-energy density (99 W/m3). For the first time, a stable power supply for the monitoring system has been realized in various weather conditions (24 h).

High Safety Electrolyte Design for Enabling High Energy-Density System of LiNi0.8Co0.1Mn0.1O2//Phosphorus by Simultaneously Adjusting Dual Electrode/Electrolyte Interfaces.

The demand for state-of-the-art high-energy-density lithium-ion batteries is increasing. However, the low specific capacity of electrode materials in conventional full-cell systems cannot meet the requirements. Ni-rich layered oxide cathodes such as Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) have a high theoretical specific capacity of 200 mAh g-1, but it is always accompanied by side reactions on the electrode/electrolyte interface. Phosphorus anode possesses a high theoretical specific capacity of 2596 mAh g-1, but it has a huge volume expansion (≈300%). Herein, a highly compatible and secure electrolyte is reported via introducing an additive with a narrow electrochemical window, Lithium difluoro(oxalato)borate (LiDFOB), into 1m LiPF6 EC/DMC with tris (2,2,2-trifluoroethyl) phosphate (TFEP) as a cosolvent. LiDFOB participates in the formation of organic/inorganic hybrid electrode/electrolyte interface layers at both the cathode and anode sides. The side reactions on the surface of the NCM811 cathode and the volume expansion of the phosphorus anode are effectively alleviated. The NCM811//RP full cell in this electrolyte shows high capacity retention of 82% after 150 cycles at a 0.5C rate. Meanwhile, the electrolyte shows non-flammability. This work highlights the importance of manipulating the electrode/electrolyte interface layers for the design of lithium-ion batteries with high energy density.

4]Helicenium Ion as Bipolar Redox Material for Symmetrical Fully Organic Pole‐less Redox Flow Battery

AbstractLong duration storage batteries such as Redox Flow Batteries (RFBs) are promising storage system to address the energy storage requirement that our society will require in the years to come. Recent effort has been focused on the development of metal free and high energy density system such as all‐organic non‐aqueous redox flow batteries (NAORFBs). However high‐voltage NAORFBs currently use distinct anolytes and catholytes, which are separated by a membrane sensitive to osmotic pressure, resulting in rapid capacity and energy density degradation over time. To address this issue, symmetric organic redox flow batteries (SORFBs) have been proposed as an elegant solution. We have introduced dimethoxyquinacridiniums (DMQA+) ions as efficient bipolar redox molecules (BRMs) in static H‐cell conditions. In this study, we present the first application of DMQA+ ions in a complete flow RFB prototype, showcasing their ability to operate with polarity reversal. Key kinetic properties were evaluated through cyclic voltammetry and DFT calculations. While coulombic and energy efficiency metrics were moderate, pegylated DMQA+ demonstrated impressive capacity retention of over 99.99 % and the capability to operate under polarity inversion, making it a highly attractive choice for grid‐scale, long‐lifespan energy storage applications.

Self-similar solutions for the non-equilibrium nonlinear supersonic Marshak wave problem

Similarity solutions to the nonlinear non-equilibrium Marshak wave problem with a time dependent radiation driving source are presented. The radiation transfer model used is the gray, non-equilibrium diffusion approximation in the supersonic regime. These solutions constitute an extension of existing non-equilibrium supersonic Marshak wave solutions, which are linear to the nonlinear regime that prevails in realistic high energy density systems. The generalized solutions assume a material model with power law temperature dependent opacities, a material energy density that is proportional to the radiation energy density, and a surface radiation temperature drive that obeys a temporal power law. The solutions are analyzed in detail, and it is shown that they take various qualitatively different forms according to the values of the opacity exponents. The solutions are used to construct a set of standardized benchmarks for supersonic non-equilibrium radiative heat transfer, which are nontrivial but straightforward to implement. These solutions are compared in detail to implicit Monte Carlo and discrete-ordinate transport simulations as well gray diffusion simulations, showing a good agreement, which demonstrates the usefulness of these solutions as a code verification test problem.

Synergistic effect of lithium salt and trimethyl phosphate for enhanced interface stability in solid-state lithium metal batteries

Polymer electrolytes hold significant potential in solid-state battery applications due to their high flexibility and scalable manufacturing capabilities. However, it is still necessary to address the safety problems and poor rate performance. Herein, the synergistic effect of trimethyl phosphate (TMP) and lithium difluoro(oxalate)borate (LiDFOB) in the in-situ fabricated poly-butyl acrylate (PBA) quasi-solid electrolyte (QSE) is investigated. The non-flammable additive, TMP, has proven to combine with LiDFOB in the electrolytes as TMP-DFOB− pair. The TMP-DFOB− pair can promote the formation of a B–O, B–F, LiF, and Li3P containing solid electrolyte interphase (SEI) on the lithium anode, enabling stable lithium striping-plating processes. Besides, it enhances the formation of a LiF-rich cathode electrolyte interphase (CEI) and promotes intimate contact between the cathode active materials and PBA-QSE, thereby enhancing the rate performance. Therefore, the Li/PBA-LiDFOB-0.1TMP/LiFePO4 (LFP) cell delivers discharge capacity of 132 mAh g−1 with a remarkable capacity retention of 95.68 % after 500 cycles at 1 C. Even at 4 C, the discharge capacity reaches 92.1 mAh g−1. This non-flammable PBA-LiDFOB-TMP QSE exhibits potential application in high energy density systems. Furthermore, this work provides new insights into strategies for improving rate performance from lithium salts and functional additives aspects.

Enhanced electrolytic immersion cooling for thermal crisis mitigation in high-energy–density systems

Motivated by the increasing need for effective cooling solutions in high-energy–density systems, this experimental study presents the two-phase cooling of a superheated SS 316L sample via immersion quenching in saturated deionized (DI) water at atmospheric pressure conditions with and without a DC electric field. We investigate the effect of the applied electric field, electrode polarity, and in-situ oxidation on quenching characteristics such as the cooling profile, vapour layer behaviour, minimum film boiling temperature (Tmin), and heat transfer rate. The cooling curves of samples quenched with the application of an electric field shift towards the left compared to the sample quenched without an electric field. The cathode sample at 200 V exhibits 33 % faster cooling than the bare sample (0 V). Overall, the in-situ oxidised SS 316L cathode sample at 200 V exhibits a 55 % reduction in film boiling duration, and Tmin increased from 268 °C to 322 °C compared to the bare sample (0 V). The visualisation studies highlight that the liquid–vapour interface experiences a series of oscillations followed by temporal collapse due to electrostatic attraction and electrolytic activity. The obtained results show that hydrogen-rich vapour bubbles increase heat transfer performance. The evolution of hydrogen and its adsorption at the sample surface reduces the activation energy for bubble nucleation and improves the bubble density via liquid pumping. These insights open the pathway for employing hydrogen bubbles for handling ultra-high thermal loads in high-energy density systems, and the specific case of a revised design of concentrating solar receiver is considered based on the present findings.

Construction of an ultra-stable mixed conductive layer to stabilize the solid-state electrolyte/Na interface by in-situ interface chemistry

The quest for high energy density, essentially safe, and cost-effective energy storing systems is powering the evolution of solid-state sodium metal batteries (SSSMBs). However, insufficient Na/solid-state electrolyte (SSE) interface contact leads to the formation of sodium dendrites, causing premature cell failure and safety issues that limit their practical application. Here, a novel ultra-stable mixed conductive layer (MCL) composed of Na15Sn4 and NaF is introduced at the Na|Na3Zr2Si2PO12 (NZSP) interface through in-situ interface chemistry. Such an MCL not only enables the transformation of the NZSP surface from sodiophobic to sodiophilic to achieve intimate contact with Na but also homogenizes the Na+ flux without dendritic sodium. Benefiting from the construction of the multifunctional interface, a high critical current density (CCD) of 1.3 mA cm−2 and an exceptionally long cycle life of 6000 h at 0.3 mA cm−2 are achieved for the Na|SnF2@NZSP|Na cell at room temperature (RT). Furthermore, the Na|SnF2@NZSP|Na3V2(PO4)3 full cell shows excellent cycling performance (91 % of maintained capacity for over 500 cycles at 1 C) and rate capability (101.4 mAh/g at 5 C) at RT. This work presents a validated method for the coordinated regulation of interfacial transfer kinetics and inhibition of sodium dendrite growth.

Same-sided successive-shock HED instability experiments

Inertial confinement fusion (ICF) and high-energy density (HED) physics experiments experience complicated forcing for instability growth and mix due to the ubiquitous presence of multiple shocks interacting with perturbations on multiple material interfaces. One common driver of instability growth is successive shocks from the same direction. However, there is a severe lack of analytic work and modeling validation for same-sided successive shocks since they are extremely difficult to achieve with conventional (non-HED) drivers. Successive shocks access a large instability parameter space; idealized fluid theory [K. O. Mikaelian, Phys. Rev. A 31, 410 (1985)] predicts 15 different interface evolution scenarios for a sinusoidal perturbation. Growth becomes more complex for multi-mode, compressible HED systems. The Mshock campaign is the first experiment in any fluid regime to probe a wide portion of successive shock parameter space. This is enabled by our development of a hybrid direct/indirect drive platform capable of creating independently controllable successive shocks on the National Ignition Facility. These experiments have delivered the first data capable of rigorously challenging our models and their ability to accurately capture Richtmyer–Meshkov growth under successive shocks. Single-mode and two-mode experiments have successfully demonstrated the ability to access and control the various growth scenarios of the shocked interface, including re-inversion, freeze out, and continued growth. Simulations and theoretical modeling are shown to accurately capture the experimental observations in the linear growth phase, giving us confidence in our ICF/HED design codes.

Constructing in-situ SOCl2-induced protective layer on Li anode for high-performance Li–O2 batteries containing LiI redox mediator

Li–O2 batteries have attracted wide attention on account of the ever-increasing demand of high energy density systems. However, their practical application is still facing many critical problems, especially the slurry reaction rate/serious side reactions on cathodes and the fast growth of Li dendrites/passivating layers on anodes. Therefore, we design an in-situ formed coating layer on Li metal anode by introducing thionyl chloride (SOCl2) additives into the Li–O2 system with a redox mediator (RM), LiI. The robust and uniform SOCl2-derived layer can effectively prevent the attack of O2/O2–, which inhibits the surface passivation of Li metal anode and greatly supresses the infinite dendrite growth. Additionally, the SOCl2 additive also contributes to a certain specific capacity of the Li–O2 cells at full discharge/charge conditions. Moreover, the SOCl2-derived coating layer can almost completely stop the diffusion of the soluble I-based RM on Li metal anode to eliminate contiunous side reactions between them. The symmetrical batteries containing SOCl2 display lower overpotentials and longer cycling life than those of cells without SOCl2. More importantly, the SOCl2 based Li–O2 batteries with LiI exhibit the extra-high capacity (31000 mAh g−1), ultra-small voltage polarization (∼1.4 V), and extended operation life (190 cycles).

Defect Modulation in Cobalt Manganese Oxide Sheets for Stable and High‐Energy Aqueous Aluminum‐Ion Batteries

AbstractRechargeable aqueous Al‐ion batteries (AIBs) are promising low‐cost, safe, and high energy density systems for large‐scale energy storage. However, the strong electrostatic interaction between the Al3+ and the host material, usually leads to sluggish Al3+ diffusion kinetics and severe structure collapse of the cathode material. Consequently, aqueous AIBs currently suffer from low energy density as well as inferior rate capability and cycling stability. Here, defective cobalt manganese oxide nanosheets are reported as cathode material for aqueous AIBs to improve both reaction kinetics and stability, delivering a record high energy density of 685 Wh kg−1 (based on the masses of the cathode and anode) and a reversible capacity of 585 mAh g−1 at 100 mA g−1 with a retention of 78% after 300 cycles. The impressive energy density and cycling stability are due to a synergistic effect between the substituted cobalt atoms and the manganese vacancies, which improve the structural stability and promote both electron conductivity and ion diffusion. When applied in aqueous Zn‐ion batteries, a high specific energy of 390 Wh kg−1 at 100 mA g−1 is realized while retaining 84% initial capacity over 1000 cycles. The study offers a new pathway to building next‐generation high‐energy aqueous rechargeable metal batteries.

Phase imaging of irradiated foils at the OMEGA EP facility using phase-stepping X-ray Talbot–Lau deflectometry

Abstract Diagnosing the evolution of laser-generated high energy density (HED) systems is fundamental to develop a correct understanding of the behavior of matter under extreme conditions. Talbot–Lau interferometry constitutes a promising tool, since it permits simultaneous single-shot X-ray radiography and phase-contrast imaging of dense plasmas. We present the results of an experiment at OMEGA EP that aims to probe the ablation front of a laser-irradiated foil using a Talbot–Lau X-ray interferometer. A polystyrene (CH) foil was irradiated by a laser of 133 J, 1 ns and probed with 8 keV laser-produced backlighter radiation from Cu foils driven by a short-pulse laser (153 J, 11 ps). The ablation front interferograms were processed in combination with a set of reference images obtained ex situ using phase-stepping. We managed to obtain attenuation and phase-shift images of a laser-irradiated foil for electron densities above ${10}^{22}\;{\mathrm{cm}}^{-3}$ . These results showcase the capabilities of Talbot–Lau X-ray diagnostic methods to diagnose HED laser-generated plasmas through high-resolution imaging.

Construction of 3D lithium metal anode using bi-functional composite separator: a new approach for lithium battery.

With the increasing use of Li batteries for storage, their safety issues and energy densities are attracting considerable attention. The Li metal battery (LMB) with limited capacity in the Li metal anode is one of ideal high energy-density systems due to eliminating the use of traditional anode, elevating the energy density of battery and reducing production costs. However, the side reactions between the electrolyte and metallic Li and the irreversible loss of lithium resources caused by the generation of "dead Li" will directly lead to the loss of battery capacity during the cycling process. Therefore, the cycle life of the LMB with limited capacity in the Li metal anode faces significant challenges. Herein, a bi-functional manganese oxide (MnO)/polypropylene/Li1+xAlxTi2-x(PO4)3 (LATP) composite separator is designed to construct a stable three dimensional (3D) Li metal in the surface of Cu foil for LMB. The MnO can dissolve in electrolytes with low concentration, which can be reduced to produce Mn and Li2O, functioning as nucleating seeds to induce sheet-like Li deposition. The sustainably released MnO also involves in the formation of solid electrolyte interphase (SEI) layer, which can be repaired promptly once damaged by the volume expansion of Li. The LATP coating layer is in situ transferred onto the sheet-like Li, acting as an artificial SEI layer for further protection. The constructed 3D Li metal anode with limited capacity shows improved cycle stability in LiFePO4 cell, which shows a capacity retention of 94.5% after 150 cycles. Our strategy, constructing stable 3D Li metal anode with bi-functional composite separator, will bring a new inspiration for developing high energy density LMB.

Revealing Lithium Battery Gas Generation for Safer Practical Applications

AbstractGases generated from lithium batteries are detrimental to their electrochemical performances, especially under the unguarded runaway conditions, which tend to contribute the sudden gases accumulation (including flammable gases), resulting in safety issues such as explosion and combustion. The comprehensive understanding of battery gas evolution mechanism under different conditions is extremely important, which is conducive to realizing a visual cognition about the complex reaction processes between electrodes and electrolytes, and providing effective strategies to optimize battery performances. This review aims to summarize the recent progress about battery gas evolution mechanism and highlight the gas suppression strategies to improve battery safety. New approaches toward future gas evolution analysis and suppression are also proposed. It is anticipated that this review will inspire further developments of lithium batteries on performance, gas suppression, and safety, especially in high energy density systems.

Compressor-assisted thermochemical sorption integrated with solar photovoltaic-thermal collector for seasonal solar thermal energy storage

• Compressor-assisted thermochemical sorption energy storage with solar PV/T system. • Thermal and electrical energy simultaneously stored in summer, discharged in winter. • Identify the optimal operating condition of solar PV/T coupled with the storage unit. • Chemisorption cycle using SrCl 2 achieves 100% solar fraction for domestic heating. • Higher compression ratio leads to positive effect on the life cycle of PV cells. This paper studied the performance of a compressor-assisted thermochemical sorption energy storage (CATSES) system with a solar photovoltaic-thermal collector (PV/T) to support the domestic space and hot water heating. The heat from the PV/T drives endothermic desorption, whilst the electricity from the PV/T powers the compressor to assist the low-temperature desorption. The main aim of this study was to demonstrate that the integrated system can flexibly and maximally utilise solar energy, and store solar energy in a high energy–density system with minimum loss over long-term storage. The parametric investigation on the CATSES system using SrCl 2 /NH 3 working pair was conducted for a case study in the city of Newcastle upon Tyne in the UK, which has long wintertime with high heating demand. Two different system operation modes (Case 1 and Case 2) with different strategies of solar energy usage (direct usage / storage) were studied. By using 30 m 2 PV/T collector with the CATSES reactor that contains 22 m 3 (450 kg/m 3 ) composite adsorbent and a compressor with 11.5 compression ratio, the system that operated Case 1 could achieve 100% solar fraction of annual heating demand. The achieved material-based energy storage density was around 0.6 GJ/m 3 and the storage efficiency was 0.88 with the net electricity consumption of 180 kWh (around 5% average consumption of an ordinary UK household). The system that operated Case 2 stored less heat than that of the Case 1 but was able to output more electricity.

Density reconstruction in convergent high-energy-density systems using x-ray radiography and Bayesian inference

X-ray radiography is a technique frequently used to diagnose convergent high-energy-density (HED) systems, such as inertial confinement fusion implosion, and provides unique information that is not available through self-emission measurements. We investigate the scope and limits of that information using a radiography simulation combined with the Bayesian inference workflow. The accuracy of density reconstruction from simulated radiographs of spherical implosions driven with 27 kJ laser energy is assessed, including the increase or decrease in accuracy due to the addition of Lagrangian marker layers, Poisson noise, and improved prior information. This work is the first to present the full uncertainty distributions inferred from radiography analysis in HED systems and demonstrates the importance of constructing the full posterior probability density, as opposed to a point estimate, due to the modal structure of the likelihood surface introduced by typical experimental noise sources. This general methodology can be used both for robust analysis of radiographic data and for an improved design of radiography experiments by modeling the full experimental system.

Construction of composite separator with 3D hierarchical spinel structure in Lithium-Sulfur batteries

Lithium-sulfur (Li-S) batteries are considered the most promising candidate for achieving a low-cost high-energy–density system. One of the biggest deterrents during the practical application of Li-S batteries is the shuttle effect which causes fast capacity degradation and poor rate performance. 3D CoNi2S4 with 3D interconnected porous nitrogen doping carbon was prepared by sulfurizing the precursor Prussian blue analogues. The CoNi2S4 nanoparticles are confined in the carbon framework, affording interconnected macro-mesoporous channels. The constructed 3D CoNi2S4 modified separator effectively accommodates enough electrolytes and provides more exposed active sites that suppress the shuttle effect through trapping polysulfides and accelerating the lithiation of S8 to Li2S. Thus, Li-S batteries with 3D CoNi2S4-PP separators exhibit high-rate capacity and remarkable cycle stability. Furthermore, based on the modified separators, a high sulfur loading cathode delivers an areal capacity of 5.62 mAh cm−2. The separator size expands further to assemble the 1Ah Li-S pouch cell, confirming the practicality. This work provides an efficient strategy with a modified separator for high-performance Li-S batteries.

Triallyl Isocyanurate as an Efficient Electrolyte Additive for Layered Oxide Cathode Material-Based Lithium-Ion Batteries with Improved Stability under High-Voltage.

In this study, a new electrolyte additive 1,3,5-tri-2-propenyl-1,3,5-triazine-2,4,6-(1H, 3H, 5H)-trione (TAIC) for lithium-ion batteries is reported. The additive is introduced as a novel electrolyte additive to enhance electrochemical performances of layered lithium nickel cobalt manganese oxide (NCM) and lithium cobalt oxide (LiCoO2) cathodes, especially under a higher working voltage. Encouragingly, we found protective films would be formed on the cathode surface by the electrochemical oxidation, and the stability of the cathode material–electrolyte interface was greatly promoted. By adding 0.5 wt.% of TAIC into the electrolyte, the battery exhibited outstanding performances. The thickness swelling decreased to about 6% after storage at 85 °C for 24 h, while the capacity retention of cycle-life performances under high temperature of 45 °C after the 600th cycle increased 10% in comparison with the batteries without TAIC. Due to its specific function, the additive can be used in high energy density and high voltage lithium-ion battery systems.

Improving ionic conductivity of polymer-based solid electrolytes for lithium metal batteries

Because of its superior safety and excellent processability, solid polymer electrolytes (SPEs) have attracted widespread attention. In lithium based batteries, SPEs have great prospects in replacing leaky and flammable liquid electrolytes. However, the low ionic conductivity of SPEs cannot meet the requirements of high energy density systems, which is also an important obstacle to its practical application. In this respect, escalating charge carriers (i.e. Li+) and Li+ transport paths are two major aspects of improving the ionic conductivity of SPEs. This article reviews recent advances from the two perspectives, and the underlying mechanism of these proposed strategies is discussed, including increasing the Li+ number and optimizing the Li+ transport paths through increasing the types and shortening the distance of Li+ transport path. It is hoped that this article can enlighten profound thinking and open up new ways to improve the ionic conductivity of SPEs.