High Energy Storage Capacity Research Articles

Two step pyrolysis synthesis method of graphite-enhanced Nano-Si/Pitch composite as long cycle life anode for lithium-ion batteries

Energy storage devices have become the dominant power source in various fields due to their capacity, lifespan, and eco-friendliness. However, there is a need to develop new energy storage devices with higher energy and power density to meet increasing energy demands. Silicon-based anode materials have considerable potential for developing long-lasting, high-capacity energy storage devices, specifically lithium-ion batteries. However, the practical use of these batteries faces challenges like significant volume variations, silicon instability during charging and discharging, and restricted conductivity. This work used silicon nanoparticles from waste industrial solar cells and mixed them with pitch derived from coal tar in a tetrahydrofuran (THF) solvent to form a homogenous Si@Pitch nanocomposite. Pitch-derived carbon helps hold the silicon particles together, reducing the detrimental effects of volume expansion. It acts as a matrix that accommodates the structural changes in silicon during lithiation and delithiation. The Pyrolyzed Si@Pitch-2:1 nanocomposite electrode developed through an efficient two-step pyrolysis technique demonstrated outstanding performance. When charged at a rate of 500 mA·g−1 over 200 cycles, it showed a high discharge capacity of 1524 mAh·g−1, with an average coulombic efficiency of 99.8% and a discharge capacity retention of 75.7%. Combining silicon nanoparticles and pitch derived from recycled industrial waste contributes to the impressive results. This efficient synthesis method can improve the anode materials used in lithium-ion batteries.

Electrochemical sulfur-doping as an efficient method for capacitance enhancement in carbon-based supercapacitors

Cost-efficient fabrication of electrochemical supercapacitors can herald high-capacity energy storage devices. In this work, a simple electrochemical sulfur doping in activated carbon (AC) is introduced, where the specific capacitance of the electrochemically sulfur-doped (ECD) supercapacitor is increased significantly from 147 to 440 F g−1 at 1 A g−1. Surface characterizations, especially high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDAX), and Fourier transform infrared spectroscopy (FTIR) confirm induced sulfur element in the carbon electrode after doping, as result of which the electrochemical measurement shows an increase of the specific capacitance. Moreover, a high energy density of ∼15 Wh kg−1 at 1 A g−1 and almost 90 % capacitance retention at 20 A g−1 after 5000 cycles is achieved. In addition, joint density functional theory (JDFT) is used for the rational design and verification of high-energy-density supercapacitors, supporting our experimental observations. This result paves the way toward further investigations on acid-assisted elemental doping of AC materials for energy storage devices.

Biomass Derived Flexible Free-Standing Electrodes for a High Performance Supercapacitor

Global energy demand, the depletion of fossil fuels, and environmental deterioration have spurred a search for significant improvements in energy conversion and storage. The need for efficient methods of electrical energy storage for on-demand use is critical. Batteries and supercapacitors (SCs) are two of the main energy-storing technologies. SCs and batteries are frequently used in everyday items like smartphones, wearable electronics, electric cars, and portable electronic devices. Supercapacitors (SCs) continue to generate a lot of attention due to their higher energy storage capacity than conventional capacitors and faster rate performance than rechargeable batteries. Supercapacitors, on the other hand, have a high-power density (>10 kWkg-1), extended cycle stability, and an increased capacity for charging and discharging quickly. Supercapacitors are divided into two major categories: EDLC and pseudo-capacitors, depending on the charge storage mechanism. At the electrode-electrolyte contact in EDLC, a double layer of charge is created. Charge transfer reactions between the electrode and electrolyte cause pseudo-capacitance to arise. Compared to EDLCs, pseudocapacitive materials have a greater capacitance. Materials that are pseudo-capacitative include transition metal oxides (TMOs) like, Fe2O3, CoO, NiO, ZnO2, TiO2, and V2O5. which are good candidates for high-performance supercapacitors. Herein, we have proposed a pseudocapacitive material functionalized carbon fabrics produced from cellulosic-based biomass material as a free-standing electrode for supercapacitor application. The fibrous electrode not only provides good mechanical flexibility but also a large surface area for electron transportation in the charging-discharging process. An excellent specific capacitance of ~ 1024 Fg-1 was exhibited in the three-electrode system. An electrochemical study for a full-cell asymmetric supercapacitor was also carried out which showed that the electrodes have an appreciable energy density of ~ 32 Wh kg-1 at a power density of ~ 120 W kg-1. In addition, a flexible asymmetric supercapacitor was also fabricated. A specific capacitance of ~ 40 Fg-1 was achieved in the device. Also, after bending at different angles there was no change in the cyclic voltammetric curve, suggesting that functionalized carbon fabric has good flexibility. Keywords : Supercapacitor, Cellulosic material, Free-standing, Carbon fibre

Visualising Chemical Transformations in Si-Based Electrodes through Operando Tomography

The development of the modern Li-ion batteries requires new materials which will be capable of delivering high energy storage capacities. In such quest, anode materials operating under alloying mechanism have been recognised among the others as a potential replacement for conventional graphite-based anodes in Li-ion batteries. Among those, Si has long been viewed as the main candidate for such a role, as the Li storage capacity of Si is ten times higher than that of graphite. While more than a decade of research was dedicated to improve poor cycling stability of Si-based anodes, the progress in stabilisation of Si cyclability is still partially impeded by the lack of complete fundamental understanding of the chemical transformations taking place during cycling. Despite the relative simplicity of the electrochemical processes underlying the cycling mechanism of Si, the true atomistic and morphological changes are not fully understood. Furthermore, the formation of amorphous Li-Si phases during lithiation and delithiation substantially restricts the set of characterisation techniques, which could be applied to reveal the details of the cycling mechanism. In general, the materials operating under allowing mechanism in LIBs and other battery chemistries share the similar level of complexity. This calls for new experimental and computational methods for characterisation of Si and other alloying materials with use of operando mode, which will help to link the chemical transformations at different scales to the electrochemical performance. In this presentation, we will demonstrate a characterisation methodology, which illustrates the possibility of retrieving new insights into the cycling mechanism by conducting operando pair distribution function computed tomography (PDF-CT) measurements using electrodes based on amorphous silicon (Si) as an example. The amorphous nature of Si and its lithiated forms complicates the analysis of this material system and, thus, Si-based anodes represent a perfect platform for evaluation of the new characterisation methods. The PDF-CT methodology demonstrated herein allows spatially resolved analysis of amorphous materials such as Si and detect the structural changes during lithiation/delithiation in a specially designed battery cell. Furthermore, this method could be utilised for creating a 3D structural map of electrodes fabricated from amorphous active materials (or materials which can form amorphous phases during cycling) and for understanding of structural and morphological changes during cycling.

Designing Metal Complexes for Redox Flow Batteries By High-Throughput Synthesis

Redox flow batteries (RFBs) are an attractive device for high-capacity energy storage systems. Due to the disadvantages of vanadium RFBs such as high cost and limited temperature operability [1], researchers have been developing new redox couples to replace vanadium. The use of relatively inexpensive transition metals (Fe, Cr, Co, etc.) in combination with ligands to form metal-ligand complexes has received considerable attention [2]. The redox potential of a metal ion of a metal-ligand complex can be tuned by forming a complex with a ligand, and the metal-ligand complex form helps alleviate the crossover problem [3].A major challenge in the discovery and development of functional materials is to find and select the most optimized candidates from millions of possible materials [4]. High-throughput Synthesis (HTSy) enables simultaneous screening, synthesis and characterization of a large number of different material classes, providing unprecedented throughput and reproducibility. Therefore, HTSy can save energy, time, and cost for more efficient discovery of advanced functional materials [5]. In this study, based on HTSy methods, we used an automatic synthesis device (OT-2 liquid pipetting robot) to mix and heat metals (Ni, Cr, Cu, etc.) and ligand liquids to automatically design metal complexes. At the same time, a robot platform is developed to perform high-throughput electrochemical tests to quickly select suitable metal complexes for RFBs, and then conduct further related RFBs performance tests.

All-Solid-State Battery Safety Investigation in Calorimeter Coupled with Fast X-Ray Radiography

All-solid-state battery (ASSB) are expected to be a solution to increase energy density in Li-ion technology. However, high-energy storage capacities make the safety a crucial issue. The main reactions leading to thermal runaway in conventional LiB are anode/electrolyte at 110 °C, electrolyte decomposition at 150 °C and cathode/electrolyte at 300 °C. Therefore, without liquid electrolyte, it can be expected that ASSB are less likely to have a thermal runaway.To assess safety of such non-fully mature battery technologies, a new methodology is proposed and a closed calorimeter was designed to perform operando experiments in abuse conditions with high-speed synchrotron X-ray radiography and measurement of temperature, pressure and energy. The data and image of thermal runaway of all-solid-state batteries are presented and compared to the result of Li-ion batteries with liquid electrolyte. An 11 % decrease of heat release was measured for cell with solid electrolyte. Gas volume, amount of matter that reacts in the cell and reaction kinetics have also been compared.Such a methodology allows deepening hypotheses on associated material degradation and that can assist in development of new battery technologies, by evaluating battery safety from the start of the design from battery composition to cell shape.

Boosting lithium polysulfide conversion via TiO2-supported niobium catalyst for lithium sulfur battery

Lithium sulfur (Li–S) batteries demonstrate enormous promise as a high-performance high-capacity energy storage solution but are severely limited by a low cycle life which stems from rapid capacity decay due to the low conductivity of lithium polysulfides and the poor kinetics of the lithium sulfur reduction reaction, which combined lead to the loss of active cathodic material. In this work, titanium oxide (TiO2) nanostructures are used as a host for a niobium catalyst which accelerates the conversion of polysulfides. Cells containing the TiO2-supported niobium catalyst demonstrated a very high level of stability, with a specific capacity decay rate of 0.045 % per cycle over 350 cycles. Li–S cells using this cathode host material also demonstrated high initial specific capacities, with initial capacities as high as 961 mAh g−1 at 0.2 C and 629 mAh g−1 at 3.0 C.

Coupling effect of radiative cooling and phase change material on building wall thermal performance

Phase change material (PCM) featured with high latent heat thermal energy storage capacity and isothermal phase transition is employed into building walls decorated with radiative cooling (RC) coating, in order to modify the cooling effect on building thermal performance. Numerical analysis indicates that the RC coating causes exterior temperature of P-RC walls lower than ambient temperature, achieving maximum exterior temperature drop of 13.63 °C. Thermal buffer effect of PCM enables to shave the temperature peak and shift the temperature valley, inducing exterior temperature of the P-RC wall to fluctuate slightly in comparison to the RC wall. Interior temperature of the P-RC wall is found to approach to target temperature tightly. PCM located closer to the outside completes phase transition more rapidly, which is beneficial to levelling radiative cooling of RC coating. Exterior temperature of P-RC walls increases with augment of solar radiation intensity, ambient temperature and indoor temperature. Augment of PCM thickness, ambient temperature or indoor temperature is conducive to interior temperature. Latent heat thermal energy storage of PCM enlarges effective thermal capacity of walls, which is favorable to maintain interior temperature within target temperature. In conclusion, studied results highlight that radiation cooling can be improved by PCM, with substantial benefits to develop passive cooling available to building energy conservation.

Geological energy storage in Aotearoa New Zealand a technical, geological and social overview

ABSTRACT Aotearoa New Zealand is transitioning to a low emissions economy with an aspirational target of 100% renewable electricity production by 2030. The renewable energy sources that are increasingly relied upon bring with them challenges relating to intermittency of supply over the short term as well as over the medium to long term (as a result of varying rainfall impacting hydro generation). Long-term and high-capacity energy storage solutions are therefore critical to the government’s Just Transitions renewable energy strategy. Geological Energy Storage (GES) is a potential solution for Aotearoa New Zealand’s energy storage needs. The geological subsurface is an efficient long-term and high-capacity energy storage medium for compressed gas or fluids which can be stored and later decompressed and used to regenerate energy. GES has been proven to be feasible in natural and manmade underground voids (i.e. salt caves, mine shafts, tunnels, and boreholes), and in subsurface pore spaces (i.e. saline aquifers and depleted gas and oil reservoirs) where the highest storage potential is found. This work provides a high-level overview of technical, geological, and social aspects of this alternative energy storage solution, focusing on the Taranaki region and the Just Transitions energy action plan as it may be implemented there.

NixB/rGO as the cathode for high-performance aqueous alkaline zinc-based battery

Aqueous alkaline zinc batteries (AZBs) exhibit great potential due to their high capacity, high safety and low cost. However, despite these advantages, the lack of high stability and high utilization rate makes the search for high-performance cathode materials a great challenge. Here, an amorphous nickel boride/rGO (NixB/rGO) complex structure was designed. As a result of abundant unsaturated active sites and synergistic electronic effects, amorphous NixB exhibits excellent energy storage properties. As well as having high electrical conductivity, rGO avoids aggregation of NixB nanoparticles, ensuring that NixB/rGO electrodes have a high energy storage capacity. The structure has a strong adhesion between NixB and rGO, which protects its stable structure and extends its life. More importantly, the NixB/rGO//Zn full battery shows remarkable capacity (228.4 mAh/g at 2 A/g), extraordinary cycle durability (93.7% retained after 1000 cycles) and strong energy density 399.7 Wh/kg, when coupled with NixB/rGO cathode. This work will also shed light on other nickel-zinc batteries in order to achieve super durability and capacity.

Running-Specific Prosthesis

Sports help children “develop physical skills that contribute to a lifetime of physical involvement; … learn social and emotional skills; develop moral values; and acquire a better sense of self through increased perceived competence, self-esteem, and self-confidence” (Ewing, Gano-Overway, Branta, & Seefeldt, 2002). Lower-leg amputations jeopardize children’s ability to continue participating in sports, as it removes a part of the body that is essential for running and sports participation. Running-specific prostheses (RSPs), a type of lower-limb prosthesis, provide a solution to this issue. Compared to daily-use prosthetics, running-specific prosthetics have a higher energy-storage capacity, are more flexible, and are more springy, allowing them to mimic the nature of running biological legs better than daily-use prosthetics. RSPs also have customizations that are specific to the physical traits and activity of an amputee, allowing an amputee to play a plethora of sports. Although children must overcome challenges regarding the change in biomechanics while running with an RSP and accounting for the rapid growth of children, RSPs can provide amputees the opportunity to return to the sports environment.

Effects of graphene doping on shape stabilization, thermal energy storage and thermal conductivity properties of PolyHIPE/PEG composites

The development of clean and renewable energy sources has been necessitated by the ever-increasing energy consumption, increasing environmental degradation caused using fossil fuels and concerns over the rise in CO2 spreading. Functional phase change materials (PCMs)' energy storage capacity is appealing owing to their environmental friendliness, superior thermal energy storage (TES) capacity, and capability to improve energy efficiency. A series of hierarchical porous high internal phase emulsion polymer (PolyHIPE) materials with high PCM impregnation capacity were synthesized in this investigation. It has been achieved to encapsulate 80 % by mass of polyethylene glycol (PEG) into the PolyHIPE structure. However, the efficiency of energy storage and conversion systems is affected by a wide variety of factors; one of them is poor thermal conductivity. The development of carbon-based materials like graphene is particularly promising in the disciplines of energy storage and conversion. With this intention, the synthesis of composite PCMs in which the heat conductivity has been enhanced with graphene at three different ratios (wt% 3, 5, and 10) has been performed, conducting comprehensive investigations. The produced composite PCMs have an energy storage capability of over 120 J·g−1 and high thermal and structural stability. In the polyHIPE/graphene structures produced in the absence PCM, the thermal conductivity value exhibits a notable enhancement of up to 125 % due to the increased amount of graphene compared to the polyHIPE material. Following the impregnation of PolyHIPE@Graphene with PEG, it was observed that the thermal conductivity value improved by up to 51.2 % in comparison to PCM. The addition of graphene also gradually shortened the heat storage-release time. In short, herein a series of PCM composites with high energy storage capacity, capable of trapping different PCMs within their structure, has been proposed for TES applications. The manufactured composite PCMs have the potential to be used for a wide range of things, like maintaining the temperature of batteries and photovoltaic solar cells, packaging perishable foods, and providing thermal comfort in textiles and medicinal materials.

A Polytetrafluoroethylene-Based Solvent-Free Procedure for the Manufacturing of Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) have recently become popular for energy storage due to their high energy density, storage capacity, and long-term cycle life. Although binders make up only a small proportion of LIBs, they have become the key to promoting the transformation of the battery preparation process. Along with the development of binders, the battery manufacturing process has evolved from the conventional slurry-casting (SC) process to a more attractive solvent-free (SF) method. Compared with traditional LIBs manufacturing method, the SF method could dramatically reduce and increase the energy density due to the reduced preparation steps and enhanced electrode loading. Polytetrafluoroethylene (PTFE), as a typical binder, has played an important role in fabricating high-performance LIBs, particularly in regards to the SF technique. In this paper, the development history and application status of PTFE binder was introduced, and then its contributions and the inherent problems involved in the SF process were described and analyzed. Finally, the viewpoints concerning the future trends for PTFE-based SF manufacturing methods were also discussed. We hope this work can inspire future research concerning high-quality SF binders and assist in promoting the evolution of the SF manufacturing technology in regards to LIBs.

A proposal for advanced supplementary technologies and a hybrid system with gas-cooled fast reactor concept ALLEGRO

A coupling of advanced reactors with high-capacity energy storage and other innovative non–nuclear energy technologies is a way to increase the flexibility and utilisation factor of the future nuclear systems and to diversify its energy outputs. In this paper, the basic layout of a hybrid system for a gas-cooled fast reactor is proposed. The system is composed of a high-temperature thermal energy storage unit coupled with a supercritical CO2 conversion cycle and both low-temperature and high-temperature hydrogen production and utilization. As a reference GFR reactor, the ALLEGRO concept is considered. The paper describes state-of-the-art and overviews potentially applicable technologies. Selection and justification of concepts of the individual parts of the hybrid system including operational conditions is also given. The R&D needs necessary for the potential implementation of the system are identified and the activities ongoing in the Czech Republic and especially in Centrum Výzkumu Řež are also described.

Multi-target neural network predictions of MXenes as high-capacity energy storage materials in a Rashomon set

Multi-target neural network predictions of MXenes as high-capacity energy storage materials in a Rashomon set

Prediction of transient melt fraction in metal foam - nanoparticle enhanced PCM hybrid shell and tube heat exchanger: A machine learning approach

Phase change materials (PCMs) have gained popularity in storing thermal energy due to their high energy storage capacity per volume. However, the low performance of the PCM heat exchanger (HX) is primarily due to poor thermal conductivity. The performance of these systems can be improved by using metal foams, nanoparticles, fins, etc. In the present work, the melt fraction (MF) in PCM shell and tube (ST) heat exchanger (HX) with a hybrid combination of metal foam + Graphene nanoplatelets (GNP) nanoparticles (NPs) is predicted using the Machine learning (ML) algorithms. This study analyzes 0.93, 0.95, and 0.97 porosity copper metal foams and 0.5% and 1% volume fraction GNP NPs considering the orientation (0°, 30°, 45°, 60° and 90°) effects of HX. Numerical simulations are carried out to collect the data, to train, cross-validate, and testing. Linear regression (LR), support vector regression (SVR), XGBoost (XGB), and K nearest neighbor (K NN) ML algorithms are used to predict the MF of the PCM in HX with respect to time. MF is predicted during both the melting and solidification processes. Among the ML models selected, the LR model has predicted the transient variation of MF with the highest accuracy during both melting and solidification.

Synergistic integration of Bi2O3||CoWO4 for asymmetric supercapattery: A binder-free approach ensuring high endurance cycling stability

Supercapatteries are becoming increasingly popular as energy storage devices due to their remarkable electrochemical characteristics, which combine a high energy storage capacity, similar to batteries, and a high-power output, similar to supercapacitors. In this study, the assembly of Bi2O3/Carbon cloth (anode) and CoWO4/Nickel foam (cathode) electrodes was carried out using a PVA-KOH gel electrolyte. The device operated within a potential range of 1.55 V and exhibited a specific capacity of 423 C/g at a 1 A/g current density. Additionally, the prepared solid-state device showed remarkable electrochemical stability, retaining over 96 % coulombic efficiency and 90 % capacity after 10,000 GCD cycles. Furthermore, the fabricated asymmetric supercapattery demonstrated an energy density of 115.11 Wh/kg and a specific power density of 6005 W/kg. The ability of the fabricated adaptable supercapacitor to power an LED highlights its potential in flexible applications without compromising functionality. This presents a promising outlook for the advancement of electrochemical energy storage devices.

Managing reservoir dynamics when converting natural gas fields to underground hydrogen storage

On the path to a net-zero-carbon economy, large-scale energy storage will be an essential part of a renewable energy system. Hydrogen generated from renewable or zero-carbon sources has significant potential as an energy storage medium, by allowing for long-duration and high-capacity energy storage. At the volumes anticipated, however, underground storage systems will likely be essential. Much like the current natural gas system, underground hydrogen storage would provide a safe and cost-effective complement to smaller surface storage infrastructure. Recently, there has been significant interest in the possibility of converting existing gas storage systems to hydrogen storage, though many uncertainties exist in such a process. This paper explores the reservoir dynamics of natural gas/hydrogen gas mixtures and the resulting impacts on storage conversion and gas deliverability. Two specific topics are addressed. First, a novel viscosity model for hydrogen-containing gas mixtures is developed, which shows better agreement with experimental measurements than the widely-used Lohrenz-Bray-Clark model. Second, detailed reservoir simulations are used to investigate cost-effective injection/withdrawal strategies for converting a natural gas storage system to one that stores hydrogen/natural-gas blends. The critical role of buoyancy and gravity override is described, and recommendations are made regarding key reservoir characteristics and injection strategies for managing this behavior.

Enhancing the charge transfer and redox characteristics in energy storage devices with a layered ZnNbS@graphene nanocomposite electrode material for biomedical application

Hybrid supercapacitors, a type of device that integrates the functionalities of both supercapacitors and batteries, exhibit significantly enhanced power and energy densities. Two-dimensional materials particularly graphene with remarkable characteristics such as conductivity, sensitivity, and storage capacity, have garnered significant attention in the realm of energy storage. Herein, a composite electrode of zinc niobium sulfide (ZnNbS) and graphene (Gr) is designed and measured the electrochemical and biomedical applications. The composite electrode ZnNbS@Gr (75/25 ratio) showed a high value of specific capacity of 1573.01 Cg−1, much better than pristine ZnNbS (854.32Cg−1) because of the improvement in charge transfer and redox characteristics. Further, a hybrid supercapacitor device (ZnNbS@graphene//AC) is designed and achieves a specific capacity (179.2 C/g) at 1.5 A/g. The energy density is establish 42.1 WhKg−1, whereas the power density is 2500 WKg−1. This device is measured up to 5000 charging and discharging cycles, obtained a high value of capacity recantation of 96 %. Besides, this device is used to accurately detect the glucose to a small amount of 0.01 mM. The conclusions of our investigation provide a remarkable beginning for the advancement of high-capacity energy storage systems and biomedical applications.

Laser-induced manganese oxide/graphene composite electrodes with commercial-level mass loading towards high-performance supercapacitors

Combining of graphene with pseudocapacitance metal oxide is effective to construct supercapacitor electrode with high energy storage capacity. However, balancing the contradiction between high load of metal oxide and high stability of electrode is still challenging. Herein, a novel supercapacitor electrode composed of 3D graphene and manganese oxide is in-situ fabricated by laser carbonization of polyimide (PI) foam loaded with manganese acetate precursor. Due to the rich porous structure and super hygroscopicity of PI foam, high content manganese acetate is uniformly loaded into the network of PI foam. Under laser irradiation, PI foam is carbonized to form 3D porous graphene, while the generation of MnO-Mn3O4 and its uniform loading on graphene is achieved synchronously. The obtained composite electrode exhibits a commercial-level mass loading up to 8 mg cm−2, with a 48.6% weight ratio of MnO-Mn3O4. As a result, an ultra-high specific capacitance of 1525 mF cm−2 can be obtained for the composite electrode at the optimal doping concentration of 0.3 mol L− 1. Notably, the composite electrode also exhibits excellent cycling stability of 94.75% retention rate after 6000 cycles. The maximum area specific capacitance of the micro supercapacitor with PVA/LiCl gel electrolyte is 410.19 mF cm−2, the maximum energy density and power density are 82.04 μWh cm−2 and 400 μW cm−2, respectively.