Emerging Energy Storage Research Articles

Electrospinning Polyanionic Materials for High‐Rate Na Storage

AbstractAs emerging energy storage devices, sodium‐ion batteries (SIBs) are perceived as promising alternatives to lithium‐ion batteries (LIBs) due to their low cost and high safety. The cathodic side plays a crucial role in determining the energy density as well as the service life of SIBs, and the polyanionic cathode materials are featured by excellent cycle stability, flexible operating voltage and suitable overall electrochemical properties. However, the intrinsic inferior electronic conductivity limits their rate performance. Recently, the possibility of employing advanced electrospinning techniques to fabricate polyanionic materials has been explored. The facile electrospinning can greatly facilitate the ionic and electronic conduction of cathodes by constructing three‐dimensional (3D) conductive networks with the one‐dimensional (1D) nanofibers, and thus improves their electrochemical performance. In this review, we summarize the research progress of the electro‐spun polyanionic cathodic materials and their applications in SIBs, and present future prospects as well as challenges of the electro‐spun polyanions faced to the ever‐increasing demand of advanced energy storage.

Measures to Improve The Vanadium Flow Battery

As a kind of emerging energy storage measure, the vanadium flow battery utilizes the ion exchange of vanadium ions to store and discharge energy. Among the existing energy storage technologies, it has high potential and significance due to its several advantages. However, there are still aspects that can be improved and promoted: in battery diaphragm, the voltage and current efficiency could be improved by modifying the ion permeability; The cost of electrolyte is high which can still optimize by selecting low-cost material, through mixing the electrolyte, the cycle life can be extended as well as enable the discharge capacity regeneration; Electrode has the problem of corrosion that affects the lifetime of an electrode, meanwhile, reduce the battery efficiency. In this article, the research progress of vanadium flow battery and the defective aspects of it is investigated, and based on the available cases, the possible solutions and suggestions for the existing problems in battery cells, electrolytes, and electrodes are analyzed. At last, the overall prospect of the vanadium flow battery itself is also discussed.

Enhancing the performance of Ni-rich lithium metal batteries through the utilization of amine-functionalized 1D/3D nano shields and additives in high-voltage operation

The development of high-energy–density lithium metal batteries (LMB) is of paramount importance for various emerging energy storage applications, and high-voltage operating system based on high-capacity nickel-rich layer LiNixCoyMn1−x−yO2 (Ni-rich NCM, x ≥ 0.6) cathode combined with a Li metal anode is a representative promising solution. However, it is challenging to stabilize the lithium metal anodes with severe operating conditions, mainly because dissolved transition metal (TM) ions from the cathode trigger harmful side reactions, such as electrolytic decomposition and the growth of dendritic Li structures, resulting in serious safety hazards. In this study, we fabricated an ion-entrapping functional separator using amine-functionalized 1D or 3D inorganic particles confirmed by DFT calculation. Then, we applied in the Ni-rich LMB, demonstrating suppression of TM ion cross-over of 47% compared to conventional PE separators leading to improved cycle numbers and capacity retention at high-voltage operation. Further, combining functional additive introduction with the transition metal cross-over shielding separator resulted in synergistic ion capturing up to 84%. The results of this study provide new insights into the design of advanced LMB for high-energy–density.

Cobalt Vanadate (Co3V2O8) Hollow Microspheres as a Polysulfide Adsorption and Conversion Catalyst for Li–S Batteries

A lithium–sulfur battery (Li–S) is considered as one of the most suitable emerging energy storage technologies for electric vehicles (EVs) due to its higher specific capacity, energy density, and low cost. However, the dissolution of lithium polysulfides (LiPS) in an electrolyte causes a huge shuttle effect, which results in poor cycle life and rate performance. Herein, Co3V2O8 (CVO) hollow microspheres have been prepared by the solvothermal method and used as catalyst additives to the sulfur electrode (cathode host). It was found that CVO acts as a bifunctional additive, the vanadium and oxygen sites immobilize the LiPS through V–S and Li–O interactions, while the cobalt site facilitates the rapid conversion of long-chain LiPS into short ones (Li2S2/Li2S). Furthermore, the hollow microspheres act as a sulfur reservoir and can confine (encapsulate) more LiPS during the electrochemical conversion process, thus inhibiting the shuttle effect. In this work, the chemical adsorption and polysulfide conversion ability of CVO is corroborated by XPS and cyclic voltammetry studies, respectively. Even at a higher sulfur loading of 5.4 mg cm–2, CVO containing the Li–S cell (denoted as S@CVO/CNT Vs Li) demonstrates an initial discharge capacity of 694 mAh g–1 at 0.5 C, and after 200 cycles, the observed capacity is 566 mAh g–1, which amounts to 81% capacity retention. Similarly, the cell delivers an excellent rate capability of up to 5 C rate. At the 1 C rate, the cell shows an initial discharge capacity of 904 mAh g–1 (S-loading of 3 mg cm–2) and 692 mAh g–1 after 300 cycles with 77% capacity retention.

Multidimensional Factors Influencing Renewable Energy Storage Deployment: PESLTE Analysis

The share of renewable energy in heat and power generation is expected to increase significantly and reach record levels in the coming decades. As a result, emerging energy storage technologies will be key elements in balancing the energy system. Compared to power generation technologies, storage technologies are considered one of the most complicated and least understood technologies for decarbonizing the energy system. There is still lack of understanding among scientists and policymakers about the choice of optimal integration of energy storage in carbon-neutral energy systems, as there are many multidimensional factors that influence this. In this study, the PESLTE analytical framework and composite index methodology is applied to examine the multidimensional factors that influence the deployment of renewable energy storage technologies: political (national and international level policy targets, appropriate regulation), economic (CAPEX, LCOE), social (public acceptance, knowledge and on-site capacity on RES storage in local energy supply enterprises), legal (level of bureaucracy and time of approval), technological (TRL, response time, efficiency level of complexity for technology to be integrated in the existing grid), and environmental (specific need for specific geographical condition, landscape friendliness, potential environmental risk, potential creation of environmental benefits, lifetime of technology, environmental impact).

Thermodynamic and kinetic properties of calcium hydride

Calcium hydride has shown great potential as a hydrogen storage material and as a thermochemical energy storage material. To date, its high operating temperature (above 800 °C) has not only hindered its opportunity for technological application but also prevented detailed determination of its thermodynamics of hydrogen sorption. In addition, calcium metal suffers from high volatility, high corrosivity from Ca (and CaH2), slow kinetics of hydrogen sorption, and the solubility of Ca in CaH2. In this work, a literature review of the wide-ranging thermodynamic properties of CaH2 is provided along with a detailed experimental investigation into the thermodynamic properties of molten and solid CaH2. The thermodynamic values of hydrogen release from both molten and solid CaH2 were determined as ΔHdes (molten CaH2) = 216 ± 10 kJ mol−1.H2, ΔSdes (molten CaH2) = 177 ± 9 J K−1 mol−1.H2, which equates to a 1 bar hydrogen equilibrium temperature for molten CaH2 of 947 ± 65 °C. Similarly, in the solid-state: ΔHdes (solid CaH2) = 172 ± 12 kJ mol−1.H2, ΔSdes (solid CaH2) = 144 ± 10 J K−1 mol−1.H2. Moreover, the activation energy of hydrogen release from CaH2 was also calculated using DSC analysis as Ea = 203 ± 12 kJ mol−1. This study provides the first thermodynamics for the Ca–H system in over 60 years, providing more accurate data on this emerging energy storage material.

Polyaniline‐coated V2O5 as a high‐performance cathode material for Zn‐ion batteries

AbstractIntroductionDue to the advantages of environmental compatibility, low cost, and safety, aqueous zinc‐ion batteries (ZIBs) have stood out as the emerging energy storage devices among metal‐ion batteries. However, most cathode materials suffer from slow Zn2+ diffusion rates, resulting in poor charge–discharge rates and cycle life of state‐of‐the‐art ZIBs.Objective and MethodIn this work, a polyaniline (PANI) coating method is proposed to improve the Zn2+ diffusion kinetics and stability of the V2O5 cathode. The coating of PANI can maintain the structural stability of V2O5. Moreover, PANI is conducive to improving the electronic conductivity and increasing the intercalation/deintercalation capacity of V2O5 by promoting the diffusion process of Zn2+ ions, thereby increasing the charge–discharge capacity of ZIBs.ResultsEventually, the electrochemical performance of the PANI‐coated V2O5 electrode is significantly improved, delivering a high discharge specific capacity of 0.374 mAh cm−2 at the current density of 2 mA cm−2 and improved capacity retention of 83% after 500 cycles. This work demonstrates the positive effect of the PANI‐coating strategy on improving the electrochemical performance of V2O5 electrodes.

A Review of Cobalt-Based Metal Hydroxide Electrode for Applications in Supercapacitors

Supercapacitors are the cutting-edge, high performing, and emerging energy storage devices in the future of energy storage technology. It delivers high energy and produces higher specific capacitances. This research study provides insights into supercapacitor materials and their potential applications by examining different battery technologies compared with supercapacitors’ advantages and disadvantages. Transition metal hydroxides (cobalt hydroxides) have been studied to develop electrodes for supercapacitors and their use in various fields of energy and conversion devices. Cobalt-based metal oxides and hydroxides provide high-capacitance electrodes for supercapacitors. Metal hydroxides combine high electrical conductivity and excellent stability over time. The metal oxides used to prepare the electrodes for supercapacitors are cobalt-based metal oxides and hydroxides. It is stronger than most of the other oxides and has tremendous electrical conductivity. Cobalt hydroxides are also used in supercapacitors instead of other metal hydroxides, such as aluminum hydroxide, copper hydroxide, and nickel hydroxide. This study gives a complete overview of the preparation, synthesis, analysis, and characterization of cobalt hydroxide thin film electrodes by using the electrochemical deposition technique, parameters measurements, important characteristics, material properties, various applications, and future enhancement in supercapacitors.

THESEUS: A techno-economic design, integration and downselection framework for energy storage

Optimal selection of energy storage technologies is critical to ensure reliable integration of intermittent and often uncertain renewable energy in electricity grids. The consideration of a diverse set of energy storage technologies is required for a more sustainable deployment of energy storage. We present THESEUS (TecHno-Economic framework for Systematic Energy storage Utilization and downSelection), which is a comprehensive framework for the optimal selection, design and operation of energy storage systems. THESEUS includes rigorous models of major energy storage technologies at different maturity levels, such as thermal storage using phase-change materials or molten salt, cryogenic storage, mechanical storage in the form of compressed air and pumped hydro storage, chemical storage using hydrogen, and electrochemical storage in the form of lithium-ion, sodium sulfur and vanadium flow batteries. An illustrative case study on state-wide prospective energy storage shows that storage integration with fossil power plants could reduce the cost of meeting the grid energy demand by 20%, with mechanical storage as the best suited technology. Although high-temperature thermal storage has low storage efficiency, it is optimal for integration with renewable energy plants. In addition, Li-ion batteries are optimal for high ramping but low storage duration requirements. Such insights can enable the deployment of both existing and emerging energy storage technologies to facilitate a smooth transition to a clean energy future.

A Secondary Al-CO2 Battery Enabled by Aluminum Iodide as a Homogeneous Redox Mediator.

As an emerging energy storage concept, Al-CO2 batteries have not yet been demonstrated as a rechargeable system that can deliver a high discharge voltage and a high capacity. In this work, we present a homogeneous redox mediator to access a rechargeable Al-CO2 battery with an ultralow overpotential of 0.05 V. In addition, the resulting rechargeable Al-CO2 cell can maintain a high discharge voltage of 1.12 V and delivers a high capacity of 9394 mAh/gcarbon. Nuclear magnetic resonance (NMR) analysis indicates that the discharge product is aluminum oxalate which can facilitate the reversible operation of Al-CO2 batteries. The rechargeable Al-CO2 battery system demonstrated here holds great promise as a low-cost and high-energy alternative for future grid energy storage applications. Meanwhile, the Al-CO2 battery system could facilitate capture and concentration of atmospheric CO2, ultimately benefiting both the energy and environmental sectors of society.

Probing Redox Properties of Extreme Concentrations Relevant for Nonaqueous Redox-Flow Batteries

Redox-flow batteries are an emerging energy storage technology that can pair with intermittent renewable energy technologies. There remains a need, however, to understand physicochemical relationships among the solvent, electrolyte salt, and redox-active molecules that comprise catholyte and anolyte solutions. To examine this relationship, we detail a systematic study wherein the concentrations of the redox-active molecule 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and TBAPF6 electrolyte salts are varied over concentrations of 1 mM to over 1000 mM in acetonitrile. Three series were investigated: (1) varying the concentration of TEMPO while holding the concentration of TBAPF6 constant, (2) varying the concentration of TBAPF6 while holding the concentration of TEMPO constant, and (3) varying both the concentration of TEMPO and TBAPF6 with a 5:1 TBAPF6:TEMPO ratio. Cyclic voltammetry data from macro- and microelectrodes were used to quantify diffusion coefficients and heterogeneous electron transfer rates, and these metrics were connected to the conductivity and viscosity to develop clear trends over the entire concentration range. Fundamental chemical interactions that lead to changes in physical properties were implicated via vibrational spectroscopy and molecular dynamics (MD) simulations. Trends in conductivity and viscosity for systems were inversely related and correlated to trends in diffusion coefficients and heterogeneous electron transfer rates. Intuitively, faster diffusion and electron-transfer rates occurred with lower TEMPO concentrations and higher TBAPF6 concentrations, with the majority of conditions falling in the general proximity of literature values (k0 = 0.1–0.5 cm/s, D ≈ (2.0–4.0) × 10–5 cm2/s). At the highest TBAPF6 concentrations, vibrational spectroscopy and MD simulations show that intermolecular interactions were more nuanced, and solvation and ion-pairing effects begin to influence electrochemical and physical properties. This functional approach including electrochemical and physical characterization paired with MD simulations provides a template for methodically studying systems for redox flow battery applications.

Carbon Confined Mesoporous Catkin-like SnPS3 Nanostructure for Lithium Storage with Great Superiority

Metal phosphosulfides (MPSs) are members of a category of emerging energy storage and conversion materials, particularly having significant potentials in lithium storage due to their phosphorus and sulfur dual anion centers and unique two-dimensional channels. Nevertheless, it is still very challenging for the controllable design and synthesis of MPSs nanomaterials with complex-element components. Herein, a distinctive carbon confined mesoporous catkin-like SnPS3 nanostructure (SnPS3@C) is controllably synthesized and fabricated based on the partial volatilization of the reduced tin and the following bottom-up phosphosulfuration by a chemical vapor deposition method. As the anode material of lithium ion batteries, the catkin-like SnPS3@C offers multiple active centers for lithium insertion, complete carbon shell to protect inner active materials, interlaced fibrous networks for efficient electron transfer as well as abundant inner mesopores for Li+ diffusion and volume buffer, thus showing prominent structure advantages in lithium storage. The catkin-like SnPS3@C electrode demonstrated superior electrochemical capability with a very high reversible capacity (1302 mAh g–1 at 300 mA g–1), excellent rate property (630 mAh g–1 at 8000 mA g–1) and distinguished cycling stability (1030 mAh g–1 after 1000 cycles at 1000 mA g–1). This work offers a new avenue to develop high-performance MPSs materials for advanced lithium ion batteries.

Near‐Room‐Temperature Quasi‐Solid‐State F‐Ion Batteries with High Conversion Reversibility Based on Layered Structured Electrolyte

AbstractSolid‐state fluoride ion batteries (SSFIBs) are anion‐shuttle‐driven and alkali‐metal‐free emerging energy storage systems, and have the advantages of low cost, high safety, and energy density. However, the current major challenges of SSFIBs or quasi‐SSFIBs are the lack of high‐conductivity fluoride electrolytes and the difficulty of mild‐temperature operation of full cells. Here, a 2D fluoride conductor (KSn2F5) synthesized by mechanochemical method is employed as the compatible solid electrolyte with a high F‐ion conductivity of 10−4 S cm−1 at 60 °C. The high concentration and frequent hopping of charge carriers in F‐vacancy‐rich KSn2F5 contribute to the higher ionic conductivity compared to most reported fluoride structures. Integrating this layered electrolyte with high‐voltage CuF2 cathode and Sn/SnF2 anode, a highly reversible cycling of conversion‐type quasi‐SSFIBs with a discharge capacity of 150 mAh g−1 for at least 70 cycles at 60 °C is achieved. The interface engineering aided by tetra‐n‐butylammonium fluoride salt facilitates the F‐ion transfer between cathode and electrolyte and fluorination/defluorination conversion mechanism of CuF2 cathode with optimized multiphase and nanodomain distributions.

Geological risk and uncertainty for underground storage of buoyant fluids, lessons learned in Illinois

Abstract This paper describes selected natural gas storage and carbon capture and storage (CCS) case studies from Illinois, USA, their general applicability to subsurface buoyant fluid storage, and summarizes lessons learned. In Illinois, a 70-year history of sustained natural gas storage has provided a foundational understanding of risk associated with using the subsurface for storing buoyant fluids. In addition to natural gas storage, over 3 million tonnes of CO 2 have been injected into the Cambrian Mt Simon Sandstone at the Decatur, IL CCS project site. In Illinois, many of the storage projects are in the Mt Simon Sandstone, a saline (aquifer) reservoir. In gas storage fields the characterization of faulting and seal properties has historically not been adequate. Identification of Precambrian palaeotopography is essential when completing initial site assessment in reservoirs close to the Precambrian contact. The presence of basement palaeotopographical highs increases the risk of not having a storage reservoir and increased chance of induced seismicity. The Cambrian Mt Simon Sandstone of the Illinois Basin has some of the most suitable strata in the midwestern USA for the sequestration of CO 2 and storage of energy in the form of natural gas. The improved understanding gained from natural gas storage and from carbon sequestration is also directly applicable to assessing the potential of emerging energy storage technologies, such as compressed air energy storage (CAES) and geological hydrogen storage.

Solar power applications and integration of lithium iron phosphate batteries in off-grid photovoltaic system

Lithium iron phosphate battery is a type of rechargeable lithium battery that has lithium iron phosphate as the cathode material and graphitic carbon electrode with a metallic backing as the anode. It is a relatively new emerging energy storage battery that is Cobalt-free and Nickel-free. However, its integration with solar PV systems and the specific precautions for its use is not well known to most technicians and installers, especially in developing countries. In this paper, the issues on the applications and integration/compatibility of lithium iron phosphate batteries in off-grid solar photovoltaic systems are discussed. Also, the characteristics, properties, advantages, and disadvantages of the battery are presented. From the study, it is shown that if the battery operates with a charge control algorithm specially set for long charge durations, the energy storage system is an ideal choice for an off-grid photovoltaic system. This is due to their high energy density, long cycle life, relatively low cost compared to Li-ion, high safety, low toxicity, low risk of thermal runaway or combustion, low self-discharge rate, high capacity, lightweight, lower environmental impact, low maintenance, high cell voltage, fast charging, high-temperature stability, high discharge power, a good lifetime when deep cycled, etc. Additionally, the advantages have made the battery to be highly valued in energy storage, backup power, vehicle use utility-scale stationary applications, electric vehicles, commercial batteries , solar power, and other renewable energy applications, etc.

Realizing Renewable Energy Storage Potential in Municipalities: Identifying the Factors that Matter

Abstract The share of renewable energy in heat and power generation is expected to increase significantly and reach record levels in the coming decades. As a result, emerging energy storage technologies will be key elements in balancing the energy system. To compensate the variability and non-controllability of seasonally generated renewable energy (RES) (daily fluctuations in solar radiation intensity, wind speed, etc.) development of sufficient energy storage infrastructure in the regions will play a major role in transforming RES supply potential into reality. However, local public authorities that are responsible for creating an enabling policy environment for RES infrastructure development in regions encounter numerous challenges and uncertainties in deploying sufficient energy accumulation that often remain unanswered due to a lack of knowledge and on-site capacity, which in turn significantly hinders the regional path to climate neutrality. In this study, the PESLTE analytical framework and composite index methodology is applied to examine the multidimensional factors that influence the deployment of renewable energy storage technologies in municipalities: political, economic, social, legal, technological, and environmental. Developed model is approbated in a case study in a Latvian municipality where four different alternative energy storage technologies are compared: batteries for electricity storage, thermal energy storage, energy storage in a form of hydrogen, and energy storage in a form of biomethane.

Towards a comprehensive data infrastructure for redox-active organic molecules targeting non-aqueous redox flow batteries

The D3TaLES database and data infrastructure aim to offer readily accessible and uniform data of varying types for redox-active organic molecules targeting non-aqueous redox flow batteries.

A practical perspective on the potential of rechargeable Mg batteries

Emerging energy storage systems based on abundant and cost-effective materials are key to overcome the global energy and climate crisis of the 21st century.

Sugarcane waste-derived activated carbon for lithium-sulfur batteries with enhanced performance by thiourea doping

In this work, bio-renewable sugarcane bagasse and leaf were utilized for the preparation of activated carbon (BAC and LAC), which was then employed as the host material in lithium-sulfur (Li-S) batteries. The activated carbon, for the first time, was doped with nitrogen and sulfur via the addition of thiourea during the synthesis of carbon char via a simple, one-step hydrothermal method. The activated carbon was used to fabricate the cathodes of the CR2032 coin cells. The amount of added thiourea was found to influence the nitrogen/sulfur content, porosity, amorphous/graphitic structure, and performance of the activated carbon. At 0.2C, BAC2 (4.15 wt% thiourea doping) gave the highest specific capacity of 478 mAh⸳g-1 among the bagasse-derived activated carbon, while LAC3 (8.3 wt% thiourea doping) yielded the highest specific capacity of 521 mAh⸳g-1 among the leaf-derived activated carbon. They also demonstrated an excellent capacity retention of 72% and 83%, respectively, after 100 cycles. Furthermore, thiourea doping also improved the rate performance, by providing fast interfacial processes. Based on these results, the obtained activated carbon demonstrates the potential for the fabrication of high-performance Li-S batteries. Also, this work highlights the practical utilization of both sugarcane wastes for these emerging energy storage devices.

Ultrathin Ti3C2Tx nanosheets modified separators for lithium–sulphur batteries

AbstractCurrently, among the various emerging energy storage systems, the lithium–sulphur (Li‐S) battery is expected to be one of the next‐generation lithium secondary batteries with high efficiency. However, the practical application of Li‐S batteries still faces many obstacles. To solve the shuttle effect of lithium polysulphides, ultrathin Ti3C2Tx nanosheets were prepared through the in‐situ acid etching method and applied to separator modification to suppress the shuttle effect of lithium polysulphides. Ultrathin Ti3C2Tx nanosheets with enlarged interlayer spacing accelerated the migration of Li+. The abundant termination groups on the surface of Ti3C2Tx played the role of the lithium polysulphide capture centre. When the mass loading of separator modification materials was set as 0.025 mg cm−2, the as‐prepared battery exhibited a reversible specific capacity as high as 780 mAh g−1 after 200 cycles at 0.2 C, and the single‐cycle capacity decay rate was only 0.09%.