Current Energy Storage Research Articles

Mg2+ ion-powered hybrid supercapacitor with β-MnO2 as a cathode and α-Fe2O3 as an anode

Commercial electrochemical supercapacitors are expensive, toxic, and have inadequate energy density at a high power density. To overcome above complications, researchers are focusing on aqueous magnesium-ion-based supercapacitors via bivalent Mg2+ ions. Herein, the facile hydrothermal method was employed for the synthesis of the β-MnO2 and α-Fe2O3 electrodes, which are confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) techniques. We fabricated a Mg2+-based hybrid supercapacitor (Mg-HSC) with β-MnO2 as a cathode, α-Fe2O3 as an anode, and 1 M MgSO4 as an electrolyte; β-MnO2 exhibited a specific capacitance of 1867 F/g while α-Fe2O3 showed 1896 F/g. The good performance is attributed to small ions of Mg2+ and its bivalent nature. The Mg-HSC exhibited excellent specific capacitance of 230.0 F/g at 1 A/g current density in a wide voltage range of 0 to 1.7 V. The Mg-HSC showed 82.1 Wh/kg energy density at 6153.8 W/kg power density. Moreover, this configured device showed superior long-term cycling stability with capacitance retention of >96.2% over 5000 cycles at 15 A/g current density. The facile synthesis method of electrode materials and the bivalent MgSO4 yield into the high-performance hybrid supercapacitor which can compete with current electrochemical energy storage devices.

Atomistic modeling of Li- and post-Li-ion batteries

Alkali metal ion batteries, and in particular Li-ion batteries, have become a key technology for current and future energy storage. The inherent complexity of batteries and their components make computational approaches on different length and time scales indispensable for gaining atomistic insights as well as for predicting new materials with improved properties. In this comprehensive review, the theoretical concepts that underlie the functioning of Li- and post-Li-ion batteries are presented, followed by a discussion of the most prominent computational methods and their applications, currently available for the investigation of battery materials on the atomistic scale.

Strain Engineering of Energy Storage Performance in Relaxor Ferroelectric Thin Film Capacitors

AbstractDielectric energy storage capacitors are receiving a great deal of attention owing to their high energy density and fast charging–discharging speed. The current energy storage density of dielectrics is relatively low and cannot meet the requirements of miniaturization of pulsed power equipment. Therefore, increasing the energy storage density of dielectrics has become a research hotspot. Herein, using phase‐field simulations to design polymorphic nanodomains, the strain engineering of energy storage performance of binary and ternary solid solution relaxor ferroelectric films is investigated. The results show that the energy storage performance of the ternary film is better than that of the binary film due to the polymorphic nanodomains. In addition, as the film in‐plane strain is modified from −2% to 2%, the energy density is improved by 80%, and the efficiency also increases from 52% to 77%. This work proves the remarkable energy storage performance of polymorphic films and provides a theoretical basis to optimize the energy‐storage performance of ferroelectric thin‐film capacitors by adjusting the misfit strain.

Albero: An alternative natural material for solar energy storage by the calcium-looping process

Large-scale thermochemical energy storage (TCES) is gaining relevance as an alternative to current thermal energy storage systems in Concentrated Solar Power plants. Among the different systems, the reversible reaction between CaO and CO2 stands out due to the wide availability and low cost of the raw material: limestone. Direct solar absorption of the storage media would improve the efficiency of solar-to-thermal energy storage due to reduced thermal transfer barriers, but the solar optical absorption of CaCO3 is poor. In this work, we propose the use of a Ca-rich calcarenite sedimentary rock so-called albero as an alternative to limestone. We demonstrate that this reddish material exhibits an average solar absorptance that is approximately ten times larger than limestone. Moreover, the multicycle carbonation/calcination performance under different experimental conditions has been studied by thermogravimetry, and similar values to those exhibited for limestone have been obtained. Besides, the material is cheap (6 €/ton), and simulations showed that the use of this material would significantly improve the overall CaL-CSP efficiency at the industrial level.

Superionicity in Ionic-Liquid-Based Electrolytes Induced by Positive Ion-Ion Correlations.

In ionic-liquid (IL)-based electrolytes, relevant for current energy storage applications, ion transport is limited by strong ion-ion correlations, generally yielding inverse Haven ratios (ionicities) of below 1. In particular, Li is transported in anionic clusters into the wrong direction of the electric field, requiring compensation by diffusive anion fluxes. Here, we present a concept to exploit ion-ion correlations in concentrated IL electrolytes beneficially by designing organic cations with a Li-coordinating chain. 1H NMR and Raman spectra show that IL cations with seven or more ether oxygens in the side chain induce Li coordination to organic cations. An unusual behavior of an inverse Haven ratio of >1 is found, suggesting an ionicity larger than that of an ideal electrolyte with uncorrelated ion motion. This superionic behavior is consistently demonstrated in both NMR transport/conductivity measurements and molecular dynamics (MD) simulations. Key to this achievement is the formation of long-lived Li-IL cation complexes, which invert the Li drift direction, yielding positive Li+ ion mobilities for the first time in a single IL-solvent-based electrolyte. Onsager correlation coefficients are derived from MD simulations and demonstrate that the main contributions to the inverse Haven ratio, which induce superionicity, arise from enhanced Li-IL cation correlations and a sign inversion of Li-anion correlation coefficients. Thus, the novel concept of coordinating cations not only corrects the unfortunate anionic drift direction of Li in ILs but even exploits strong ion correlations in the concentrated electrolyte toward superionic transport.

Polyoxometalate Ionic Sponge Enabled Dendrite-Free and Highly Stable Lithium Metal Anode.

Metallic lithium batteries are holding great promises for revolutionizing the current energy storage technologies. However, the formation of dendrite-like morphology of lithium deposition caused by uneven distribution of Li+ might cause severe safety concerns of batteries. In this study, a polyoxometalate (POM) cluster, H5 PMo10 V2 O40 (PMo10 V2 ), is added to the conventional electrolyte that can construct a lithium-rich layer and inhibit the growth of Li dendrites effectively. The Li-rich layer can fill any lack of lithium ions on the surface of the metal anode, making the electric field strength consistent across the anode surface, thereby inhibiting the formation of lithium dendrites. Consequently, a significantly prolonged cyclic lifespan is obtained for both Li/Li symmetric cells and Li/LiCoO2 (Li/LCO) full cells. The cells with LCO positive maintains a high reversible specific capacity of 108.5mAhg-1 after 300 cycles when electrolyte with PMo10 V2 additive is used, compared to 31.5mAhg-1 for the untreated electrolyte. The findings indicate that POMs endowed as "ionic sponge" can be widely deployed in lithium metal batteries.

High‐Performance Charging Method for Cold Energy Storage Using Foam Freezing

Foam freezing has an obvious advantage over the current conventional phase change cold energy storage method in charging performance. The maximum theoretical cold energy charging coefficient of foam freezing is as high as 237.1 W/m2K. Foam freezing brings a new dawn for solving the problem of gradual attenuation of the phase change cold storage charging rate. More details can be found in article number 2100647, Zhaoliang Jiang and co-workers.

Progress and Trends in Nonaqueous Rechargeable Aluminum Batteries

AbstractIt is important to research new energy storage technology for substituting the deficiencies of current energy storage devices, i.e., the poor energy density of lead‐acid batteries, the high cost of lithium‐ion batteries, etc. Rechargeable aluminum batteries (RABs) are regarded as one of the most promising storage devices due to the abundance of the materials required, superior security, and decent energy density of aluminum anodes. Nevertheless, there are some significant challenges, such as the developing energy density of cathodes, corrosion, and the high cost of electrolytes, which set obstacles to the industrialization of RABs. For avoiding the pitfalls of RABs research and boosting the development of RABs, the recent progress and trends in RABs covering mechanisms, components of RABs (electrodes, electrolytes, separators, and current collectors) and technology of assembly and packaging of devices are summarized and proposed.

The Role of Critical Raw Materials for Novel Strategies in Sustainable Secondary Batteries

Energy storage technology is destined to play a central role to pave the way for a sustainable society. Although lithium‐based technology has covered the majority of energy storage necessities until now, the development of safe, clean, and recyclable technology to future transport sector, breakthroughs in materials and methods involving sustainable resources are crucial. In addition, materials, synthetic processes and final devices should be properly selected to contribute to the development of a sustainable ecosystem as well as fulfill the demands of high energy density batteries. Currently, tremendous research efforts are focused on new battery chemistries based on postlithium technology, as solid‐state, metal–sulfur, and metal–air batteries, which present many advantages as well as challenges. Therefore, new strategies to reduce the impact of critical raw materials used in lithium technology together with novel methods to recuperate need to be developed to obtain full sustainability. In this context, the present review discusses the current electrochemical energy storage, as well as raw materials, and the technical challenges involved. In addition, it provides a perspective on strategies and opportunities and the most important difficulties to overcome for a sustainable electrochemical energy storage.

Preliminary Component Design and Cost Estimation of a Novel Electric-Thermal Energy Storage System Using Solid Particles

Abstract Energy storage will become indispensable to complement the uncertainty of intermittent renewable resources and to firm the electricity supply as renewable power generation becomes the mainstream new-built energy source and fossil fuel power plants are phased out to meet carbon-neutral utility targets. Current energy storage methods based on pumped storage hydropower or batteries have many limitations. Thermal energy storage (TES) has unique advantages in scale and siting flexibility to provide grid-scale storage capacity. A particle-based TES system is projected to have promising cost and performance characteristics to meet the future growing energy storage needs. This paper introduces the system and components required for particle TES to become technically and economically competitive. The system integrates electric particle heaters, particle TES within insulated concrete silos, and an efficient air-Brayton combined-cycle power system to provide power for storage durations up to several days via low-cost, high-performance storage cycles. Design specifications and cost estimation of major components in a commercial-scale system are presented in this paper. A techno-economic analysis based on preliminary component designs and performance indicates that particle TES integrated with an air-Brayton combined-cycle power system has a path to achieve the targeted levelized cost of storage of 5 ¢/kWh-cycle at a round-trip efficiency of 50% when taking low-cost energy-specific components and leveraging basic assets from existing thermal power plants. The cost model provides insights for further development and economic potentials for long-duration energy storage.

Optimal location of accurate HVDC and energy storage devices in a deregulated AGC integrated with PWTS considering HPA-ISE as performance index

This article determines the optimal location of accurate high voltage direct current (AHVDC) tie-line and energy storage devices (ESD) on system dynamics of three-area thermal-precise wind turbine systems (PWTS) under the deregulated scenario. The thermal system with an AC tie-line is integrated with PWTS, AHVDC tie-line, and ESD like redox flow battery, ultra-capacitor. A new controller, namely fractional-order proportional-integral and integer-order integral-derivative with filter (FOPI-IDN) is utilized. Its gains are optimized by a meta-heuristic algorithm namely a crow-search algorithm subjecting to a minimization of a new performance index named hybrid peak area - integral squared error (HPA-ISE). The superiority of FOPI-IDN is tested over classical controllers like FOPI, PIDN, and FOPIDN and found to be better than others. A new study has been carried out to compare the performance of HPA-ISE, which shows better performance over ISE. The effect of PWTS is analyzed, and its integration gives better system dynamics. System responses with parallel AC-AHVDC tie-line, ESD explore better performance and improve the system dynamics. Further, the optimum location of ESD and parallel AC-AHVDC are found out in the disturbed area.

In Situ Characterization of the Solid Electrolyte Interphase in Lithium Ion Batteries

The increasing global energy demand has fueled considerable effort into improving upon current energy storage technologies to keep in step with this demand. Improving current energy storage technologies, such as lithium ion batteries (LIBs), requires insight and understanding of the fundamentals of their operation. A key component of LIBs is the solid-electrolyte interphase (SEI), which develops at the interface between the electrode and the electrolyte as a result of reaction with, and degradation of, the battery electrolyte [1]. This passivating layer is vital to the operation and performance of batteries, but little is known of its exact structure since these electrode/electrolyte interfaces are buried deep within the battery, and so are difficult to “look” at using standard characterization techniques [2]. So-called “post-mortem” studies, which involve taking batteries apart inside a glove box, are methodologically simple, but may alter the SEI surface chemistry due to exposing highly reactive materials to contaminants inside a glove box.Here we introduce a platform for in situ characterization of electrode/electrolyte interfaces, capable of operation and disassembly of LIB components (anode, cathode and electrolyte) completely in situ without the need to transfer materials to a glove box prior to characterization. We demonstrate the capabilities of the platform using interface sensitive techniques, including data from one of the first lab-based hard X-ray photoelectron spectrometers, which is based at the Henry Royce Institute at the University of Manchester. Electrochemical data is also presented, demonstrating the electrochemical characterization abilities of the platform, and shows potential for extending beyond studies of LIB technology.

Gradient SEI layer induced by liquid alloy electrolyte additive for high rate lithium metal battery

Current energy storage device has fallen short behind from the fast growing requirement for (hybrid) electric vehicles and portable devices including mobile phones, which drives the lithium metal anode to be a research hot topic. However, the large volume change of lithium metal anode induces instable solid electrolyte interface (SEI) layer, which prevents its further development. A stable SEI layer required flexible surface to accommodate the large volume variation and inorganic core with low Li + partial molar volume for dendrite suppression. Herein, we achieved a gradient SEI which is composed of flexible surface-rich polycarbonate moieties and low Li + partial molar volume inorganic LiF-rich core by applying liquid alloy GaSnIn as electrolyte additive. Initially, the calculation verified that liquid alloy GaSnIn as electrolyte additive would facilitate the initial decomposition of LiPF 6 , and lead to the formation of the gradient SEI layer. In the Li||Li half‐cell test, we successfully achieved dense deposition of Li metal and in this way, the cycling performance with liquid alloy GaSnIn as electrolyte additive is greatly improved especially at high rate (10 mA cm −2 ). Voltage polarization was greatly reduced and Coulombic efficiency was effectively improved due to the gradient SEI layer achieved in the interface of Li anode and electrolyte. In the Li||LFP cell, high average coulombic efficiency (99.06%) at long cycle life (＞2500 cycles) is achieved for the liquid alloy GaSnIn‐protected Li metal anode at high areal capacity (3 mAh/cm 2 ). These results deepen our understanding on liquid alloy as a promising electrolyte additive for efficient dendrite suppressing, enabling the practical lithium metal batteries (LMBs). • We successfully achieved a gradient SEI layer through liquid alloy for lithium dendrite suppression. • Gradient SEI layer is composed of flexible surface-rich polycarbonate moieties and inorganic LiF-rich inside. • Liquid alloy GaSnIn as electrolyte additive facilitates the initial decomposition of LiPF6, facilitating the gradient SEI layer.

A Novel Package-Integrated Cyclone Cooler for the Thermal Management of Power Electronics

Abstract In order for electronics packaging power density to increase, innovations and improvements in heat transfer are required. Electrification of transportation has the potential for significant fuel and energy savings. Changing to an electrified drive train requires reliable and efficient power electronics to provide power conversion between alternating current motors and direct current energy storage. For high power transportation systems like aircrafts or heavy vehicles, the power density of power electronics needs to be improved. Power density is also an enabler for high power military devices that must be used and transported via air, ground, and sea. This paper summarizes the outcome of a collaborative and multidisciplinary research effort aimed at co-designing a novel electronics cooling device that utilizes two-phase fluid flow. Two-phase flow cooling has been known for decades as well as the risks associated with it: critical heat flux (CHF), dry-out, and thermal runaway. Our research de-risks the two-phase cooling technology by swirling the flow to remove the bubbles from the wall and confining them at the core of the cooler. The combined effects of gas phase removal, enhanced nucleation, and dramatic liquid film agitation and rupture have been quantified by our experiments: double the heat transfer coefficient with only 13% increase in pressure drop. Besides advanced fluid-dynamics, our Package-Integrated Cyclone Cooler (PICCO) utilizes cutting edge packaging and additive manufacturing technology such as direct deposition of a metal substrate and circuits (dies) on a complex helical cooler that can only be manufactured via three-dimensional printing. By co-designing and testing the cooler, we have quantified the impact of the swirled flow on the junction temperature with respect to a conventional (non-swirl) two-phase-flow-cooled power electronics package. At steady-state, our post-test thermal simulations predict a junction temperature reduction from 185 °C to 75 °C at the same power dissipation. When the heat load is unsteady (United States Environmental Protection Agency Urban Drive Cycle), the junction temperature reduction is 140 °C to 60 °C.

Power Management of AC/DC Hybrid Distribution Network With Multi-Port PET Considering Reliability of Power Supply System

In the current distribution network, photovoltaic, wind power, energy storage, and other distributed energy are widely connected, and the proportion of generalized DC load is rapidly increasing. With the development of power electronics technology, using multi-port power electronic transformer (PET) to achieve high-efficiency access of large-capacity AC/DC source and load is the current research hotspot, and AC / DC hybrid power supply is inevitable. The introduction of a large number of power electronics and the flexible coordinated control and complementary fault-tolerant advantages of PET bring challenges to the operation and maintenance management of the AC/DC hybrid power system. In this paper, the structure of the AC/DC hybrid power system with the multi-port PET cluster is introduced. Based on the idea of hierarchical and partitioned control, a three-layer and multi-time scale control mode of integrated automation system, PET cluster and PET controller is proposed; Aiming at the problem of reliability evaluation, a sequential Monte Carlo simulation method is proposed to simulate the AC/DC hybrid power system with the multi-port PET cluster. The influence of multi-port PET parallel cluster mode and port capacity limitation on the reliability of the power system is analyzed, and the effectiveness of the model and algorithm is verified. Finally, an example is given to verify that the proposed structure is conducive to improving the utilization level of renewable energy in the distribution network.

Advanced Current Collectors with Carbon Nanofoams for Electrochemically Stable Lithium-Sulfur Cells.

An inexpensive sulfur cathode with the highest possible charge storage capacity is attractive for the design of lithium-ion batteries with a high energy density and low cost. To promote existing lithium–sulfur battery technologies in the current energy storage market, it is critical to increase the electrochemical stability of the conversion-type sulfur cathode. Here, we present the adoption of a carbon nanofoam as an advanced current collector for the lithium–sulfur battery cathode. The carbon nanofoam has a conductive and tortuous network, which improves the conductivity of the sulfur cathode and reduces the loss of active material. The carbon nanofoam cathode thus enables the development of a high-loading sulfur cathode (4.8 mg cm−2) with a high discharge capacity that approaches 500 mA·h g−1 at the C/10 rate and an excellent cycle stability that achieves 90% capacity retention over 100 cycles. After adopting such an optimal cathode configuration, we superficially coat the carbon nanofoam with graphene and molybdenum disulfide (MoS2) to amplify the fast charge transfer and strong polysulfide-trapping capabilities, respectively. The highest charge storage capacity realized by the graphene-coated carbon nanofoam is 672 mA·h g−1 at the C/10 rate. The MoS2-coated carbon nanofoam features high electrochemical utilization attaining the high discharge capacity of 633 mA·h g−1 at the C/10 rate and stable cyclability featuring a capacity retention approaching 90%.

Electron structure and reaction pathway regulation on porous cobalt-doped CeO2/graphene aerogel: A free-standing cathode for flexible and advanced Li-CO2 batteries

Li-CO2 batteries present considerable prospects both in resourcing CO2 and remedying the unsatisfied performance of current energy storage devices. Herein, a porous self-supporting cathode for Li-CO2 battery is fabricated through straightforward anchoring of two-dimensional (2D) cobalt-doped CeO2 nanosheets on graphene aerogel, bypassing the addition of binder and the complicated manufacturing process. The combination of CeO2 and Co3O4 results in the reorganization of electronic structure by strongly coupled nanointerfaces, enhancing the reversible formation and decomposition of Li2CO3. Meanwhile, the unique porous structure facilitates the diffusion of CO2 and electrolyte in Li-CO2 batteries. The as-assembled Li-CO2 battery achieves a superior discharge capacity (7860 mAh/g) and competitive cycling stability (>100 cycles). In particular, a flexible Li-CO2 battery is developed with the freestanding cathode, which can provide a stable power output during multi-angle bending and folding. The improved conductivity, CO2 adsorption ability and the electrochemical reaction pathway are revealed by density functional theory (DFT) calculations in detail. This work sheds new light on the development of advanced and flexible Li-CO2 batteries for wearable electronics.

Review on Comparison of Different Energy Storage Technologies Used in Micro-Energy Harvesting, WSNs, Low-Cost Microelectronic Devices: Challenges and Recommendations

This paper reviews energy storage systems, in general, and for specific applications in low-cost micro-energy harvesting (MEH) systems, low-cost microelectronic devices, and wireless sensor networks (WSNs). With the development of electronic gadgets, low-cost microelectronic devices and WSNs, the need for an efficient, light and reliable energy storage device is increased. The current energy storage systems (ESS) have the disadvantages of self-discharging, energy density, life cycles, and cost. The ambient energy resources are the best option as an energy source, but the main challenge in harvesting energy from ambient sources is the instability of the source of energy. Due to the explosion of lithium batteries in many cases, and the pros associated with them, the design of an efficient device, which is more reliable and efficient than conventional batteries, is important. This review paper focused on the issues of the reliability and performance of electrical ESS, and, especially, discussed the technical challenges and suggested solutions for ESS (batteries, supercapacitors, and for a hybrid combination of supercapacitors and batteries) in detail. Nowadays, the main market of batteries is WSNs, but in the last decade, the world’s attention has turned toward supercapacitors as a good alternative of batteries. The main advantages of supercapacitors are their light weight, volume, greater life cycle, turbo charging/discharging, high energy density and power density, low cost, easy maintenance, and no pollution. This study reviews supercapacitors as a better alternative of batteries in low-cost electronic devices, WSNs, and MEH systems.

Fast Synergetic Control for Chaotic Oscillation in the Power System Based on Input-Output Feedback Linearization

This paper presents a fast synergetic control scheme for chaotic oscillation in a three-bus power system model. First, the coupling dynamic model of a controlled power system with the current source converter-based STATCOM device and energy storage device is established. Then, the input-output linearization process for the controlled power system is derived step by step, the control problem for the complex nonlinear power system model is completely transformed into the control of linear systems, and a fast synergetic control scheme is proposed for these linear systems. Since the designed control inputs contain complex system functions which are very difficult to obtain and reduce the engineering practicability of the designed controllers, the assumption that system functions are bounded is introduced into the controller design process, and the controllers are redesigned. The remarkable advantages of the proposed control method are that it improves the rapidity of traditional synergetic control and avoids complex system functions in control inputs. Finally, the effectiveness and the superiority of the control scheme are verified by simulation results.

Boosting zinc-ion storage capability by engineering hierarchically porous nitrogen-doped carbon nanocage framework

In virtue of combining superb power of supercapacitors and high energy of batteries, zinc-ion hybrid supercapacitors become a competitive candidate in current energy storage systems. However, the cell chemistry related to carbon cathode still suffers from the obstacles of reaction kinetics and charge storage efficiency. Herein, a three-dimensional framework of N-doped carbon nanocages is constructed through pyrolyzing and activating polypyrrole on the platform of ZIF-8, synchronously achieving hierarchical porosity and high N-doping content. Thanks to the comprehensive modulation of the morphology, pore structure, and surface chemistry, the obtained carbon shows the significant enhancement in active site exposure and diffusion kinetics. Therefore, the zinc-ion hybrid supercapacitor using this carbon cathode achieves the remarkably improved Zn-ion storage capability (124 mAh g−1 at 0.25 A g−1 with a 65.9% capacity retention at 20 A g−1, and nearly no capacity decay after 10000 cycles at 10 A g−1). Moreover, this device exhibits superior energy/power densities of 107.3 Wh kg−1/16647.7 W kg−1, together with a low self-discharge rate of 3 mV h−1. Our work presents a good design strategy to develop advanced carbon-based cathodes to accelerate the development of Zn-based devices.