Large-scale Energy Storage Systems Research Articles

Research on the loss characteristics of high-voltage cascaded energy storage systems based on IGCTs

High-voltage cascaded energy storage systems have become a major technical direction for the development of large-scale energy storage systems due to the advantages of large unit capacity, high overall efficiency, satisfactory economy, reliable safety, and easy access to grid dispatching. The loss characteristics analysis is the design basis of the water-cooling system of a high-voltage cascaded energy storage system, and its accurate calculation can determine the system’s safe and reliable operation of the system. This paper first introduces the four-quadrant operation principles of a cascaded H-bridge energy storage system, and analyzes the calculation method of the loss of the Integrated Gate-Commutated Thyristor based power module; On this basis, it studies the loss characteristics of the cascaded energy storage system and analyzes the influence of different modulation strategies and third harmonic injection on the loss characteristics of the energy storage system; Finally, this paper has completed the loss test for the engineering prototype module and compared the test results with theoretical calculation results to verify the accuracy of the loss calculation method of the high-voltage cascaded energy storage system.

Enhancement of lithiation on a graphane monolayer through extended H vacancy pathways: An ab initio study

The increasing interest for the need of large-scale energy-storage systems have led to the development of high-performance energy-storage devices such as lithium-ion batteries (LIBs). Two dimensional (2D) materials are promising candidates for fulfilling this requirement due to their peculiar physical properties. However, it is important to understand the role of multiple Li adatoms on the 2D materials, more especially when defects are involved. In this study, first-principles density functional theory (DFT) calculations were performed to study Li on the H vacancies (VH) following the line and zigzag pathways on a graphane sheet. The results of Li atom on a single H vacancy (VH1) reveal an immediate enhanced interaction based on the improved binding energies, high amount of charge transfer and significantly shortened Li height, as compared to those of pristine graphane counterpart. An increase in the number of H vacancies along the line pathway from one (VH1(L)) to five (VH5(L)) further improves the binding energies ranging from 1.82 eV to 2.91 eV. Considering a simultaneous increase of Li atoms and H vacancies following a line pathway (VH1(L) to five VH5(L)), the binding energies tend to reduce in order. However, it is still higher than the minimum Li standard bulk cohesive energy of 1.63 eV. We show that there is a possibility of uniform dispersion of Li atoms with less clustering on a graphane sheet. A transition from insulator to metallic character was observed from VH1(L) to VH5(L), due to an induced new Li states at the vicinity of the Fermi level, suggesting an enhancement of electronic conductivity in the graphane sheet. At five Li atom VH5(L) configuration along the line pathway, we obtained a relatively high storage capacity of 207.49 mAh/g with its corresponding lithiation potential of 1.48 V, comparable to those of well known two dimensional anode materials.

Tuning electrolyte solvation structure with Co-solvent engineering to enable highly reversible and stable Zn-graphite dual-ion batteries

Graphite-based dual-ion batteries (GDIBs) have attracted ever-growing attentions due to its non-transition metal configuration and high working potential. However, the safety concerns associated with the use of organic electrolyte make it unpractical for large-scale energy storage system. Moreover, the anodic limit of aqueous electrolytes, even the improved anodic limit derived from highly concentrated aqueous electrolytes, is not sufficient to support high graphite intercalation voltage. Herein, a co-solvent-induced hybrid aqueous/non-aqueous electrolyte has been proposed to break this bottleneck through regulating the solvation structures around anions. A series of hybrid electrolytes are prepared by controlling dimethyl carbonate (DMC) ratio and the relation between the solvation structures and anion intercalation chemistry is explored, indicating that the mutual interaction between solvent molecules and anions determines the anion intercalation behaviour. The optimized DMC-dominated solvation structures with a mass ratio of DMC to water of 1.2:1 significantly expand the anodic limit of electrolyte up to 2.54 V (vs. Zn/Zn2+). The as-designed Zn-Graphite batteries exhibit an excellent cyclic stability and reversibility (99 % capacity retention after 200 cycles at 200 mA g−1, nearly 98 % Coulombic efficiency). This work provides guidance to achieve the balance between security capability and electrochemical performances through controllable solvation structures.

Key Issues and Strategies of Aqueous Zinc-Ion Batteries

With the rapid growth of the world population and the further industrialization of modern society, the demand for energy continues to rise sharply. Hence, the development of alternative, renewable, and clean energy sources is urgently needed to address the impending energy crisis. Rechargeable aqueous zinc-ion batteries are drawing increased attention and are regarded as the most promising candidates for large-scale energy storage systems. However, some challenges exist for both the anode and cathode, severely restricting the practical application of ZIBs. In this review, we focus on the issues related to the anode (such as dendrites growth, hydrogen evolution, and surface passivation). We discuss the causes of these challenges and summarize the strategies (such as surface engineering, electrolyte modification, and 3D structural skeleton and alloying) to overcome them. Finally, we discuss future opportunities and challenges of ZIBs regarding the Zn anode.

Wireless Charging of Large-Scale Energy Storage Systems: A Hybridized Ad-Hoc Approach for High Efficiency

Wireless Charging of Large-Scale Energy Storage Systems: A Hybridized Ad-Hoc Approach for High Efficiency

Nanosheet architecture of MnO2/carbon with improved reaction kinetics toward advanced zinc energy storage

Aqueous zinc ion batteries (AZIBs) hold substantial promise for large-scale energy storage system by virtue of their good safety and cost-effectiveness. However, the typical cathode material of MnO2 is practically hampered by poor rate/cycling performance owing to its low electrical conductivity and structural fragility. Herein, a nanosheet architecture of MnO2/carbon is constructed via in situ rooting MnO2 nanoarrays on carbon substrate to achieve high-rate and long-durable zinc energy storage. The unique nano-architecture significantly promotes the reaction kinetics by supplying plentiful active sites, short diffusion pathways, and improved charge transfer conductivity. The advantageous features endow the MnO2/carbon with remarkable rate capability (175 mAh/g at 3.0 A/g) and excellent cycling lifespan (87.8 % capacity retention after 1000 cycles at 1.0 A/g). In addition, the kinetic enhancement and fundamental reaction mechanism are systematically investigated. The encouraging results will shed new insight on designing MnO2-based materials to advance the development of AZIBs.

Highly stable side-chain-type cardo poly(aryl ether ketone)s membranes for vanadium flow battery

Vanadium flow batteries (VFBs) have drawn considerable attention as an emerging technology for large-scale energy storage systems (ESSs). One of the pivotal challenges is the availability of eligible ion exchange membranes (ICMs) that provide high ion selectivity, proton conductivity, and stability under rigorous condition. Herein, a ‘side-chain-type’ strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s (PAEKs) membrane with low area resistance (0.058 Ω cm2), in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone. The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium (Q-PPhEK) demonstrated an energy efficiency above 80% over 700 cycles at 160 mA/cm2. Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment, meanwhile, more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.

Assessment of the onshore storage capacity of hydrogen in Argentina’s natural gas fields

Increasing the proportion of electricity from renewable energy sources is critical for the reduction of CO 2 emissions required to meet the commitments of the Paris Agreement. However, intermittency in energy generation due to the daily and seasonal variability of wind and solar radiation is a major challenge. Addressing this issue requires the development of large-scale energy storage systems. Low-carbon hydrogen production and storage in geological reservoirs offers a potential seasonal energy storage solution. Here, we provide the first assessment of the underground storage capacity for hydrogen in Argentina and identify sites where future clusters of low-carbon hydrogen production could be co-located with suitable geological storage sites. We outline a production-based methodology that couples historical hydrocarbon production with remaining reserves to provide a reliable estimation of the amount of hydrogen that can be stored in each reservoir. Assuming a cushion gas requirement of 50%, our results show that a combined storage capacity of 2860 TWh of hydrogen exists. This far exceeds the requirements to meet the seasonal electricity demand for residential consumption in the country. The results of our sensitivity analysis show that the two most sensitive variables are temperature and compressibility, suggesting that high-pressure shallow reservoirs are most suitable for underground hydrogen storage. We additionally propose locations for two H 2 production and storage hubs that would permit the integration of storage sites with renewable developments and natural gas reserves that could be combined with carbon capture and storage to produce low-carbon hydrogen. Thematic collection: This article is part of the Hydrogen as a future energy source collection available at: https://www.lyellcollection.org/topic/collections/hydrogen

Ultrathin Cobalt-Based Prussian Blue Analogue Nanosheet-Assembled Nanoboxes Interpenetrated with Carbon Nanotubes as a Fast Electron/Potassium-Ion Conductor for Superior Potassium Storage.

Rechargeable potassium-ion batteries (PIBs) are regarded as potential substitutes for industrial lithium-ion batteries in large scale energy storage systems due to the world's abundant potassium supplies. Althogh cobalt hexacyanocobaltate (CoHCC) exhibits broad potential as a PIB anode material, its performance is currently unsatisfactory. Herein, novel 5 nm scale ultrathin CoHCC nanosheet-assembled nanoboxes with interspersed carbon nanotubes (CNTs/CoHCC nanoboxes) are fabricated to realize a highly reactive PIB anode. The ultrathin CoHCC layers substantially accelerate electron conduction and provide numerous active sites, while the connected CNTs provide fast axial electron transport. Consequently, the optimized anode exhibits a remarkable discharge capacity of 580.9 mAh g-1 at 0.1 A g-1 and long-term stability with 71.3% retention over 1000 cycles. In situ and ex situ characterizations and density functional theory calculations are further employed to elucidate the K+ storage process and the reason for the enhanced performance of the CNTs/CoHCC nanoboxes.

Second life use of Li-ion batteries in the heavy-duty vehicle industry: Feasibilities of remanufacturing, repurposing, and reusing approaches

As the adoption of electric vehicles (EVs) accelerates, the efficient management of end-of-life lithium-ion (Li-ion) batteries becomes a pressing concern. This case study investigates sustainable second life approaches for Li-ion batteries within a leading manufacturing company in the heavy-duty vehicle industry. Employing an exploratory methodology, the study evaluates three distinct circularity approaches for second life applications: remanufacturing, repurposing, and reusing. Based on a financial model and sustainability metrics, remanufacturing emerged as the most economically viable and environmentally sustainable strategy for the company. The study also explores supplementary approaches, such as repurposing used batteries for smaller power applications and reusing them in large-scale Energy Storage Systems (ESS). Regulatory inconsistencies in battery second life are identified as a significant barrier to widespread implementation. The study concludes by advocating for a multi-stakeholder ecosystem approach and calls for the establishment of universal circularity regulations to streamline the second life of Li-ion batteries.

Development of highly stable and active intermetallic Pt-alloyed catalysts for the production of V3.5+ electrolyte in the vanadium redox flow batteries

Vanadium based battery is considered one of the most promising candidates to overcome the limitations of lithium ion battery in large-scale energy storage systems. However, the high manufacturing cost of the vanadium electrolyte has been hindered to commercialize. Although the catalytic production of vanadium electrolyte was reported, with an organic reducing agent such as formic acid is considered as a promising method, the continuous production of vanadium electrolyte is still difficult owing to the limited catalyst durability. Herein, we present the highly durable and active intermetallic Pt-alloyed catalysts, i.e., L12-Fe0.25Pt0.75/C and L12Co0.25Pt0.75/C, for the catalytic production of V3.5+ electrolyte. In the catalytic test of electrolyte production, the intermetallic L12-Fe0.25Pt0.75/C showed nearly 3 times higher activity than the commercial Pt/C catalyst. In the catalyst durability test, on the other hand, the intermetallic L12Co0.25Pt0.75/C showed only 3 % decrease of initial activity whereas the intermetallic L12-Fe0.25Pt0.75/C and commercial Pt/C exhibited ca. 9 % and ca. 20 % decrease of initial activity, respectively, for one hundred times continuous electrolyte production test. Among the catalysts tested, the intermetallic L12-Fe0.25Pt0.75/C showed the highest initial catalytic activity while the L12Co0.25Pt0.75/C exhibited the strongest catalyst durability. In terms of catalytic activity and stability, the intermetallic L12Co0.25Pt0.75/C was found to be an efficient catalyst for the practical production of V3.5+ electrolyte.

Zincophilic Metal-Organic-Framework Interface Mitigating Dendrite Growth for Highly Reversible Zinc Metal Batteries.

Aqueous Zn-ion batteries are the ideal candidate for large-scale energy storage systems owing to their high safety and low cost. However, the uncontrolled deposition and parasitic reaction of Zn metal anode hinder their commercial application. Here, the 2D metal-organic-framework (MOF) nanoflakes covered on the surface of Zn are proposed to enable dendrite-free for long lifespan Zn metal batteries. The MOF can facilitate the desolvation process to accelerate reaction kinetic due to its special channel structure. The abundant zincopilicity sites of MOF can realize the homogenous Zn2+ deposition. Consequently, their synergetic effect makes the MOF protected Zn anode good electrochemical performance with a long cycle life of 1400h at 1mA cm-2 and a high depth of discharge of 30 mAh cm-2 (DOD ≈ 54%) continued for over 700h. This work provides a novel strategy for high-performance rechargeable Zn-ion batteries.

Bifunctional electrolyte additive for stable Zn anode: Reconstructing solvated structure and guiding oriented growth of Zn

Aqueous Zn-ion batteries (AZIBs) have been considered as one of the most auspicious large-scale energy storage systems, However, the hydrogen evolution, side reaction and dendrite growth of Zn anode severely hinder its practical application and scalability. Herein, an effective and economical strategy to resolve these problems by introducing a bifunctional additive uridine into electrolyte is reported. Through theoretical calculations and experimental results, it is revealed that uridine molecules can replace some of H2O molecules in the solvated Zn2+, thus suppressing the side effects caused by H2O. In addition, it can also induce the uniform deposition of Zn on (002) plane with a close-packed morphology due to the strong absorption ability of uridine to Zn (002) plane. Benefiting from these two merits, the optimized uridine-containing electrolyte enables a highly reversible Zn plating/stripping cycling in Zn||Cu asymmetric cells for over 600 cycles with a high coulombic efficiency of 99.6% and in Zn||Zn symmetric cells for over 4500h at 1mA cm−2. As a proof-of-concept, the full cells assembled with different types of cathodes also deliver excellent cycling performance, favoring the practical application. This work has important guiding significance for improving the electrochemical performance of zinc anode.

Li2GeS3: Lithium Ionic Conductor with an Unprecedented Structural Type.

Lithium-ion batteries (LIBs) are widely used in electric vehicles, mobile electronic devices, and large-scale stationary energy storage systems. However, their liquid electrolytes present significant safety concerns due to their inherent flammability. To address this, the focus has shifted toward all-solid-state batteries (ASSBs) utilizing inorganic solid electrolytes that promise enhanced safety. In this work, we report the discovery of a new crystal structural type of Li-ion conductor, Li2GeS3, with a unique structure, synthesized by a solid-state reaction from Li2S and GeS2. It was first reported in 2000 with an orthorhombic unit cell, but its detailed crystal structure remains veiled. We have unveiled its structure for the first time, employing an ab initio structure determination technique from powder X-ray and time-of-flight neutron diffraction data. The compound has an unprecedented crystal structural type with a hexagonal P61 symmetry and a unit cell of a = 6.79364(4) Å and c = 17.90724(14) Å. Its structure is comprised of a distorted hexagonal close-packed arrangement of sulfur anions with three asymmetric metal atoms: Li1, Li2, and Ge are in tetrahedral cavities surrounded by sulfur atoms. The ionic conductivity of Li2GeS3 was measured to be 1.63 × 10-8 S cm-1 at 303 K and 2.45 × 10-7 S cm-1 at 383 K. Bond valence energy landscape calculations revealed three-dimensional lithium diffusion pathways within the structure. This novel crystal structure in Li2GeS3 holds the potential for developing high-performance ionic conductors through suitable chemical substitution and offers valuable insights into designing new ionic conductors for ASSBs.

A novel Na8Fe5(SO4)9@rGO cathode material with high rate capability and ultra-long lifespan for low-cost sodium-ion batteries

Sodium-ion batteries (SIBs) are regarded as the most promising technology for large-scale energy storage systems. However, the practical application of SIBs is still hindered by the lack of applicable cathode materials. Herein, a novel phase-pure polyanionic Na8Fe5(SO4)9 is designed and employed as a cathode material for SIBs for the first time. The Na8Fe5(SO4)9 has an alluaudite-type sulfate framework and small Na+ ion diffusion barriers. As expected, the as-synthesized Na8Fe5(SO4)9@rGO exhibits a high working potential of 3.8 ​V (versus Na/Na+), a superior reversible capacity of 100.2 mAh g−1 at 0.2 ​C, excellent rate performance (∼80 mAh g−1 at 10 ​C, ∼63 mAh g−1 at 50 ​C), and an ultra-long cycling life (91.9% capacity retention after 10,000 cycles at 10 ​C, 81% capacity retention after 20,000 cycles at 50 ​C). We use various techniques and computational methods to comprehensively investigate the electrochemical reaction mechanisms of Na8Fe5(SO4)9@rGO.

Experimental heat transfer study of an enhanced storage medium

Phase change materials (PCMs) are suitable for storing solar energy due to their high-density energy storage and ability to operate in a wide range of temperatures. However, the lower thermophysical properties of PCMs limit their use in solar energy storage applications. Therefore, the incorporation of nanoparticles has emerged as a promising technique to enhance the storage density of PCMs.Extensive studies have been conducted on the measurement of thermophysical properties of both PCMs and nano-PCMs (PCMs with nanoparticles dispersed in them). However, there has been no comprehensive study covering the following aspects: (a) the measurement of thermophysical properties of NaNO3 (PCM) and nano-NaNO3 (nano-PCM), (b) solar energy storage of NaNO3 involving both sensible heat and latent heat in the same study, (c) the construction and implementation of an experimental rig capable of studying heat transfer in PCM and nano-PCM for solar energy storage applications (with a maximum temperature of up to 350 °C), and (d) investigating the effect of nanoparticles on large-scale solar energy storage systems. Therefore, the aim of this study is to experimentally investigate all of the aforementioned points. In order to develop and test these solar storage mediums, an experimental setup has been designed and manufactured, as mentioned earlier.Furthermore, limited studies have considered sodium nitrate salt (NaNO3) as a PCM. In this study, NaNO3 is used as the base material, and two types of materials are considered: PCM1, which consists of sodium nitrate salt (NaNO3), and PCM2, which consists of sodium nitrate salt (NaNO3) with 0.75 wt% iron oxide nanoparticles (Fe2O3) added. The experiments conducted involved both steady-state and transient conditions. The results showed that the addition of nanoparticles improved the charging and discharging by 25.6 % and 23.929 %, respectively. Moreover, the specific heat capacity and latent heat of the developed PCMs increased by 17.857 % and 9.97 %, respectively. These findings suggest that PCM2, with the presence of nanoparticles, melts and discharges energy faster compared to PCM1. Overall, this study contributes to the understanding of solar energy storage using PCMs and nano-PCMs, highlighting the potential benefits of nanoparticle incorporation in enhancing their performance.

Hard carbons from automotive shredder residue (ASR) as potential anode active material for sodium ion battery

Graphite, the most prominent anode material for Li-ion battery, exhibited very poor performance in sodium ion battery. The electrochemical intercalation of Na+ ions in graphite is impeded due to smaller interlayer spacing. Here, we have reported ASR derived hard carbon as a suitable anode electroactive material for Na-ion battery. Prepared via single step selective thermal transformation, the hard carbons contain defects, heteroatoms, nanopore, and ordered carbon zones with expanded interlayer spacing. Among all the hard carbons, the hard carbon synthesised at 1100 °C, showed better electrochemical performance owing to its improved structural and morphological properties. The electrochemical study reveals that hard carbon synthesised at 1100 °C provides initial reversible capacity of 434mAh/g at a current density of 10 mA/g with a capacity retention of 53% after 100 cycles. Issues like global warming and climate changes have made human to shift their energy choices from fossil fuels to renewable sources. Although Li-ion battery is currently dominating the energy market, yet it falls short to meet the growing large scale energy storage system (EES) demand. Na-ion battery is considered as a worthy contender for growing ESS. The hard carbon studied in this work, can be a potential candidate for use as anode active material in Na-ion battery.

Large-scale energy storage system: safety and risk assessment

The International Renewable Energy Agency predicts that with current national policies, targets and energy plans, global renewable energy shares are expected to reach 36% and 3400 GWh of stationary energy storage by 2050. However, IRENA Energy Transformation Scenario forecasts that these targets should be at 61% and 9000 GWh to achieve net zero carbon emissions by 2050 and limit the global temperature rise within the twenty-first century to under 2 °C. Despite widely known hazards and safety design of grid-scale battery energy storage systems, there is a lack of established risk management schemes and models as compared to the chemical, aviation, nuclear and the petroleum industry. Incidents of battery storage facility fires and explosions are reported every year since 2018, resulting in human injuries, and millions of US dollars in loss of asset and operation. Traditional risk assessment practices such as ETA, FTA, FMEA, HAZOP and STPA are becoming inadequate for accident prevention and mitigation of complex energy power systems. This work describes an improved risk assessment approach for analyzing safety designs in the battery energy storage system incorporated in large-scale solar to improve accident prevention and mitigation, via incorporating probabilistic event tree and systems theoretic analysis. The causal factors and mitigation measures are presented. The risk assessment framework presented is expected to benefit the Energy Commission and Sustainable Energy Development Authority, and Department of Standards in determining safety engineering guidelines and protocols for future large-scale renewable energy projects. Stakeholders and Utility companies will benefit from improved safety and reliability by avoiding high-cost asset damages and downtimes due to accident events.

A highly reversible Zn anode enabled by organic/inorganic Bi-protective layer

Aqueous Zn-ion batteries (AZIBs) are regarded as one of the most promising large-scale energy storage system due to the merits of low cost and safety. However, uncontrolled Zn dendrite caused by uneven Zn2+ deposition on the surface of Zn anode is a serious challenge for the development of Zn anode. In this work, an organic/inorganic bi-protective layer is constructed on Zn electrodes and features an inorganic layer (MXene) at the bottom and a polymer layer sulfonated poly(ether ketone)(SPEEK) on the top. MXene is porous and conductive, which can diminish the local current density and have a shunting impact on Zn2+. SPEEK has good mechanical qualities to reduce the volume effect of Zn during charge/discharge procedure and avoid the direct contact among Zn and electrolyte. Therefore, the bi-protective layer SPEEK/MXene (SKME) can both limit side effects and decrease dendrite development. Therefore, the SKME@Zn electrode has extremely long plating/stripping cycling period of 1300 h at 0.5 mA cm−2. The SKME@Zn//V2O5 full batteries display higher cycle stability than the bare Zn//V2O5 and MXene@Zn//V2O5 systems, indicating that this organic/inorganic bi-protective layer has practical application prospects.

Research on Parallel Control Strategy of Grid-forming of Power Conversion System

A high proportion of power electronic equipment, distributed energy, and other new energy access to the grid system, low inertia and low damping to the power grid system, these kinds of power grid characteristics in power electric wire aging remote mountains or island areas, therefore, need energy storage system under the microgrid can provide inertial support for load or grid, improve the system damping characteristics. On this basis, the grid-forming control is proposed, so that the power conversion system can work under the off-grid, and can provide inertia and damping to maintain the system stability. In addition, large-scale energy storage systems often require multiple machines operating in parallel. In this paper, the topology of NPC for a power conversion system is studied and analyzed in off-grid mode.