Large-scale Energy Storage Research Articles

Building Robust Manganese Hexacyanoferrate Cathode for Long-Cycle-Life Sodium-Ion Batteries.

Manganese Hexacyanoferrate (Mn─HCF) is a preferred cathode material for sodium-ion batteries used in large-scale energy storage. However, the inherent vacancies and the presence of H2O within the imperfect crystal structure of Mn─HCF lead to material failure and interface failure when used as a cathode. Addressing the challenge of constructing a stable cathode is an urgent scientific problem that needs to be solved to enhance the performance and lifespan of these batteries. In this review, the crystal structure of Mn─HCF is first introduced, explaining the formation mechanism of vacancies and exploring the various ways in which H2O molecules can be present within the crystal structure. Then comprehensively summarize the mechanisms of material and interfacial failure in Mn─HCF, highlighting the key factors contributing to these issues. Additionally, eight modification strategies designed to address these failure mechanisms are encapsulated, including vacancy regulation, transition metal substitution, high entropy, the pillar effect, interstitial H2O removal, surface coating, surface vacancy repair, and cathode electrolyte interphasereinforcement. This comprehensive review of the current research advances on Mn─HCF aims to provide valuable guidance and direction for addressing the existing challenges in their application within SIBs.

A W/Al Co-doped Na0.44MnO2 Cathode Material for Enhanced Sodium-Ion Storage.

The Na0.44MnO2 cathode has attracted enormous interest owing to its low cost, low toxicity, and stable structure, but its practical application is still hindered by the limited sodium storage sites. Element doping is widely used to improve its capacity. However, cation and anion substitution could barely reach a satisfactory compromise between the structural stability and reversible capacity. Herein, we show that the above issue could be overcome via the synergetic effect of W and Al substitution. Combining the electrochemical and in situ X-ray powder diffraction (XRD) measurements, we reveal that the substitution of W effectively facilitates the tunnel-to-layered phase transformation, while the further substitution of Al eliminates the Na+/vacancy ordering during the extraction/insertion of Na+ ions, resulting in a layered Na0.44Mn0.94W0.01Al0.05O2 (NMO-1W5Al) with negligible Na+/vacancy ordering upon cycling. In addition, NMO-1W5Al represents a wider Na+ interlayer spacing to accelerate the diffusion of Na+, which improves the rate performance. The high specific capacity, remarkable rate performance, and high cycling stability of NMO-1W5Al are promising for large-scale energy storage systems.

Model‐Driven Manufacturing of High‐Energy‐Density Batteries: A Review

AbstractThe rapid advancement in energy storage technologies, particularly high‐energy density batteries, is pivotal for diverse applications ranging from portable electronics to electric vehicles and grid storage. This review paper provides a comprehensive analysis of the recent progress in model‐driven manufacturing approaches for high‐energy‐density batteries, highlighting the integration of computational models and simulations with experimental manufacturing processes to optimize performance, reliability, safety, and cost‐effectiveness. We systematically examine various modeling techniques, including electrochemical, thermal, and mechanical models, and their roles in elucidating the complex interplay of materials, design, and manufacturing parameters. The review also discusses the challenges and opportunities in scaling up these model‐driven approaches, addressing key issues such as model validation, parameter sensitivity, and the integration of machine learning and artificial intelligence for predictive modeling, process optimization, and quality assurance. By synthesizing current research findings and industry practices, this paper aims to outline a roadmap for future developments in model‐driven manufacturing of high‐energy density batteries, emphasizing the need for interdisciplinary collaboration and innovation to meet the increasing demands for energy storage solutions.

Strong Replaces Weak: ​Hydrogen Bond-Anchored Electrolyte Enabling Ultra-Stable and Wide-Temperature Aqueous Zinc-Ion Capacitors.

Despite aqueous electrolytes offer a great opportunity for large-scale energy storage owing to their safety and cost-effectiveness, their practical application suffers from the parasitic side reactions and poor temperature adaptability stemming from weak hydrogen-bond (HB) network in free water. Here, we propose the guiding thought "strong replaces weak" to design hydrogen bond-anchored electrolyte by introducing sulfolane (SL) for disrupting the regular weak HB network and contributing to superior temperature tolerance. Judiciously combined experimental characterization and theoretical calculation confirm that SL can remodel the primary solvation shell of metal ions, customize stable electrode interface chemistry and restrain the side reactions. Consequently, symmetric supercapacitor constructed by activated carbon (AC) electrodes is able to fully work within a voltage range of 2.4 V and reach high capacitance retention of 89.8% after 60000 cycles. Additionally, Zn anodes exhibit ultra-stable Zn plating/stripping behaviors and a wide temperature range (-20 ~ 60 °C), and zinc-ion capacitor (Zn//AC) also delivers an excellent cycling stability with capacity retention of 99.7% after 55000 cycles, implying that the designed electrolyte has practical application potential in extreme environments. This work proposes a novel critical solvation strategy that paves the route for the construction of ultra-stable and wide-temperature aqueous energy storage devices.

Building electrode/electrolyte interphases in aqueous zinc batteries via self-polymerization of electrolyte additives

Abstract Aqueous zinc batteries offer promising prospects for large-scale energy storage, yet their application is limited by undesired side reactions at the electrode-electrolyte interface. Here, we report a universal approach for in situ building an electrode/electrolyte interphase (EEI) layer on both the cathode and anode through the self-polymerization of electrolyte additives. In an exemplified Zn||V2O5·nH2O cell, we reveal that the glutamate additive undergoes radical-initiated electro-polymerization on the cathode and polycondensation on the anode, yielding polyglutamic acid-dominated EEI layers on both electrodes. These EEI layers effectively mitigate undesired interfacial side reactions while enhance reaction kinetics, enabling Zn||V2O5·nH2O cell to achieve a high capacity of 387 mAh g−1 at 0.2 A g−1 and maintain over 96.3% capacity retention after 1500 cycles at 1 A g−1. Moreover, this interphase-forming additive exhibits broad applicability to varied cathode materials, encompassing VS2, VS4, VO2, α-MnO2, β-MnO2, and δ-MnO2. The methodology of utilizing self-polymerizable electrolyte additives to construct robust EEI layers opens a novel pathway of interphase engineering for electrode stabilizing in aqueous batteries.

Challenges and Modification Strategies on High-Voltage Layered Oxide Cathode for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have attracted great attention due to their advantages on resource abundance, cost and safety. Layered oxide cathodes (LOCs) of SIBs possess high theoretical capacity, facile synthesis and low cost, and are promising candidates for large scale energy storage application. Increasing operating voltage is an effective strategy to achieve higher specific capacity and also high energy density of SIBs. However, at high operating voltages, LOCs will undergo a series of phase transitions in bulk phase, leading to huge change of volume and layer spacings accompanied by severe lattice stress and cracking formation. Degeneration of surface also occurs between LOCs and electrolytes, resulting in sustained growth of cathode electrolyte interphase (CEI) and release of O2 and CO2. These induce structural destruction and electrochemical performance degradation in high voltage regions. Recently, many strategies have been proposed to improve electrochemical performance of LOCs under high voltages, including bulk element doping, structural design, surface coating and gradient doping. This review describes pivotal challenges and occurrence mechanisms at high voltages, and summarizes strategies to improve stability of bulk and surface. Viewpoints will be provided to promote development of high energy density SIBs.

Enhanced Efficiency of Latent Heat Energy Storage by Inclination

Latent heat storage (LHS) has emerged as a promising solution for addressing the challenges of large-scale and long-term energy storage, offering a clean and reusable system. Being in the developmental stage, and with only limited theoretical predictions being available, there is a need to enhance the efficiency of LHS systems. In this study, we use numerical simulations to study the melting process of a phase-change material (PCM) in a rectangular domain. A significant enhancement in the melt rate of the PCM is found by a simple inclination of the domain, with a 60% increase in melt rate compared to a standard square unit without inclination through enhanced heat transfer. We establish a theoretical relation for the optimal PCM melt rate, based on the inclination angle and the domain aspect ratio, outlining the optimal conditions for the PCM melt rate, which is solely dependent on the domain geometry. We further propose a heat-transfer model that predicts the optimal aspect ratio for achieving the maximum melt rate as a function of the Rayleigh and Prandtl numbers. Published by the American Physical Society 2024

Localized Water Restriction in Ternary Eutectic Electrolytes for Ultra-Low Temperature Hydrogen Batteries.

Proton batteries are promising candidates for next-generation large-scale energy storage in extreme conditions due to the small ionic radius and efficient transport of protons. Hydrogen gas, with its low working potentials, fast kinetics, and stability, further enhances the performance of proton batteries but necessitates the development of novel electrolytes with low freezing points and reduced corrosion. This work introduces a localized water restriction strategy by incorporating a tertiary component with a high donor number, which forms strong bonds with water molecules. This approach restricts free water molecules and reduces the average hydrogen bond ratio and strength. As-prepared ternary eutectic electrolytes lowered the freezing point to -103 °C, significantly lower than the traditional binary electrolyte (9.5 m H3PO4, -93 °C). This electrolyte is highly compatible with the Cu0.79Co0.21[Fe(CN)6]0.64·4H2O (CoCuHCF) cathode, reducing material dissolution and current collector corrosion. The H2||CoCuHCF battery using this electrolyte demonstrated a high-power density of 23664.3 W kg-1, excellent performance at -80 °C, and stable cyclability over 1000 cycles (> 30 days) at -50 °C. These findings provide a framework for proton electrolytes, highlighting the potential of hydrogen batteries in challenging environments.

Early Warning of Energy Storage Battery Fault Based on Improved Autoformer and Adaptive Threshold

To enhance voltage prediction accuracy in energy storage batteries and address the limitations of fixed threshold warning methods, a fault warning approach based on an improved Autoformer model and adaptive thresholds is proposed. First, a spatiotemporal filtering layer is introduced into the autocorrelation mechanism to analyze the trend features of voltage sequences across different frequency domains. Additionally, an adaptive gating residual connection is used to link the sublayer and current layer output features, which helps to improve the model's adaptive feature selection capability. This innovation enables the development of a robust voltage prediction model based on the enhanced Autoformer. Then, a similarity‐based adaptive threshold, using interval estimation, is employed to rapidly track variations in battery voltage, enabling dynamic adjustment of voltage thresholds. Finally, the proposed method is validated with real voltage data from an operational energy storage station. The experimental results shows that the proposed model has higher accuracy and robustness compared to similar methods. The adaptive threshold can reduce the false alarm rate by ≈18% and issue alarms at three sampling points ahead of the battery management system alarm, improving fault warning accuracy and illustrating that early fault warning is effectively and practically carried out using the method.

Two-Dimensional ABS4 (A and B = Zr, Hf, and Ti) as Promising Anode for Li and Na-Ion Batteries.

Metal ion intercalation into van der Waals gaps of layered materials is vital for large-scale electrochemical energy storage. Transition-metal sulfides, ABS4 (where A and B represent Zr, Hf, and Ti as monolayers as anodes), are examined as lithium and sodium ion storage. Our study reveals that these monolayers offer exceptional performance for ion storage. The low diffusion barriers enable efficient lithium bonding and rapid separation while all ABS4 phases remain semiconducting before lithiation and transition to metallic states, ensuring excellent electrical conductivity. Notably, the monolayers demonstrate impressive ion capacities: 1639, 1202, and 1119 mAh/g for Li-ions, and 1093, 801, and 671 mAh/g for Na-ions in ZrTiS4, HfTiS4, and HfZrS4, respectively. Average voltages are 1.16 V, 0.9 V, and 0.94 V for Li-ions and 1.17 V, 1.02 V, and 0.94 V for Na-ions across these materials. Additionally, low migration energy barriers of 0.231 eV, 0.233 eV, and 0.238 eV for Li and 0.135 eV, 0.136 eV, and 0.147 eV for Na make ABS4 monolayers highly attractive for battery applications. These findings underscore the potential of monolayer ABS4 as a superior electrode material, combining high adsorption energy, low diffusion barriers, low voltage, high specific capacity, and outstanding electrical conductivity.

Multi-scenario optimization and performance evaluation of integrated energy system considering co-scheduling of EVs and stationary energy storage

Multi-scenario optimization and performance evaluation of integrated energy system considering co-scheduling of EVs and stationary energy storage

Expansion force signal based rapid detection of early thermal runaway for pouch batteries

With the extensive application of lithium-ion batteries in electric vehicles and energy storage stations, thermal safety issues have increasingly become the focus of public attention. To alleviate the safety concerns, a qualified battery management system (BMS) must be able to detect and warn of thermal abuse before it develops into a thermal runaway (TR). For the first time, the expansion force characteristics of the pouch battery module during the early heating stage of TR under typical working conditions are analyzed, which proves that the expansion force signal can reflect the internal abnormal heating earlier than the terminal voltage and the surface temperature, and has better noise resistance. Furthermore, the electromechanical coupling model (EmCM) is improved for more accurate open-loop expansion force estimation. On this basis, an expansion force based early TR rapid detection framework is proposed with less 3 min expend in tests, in which the Kalman filter ensures the stability and convergence/divergence of the observer estimation error, and the reliability of fault judgment is ensured by the adaptive threshold designed by the model structure.

Optimization of PV benefits for Electric Vehicles Charging Station Using a Deterministic Method and Fuzzy Inference System Method

Utilizing renewable energy, specifically Photovoltaic (PV), for Electric Vehicle (EV) charging presents diverse technical and economic opportunities, reflecting a recent trend in innovation and research to address global transportation challenges while highlighting the value of renewable sources. In this context, this paper aims to devise an optimal power management strategy for an EV charging station powered by a PV-based microgrid (MG). The main purpose is to improve the benefits of PV production in recharging EVs to increase self-consumption, decrease dependency on the power grid, and reduce energy costs. Production data from a real-scale MG at the Catholic University in France were used as a case study. This MG comprises a heterogeneous fleet of EVs, PV sources, stationary storage, EV charging stations, and a connection to the power grid. The optimization of PV benefits relies on leveraging the knowledge of EV characteristics to modulate their charge profile. In this context, two methods are used and compared for the modulation of the EVs' charging profile: a deterministic method and a Fuzzy Inference System (FIS)-based method. For each method, different scenarios emerge based on the knowledge or lack thereof of the EVs' characteristics. This methodology permits the optimal distribution of energy among multiple EVs and regulates the necessary power to achieve the desired charge level upon departure. It encourages charging through PV production, resulting in reduced energy costs. The comparison of total costs reveals notable differences between the deterministic and FIS approaches for both slow and fast charging modes. In the case of slow charging, the deterministic approach achieves savings of -863.4 c€/day, whereas the FIS method delivers greater savings of -898.7 c€/day. For fast charging, the deterministic approach yields savings of -524.6 c€/day, while the FIS method results in even higher savings of -540.7 c€/day. These results highlight that the FIS approach enables better cost management, primarily due to more efficient utilization of PV energy. Additionally, simulation results from MATLAB/Simulink confirm the effectiveness of the FIS-based method, which improves PV energy utilization to 98.20%, compared to 81.60% with the deterministic approach. This highlights the superior efficiency of the proposed FIS.

The Complex and Spatially Heterogeneous Nature of Degradation in Heavily Cycled Li-ion Cells

As service lifetimes of electric vehicle (EV) and grid storage batteries continually improve, it has become increasingly important to understand how cells perform after extensive cycling. The multifaceted nature of degradation in Li-ion cells can lead to complex behavior that may be difficult for battery management systems or operators to model. Accurate characterization of heavily cycled cells is critical for developing accurate models, especially for cycle-intensive applications like second-life grid storage or vehicle-to-grid charging. In this study, we use operando synchrotron x-ray diffraction (SR-XRD) to characterize a commercially manufactured polycrystalline NMC622 pouch cell that was cycled for more than 2.5 years. Using spatially resolved synchrotron XRD, the complex kinetics and spatially heterogeneous behavior of such cells are mapped and characterized under both near-equilibrium and non-equilibrium conditions. The resulting data is complex and multifaceted, requiring a different approach to analysis and modelling than what has been used in the literature. To show how material selection can impact the extent of degradation, we compare the results from polycrystalline NMC622 cells to an extensively cycled single-crystal NMC532 cell with over 20,000 cycles—equivalent to a total EV traveled distance of approximately 8 million km (5 million miles) over six years.

Proposal design and thermodynamic optimization of an afterburning-type isothermal compressed air energy storage system integrated with molten salt thermal storage

The isothermal compressed air energy storage is a potential technique for large-scale energy storage. In this study, the molten salt thermal storage is integrated with the afterburning-type isothermal compressed air energy storage system, which uses liquid piston compression technique, to enhance the thermal performances. Thermodynamic models of the hybrid energy storage system were developed, and the genetic algorithm was used to optimize multiple parameters to enhance the energy efficiency. Four operation modes, i.e., the high, medium-high, medium-low, and the low output power modes were proposed, to enhance the operational flexibility of the hybrid energy storage system. When the system operates in the operation mode of medium-low output power, a portion of afterburning heat is stored in the molten salt and used in the operation mode of low output power. Results show that the roundtrip efficiency of high, medium-high, medium-low, and the low output power modes are 63.57 %, 59.33 %, 57.13 %, and 83.28 %, respectively. Exergy analysis was carried out to quantify the irreversibilities of key components. In the three modes of operation with afterburning, the combustion chamber has the highest portion of exergy loss, and in the operation mode without afterburning, the exergy loss of heat exchangers is higher than that of expanders.

Ultrafast Lattice Engineering for High Energy Density and High-Rate Sodium-Ion Layered Oxide Cathodes

Sodium-ion batteries attract significant interest for large-scale energy storage owing to abundant sodium reserves, while challenges remain in the high synthesis energy consumption, long synthesis period, and poor electrochemical performance of sodium-ion layered oxide materials. This study presents a general high-temperature thermal shock (HTS) strategy to synthesize and optimize sodium-ion layered oxides. The rapid ramping, sintering, and cooling processes minimize volatile sodium loss during HTS, facilitating the improvement of phase purity and effectively optimizing the microstructure of materials in a non-equilibrium state. As a proof of concept, Mn-based Na0.67MnO2 treated with HTS (NMO-HTS) suppresses Mn ion vacancy within transition material layers, thereby increasing the redox centers and lowering the Mn 3d orbital energy level. Besides, the formation of transition metal layer stacking faults mitigates the structural transformation and Na+-vacancies ordering arrangement during cycling. Consequently, the energy density of the NMO-HTS increases by 21.5% to 559 Wh kg-1, with an outstanding rate capability of 108 mAh g-1 at 10C and an impressive capacity retention of 93.7% after 300 cycles at 1C. In addition, we demonstrate the universality of HTS in synthesizing various other sodium-ion layered oxides, including nickel-based and iron-based cathodes, as well as in activating degraded materials.

Cu@Cu31S16 cathode for high-performance aqueous zinc-ion battery

Abstract Among various battery systems, aqueous zinc-ion batteries demonstrate significant potential for large-scale energy storage applications. However, the relatively large radius of zinc ions makes it challenging for them to intercalate into cathode materials, resulting in a limited variety of host materials suitable for Zn2+ storage. Therefore, researching appropriate cathode materials is a crucial component of the practical application of aqueous zinc-ion batteries. In this study, we prepare two binderless, conductor-less, current collector materials Cu@Cu31S16 cathodes, by in-situ etching of copper foil with a polysulfide precursor solution. The results indicate that Cu31S16 not only exhibits excellent stability and conductivity but also features rapid ion migration kinetics and low Zn2+ diffusion barriers.

Deciphering the multi-electron redox chemistry of metal-sulfide electrode toward advanced aqueous Cu ion storage

While neutral aqueous metal batteries, featuring cost-effectiveness and non-flammability, hold significant potential for large-scale energy storage, their practical application is hampered by the limited specific capacity of cathode materials (less than 500 mAh g−1). Herein, capacity-oriented CoS2 and rate-optimized Co9S8 cathodes are developed based on the aqueous copper ion system. The charge-storage mechanism is systematically investigated through a series of ex-situ tests and density functional theory calculations, focusing on the reversible transitions of Co9S8→Cu7S4→Cu9S5/Cu1.8S and CoS2→Cu7S4→Cu2S, which are associated with the redox reactions of Cu2+/Cu+‖Co2+/Co and Cu2+/Cu+‖S22−/S2−, respectively. The electrochemical results show that CoS2 can exhibit a superior capacity of 619 mAh g−1 at 1 A g−1 after 400 cycles, while Co9S8 maintains an outstanding rate performance of 497 mAh g−1 at 10 A g−1 (the retention rate is 95% compared to 521 mAh g−1 at 1 A g−1). As a proof of concept, an advanced CoS2//Zn hybrid aqueous battery demonstrates a working voltage of 1.20 V and a specific energy of 663 Wh kgcathode−1. This work provides an alternative direction for developing sulfide cathodes in energetic aqueous metal batteries.

Imidazolium-based ionic liquids as proton reservoir for stable polyaniline cathode in zinc-iodine batteries

Aqueous zinc (Zn)-iodine (I2) batteries (ZIBs) are promising large-scale energy storage systems with high safety and low cost. However, the practical application of ZIBs is hindered by the dissolution of I3- ions, which leads to the shuttle effect and the loss of active iodine. Herein, we adopt an electrolyte modification strategy using two imidazolium-based ionic liquids (1-butyl-3-methylimidazolium iodide ([BMIM]I) and 1-ethyl-3-methylimidazolium iodide ([EMIM]I)) as electrolyte additives to restrain the dissolution of I3- ions and enhance the performance of ZIBs. To be specific, the imidazole rings in [BMIM]+ and [EMIM]+ can be used as the proton sources, promoting the conversion of imine to protonated amines –NH+= in the polyaniline and subsequent adsorption of I3- ions. Therefore, the dissolution of I3- ions and shuttle effect are prevented, facilitating the reaction kinetics of cathode. As a proof of concept, the ZIB using [BMIM]I and [EMIM]I as electrolyte additives demonstrates remarkable cycling performance (72.2 % capacity retention after 1000 cycles) at a high current density of 20 mA cm−2

A donor-acceptor conjugated bipolar polymer with multielectron redox sites for long-cycle-life and high-rate aqueous zinc dual-ion batteries

Aqueous zinc-ion batteries (AZIBs) have hugely latent advantages in large-scale energy storage due to its innate safety, reasonable price, and sustainability. However, most AZIB cathode materials suffer from short cycling life and poor rate performance. Herein, a bipolar donor-acceptor (D-A) conjugated microporous polymer (PTZ-BDTB), consisting of electron-withdrawing benzo[1,2-b:4,5-b’]dithiophene-4,8-dione (BDTB) units and electron-donating phenothiazine (PTZ) units, is developed as the cathode material of aqueous zinc dual-ion batteries (AZDIBs). The D-A type structure design could reduce the band gap, thus promoting electron transfer in the polymer framework. Therefore, the PTZ-BDTB cathode in a 30 mol/kg (m) ZnCl2 water-in-salt electrolyte exhibits a high reversible capacity of 202 mA h g−1 at 0.05 A g−1 with excellent rate performance (109 mA h g−1 at 15 A g−1), which is far superior to its counterpart polymers PPTZ and PB-BDTB. Impressively, PTZ-BDTB shows ultra-stable cycle performance with capacity retention ratios of 76.2% after 460 cycles at 0.05 A g−1 and 96% after 27000 cycles at 5 A g−1. PTZ-BDTB also exhibits a low self-discharge ability with capacity retention about 76.4% after resting the battery for 28 days. These results demonstrate that D-A type structural design is a promising strategy for constructing high performance cathode materials for AZDIBs.