Large-scale Energy Storage Research Articles

Success in construction management of dams: an empirical study

The current body of research lacks adequate investigation of project success, especially for dam construction projects. Despite the considerable body of research in the field of project management, an empirical examination of the performance of dam projects, which carry substantial economic, social, and environmental impacts, is still lacking. This research attempts to fill the gap by conducting a survey among construction professionals who have experience with dams. Alongside the continuing construction projects to augment and upgrade existing dams, there is currently an unprecedented surge in the number of new dams planned or under construction. This is driven by the energy transition towards achieving net zero targets, with a focus on pumped-hydro schemes as an efficient form of large-scale energy storage. Exploratory factor analysis and structural equation modeling (SEM) are applied to explore critical success factors (CSFs) and success criteria (SC) and their relationships. This paper offers valuable recommendations for professionals to improve project performance and adds to the limited literature on dam construction project success. Construction professionals can optimize their efforts by strategically implementing the project elements presented in this research. This ultimately leads to improved project outcomes, increased efficiency, and lower costs.

Pb-MOF derived lead‑carbon composites for superior lead‑carbon battery

Lead‑carbon batteries (LCBs) provide considerable potential for large-scale energy storage, whereas exploring porous carbon negative additives with excellent mitigation of sulphation and parasitic hydrogen evolution remains challenging. Herein, lead‑carbon composite (PM@Cx) was prepared from simple pyrolysis of the electro-synthesized Pb-MOF precursor with waste lead paste as sacrificial anode for enhancing the performance of LCBs. The innovative transformation of waste lead paste into Pb-MOF enabled the uniform distribution of Pb atoms in the composite material and the in-situ generation of PbC heterojunction after pyrolysis. Benefitting from the presence of Pb nanoparticles and encapsulated structures, PM@Cx exhibits excellent inhibition of hydrogen evolution and increased affinity for carbon with active materials. Owing to the synergistic interaction of the above characteristics, the discharge capacity of the battery with PM@C500 reaches 3.75 Ah at 0.1C, which is 26.7 % enhancement compared to the control (2.96 Ah). The cycling lifespan is 6377 cycles at HRPSoC operating condition, 3 times of the control. This study provides innovative insights into the recycling of waste lead paste and the design of lead‑carbon composites for LCBs to inhibit negative sulphation and hydrogen evolution.

Dual carbon confining SnO2 nanocrystals as high-performance anode for sodium-ion batteries

The increasing global demand for sustainable energy sources has driven research into sodium-ion batteries (SIBs) for large-scale energy storage. However, their electrochemical performance is hindered by poor reaction kinetics and significant volume expansion in electrode materials. In this work, we developed a dual-carbon-confined SnO2 nanocrystal anode (CNTs@SnO2@NC) designed for high-performance SIBs. This innovative structure uses carbon nanotubes (CNTs) and a nitrogen-doped carbon (NC) coating to stabilize SnO2, ensuring structural integrity during charge/discharge cycles. The CNTs network in CNTs@SnO2@NC can alleviate the agglomeration of SnO2 nanocrystals to a certain extent; With its superior electronic conductivity, CNTs can enhance the anode's conductivity and function as an electronic highway; The sodiophilic properties and good electrical conductivity of CNTs enable sodium ions to migrate rapidly on the surface of the nanotubes. Moreover, numerous external defects and active sites generated by nitrogen doping enhance the sodium ion absorption capabilities; The existence of nitrogen-doped carbon coating can effectively accommodate the volume changes of SnO2 and enhance the structural stability of CNTs@SnO2@NC composites during the repeated charge and discharge cycles. As a result, the CNTs@SnO2@NC composite demonstrates excellent electrochemical performance, achieving capacity of 235 mAh g−1 at 0.1 A g−1 over 100 cycles and 102 mAh g−1 at 1.0 A g−1 over 300 cycles. In a full-cell configuration with a Na3V2(PO4)3 cathode, it delivers 38 mAh g−1 at 100th cycle at 0.1 A g−1. This study underscores the substantial improvements achieved by dual-carbon confinement for high-performance SIB anodes, offering a promising direction for future anode material design.

Poly(3,4-ethylenedioxythiophene)-Coated Vanadium-Doped MnO2 Nanorods for High-Performance Flexible Aqueous Zinc-Ion Battery Cathode.

Manganese-based aqueous zinc-ion batteries (AZIBs) are considered promising cathode materials for large-scale energy storage applications due to their low cost and high safety. However, the primary constraints on achieving high specific capacity and cycling stability are the inherent low conductivity and suboptimal structural stability of the AZIB cathodes. Herein, we report a high-performance poly(3,4-ethylenedioxythiophene) (PEDOT)-coated vanadium-doped MnO2 nanorod (NR) electrode for AZIBs. First, vanadium-doped MnO2 (V-MnO2) NRs were synthesized by a simple hydrothermal synthesis method. The V-MnO2 NRs were further encapsulated with a nanolayer of PEDOT through an in situ polymerization process, which was subsequently treated with sulfuric acid to achieve a smooth surface. The V doping creates oxygen vacancies within the MnO2, allowing for the rapid embedding and diffusion of Zn2+. The PEDOT nanolayer greatly enhances the conductivity and structural stability of the V-MnO2. Benefiting from the unique features, an optimal composite NRs electrode exhibits a high specific capacity of 250 mAh g-1 at 0.4 A g-1, a high energy density (388 Wh kg-1 at 151 W kg-1), and excellent stability over 5000 cycles at 3 A g-1. In addition, the flexible pouch cell assembled with the electrode shows good stability under bending. Given the positive outcomes, the material holds great potential for use as a cathode in next-generation flexible energy storage systems.

Optimised Two-Layer Configuration of SESS-CCHP System Considering Wind and Light Output Correlation and Load Sensitivity

With the gradual depletion of fossil energy sources and the diversification of users’ energy demand, combined cooling, heating and power (CCHP) microgrids have become a hot technology to improve energy efficiency and promote efficient and synergistic energy operation. However, the uncertainty and correlation of wind power and photovoltaic (PV) outputs have posed a great challenge to the reliability of CCHP system operation, so CCHP systems are often equipped with energy storage devices to improve system flexibility to ensure the reliability of energy supply. However, system-owned reserves still have shortcomings such as high investment O&M costs and large space requirements. As an emerging model, “shared energy storage” can reduce the investment pressure of users and open up new ways for the economic and stable operation of CCHP systems. Therefore, based on the scenario of wind and solar power correlation and considering different types of load flexibility, this paper proposes to construct a shared energy storage station (SESS)-CCHP double-layer synergistic optimal allocation model. The model incorporates the consideration of the actual operation strategy of the CCHP system in the planning stage of energy storage. An example analysis shows that SESS reduces the total operating cost of the CCHP system by 25.96% and improves the new energy consumption rate by 10.46% compared with no energy storage. Compared with the system independently configured with energy storage, the cost saving is 2.14%, thus validating the effectiveness of the proposed model.

Identifying the β-to-α phase transition during the long cycling process in Na2FePO4F cathode

Na2FePO4F has emerged as a promising cathode for large-scale electrochemical energy storage, primarily due to its abundance of raw materials and distinctive two-dimensional ion channels. Counterintuitively, pristine Na2FePO4F lacks the long-term stability typically seen in polyanionic cathodes, which severely impedes its practical application. Traditionally, the origin of this problem has been only phenomenologically attributed to the poor intrinsic electronic conductivity and structural instability of Na2FePO4F. Here, we identify that rapid capacity fading of Na2FePO4F is closely related to the β-to-α phase transition during the long cycling process. Furthermore, we develop a practical high-entropy doping strategy and the corresponding microstructure engineering to mitigate the impact of the phase transition on the crystal structure, thereby increasing the capacity retention from 56 % to 94 % over 400 cycles at 0.5C in coin cell, and attain almost 100 % capacity retention after 300 cycles at 0.1C in pouch cell. Overall, this work unveils the mechanism of rapid capacity decay in Na2FePO4F and lays the groundwork for the rational design of durable polyanionic electrodes.

Engineering of charge density at the anode/electrolyte interface for long-life Zn anode in aqueous zinc ion battery.

The aqueous zinc ion battery emerges as the promising candidate applied in large-scale energy storage system. However, Zn anode suffers from the issues including Zn dendrite, Hydrogen evolution reaction and corrosion. These challenges are primarily derived from the instability of anode/electrolyte interface, which is associated with the interfacial charge density distribution. In this context, the recent advancements concentrating on the strategies and mechanism to regulate charge density at the Zn anode/electrolyte interface are summarized. Different characterization techniques for charge density distribution have been analysed, which can be applied to assess the interfacial zinc ion transport. Additionally, the charge density regulations at the Zn anode/electrolyte interface are discussed, elucidating their roles in modulating electrostatic interactions, electric field, structure of solvated zinc ion and electric double layer, respectively. Finally, the perspectives and challenges on the further research are provided to establish the stable anode/electrolyte interface by focusing on charge density modifications, which is expected to facilitate the development of aqueous zinc ion battery.

Bismuth Single Atoms Regulated Graphite Felt Electrode Boosting High Power Density Vanadium Flow Batteries.

Vanadium flow batteries (VFBs) are considered one of the most promising candidates for large-scale energy storage. However, VFBs suffer from relatively low power density due to severe electrochemical polarization. Herein, we report Bi single atoms supported by an N-doped carbon-regulated graphite felt electrode (Bi SAs/NC@GF) with high electrocatalytic activity and stability, owing to the greatly improved active sites and optimized Bi-N4 configuration. Electrochemical in situ characterization and theoretical calculations elucidate the desolvation process and specific inner sphere reaction mechanism of [V(H2O)6]3+/[V(H2O)6]2+. As a result, a VFB single cell assembled with Bi SAs/NC@GF achieves a much higher energy efficiency of 81.1% at 240 mA cm-2 than NC@GF (70.5%). Moreover, a 5 kW VFB stack equipped with Bi SAs/NC@GF is assembled for the first time and ran stably for over 400 cycles. This work confirms that a single-atom catalyst is efficient for scalable VFBs with high power density and low cost.

Life-cycle environmental impacts of reused batteries of electric vehicles in buildings considering battery uncertainty

Advancements in various technologies have made it possible to recycle end-of-life batteries from electric vehicles (EV) into a stationary energy storage system (ESS) within residential buildings. As a result, promoting a circular economy between buildings and means of transportation has emerged as a major concern. Therefore, this study aimed to quantitatively assess the environmental impacts (life -cycle carbon Carbon dioxide (CO2) emissions) of ESS utilizing used batteries instead of new batteries from the life cycle perspective of lithium-ion batteries (LIBs) considering the uncertainty in energy communities. To this end, a probabilistic life cycle assessment (LCA) was performed using a Monte Carlo simulation of the energy community of South Korea. The results of this study demonstrated that reusing batteries as ESS in buildings could further improve the overall environmental sustainability of the ESS compared to using new batteries. As a result, when reused batteries were utilized, annual carbon emissions decreased by 2.8 %–18.5 % according to battery usage purposes. More specifically, it was shown that battery reuse can reduce greenhouse gas emissions and environmental impacts. To more rationally evaluate life-cycle CO2 emissions from a resource circulation perspective, the usage purpose and efficiency of the battery should be considered during the entire battery life cycle (transportation and building sectors). These findings are expected to provide valuable insights to policymakers, industrial sectors, and research institutes related to battery reuse and to help guide the future of transportation and building sectors in a sustainable direction from a resource circulation perspective.

Efficient Electron Injection into Graphullerene Enables Reversible NaC2 Sodium Storage.

Sodium-ion batteries are emerging as promising alternatives to conventional lithium-based technology, offering solutions to challenges in large-scale grid storage. However, the capacity of conventional graphite-based anodes for storing Na-ions is inherently limited by suboptimal thermodynamic interactions and irreversible structural changes that occur in the anode during charge-discharge cycles. Herein, we present a computational design that explores the potential of graphullerene, a two-dimensional framework with interconnected fullerene moieties, for the reversible storage of Na-ions. A unique aspect of this design is the electron injection capacity into the graphullerene anode, reaching 15 electrons per fullerene moiety, which is the highest limit to date. This advancement enables large-scale Na-ion storage up to the stoichiometry of NaC2, exhibiting specific capacity of 551 mAhg-1 and averaged open circuit voltage of 0.18 V vs Na/Na+. In addition, the multilayered arrangement of stored Na-ions enhances the Na-ion diffusivity on the graphullerene surface, leading to rapid insertion and extraction kinetics. Thus, raising the electron injection limit offers a promising strategy to transform carbon-based anodes into suitable candidates for reversible Na-ion storage, without relying on artificial defect introduction or doping.

Electrochemical constructing versatile ZnAl-LDH artificial interface layer coated (002)-textured Zn for highly reversible zinc anodes

Rechargeable aqueous zinc-ion batteries (AZIBs), renowned for their high safety, cost-effectiveness, and high energy density, are regarded as an alternative for large-scale energy storage. However, persistent challenges remain in achieving highly reversible AZIBs, primarily centered around the notorious issues associated with the Zn anode. Here, a zincophilic Zn-Al layered double hydroxide (ZnAl-LDH) artificial interface layer coated highly (002)-textured Zn metal anode (SZ/LDH@Zn) with an integrated design are successively constructed by electrochemical methods. Comprehensive characterizations and theoretical calculations reveal that the preferred (002)-textured Zn couping with the zincophilic ZnAl-LDH coating layer not only can effectively regulate the interfacial electric field and Zn2+ flux distribution, guiding a uniform and horizontal Zn2+ deposition but also provide inherent Zn2+ diffusion channels, accelerating its interfacial transport kinetics. Moreover, the ZnAl-LDH layer with good chemical stability acted as a robust physical barrier, impeding direct contact between the electrolyte and Zn anode, thus curbing interfacial side reactions. As a result, the SZ/LDH@Zn||SZ/LDH@Zn symmetric cell delivers unprecedented cycling stability of 5500 h (about 230 days) at 1 mA cm−2, 1 mA h cm−2. The SZ/LDH@Zn||Cu asymmetric cell achieves superior reversibility with a high average Coulombic efficiency of 99.85 % over 3800 cycles. More significantly, the SZ/LDH@Zn||NaV3O8·xH2O full cell with a low N/P ratio (3.62) exhibits an impressive areal capacity of 5.36 mA h cm−2 and reliable operation over 1500 cycles. This work offers a facile and controllable electrochemical coupling strategy to build a highly stable Zn metal anode.

How sustainability can get a competitive advantage: State of the art for stationary battery storage systems

Stationary battery storage systems are becoming a critical energy infrastructure around the world. Therefore, responsible handling of battery materials is a fundamental precondition to avoid future social, environmental, and political conflicts. Global battery regulations support sustainable batteries to drive new business models on reuse, remanufacturing and recycling. With strict environmental market entry barriers, the EU will set minimum sustainability standards with the new EU-Battery Directive. The US Inflation Reduction Act provides financial incentives for a scale-up of the domestic battery industry. A hotspot analysis for the residential storage system VARTA.wall shows that a combination of reuse and recycling strategies can reduce the climate change impact by up to 45% and mineral resource use by up to 50% compared to initial battery designs. However, specific sustainability criteria and manufacturer-independent standards need to be set up by politics and industry organizations to bring the necessary technical and logistic infrastructure to the market. The challenge is to set up sustainability criteria strict enough to ensure responsible material handling but still allow cost-effective, practical solutions as well as affordable battery standards. Therefore, our analysis shows the limits of current and the need for future regulations to shift market incentives to sustainable batteries and their infrastructure.

Reutilization of Silver-Impregnated Activated Carbon (SAC) Cartridges with Surface Modification for Supercapacitor Electrodes for Large-Scale Energy-Storage Applications

The strategy of converting waste materials into new functional materials is a promising approach for energy-storage applications, particularly in the case of silver-impregnated activated carbon (SAC). SAC, which is typically derived from coconut shells, is primarily used for water purification in home-based filters due to its excellent antibacterial properties. However, the silver concentration is low, and it tends to leach out after a certain period, resulting in waste. To address this issue, SAC was used as a precursor for electrodes in supercapacitor applications. Additional surface treatments, such as heteroatom doping, are also being employed to improve the electrical conductivity and wettability of SAC. Nitrogen was introduced using urea as a precursor to enhance the properties of SAC. XRD analysis confirmed the structural analysis of activated carbon and nitrogen-activated carbon. Morphological analysis revealed the formation of micropores on the surface of the samples. FTIR analysis confirmed the presence of functional groups in the samples. Raman spectra showed the presence of defects after the introduction of nitrogen atoms into the carbon lattice, with higher relative [Formula: see text] compared to AC. Multipoint bet analysis was conducted, and the surface area of the sample was found to be approximately 815[Formula: see text]m2g[Formula: see text], with pore sizes of 810[Formula: see text]m2g[Formula: see text]. Electrochemical analysis was carried out in both three- and two-electrode configurations. The specific capacitance of NAC in cyclic voltammetry and galvanostatic charge–discharge analysis was found to be higher than that of AC because the nitrogen atoms reduced the ionic charge transfer resistance between the electrode and electrolyte surface. Electrochemical impedance spectroscopy (EIS) was also conducted, confirming the solution resistance with 1.5[Formula: see text]Ohm.

Selective Lithium separation from Li/Co/Ni mixtures using optimized flow-electrode capacitive deionization

The increasing need for lithium has heightened its significance as a crucial resource in numerous sectors, particularly in realms of portable electronics, electric vehicles (EVs), and large-scale energy storage systems. However, the finite availability of lithium resources and environmental concerns associated with its extraction underscore the significance of developing an efficient recycling method. In this study, we explored the potential of recovering lithium from waste battery leachate using an emerging technology known as flow-electrode capacitive deionization (FCDI). Unlike traditional capacitive deionization (CDI), FCDI offers continuous desalination capabilities, making it particularly suitable for recycling industries. While FCDI exhibits promise in recovering waste battery leachate, its inherent lack of selectivity presents a challenge. To address this issue, we tried to tune its selectivity towards lithium by employing a layer-by-layer deposition method to modify a cation exchange membrane (CEM) with poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS) functional multilayers. This strategic modification of CEM was performed by alternatively depositing positively charged PAH and negatively charged PSS multilayers, which switched an innate divalent cation preference of CEM into a monovalent cation preference based on differences in ion sizes and charge densities. The membrane was used to treat a synthetic leachate mixture from wasted batteries, with a molar ratio of 30 mM:44 mM:4 mM for Li:Co:Ni, demonstrating a Li selectivity of 12.88 over Co and Ni with an exceptionally low energy consumption of 0.57 Wh/molLi. We believe our approach can lead to new technologies that address shortcomings of existing lithium recycling method and expand the application not only to lithium recycling, but also to future lithium production technologies and removal of specific ions such as for toxin removal.

Thermodynamic analysis of an advanced adiabatic compressed air energy storage system integrated with a high-temperature thermal energy storage and an Organic Rankine Cycle

Advanced adiabatic compressed air energy storage (AA-CAES) system has drawn great attention owing to its large-scale energy storage capacity, long lifespan, and environmental friendliness. However, the performance of the air turbine during the discharging process is limited by the low temperature of the compression heat. Thus, this study proposes an integrated AA-CAES system incorporating high-temperature thermal energy storage and an Organic Rankine Cycle (ORC). The high-temperature thermal energy storage is introduced to heat the discharging compressed air to enhance the air turbine performance, and the Organic Rankine Cycle is integrated to utilize the waste heat. Notably, two preheaters are deployed in a special tandem to recover the heat from the air exiting the turbine and the water exiting the hot water tank, respectively. This paper develops a thermodynamic model to simulate the proposed system, assessing the effects of heat storage temperature, ambient temperature, and inlet conditions of the air turbine on performance metrics, including exergy efficiency and exergy destruction. The simulation results indicate that, compared to thermal oil and Hitec salt, employing solar salt as the heat storage medium for the solar thermal collection and storage unit yields the best performance. The energy storage efficiency, roundtrip efficiency, exergy efficiency, exergy conversion coefficient, and energy storage density of this system are 115.6 %, 65.7 %, 78 %, 79.4 %, and 5.51 kWh/m3, respectively. Exergy analysis reveals that the exergy efficiency of interheaters (IH) is the lowest at 76.7 %, while air turbines (ATBs) exhibit the highest exergy efficiency at 91.2 %. Moreover, due to the irreversible processes of compression, expansion, and throttling, ATBS, compressors, and throttle valves collectively contribute to an exergy destruction rate as high as 79.2 %. The parameter analysis demonstrates that low ambient temperature, high inlet temperature, and high inlet pressure of the air turbine enhance energy storage performance.

Solid-state Batteries: Overcoming Challenges and Harnessing Opportunities for a Sustainable Energy Future

Herein we reviewed solid-state batteries (SSBs) as an emerging and promising alternative to conventional lithium-ion batteries, offering enhanced energy density, safety, and longevity. Solid-state batteries (SSBs) use a solid electrolyte instead of the liquid or gel electrolytes found in conventional lithium-ion batteries. SSBs can achieve energy densities of up to 500 Wh/kg, compared to 350 Wh/kg for conventional lithium-ion batteries. This paper explores the potential of SSBs to revolutionize grid stability and energy storage. The unique characteristics of SSBs, including their solid-state electrolytes (SSEs) and absence of liquid components, significantly mitigate safety concerns associated with traditional batteries. Moreover, SSBs exhibit higher faster charging rates, making them ideal for applications demanding high energy storage capacity and rapid response times. The paper further discusses the key challenges and advancements in SSB development, including material selection, manufacturing processes, and cost reduction. It also highlights the anode and cathode materials but also the interface challenges faced during the design and development of SSBs. By addressing the limitations of current energy storage solutions, SSBs offer a promising pathway toward a more resilient and sustainable energy future.

Engineering the mass transport properties in potassium-ion intercalated pristine Prussian blue for sustainable potassium-ion batteries

Potassium-ion batteries (PIBs) could be a cheaper and more abundant alternative to lithium-ion batteries, offering faster charging and suitability for large-scale energy storage. Prussian blue (PB) is prepared through a simple wet chemical method, and its intercalation affinity for K+ ions is tested using linear sweep voltammetry (LSV). The diffusion resistance (Rw: ∼116 Ω Hz1/2) and low-frequency region slope (m: ∼0.63) are found high for the third LSV drive (Seg-3), indicating passivation of the PB surface which leads to a double-layer formation. Most of the K+ ions are intercalated into PB until three LSV segments. After that PB surface is passivated and prohibits further LSV-driven K+ ions intercalation. On average, the Seg-3 sample exhibits a 58 % higher lattice strain in comparison to the as-prepared PB. A capacity of 27 mAh g−1 @ 2 mA g−1 in aqueous media is recorded for the Seg-3 sample and a capacity drop of 4 mAh g−1 and Coulombic efficiency of 99.3 % is recorded under 100 cycles. These findings are further comprehensively validated through multi-technique approaches. The observed affinity and single-stage LSV-driven intercalation of K+ ions highlight the perspective of PB as an electrode material for aqueous potassium ion batteries (a-PIBs).

Enhanced electrochemical stability and ion transfer rate: A polymer/ceramic composite electrolyte for high-performance all-solid-state lithium-sulfur batteries

All-solid-state (ASS) lithium-sulfur (LiS) batteries utilizing composite polymer electrolytes (CPEs) represent a promising avenue in the domain of electric vehicles and large-scale energy storage systems, leveraging the combined benefits of polymer electrolytes (PEs) and ceramic electrolytes (CEs). However, the inherent weak interface compatibility between PEs and CEs often leads to phase separation, thereby impeding the transposition of Li+. In this study, the trimethoxy-[3-(2-methoxyethoxy)propyl]silane (TM-MES) is introduced as a chemical agent to form bonds with polyethylene oxide (PEO) and Li10GeP2S12 (LGPS), resulting in the development of a novel composite polymer electrolyte (CPETM-MES). This innovative approach mitigates phase separation between PEs and CEs while concurrently enhancing the protective capabilities of LGPS against decomposition at the interfaces of both the Li anode and sulfur cathode. Moreover, the CPETM-MES exhibits superior mechanical toughness, an expanded electrochemical window, and elevated ionic conductivity. In the symmetric cell, it demonstrates an extended operational lifespan exceeding 1800 h, and the current density can reach up to 1.05 mA/cm2. Furthermore, the initial discharge capacity of ASS LiS batteries utilizing CPETM-MES attains 1227 mAh/g and maintains a capacity of 904 mAh/g after 100 cycles. Notably, a high-energy-density of 2454 Wh/kg is achieved based on the sulfur cathode.

A voltage-decoupled Zn-Br2 flow battery for large-scale energy storage

The flow battery represents a highly promising energy storage technology for the large-scale utilization of environmentally friendly renewable energy sources. However, the increasing discharge power of rechargeable battery results in a higher charge voltage due to its coupling relationship in charge-discharge processes, intensifying the burden of renewable energy power systems. Herein, we proposed a voltage-decoupled Na+-conducting Zn-Br2 flow battery (Ud-Na-ZBFB). Within a pH-regulation strategy, both neutral Zn/Zn2+ and alkaline Zn/Zn(OH)42− negative redox couples are integrated into one device, so as to increase discharge voltage a 0.5 V theoretical increase while remains a low charge voltage. The proof-of-concept Ud-Na-ZBFB demonstrates an unprecedented voltage characteristic, achieving a discharge voltage of up to 2.18 V while maintaining a remarkably low charge voltage of 1.78 V at a current density of 20 mA cm−2. Benefiting from the high discharge voltage, the peak power density of Ud-Na-ZBFB reaches 580 mW cm−2, nearly twice higher than the traditional ZBFB. Besides, the Ud-Na-ZBFB cycling operates for 45 h with excellent stability and resilience. With the “cycle-to-stage” operational mode, battery state of Ud-Na-ZBFB can be completely recovered after a long-term operation stage with several cycles, which electrolyte utilization efficiency of one stage is up to 41 %. This work offers a brand-new utilization pattern for high-power rechargeable battery that possesses a great potential in energy storage application scenes.

Research progress of aerogel used in lithium-ion power batteries

In recent years, with the rapid development of clean energy vehicles (i.e., electric vehicles and hybrid electric vehicles) and electrochemical energy storage stations, safety accidents have significantly increased. However, the abuse conditions such as overheating, overcharging, mechanical abuse, short circuits, etc., can result in thermal runaway of lithium-ion batteries (LIBs). Severe thermal runaway can lead to battery fire and even explosion, thereby threatening the safety of personnel. The application of a few aerogels to the thermal insulation layer between the cells of the lithium-ion battery modules can strengthen the safety of batteries. Among many aerogels, oxide aerogels show excellent insulation and high-temperature resistance. Therefore, aerogels, especially oxide aerogels, have aroused widespread research interest. This paper introduces the mechanism of thermal runaway of LIBs and systematically reviews several important oxide aerogels and the derived composites, especially those based on SiO2, Al2O3, and ZrO2 aerogels. The mechanical strength and high-temperature resistance of those aerogels are discussed. The application of aerogel in LIBs is also investigated in detail, and the all-around effect is caused by the introduction of aerogel materials. In addition, the thermal protection safety strategy of aerogel thermal insulation layers is proposed. It is supposed that this review could enable readers to deepen their understanding of this field.