Efficient Energy Storage Research Articles

Cerium Metal-Organic Framework Composites for Supercapacitor Energy Storage

Supercapacitors have emerged as efficient energy storage devices, offering high power density, long cycle life, and rapid charge-discharge capabilities. Advanced materials such as carbon nanotubes (CNTs) and graphene oxide (GO) stand out due to their exceptional electrochemical properties, including open structures and chirality, with capacities ranging from 300 to 1300 mAh g-1. However, the search for cost-effective and highly conductive materials continues to challenge researchers. Metal-Organic Frameworks (MOFs) have surfaced as strong candidates due to their vast surface area, inherent conductivity, and affordability. Nonetheless, the relatively low conductivity of pristine MOFs necessitates composite integration for optimal performance. This review focuses on cerium-based MOF (Ce-MOF) composites, analyzing their structural and electrochemical properties. Key aspects, including synthesis methods, structural characterization, and electrochemical evaluation through cyclic voltammetry and galvanostatic charge-discharge techniques, are discussed in detail. The integration of functional composites into MOFs enhances cycling stability and minimizes capacitance loss over extended use. This review aims to inspire further research into Ce-MOF composites, underscoring their potential as high-performance materials for supercapacitor applications.

Superior Temperature Sensing and Capacitive Energy-Storage Performance in Pb-Free Ceramics.

The ultrafast charge/discharge rate and high power density (PD) endow lead-free dielectric energy storage ceramics (LDESCs) with enormous application potential in electric vehicles. However, their low energy storage density and single energy storage performance (ESP) limit their further development and applicability in rugged environments. Here, through the design of vacancy defects and phase structure regulation, Pb-free (Bi0.5Na0.5)TiO3-based ceramics with an optimal composition can achieve a large maximum polarization (>44 µC cm-2) under a moderate electric field (410kV cm-1), resulting in an extremely high recoverable energy storage density (≈6.14 J cm-3), nearly ideal energy storage efficiency (91.32%), a very short time (≈67ns) to release 90% of the energy, and a high PD (243.57 MW cm-3). More importantly, the energy storage capacities of these ceramics remain stable over a wide temperature range (25-220 °C) and for a wide range of fatigue cycles (1-106). Additionally, the real-time temperature sensing performance with high sensitivity (with a relative sensitivity of up to ≈0.04 K-1) in the ceramics is developed based on Yb3+ and Tm3+ codoping, which further supports the potential application of LDESCs to automotive batteries with a temperature monitoring function.

Trends and Emerging Themes in Thermal Energy Storage: A Bibliometric Study

Thermal energy storage (TES) systems play a pivotal role in the efficient integration of renewable energy sources into the global energy landscape. This bibliometric analysis delves into the evolving research landscape of TES systems, focusing on nearly 19000 scientific papers from the Scopus database as the primary source to identify key research trends, influential authors, and leading institutions shaping the field between 2000 and 2023. The analysis reveals a substantial surge in TES research over the past two decades due to factors such as advancing technology and increasing incentives. China has emerged as a global leader in this domain, followed closely by the United States and India. Xi'an Jiaotong University, De Lleida University, and Tsinghua University are the most prolific institutions in this field. The Journal of Energy Storage is the most frequently paper-published, followed by Applied Thermal Engineering and Applied Energy. Key research themes identified include the development, design, and optimization of heat storage systems, TES system integration with renewable energy sources, and the exploration of phase change materials for efficient energy storage. The analysis also highlights the contributions of prominent researchers in the field. Cabeza LF, Li Y, and Wang Y are identified as the most prolific authors, having made significant contributions to the advancement of TES technology. The increasing demand for sustainable and efficient energy solutions has spurred significant interest in TES systems. As the world transitions towards a low-carbon future, TES systems offer a promising solution for storing excess renewable energy and ensuring a reliable and sustainable energy supply.

Solid-State Battery Developments: A Cross-Sectional Patent Analysis

Solid-state batteries (SSBs) hold the potential to revolutionize energy storage systems by offering enhanced safety, higher energy density, and longer life cycles compared with conventional lithium-ion batteries. However, the widespread adoption of SSBs faces significant challenges, including low charge mobility, high internal resistance, mechanical degradation, and the use of unsustainable materials. These technical and manufacturing hurdles have hindered the large-scale commercialization of SSBs, which are crucial for applications such as electric vehicles, portable electronics, and renewable energy storage. This study systematically reviews the global SSB patent landscape using a cross-sectional bibliometric and thematic analysis to identify innovations addressing key technical challenges. The study classifies innovations into key problem and solution areas by meticulously examining 244 patents across multiple dimensions, including year, geographic distribution, inventor engagement, award latency, and technological focus. The analysis reveals significant advancements in electrolyte materials, electrode designs, and manufacturability. This research contributes a comprehensive analysis of the technological landscape, offering valuable insights into ongoing advancements and providing a roadmap for future research and development. This work will benefit researchers, industry professionals, and policymakers by highlighting the most promising areas for innovation, thereby accelerating the commercialization of SSBs, and supporting the transition toward more sustainable and efficient energy storage solutions.

Design of Chitin Partial Dissolution System for Construction of High‐Efficiency Energy Storage Porous Carbon

Chitin is a cost‐effective and abundant resource, enriched with nitrogen and oxygen elements, making it an ideal precursor for carbon‐based materials. However, traditional methods for preparing activated carbon from chitin often require substantial amounts of activators and complex carbonization processes, leading to suboptimal energy storage efficiency. This study presents a partial dissolution system achieved by modulating the mass ratio of chitin to activators (KOH and urea) and optimizing freeze‐thaw cycles. When chitin/KOH/urea is mixed at a 1:1:1.5 mass ratio and subjected to three freeze‐thaw cycles, the resulting porous carbon demonstrates a high specific surface area of 1783 m2 g−1 with significant N (4.75%) and O (11.16%) doping. The electrode achieves a specific capacitance of 309.1 F g−1 at 0.5 A g−1 in a three‐electrode system with 6 m KOH as the electrolyte. After 5000 charge–discharge cycles at 5 A g−1, the capacitance retention rate remains at 91.08%, indicating excellent cycling stability. When assembled into a symmetrical supercapacitor, it exhibits an energy density of 5.69 Wh kg−1 at a power density of 4996.1 W kg−1, demonstrating remarkable energy storage performance. This work introduces a novel method for preparing chitin‐derived porous carbon materials.

Innovative Approaches to Bridging Energy Supply and Demand Gaps Through Thermal Energy Storage: A Case Study

This study investigates innovative solutions for balancing energy supply and demand using long-term thermal energy storage (TES) systems, with a focus on tank thermal energy storage (TTES) for European buildings, which account for approximately 40% of energy consumption in the European Union. Research conducted at the Technical University of Košice explores the potential of TTES systems for efficient and long-term energy storage. The accumulation is carried out in three existing underground tanks of different volumes. Among various outputs, we present the cooling process resulting from covering the water surface and the effect of tank size on cooling. The findings indicate that covering the water surface in the tanks can effectively double the energy retention time, thereby extending the cooling period. A tank with a larger volume cools slower and better ensures the formation of temperature layers. Temperature layering allows for better utilization of the tanks’ potential in terms of energy. The overall result is a significant reduction in heat losses and CO₂ emissions. These results demonstrate the critical role of TTES in stabilizing renewable energy sources, especially solar energy, to support sustainable energy solutions in buildings by providing reliable and long-term energy storage.

Advanced characterization of confined electrochemical interfaces in electrochemical capacitors.

The advancement of high-performance fast-charging materials has significantly propelled progress in electrochemical capacitors (ECs). Electrochemical capacitors store charges at the nanoscale electrode material-electrolyte interface, where the charge storage and transport mechanisms are mediated by factors such as nanoconfinement, local electrode structure, surface properties and non-electrostatic ion-electrode interactions. This Review offers a comprehensive exploration of probing the confined electrochemical interface using advanced characterization techniques. Unlike classical two-dimensional (2D) planar interfaces, partial desolvation and image charges play crucial roles in effective charge storage under nanoconfinement in porous materials. This Review also highlights the potential of zero charge as a key design principle driving nanoscale ion fluxes and carbon-electrolyte interactions in materials such as 2D and three-dimensional (3D) porous carbons. These considerations are crucial for developing efficient and rapid energy storage solutions for a wide range of applications.

Enhanced energy storage performance of layered polymer composites with an ultralow loading rate of TNSs@PDA

Polymer-based dielectric nanocomposites have attracted much attention since they have advantages such as high power density and stability. The introduction of inorganic fillers is one of the strategies to enhance the discharge energy density (Ud) of polymer composite dielectrics. However, the negative coupling effect of relative dielectric permittivity (εr) and breakdown strength (Eb) is the key reason for the difficulty in achieving high energy storage density. In this work, polydopamine-modified titania nanosheet (TNSs@PDA) was fabricated, which has been used as fillers for monolayer TNSs@PDA/P(VDF-HFP) composites. The monolayer TNSs@PDA/P(VDF-HFP) composite with 0.2 wt% TNSs@PDA (0.2 wt% 1 L) has a low dielectric loss of 0.038 and its εr increased to 11.94 at 10 kHz, which corresponded to 129 % of that of P(VDF-HFP) (∼ 9.25). Additionally, the monolayer 0.2 wt% 1 L composite film was hot pressed with PEI and P(VDF-HFP) films to form a sandwich structure, which has a high Eb of 599.3 kV/mm, a high Ud of 9.97 J/cm3, a low dielectric loss of 0.025, and an energy storage efficiency of 82 %. This study provides an effective approach for designing polymer composites that combine high Ud with high energy storage efficiency.

Current Collectors for Supercapacitors: Objectives, Modification Methods and Challenges

AbstractSupercapacitors (SCs) have emerged as promising candidates for efficient and sustainable energy storage devices due to their unique merits, including high power density and long lifespan. However, despite these advantages, SCs face significant challenges related to their relatively low energy density. Current collectors are critical components of SCs, which significantly impacts the efficiency and overall performance by connecting active materials and external devices. However, the reviews on SCs are predominantly focused on electrode active materials or electrolyte materials, with insufficient comprehensive summaries regarding current collectors. This review focuses on the research progress related to current collectors in SCs. Firstly, the article outlines the modification objectives mechanism and inherent nature of SC current collectors. Building on this foundation, the authors further classify the current collector materials towards metallic, carbon‐based, polymers and other ones and highlights their modification strategies. Finally, the future development trends and challenges of SCs current collectors are comprehensively discussed.

Wood-based phase change energy storage composite material with reversible thermochromic properties

With the continuous increase in global energy demand and environmental challenges, the efficient utilization and storage of energy have become critical areas of scientific research. This study presents the preparation and performance assessment of a wood-based phase change composite (TPW) with reversible thermochromic properties. Thermogravimetric analysis (TG) confirmed thermal stability across 26 °C to 270 °C, while differential scanning calorimetry (DSC) demonstrated that TPW has good thermal cycling performance, and suitable phase change temperature at about 34 °C. Thermal insulation tests showed that TPW can reduce heat exchange between inside and outside environment, maintaining the internal temperature for longer time. Below the transition temperature, the material displays a bluish-purple color, transitioning to light yellow upon heating, with a notable color difference (ΔE⁎) increase from 3.46 to 67.89. Since the phase transition temperature close to human body temperature, enhances TPW’s compatibility for applications in home decor, temperature indicators, and anti-counterfeit labeling. This research contributes novel insights and foundational data for advancing wood-based functional materials in sustainable applications.

Leveraging Feature Sets and Machine Learning for Enhanced Energy Load Prediction: A Comparative Analysis

Accurate cooling consumption forecasts are crucial for optimizing energy management, storage, and overall efficiency in interconnected HVAC systems. Weather conditions, building characteristics, and operational parameters significantly impact prediction accuracy. Since meteorological conditions highly influence cooling demand, leveraging external air data and user metrics offers a promising approach to estimate a building's hourly cooling energy usage. This study addresses the gap in existing research by comprehensively analyzing the performance of various machine learning algorithms, including ensemble learning and deep learning models, to improve prediction accuracy. By leveraging weather conditions, building characteristics, and operational parameters, we aim to predict cooling consumption across multiple systems (Cooling Ceiling, Ventilation, Free Cooling, and Total Cooling). Data from four weather stations, encompassing diverse features relevant to the European Central Bank (ECB) building's cooling consumption in Frankfurt, were employed. Our methodology includes the use of K-Nearest Neighbor, Decision Tree, Support Vector Regression, Linear Regression, Random Forest, Gradient Boosting, XGBoost, Adaboost, Long-Short-Term Memory, and Gated Recurrent Unit. Models. The results consistently demonstrate the superiority of the Random Forest model across different weather stations and feature sets. This model achieved a Mean Squared Error of approximately 0.002-0.003, Mean Absolute Error of around 0.031-0.034, and Root Mean Squared Error of about 0.052-0.069. These findings contribute to improved building cooling load management, promoting insights into optimal energy utilization and sustainable building practices. Doi: 10.28991/ESJ-2024-08-06-01 Full Text: PDF

High-temperature (800 °C) performance of spodumene slag-based ternary sulphate composite phase change materials with improved mechanical property

The large deployment of electric vehicles leads to decarbonised road transport. However, the mining and smelting of lithium resources will continue to increase, which generates lithium slag and urgently needs to be recycled. The integration of spodumene slag with ternary sulphate presents a green and promising approach to achieve resource recycling and high-performance composite phase change material (CPCM). Herein, toughened and strengthened CPCMs are prepared by the hybrid sintering method with mechanical properties better than reinterned glass, even after high-temperature thermal cycling. After the cold compression and hot sintering process, the production of colloidal sodium silicate bonds the ternary sulphate with the spodumene slag skeleton, which greatly enhances the strength of the CPCM for efficient and durable thermal energy storage (TES). The Hydroxyl polar group of sodium silicate interacts with the skeleton and leads to a record-breaking compressive strength of 155.23 MPa, and the CPCM can support its stacking of 23.6 m and 15 kg loading test at 700 °C. A negligible mass loss of 0.26 wt% was observed after 50 thermal cycles at 800 °C. Moreover, the CPCMs exhibit a high TES density of up to 873.0 J/g in the temperature range of 100–800 °C. High charging and round-trip efficiency in the heat recovery process from spodumene roasting is also achieved, as it is 5 % and 19 % higher than the common magnesium bricks, respectively. The CPCM achieves high thermal efficiency TES, and it is the effective resource recycling of lithium slag with simple material preparation, which, from two angles at once, attacks the carbon emission from the life cycle of the lithium-ion battery.

Good Things In Store For Those Who Connect

Why a connected IoT infrastructure is going to be critical when it comes to creating an efficient battery energy storage system.

Hydropneumatic Storage Methodology Towards a New Era of Hybrid Energy System's Efficiency and Flexibility

This research explores the link between hydropneumatic energy storage capacity and the efficiency and flexibility of hybrid energy systems in water-energy solutions. A new methodology is introduced, featuring mathematical models, experimental data collection, and hydraulic simulations using 1D and 2D CFD models for hydropneumatics modeling. A promised energy storage efficiency of around 30-50% was obtained on a small lab scale. The optimization of hybrid systems through Solver and Python algorithms with various objective functions enables optimal design choices tailored to specific needs such as drinking water supply, irrigation, or industrial processes. Hydropneumatic vessels emerge as an effective storage solution, combining pumped storage and hydropower in one circuit. When integrated with renewable sources, such as solar (PV) and wind energy, they offer a flexible, long-lasting energy management system, applicable across different water-energy sectors to support Sustainable Development Goals. A case study with 4.8 Mm³/year water allocation, producing 1000 MWh of hydropower and 13500 MWh of solar energy, achieved 100% water reliability and a 25-year cash flow of 2.5 million euros.

Role of samarium doping in ZnSe electrode material with increased electrocapacitive properties for supercapacitor energy storage applications

Researchers have recently paid great attention to different transition metals-basedsupercapacitor electrode materials, which haveincreased interest due to their excellent energy storage applications. In this regard, electrodes based on samarium-doped materials have shown impressive promise for higher-performingsupercapacitors and energy-storing devices in many industries. In the present work, Sm-doped ZnSe electrode material was fabricated by using a simple hydrothermal method and then characterized structurally and morphologically by various physical characterizations. When prepared Sm-doped ZnSewasevaluated in three electrode configurations,then displayedan impressive specific capacitance(923.43F/g), high energy density (45.43 Wh/kg) along with power density (297.6 W/kg)at 1 A/g,higher as compared with ZnSe. According to EIS characterization small charge transfer resistance (0.10 Ω) of the doping material was calculated while chronoamperometry data showed that the fabricated electrode exhibited higher stability of 30 h. This work shows that doping of Smto ZnSeenhances energy storage efficiency and suggests great energy storage abilities in supercapacitors and other energy storage devices.

Three-dimensional allium flower-like iron-cobalt sulfide nanomaterials for high-performance supercapacitors

Supercapacitors with their improved performance in high energy density and long-term cycling stability have been the growing trend in recent years for fulfilling the demand of efficient energy storage systems. Herein, we report morphology-controlled three-dimensional (3D) Allium flower-like bimetallic iron-cobalt sulfide (3D-FeCoS AF) nanomaterials on nickel foam (NF) electrodes using a single-step electrochemical deposition strategy. The self-standing bimetallic 3D-FeCoS AF nanostructures show good performance towards the supercapacitance applications. The 3D-FeCoS AF nanostructures delivered a specific capacitance of ∼375.7 F g−1 at a current density of 1.0 A/g. The possible electron cloud delocalization among the FeS nanostructures through d-bands leads to the lower charge transport resistance at the 3D-FeCoS AF electrode–electrolyte interfaces and improved conductivity. The 3D-FeCoS AF electrode demonstrated excellent specific capacity and rate performance in a 2.0 M KOH electrolyte. Owing to their enormous electrochemical active surface area (ECSA) and distinctive 3D nanosheet morphology, the present 3D-FeCoS electrode holds great potential for the fabrication of additional transition metal sulfide materials for excellent supercapacitor performances. The findings of this study suggest promising prospects for the utilization of these materials in practical supercapacitance applications.

Sustainable supply chain management in U.S. healthcare: Strategies for reducing environmental impact without compromising access

The U.S. healthcare sector’s supply chain operations are responsible for about 8.5% of all national greenhouse gas (GHG) emissions. In healthcare, traditional supply chain management has focused on cost efficiency to the detriment of environmental considerations leading to higher emissions, waste, and resource depletion. The focus of this study is to investigate strategies for making sustainable supply chain management (SSCM) in the U.S. healthcare system, while reducing environmental impact at minimal cost to patient care quality. The objectives of the study are to evaluate the current state of healthcare supply chains, explore sustainable practices, evaluate emerging technologies, propose an SSCM implementation framework, and explore policy implications. Sustainable supply chain management can be achieved by forming the key strategies: comprehensive waste reduction and recycling programs, adoption of energy efficient transportation and storage solutions, green energy sourcing, and use of data driven inventory management that would help optimize inventory, along with other technologies like blockchain, IoT and artificial intelligence that could achieve transparency and efficiency. The research wouldn't go into specific case studies but would likely look at institutions that have already been able to implement these practices. The findings indicate that considerable environmental footprint reduction of the U.S. healthcare sector is possible without sacrificing access to high quality care through adoption of SSCM practices. But it requires joint efforts from policymakers, healthcare providers and industry partners. The long-term goal is a sustainable, resilient healthcare system that will integrate environmental stewardship with high quality care, that will help mitigate climate change and acknowledge the interdependence of environmental and human health.

Photocatalysis mediated removal of diclofenac potassium and energy storage efficiency of bismuth doped cerium tungstate

This work reports synthesis of bismuth doped cerium tungstate (Ce2-xBix(WO4)3 where; x = 0.00, 0.01, 0.03, 0.05, 0.07, 0.09) followed by its optical, structural, and morphological characterization. X-ray diffraction analysis showed the presence of a single monoclinic phase together with successful bismuth doping. Scherrer's equation revealed a decrease in crystallite size from 28 nm (x = 0) to 13 nm (x = 0.05), followed by an increased crystallite size at x ≥ 0.07. BET surface area measurements revealed highest surface area (53.7 m2/g) of Ce2-xBix(WO4)3 (x = 0.05) among all compositions greater than the surface area (3.5 m2/g) of undoped cerium tungstate. The photocatalytic potentials of as-synthesized materials against diclofenac potassium, were observed as follows: Ce2(WO4)3 < Ce1.91Bi0.09(WO4)3 < Ce1.93Bi0.07(WO4)3 < Ce1.99Bi0.01(WO4)3 < Ce1.97Bi0.03(WO4)3 < Ce1.95Bi0.05(WO4)3. Under optimized conditions, the degradation efficiency of Ce1.95Bi0.05(WO4)3 reached up to 89.2 % in 120 min together with excellent reusability of the photocatalyst upon consecutive five runs, ensuring its effective usage for wastewater treatment. Among different compositions, the maximum dielectric constant (3.7075× 105) was observed for Ce1.95Bi0.05(WO4)3, with a loss tangent of 0.494 at 20 Hz. In contrast, Ce1.93Bi0.07(WO4)3 and Ce1.91Bi0.09(WO4)3 exhibited relatively lower dielectric constants of 3.0499 × 105 and 2.8444 × 105, respectively, highlighting the importance of optimal dopant concentration for effective performance. These encouraging results suggest the multifunctional role of bismuth doped cerium tungstate in high frequency energy devices for efficient charge transmission as well as its effectiveness as a superb photocatalyst for removing persistent pollutants in water remediation.

Additive Fabrication of Polyaniline and Carbon-Based Composites for Energy Storage.

The growing demand for efficient energy storage systems, particularly in portable electronics and electric vehicles, has led to increased interest in supercapacitors, which offer high power density, rapid charge/discharge rates, and long cycle life. However, improving their energy density without compromising performance remains a challenge. In this study, we developed novel 3D-printed reduced graphene oxide (rGO) electrodes coated with polyaniline (PANI) to enhance their electrochemical properties. The rGO 3D-printed electrodes were fabricated using direct ink writing (DIW), which allowed precise control over thickness, ranging from 4 to 24 layers. A unique ink formulation was optimized for the printing process, consisting of rGO, cellulose acetate (CA) as a binder, and acetone as a solvent. The PANI coating was applied via chemical oxidative polymerization (COP) with up to five deposition cycles. Electrochemical testing, including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS), revealed that 12-layer electrodes with three PANI deposition cycles achieved the highest areal capacitance of 84.32 mF/cm2. While thicker electrodes (16 layers and beyond) experienced diminished performance due to ion diffusion limitations, the composite electrodes demonstrated excellent cycling stability, retaining over 80% of their initial capacitance after 1500 cycles. This work demonstrates the potential of 3D-printed PANI/rGO electrodes for scalable, high-performance supercapacitors with customizable architectures.

Enhanced photo-thermal conversion in phase change materials by Cu-Zn Bi-metallic metal-organic framework and expanded graphite

Photothermal phase change materials (PCM) are employed for the efficient conversion and storage of solar energy. In this work, a Cu-Zn bi-metallic metal-organic framework (MOF) was synthesized and combined with expanded graphite (EG), followed by high-temperature carbonization to prepare the supporting material for polyethylene glycol (PEG). Through the high-temperature carbonization process, nano-metallic copper is uniformly dispersed on the surface of the EG, accompanied by the formation of a new porous structure resulting from the evaporation of Zn vapour. The nano metallic copper particles enhance the thermal conductivity and photo-thermal conversion efficiency of the composite PCM, while the porous structure generated by Zn vapour improves the adsorption capacity of PEG. The composite PCM demonstrated a high phase change enthalpy of 174.6 J/g and excellent thermal reliability, with only a 2.29 % reduction in enthalpy after 200 melting-freezing cycles. Additionally, the thermal conductivity of the composite PCM reached 6.096 W/(m·K) which is 26.1 times higher than that of pure PEG, while the photo-thermal conversion efficiency achieved was 88.69 %. These properties indicate that the PEG/EG/Cu-Zn-MOF derived carbon composite PCM has great potential for applications in solar energy storage and conversion.