To tackle energy shortages and their uneven distribution, we propose a novel and advantageous coupled system that integrates Ca-looping thermochemical energy storage and pumped thermal electricity storage. In this system, charging is accomplished by using a heat pump to supply heat for the dehydration process, while discharging leverages the heat generated from hydration to produce electricity. This approach effectively eliminates thermal dissipation losses during storage, enabling long-term, large-scale energy storage. Our analysis highlights the impact of various operating parameters on cycle efficiency. Increasing the cycle pressure ratio during charging positively affects cycle efficiency but also increases a greater burden on the system, leading to diminishing marginal returns. The absorption temperature of the heat pump and dehydration temperature should be closely aligned to optimize performance. Minimizing the pinch temperature is crucial to enhance thermal energy utilization. During discharging, increasing the pressure ratio or aligning the intermediate pressure with the ideal value boosts the net power of the cycle, thereby enhancing cycle efficiency. Higher heat absorption temperatures of the generator and hydration temperatures, along with elevated storage temperatures of Ca(OH)₂, improve outcomes. However, the preheating temperatures of CaO and H₂O have a small impact. We employed the black-box concept, pinch analysis, and an improved genetic algorithm for optimization. This approach effectively controls exergy loss in the heat exchange network, achieving a maximum cycle efficiency of 65.96%. These results demonstrate the system competitiveness as a viable energy storage solution.

In recent decades, MgSO₄·7H₂O (epsomite) has attracted significant attention as a promising thermochemical-based thermal energy storage material due to its high theoretical energy density, wide availability, and affordability. Despite extensive research efforts, progress in achieving high-energy density has been limited, primarily due to inadequate understanding of its reaction mechanisms and unfavorable dehydration/hydration kinetics. This study systematically investigated the hydration/dehydration kinetics and cyclability of MgSO₄·7H₂O. The results reveal that the dehydration process is influenced by the heating rate, with an optimal rate of 5 ℃/min, resulting in a seven-step MgSO₄·7H₂O dehydration process with a dehydration heat close to the theoretical value. The reaction kinetic analysis indicated that the rate of hydration was approximately 50% lower than that of dehydration. In addition, thermal cycling tests of MgSO₄·7H₂O under the conditions of this study (small sample size) indicated good cyclability, with hydration rates increasing with increasing cycling numbers up to approximately 10 cycles where level-off occurs. These results are consistent with scanning electron microscopy analyses, which revealed the formation of cracks and channels in the salt hydrate particles, facilitating mass transfer and improved kinetics.

Zeolite adsorption heat storage technology offers several advantages, such as high energy storage density, low operating temperatures, and minimal heat loss during long-term storage, making it a promising solution for thermal energy applications in buildings. The thermal output performance of the reactor, a critical component of adsorption heat storage systems, is significantly influenced by its structural dimensions and operating conditions. However, the influence of the reactor design variables (structural parameters and operating conditions) on thermal output performance remains unclear, limiting effective optimization. In this study, a numerical model of an adsorption heat storage reactor was developed, and the thermal output optimization objectives were proposed. Sensitivity analysis was performed to evaluate the effects of the key design variables on the optimization objectives. The findings revealed that inlet air temperature and humidity significantly influenced outlet temperature, with absolute humidity being the main factor affecting heat release per unit volume. The airflow rate primarily affects the response time of the thermal output. Based on these findings, this study further examines the relationships between the design variables and optimization objectives, establishing the priority of the reactor's design variables. Therefore, a comprehensive design approach and process for heat storage reactors was proposed.

Calcium looping technology is increasingly recognized as a promising thermal chemical energy storage technology solution due to its high thermal storage density, cost-effective raw materials, and eco-friendliness. However, conventional modeling methods have limitations in terms of heat and mass transfer and the mechanical stability of porous structures. These limitations hinder the widespread adoption of calcium looping technology. This study innovatively introduces a hierarchically porous structure modeling approach to successfully develop a CaO-based thermal energy storage module with a hierarchically porous structure, excellent cycling stability, and robust mechanical characteristics by combining foaming technology and a template sacrifice method, as well as the incorporation of polyvinyl pyrrolidone as a binder. The experimental results indicate that the thermal energy storage module exhibits a large-span porous structure ranging from 60 nm to 1.2 mm, effectively integrating the material and structural design. The self-supporting structure eliminates the problem of reduced energy storage density caused by the introduction of inert support materials. After 100 cycles of stability and compressive strength tests, the thermal energy storage module maintained its structural integrity with an energy storage density of 1094 kJ/kg and compressive strength of 0.31 MPa. Furthermore, the synthesis strategy of the proposed thermal energy storage module is simple and efficient, avoiding complex procedures and reliance on expensive equipment, making it suitable for large-scale industrial production. This study offers novel insights and solutions for using calcium looping technology in the field of thermal chemical energy storage, with the potential to advance its development and commercialization.

The combined Ca/Cu thermochemical energy storage process provides an efficient method for storing and releasing hydrogen through simple gas-solid reactions, demonstrating strong industrial potential. Despite its broad application prospects, the carbonation performance of Ca/Cu composites tends to decay over extended cycling. To address this issue, we investigated the effect of support modification on the thermochemical energy storage characteristics of Ca/Cu composites. Experimental results indicated that Ca/Cu composites modified with ZrO₂ using the Pechini method outperformed those prepared via solution combustion synthesis, co-precipitation, and wet mixing. These ZrO₂-modified composites achieved a carbonation conversion of 67.4% in the first cycle, which only slightly dropped to 64.4% after 10 cycles, retaining 96% of their original efficiency. Adding CeO₂, MgO, or ZnO as secondary support to ZrO₂-modified Ca/Cu composites significantly enhanced the carbonation performance. Notably, Ca/Cu composites co-modified with ZrO₂ and MgO demonstrated the highest performance. With 5% of ZrO₂ and MgO, these composites maintained an average carbonation conversion rate of 74.9% over 10 cycles, which is 15.4% higher than composites modified with ZrO₂. In conclusion, the Ca/Cu composites synthesized in this study are highly significant for the practical application of the combined Ca/Cu thermochemical energy storage process.

A charging/discharging model of a two-dimensional porous medium MgSO₄·7H₂O/MgSO₄ was developed using reaction kinetics to investigate the energy storage characteristics of MgSO₄ as a thermochemical material. This study examined the reaction rate, temperature distribution, and water vapor concentration distribution during heat and mass transfer in charging/discharging units. This study also examined the influence of inlet air temperature (T_in) and inlet air velocity (U_in) on unit performance and thermal efficiency. The results indicate that during the charging process, heat storage increases by approximately 3.13% for every 10 ℃ increase in T_in and by approximately 0.97% for every 0.125 m/s increase in U_in. An increase in T_in accelerates the rate of unit heat transfer and enables the water vapor pressure to reach equilibrium faster, subsequently increasing the reaction rate. Similarly, an increase in U_in enhances the water vapor transport rate and improves the convective heat transfer within the unit, thereby enhancing the kinetic properties and increasing the reaction rate, which leads to an increase in the heat storage capacity. Conversely, during the discharge process, the unit thermal efficiency exhibited an inverse relationship with heat storage capacity. The thermal efficiency decreased by approximately 0.93% for every 2.5 ℃ increase in T_in, whereas heat storage decreased by approximately 0.58% for every 0.1 m/s increase in U_in. An increase in T_in increases the equilibrium pressure of the unit and decreases its unit reaction rate, thereby reducing the effect of temperature rise of the unit. Furthermore, an increase in U_in increases the rate of water vapor transport and convective heat transfer of the unit, which subsequently increases the water vapor pressure. Ultimately, the reaction rate and thermal efficiency decreased. This study offers a theoretical foundation and practical reference for understanding the thermochemical energy storage characteristics of MgSO₄.

Cu/Ca-based thermochemical energy storage presents a novel hydrogen storage method that effectively addresses excess power consumption. However, the effectiveness of Cu/Ca composites in carbonation decreases significantly after multiple cycles, limiting their practical use. To address this issue, we employed a stabilizer modification method to improve the performance of Cu/Ca composites. First, Cu/Ca composites were prepared using the Pechini method and stabilized with different stabilizers, then evaluated in a triple-packed-bed reactor. Experimental results showed that composites modified with stabilizers maintained excellent oxidation properties over 10 cycles, with oxidation conversions consistently above 90%. Among the stabilizers tested, Y₂O₃ significantly improved the carbonation conversion of the composites compared to CeO₂ and MgO. Specifically, the 5Y-Cu-Ca composite, with a Y₂O₃/CaO/CuO molar ratio of 5∶47.5∶47.5, displayed an initial carbonation conversion of 74.6%, which decreased to 54.1% after 10 cycles. To further improve the carbonation performance of Y₂O₃-stabilized Cu/Ca composites, we adopted a dual-stabilization strategy by incorporating ZrO₂ as a second carrier and co-doping it with Y₂O₃. The most effective Y₂O₃/ZrO₂-stabilized Cu/Ca composites, with a molar ratio of 2∶1, achieved an initial carbonation conversion of 81.6%, dropping to 70.5% after 10 cycles, retaining 86% of its initial activity. In summary, the Cu/Ca composites developed in this study hold great potential for the practical application of Cu/Ca-based thermochemical energy storage technology.

Phase-change materials (PCMs) are environmentally friendly energy storage materials extensively used in thermal storage. However, their thermal conductivity is poor, and metal skeletons are usually added to improve the thermal storage efficiency of PCMs. To explore the influence of the anisotropy of the skeleton on the phase-change process of porous medium-composite materials during thermal storage, the triply periodic minimal surface (TPMS) method with good biomimetic effect is used to establish the Gyroid skeleton and anisotropic Gyroid skeleton composite materials with PCMs. The anisotropic Gyroid skeletons in three directions and the Gyroid skeleton are compared. Based on the lattice Boltzmann method, the solid-liquid phase-change process of four operating conditions is studied at the pore scale. The results show that the anisotropic Gyroid skeleton in a specific orientation enhances the heat exchange capacity of PCMs more than the Gyroid skeleton. It improves the thermal conductivity of the framework and has a smaller inhibitory effect on the natural convection within the cavity. The melting time of operating condition 2 of the anisotropic Gyroid skeleton is 14% shorter than that of the Gyroid skeleton. The temperature increase rate within the cavity is faster. At Fo=0.06, the area above the phase-change termination temperature at the cut line is approximately 16% more than that of the Gyroid skeleton, the inhibition effect on the fluid flow is smaller, and the peak velocity at the designated cut line is 13.5% higher than that of the Gyroid skeleton. The anisotropic Gyroid skeleton composite material constructed in this study enhances the heat storage rate of composite PCMs without changing the porosity, providing a theoretical basis for designing the TPMS skeleton.

Carnot batteries use thermodynamic cycles to convert and store electrical energy as thermal energy, which can be effectively integrated with industrial waste heat to facilitate a coordinated supply of cooling, heat, and electricity. This approach enhances the integration of renewable energy sources. This study investigates the thermodynamic properties of Carnot batteries, coupled with shell-and-tube thermal energy storage systems based on phase-change heat storage. We thoroughly analyzed the thermodynamic properties of the battery, considering factors such as temperature variations between the heat transfer fluid and the energy storage medium, the cumulative heat storage and release process, and the overall heat capacity. In addition, we performed a dimensionless analysis of the established two-dimensional transient model to improve the generalizability of the results. Results indicate that after the charging cycle, the outlet temperature can reach 0.83. The maximum and average power of the device were calculated as 1860 W and 624.7 W, respectively. Based on the second law of thermodynamics, it can be inferred that the stored exergy decreases sequentially along the flow direction, primarily due to the significant amount of exergy stored in the inlet PCM, with the amount of exergy released by the storage unit approaching 0 at the discharge time, t*=0.93.

Pumped thermal electricity storage (PTES) based on the subcritical organic Rankine cycle (ORC) realizes the electricity storage function through the heat pump cycle, heat storage-release process, and ORC process. PTES operates in a low-temperature zone and can use a low-temperature heat source to improve the roundtrip energy storage efficiency. This paper further studies the dynamic performance of the PTES based on subcritical ORC by building an experimental platform of the system and performing experiments and performance analysis of the entire charging-discharging cycle under the conditions of heat sources at 80 ℃ and 90 ℃. The results show that the system storage efficiency cycle increases from 21.8% to 46.1% when the low-temperature heat source increases from 80 ℃ to 90 ℃. Increasing the temperature of the heat source can significantly improve the storage efficiency cycle. Due to the unsteady state of the heat transfer characteristics of the storage-release process, the operating parameters change over time during the system charging-discharging cycle. Under the heat source condition of 90 ℃, the charging process lasts for 3120 seconds, the average coefficient of performance (COP) of the heat pump cycle is 6.27, and the compressor power grows from 1.3 kW to 3.7 kW. The discharge time is 980 seconds, and the net discharge power decreases from 5.3 kW to 1.8 kW, with an average ORC efficiency of 8%. Under the heat source condition of 80 ℃, the charging process lasts for 6480 seconds, the average COP of the heat pump cycle is 5.44, and the compressor power grows from 1.6 kW to 3.6 kW. The discharge time is 1080 seconds, and the net discharge power decreases from 4.7 kW to 2.8 kW, with an average ORC efficiency of 7.9%.

The low thermal conductivity of phase-change materials (PCMs) limits the heat transfer efficiency of phase-change energy storage systems. The problem of the low thermal conductivity of paraffin was addressed by preparing a series of nano-carbon-based composite PCMs (CPCMs) with different nano-carbon mass concentrations using a two-step method using paraffin as the substrate material and carboxylated multi-walled carbon nanotubes (MWCNT) and carbon nano-onions (CNOs) as high-thermal-conductivity media. The effects of adding the two nano-materials on the phase transition temperature, latent heat of fusion, thermal conductivity, and kinematic viscosity of CPCMs were investigated. It was found that adding nano-carbon materials had a negligible effect on the phase transition temperature, and the maximum temperature deviation was 1.811 ℃. However, the latent heat of fusion decreased with the increasing mass concentration of nanoparticles. The maximum reduction in the latent heat of fusion was 16.4%, with a mass CNO fraction of 4%. The increasing nano-carbon concentration increased the thermal conductivity and the kinematic viscosity of liquid CPCMs. The thermal conductivity of 4% CNO-PCM in liquid and solid state was 0.3167 W/(m·K) and 0.8322 W/(m·K), respectively, with the most significant increase in thermal conductivity of 80.7% and 195.9%, respectively. Compared with MWCNT, using CNOs was more conducive to enhancing the PCM thermal conductivity. This study provides an experimental basis for developing composite paraffin PCMs with high thermal conductivity and a reference for selecting CPCMs for different demands.

The metal honeycomb-enhanced phase-change energy storage system is an advanced technology for improving latent heat storage efficiency. To study its melting heat storage performance, a circulating water heating system was designed to provide a stable and uniform heat source. Subsequently, a heat storage test of enhanced phase-change materials was conducted at constant temperature, and the transfer and melting boundary evolution characteristics were obtained. The experimental results show that the metal honeycomb affects the melting heat storage efficiency in three ways: it improves thermal conductivity, weakens natural convection, and alters melting heat storage patterns. The effect of the metal honeycomb was quantified by establishing a fluid-solid-thermal coupling calculation model for melting heat storage. The calculation results indicate that the high thermal conductivity channel constructed by a 5 × 5 metal honeycomb can increase thermal conductivity by 39.7 times and reduce the natural heat transfer effect of the liquid phase to 19.1%, with an overall increase in the melting heat storage efficiency of 67.1%. The increase in the heat storage rate is primarily concentrated in the 0 < f < 0.5 stage, whereas the average heat storage rate in the 0.5 < f < 1 stage closely aligns with that of pure PCMs. Under the competition between heat conduction and natural convection heat transfer, the melting heat storage efficiency first decreases and then increases as the cell number increases, with the 3 × 3 honeycomb structure exhibiting the lowest heat storage efficiency. When the number of cells ranges from 1 × 1 to 3 × 3, natural convection in the liquid phase dominates heat transfer. However, when the number of cells exceeds 3 × 3, the heat conduction of the metal honeycomb dominates heat transfer.

The rapid development of renewable energy technologies and improvements in deep load adjustment and frequency regulation in thermal power systems have placed higher demands on the operating temperature range and thermophysical properties of molten salt storage materials. MgCl₂-NaCl-KCl (MgNaK) molten salt stands out among the potential candidates. However, complete thermophysical property data for MgNaK molten salt is lacking. In this study, we developed a machine learning potential function to accurately describe the microscopic particle interactions in MgNaK molten salt (with a composition of 45.4% mol MgCl₂, 33% mol NaCl, and 21.6% mol KCl). This model is based on energy and atomic force information obtained from first-principles molecular dynamics (FPMD) simulations. The reliability of this machine learning potential function was validated by comparing the partial radial distribution function (PRDF) and coordination number (CN) with FPMD results, showing excellent agreement. We explored how the local structure and thermal properties of MgNaK vary with temperature from atomic and electronic perspectives. The introduction of Na{}^{+} or K{}^{+} ions disrupts the tightly connected MgCl _x network structure, thereby affecting transportation properties. The density (ρ) and constant-pressure specific heat capacity (C_p ) obtained from machine learning potential function simulations were found to closely match the experimental data, with deviations of less than 2%. Furthermore, we examined the thermal conductivity (λ) of MgNaK molten salt using kinetic theory, we examined a negative linear correlation with temperature, which aligns with observations in other chloride molten salts. Based on molecular simulations and experimental measurements, we provide recommended values for λ and viscosity (η) of MgNaK molten salt across the entire operating temperature range.

With the rapid development of renewable energy, the importance of thermal energy storage systems in modern power systems has become increasingly prominent. To enhance their operational efficiency and economic viability, performance evaluation and optimization strategies based on big data analysis have become a research focus. This paper systematically explores the components and operating principles of thermal energy storage systems, analyzes the current application status of big data technology in the thermal energy storage field, and proposes a series of methods for performance evaluation and optimization.

To effectively recover low-temperature waste heat resource in the steel industry, we have integrated the low-temperature sinter cooling flue gas waste heat as a heat source in a pumped thermal energy storage (PTES) system. We constructed thermodynamic calculation models for basic PTES (B-PTES) and regenerative PTES (R-PTES) systems. The R365mfc was selected as the cycle working medium of heat pump (HP), while the R1233zd(E), R245ca and R236ea were set as the working mediums for the organic Rankine cycle (ORC). Our study examined how the HP condensation and evaporation temperatures, as well as the ORC evaporation temperature, affect the thermodynamic performance of B-PTES and R-PTES systems under different ORC working medium conditions. The results show that reducing the HP condensation temperature and increasing the evaporation temperatures of HP and ORC can improve the heating coefficient (COP_new) and power efficiency (η_ptp) of the PTES system. However, higher HP condensation temperatures, lower HP evaporation temperatures, and lower ORC evaporation temperatures decrease the system's exergy efficiency (η_ex). For identical thermodynamic parameters, the R-PTES system consistently outperforms the B-PTES system in terms of COP_new, η_ptp, and η_ex. Evaluating the overall performance, the B-PTES system achieves optimal results with R1233zd(E) as the ORC medium, followed by R245ca and R236ea. Conversely, the R-PTES system performs best with R245ca, followed by R1233zd(E) and R236ea. Specifically, when using R245ca as the ORC working medium, increasing the HP condensation temperature by 2℃ results in an average η_ex decrease of 0.5% for B-PTES and 0.53% for R-PTES. Conversely, raising the HP evaporation temperature by 2℃ leads to an average η_ex increase of 0.2% for B-PTES and 0.21% for R-PTES. Furthermore, a 2℃ in ORC evaporation temperature results in an average η_ex improvement of 0.55% for B-PTES and 0.63% for R-PTES. Overall, for systems driven by low-temperature sinter flue gas waste heat, the R-PTES system is recommended, particularly using R245ca as the cycle working medium of the ORC system.

Thermochemical energy storage using hydrated salts offers high energy density and minimal thermal losses over extended storage periods, making it a viable solution for balancing supply and demand in solar energy applications for buildings. The performance of thermal storage reactors using salt hydrates is heavily influenced by their operational conditions and structural design. However, most studies have analyzed single factors, providing limited understanding of reactor performance under multifactor interactions. To address this gap, we developed and experimentally validated a dynamic simulation model for a thermal storage reactor with salt hydrates. The model demonstrated high accuracy, achieving mean absolute errors and maximum absolute errors of 1.55 ℃ and 1.57 ℃, and 7.68 ℃ and 3.35 ℃, for desorption and adsorption outlet temperatures, respectively. Using this model, we conducted systematic analyses of how inlet temperature, inlet relative humidity, mass flow rate, and reactor volume influence reactor performance. In addition, multiple linear regression was applied to evaluate the impacts of multifactor interactions on reactor performance. The results indicated that inlet temperature is the primary factor influencing both the maximum temperature rise during desorption and the reaction time, with influence coefficients of 0.497 and -3.04, respectively. For adsorption reactions, inlet relative humidity had the most significant impact, with higher humidity boosting the maximum temperature rise and shortening reaction time. Furthermore, the combined influence of temperature and humidity exerted the greatest impact on reactions than their individual effects, particularly on reaction time. Finally, the combined effects of temperature, humidity, and reactor volume demonstrated a pronounced impact on the adsorption reaction time, with an influence coefficient of 0.0959, which was 7—240 times greater than that of various other combinations.

With the increasingly severe global energy crisis and environmental pollution problems, new energy and low-carbon technologies have become one of the key ways to solve these problems. As an important component of new energy transportation, electric vehicles have shown great potential in improving energy utilization efficiency and reducing carbon emissions through their electric thermal phase change energy storage systems. This article is based on the low-carbon background of new energy, and conducts an in-depth analysis of the thermal storage performance of electric vehicle electric thermal phase change energy storage systems. It explores the working principle of the system, dynamic thermal storage performance optimization methods, material characteristics, thermal storage efficiency and stability, as well as future research directions for related industry technologies. Through theoretical analysis and experimental verification, this article aims to provide reference for the further development of electric vehicle electric thermal phase change energy storage systems.

Solar collectors are frequently challenged by their inherent intermittency and seasonality. However, phase-change materials (PCMs) are considered a highly promising energy carrier due to their excellent thermal storage density and constant phase-change characteristics, providing a new research direction for enhancing collector stability. This paper presents the energy and exergy analysis methods for integrating phase change thermal storage technology with solar collectors and derives performance evaluation and economic analysis indicators for integrated collectors. It also summarizes that the packaging methods for PCMs in integrated collectors primarily include geometric and integral packaging, and different types of collectors use different packaging methods. Second, the paper discusses the impact of integrating PCMs on the performance and economic benefits of flat plate collectors, vacuum tube collectors, and photovoltaic/thermal collectors. It summarizes the primary technologies for optimizing the performance of integrated collectors, including increasing the heat transfer area by adding fins, enhancing the thermal conductivity of PCMs, and improving the heat transfer efficiency using micro-heat pipe technology. Finally, the impact of integrated PCMs on the comprehensive performance and economic feasibility of solar collectors was summarized. The optimization and research direction of integrated collectors were prospected to enhance their practical applicability and contribute to the efficient use of renewable energy.

With the depletion of fossil fuels and environmental concerns, integrating concentrated solar power (CSP) technology with thermal energy storage (TES) has become essential for efficient solar energy utilization. Molten salts are commonly used as heat storage materials, particularly at medium to high temperatures. Among these, MgCl₂-NaCl-KCl ternary chloride molten salt has been identified as a most promising candidate for next-generation storage systems operating above 700 ℃ thanks to its excellent thermophysical properties, high thermal stability, and low cost. The thermophysical properties of molten salts, such as melting point, specific heat capacity, density, and thermal conductivity, are crucial for the design and optimization of heat storage systems. However, the strong corrosiveness of chloride molten salts towards metallic materials is a major safety concern. To address the current challenges of the MgCl₂-NaCl-KCl molten salt, particularly in obtaining thermophysical property parameters and addressing corrosion issues, recent studies have been reviewed. These studies focus on experimental and simulation approaches to determine the thermophysical properties of the MgCl₂-NaCl-KCl molten salt. Moreover, the corrosion mechanisms affecting common nickel-based and iron-based alloys exposed to this molten salt have been explored based on existing research. Corrosion mitigation strategies are discussed from three aspects: reducing the corrosiveness of the molten salt, improving the corrosion resistance of metallic materials, and implementing corrosion monitoring systems. Finally, the current research status is summarized, and future development directions are proposed.

Thermochemical energy storage (TCES) is particularly suitable for long-term thermal energy storage due to the advantages of high energy storage density and low heat loss. This paper reviews thermochemical energy storage materials based on sorption, focusing on materials in the low to medium temperature range, including physical adsorption materials (e.g. silica gel and zeolite) and chemical sorption materials (e.g. salt hydrate). Firstly, the properties of physical adsorption materials are summarised and their use in applications is analysed. For salt hydrate-based chemical sorption materials, their reaction conditions, energy storage densities and hydration properties are described. Then, the preparation of composite material by loading salt hydrates onto porous supports is introduced and highlighted, aiming to overcome the challenges of agglomeration and deliquescence in practical applications. Meanwhile, the design of thermochemical reactors has been reviewed. The characteristics and performance of fixed bed and moving bed reactors were also compared, and further suggestions for improving heat and mass transfer were discussed. An analysis of open and closed systems was also summarised in terms of advantages and disadvantages. Further discussions on the performance of each type of system including energy efficiency, performance and system design ideas to meet different application requirements are proposed. A techno-economic analysis of thermochemical heat storage is also carried out to assess the commercialisation potential of various systems. Finally, future research directions to improve the performance and reduce the cost of adsorption-based thermochemical systems are outlined.

Thermal energy storage (TES) technology is crucial for balancing fluctuations in renewable energy sources, improving energy efficiency and increasing the flexibility of energy systems. This article highlights key insights from the "China Thermal Energy Storage Industry Development Report (2024)," providing a comprehensive overview of China's thermal energy storage industry. It focuses on the current state of thermal storage technology, its development, and notable demonstrations within the industry. The article also covers three main types of thermal energy storage technologies: sensible, latent, and thermochemical. Each technology is characterized by its characteristics and suitable applications, along with key parameters such as heat storage capacity and stability. The market scale, development trends, and relevant policies affecting the thermal storage industry are summarized. The article also emphasizes typical demonstrations of TES technology across various sectors, including buildings, district heating and cooling, power sector, and industrial processes. These examples showcase the practical applications and effectiveness of TES technology, offering valuable insights and experiences for industry promotion.

The application of big data and artificial intelligence has brought new research paths for the technological development of chemical energy storage heating systems. This article provides an overview and analysis of the optimization of big data and artificial intelligence technologies in the upgrading and configuration scheduling of heating system software and hardware. It has been proven that big data and artificial intelligence have brought technological innovation and optimization to the refined management and intelligent decision-making of chemical energy storage heating systems. In terms of operational processes, big data technology can ensure intelligence, convenience, and accuracy in data transmission, processing, and decision analysis; In terms of system architecture design, big data and artificial intelligence technologies have also brought optimization and upgrading to chemical energy storage heating systems, not only improving the data transmission efficiency of sensor networks, but also providing various logical model algorithms to achieve intelligent decision-making optimization.