Energy Storage最新文献

When discharging latent heat thermal energy storage (LHTES) systems, performance is influenced by the formation and adherence of a solid layer of phase change material (PCM) on heat eXchange (HX) surfaces. Super-liquid-repellent thin films (STFs) may be able to reduce solidifying PCM adhesion on HX surfaces during discharging, delay PCM solidification to lower temperatures, and by modifying nucleation sites potentially enable long-term seasonal thermal storage. Techniques employed previously to fabricate sintered polymeric STF coatings include chemical vapour deposition, dip-coating, spray-coating, spin-coating, layer-by-layer (LbL) assembly, sol-gel, anodizing, electrodeposition, electrospinning, so on. Dip-coating is considered attractive for fabricating thin films on simple and complex surface geometries due to process maturity, scalability, flexibility and cost-effectiveness. To identify suitable materials for preparing STFs on metal HX surfaces using the dip-coating process, more than 200 journal articles published in English during the period 2010 to 2022 were reviewed and the potential role of STFs in LHTES applications was assessed. The review identified key areas and applications stimulating STF material developments and formulations. The dip-coating of potential STF materials was classified under three major themes driving current research and development (R&D) activities, that is, high performance thin films, eco-friendly thin films and fundamental research formulations. This review provides a platform from which to develop coatings and HX systems to enable the cost-effective implementation of STFs for improved heat transfer in future mobile/stationery LHTES systems.

Sand production is a common issue in sandstone gas reservoir development, severely impacting the productivity of sandstone gas wells. In order to thoroughly investigate the sand production characteristics of high-temperature and high-pressure tight sandstone gas reservoirs, this study focuses on six core samples from tight sandstone gas reservoirs(three samples with fractures), under reservoir conditions (185 MPa, 160°C), sand production experiments were conducted to thoroughly investigate the sand production patterns in sandstone reservoirs under the combined influence of different effective stresses and production pressure differentials. The results indicate: (1) under the simultaneous increase of effective pressure and production pressure differential, sand production near the wellbore (r = 0.1 m) becomes more likely in the reservoir; (2) in actual reservoirs without fractures near the wellbore (r = 0.1 m), sand production phenomena do not occur; (3) reservoirs with fractures near the wellbore (r = 0.1 m) are more prone to sand production, under an effective stress of 90 MPa, with specimens containing fractures exhibiting a 76.48% lower critical sand production pressure gradient compared to those without fractures; (4) when the pore fluid pressure is 95 MPa, the maximum gas production rate for Well X without sand production is 12.4 × 10⁴ m³/d. The experimental results have guiding significance for the rational production of gas wells in this type of reservoir.

One of the primary types of sensible heat storage systems in drying applications is the packed rock bed. However, to create large-scale heat storage systems for industrial use, one must comprehend the hydrodynamic and effectiveness of the heat transport mechanism inside the bed. In this study, the thermal storage unit uses river rock as heat storage materials with equivalent particle diameters of 36 mm in bed 1 and 56 mm in bed 2. The rocks were stacked in a truncated cone-shaped concrete wall section with an average diameter and depth of 1.1 m and 1.3 m, respectively and a volume of 2.32 m³. During the charging phase, two airflow configurations were used, one from the top with an air mass flow rate of 0.753 and 0.332 kg/m²-s and the other from the bottom with an air mass flow rate of 0.955 kg/m²-s. During the discharging phase, the entire flow configuration is from the bottom section. It was observed that the mass flow rate and particle equivalent diameter had an important effect on the thermal performance and behaviour of the rock bed during charging and discharging operations. Maximum efficiency was achieved with an airflow configuration provided from the bottom when charging at 0.955 kg/m².s. Consequently, a sizable quantity of heat or energy (60 MJ) was retained. It was also observed that the relationship between air mass flow rate and particle size was significant, with smaller particles retaining more energy. When comparing bed 1 with bed 2 at this air mass flow rate, bed 1 stored 2.1 times more energy than bed 2. A wind tunnel experiment was used to measure the pressure drop in the packed rock bed. The pressure drop in the bed increases with an increase in particle Reynolds number and decreases with an increase in particle size. Rock bed heat transfer coefficient and Nusselt number were calculated using the correlation that has already been established in the literature smaller particles showed higher heat transfer coefficients and lower Nusselt numbers. This is due to the increase in particle-to-particle interaction and larger particle surface areas. For a given Reynolds number, the Nusselt number increases with the size of the rock particle.

In this research, a novel solar latent heat thermal energy storage (LHTES) system, including the cylindrical enclosures filled with a phase change material (PCM), is proposed, which can be installed on the building windows to alleviate the drawbacks of traditional PCM-filled double-glazed windows, such as daylight hindrance and leakage. The lattice Boltzmann method (LBM) is used to simulate the volumetric radiation-conduction melting of the PCM within a single cylinder of the proposed LHTES system with considering more realistic conditions such as convective boundary condition, shadow effect, and variable solar radiation angle compared with the available works in the literature. As such, several boundary conditions are assessed, and parameters such as cylinder diameter, extinction coefficient, scattering albedo, solar angle, shadow effect, and natural convection heat transfer coefficient are studied on the time history of the melting fraction and charging time. The results revealed that considering the applied conditions, such as convection heat loss to the environment and shadow, significantly affects the charging time of the system. It is shown that the charging time for convective boundary condition with $��h�=�4�$, $��8�$, and $��12��W��m^{�-�2�}��K^{�-�1�}�$ increases, respectively, by 11%, 30%, and 50% relative to a case with the insulated boundary condition without the shadow effect and 38%, 91%, and 175% compared with the insulated case with a 90° shadow.

The development of modern solid-state batteries with high energy density has provided the reliable and durable solution needed for over-the-air network connectivity devices. In this study, a NASICON-type Na₃Zr₂Si₂PO₁₂ (NZSP) ceramic filler was prepared using the sol-gel method and then a polymer-integrated solid electrolyte consisting of polyethylene oxide (PEO), NZSP, and sodium perborate (SPB) was prepared by Stokes' solution casting process. Through physico-chemical and electrochemical characterization techniques, the morphology, electrochemical, and thermal properties of the prepared solid electrolyte sample were carefully studied. The PEO/NZSP/SPB electrolyte developed for all-solid-state sodium-ion batteries (ASSSBs) exhibited a strong ionic conductivity, a large window for electrochemical stability, and was effective in controlling the growth of sodium dendrites. Furthermore, the polymer-integrated solid electrolyte showed impressive rate capability, high discharge capacity (73.2 mAh g⁻¹) at 0.1 mA cm⁻², and good faradaic efficiency (98%) even after 100 cycles. These results reveal that the PEO/NZSP/SPB electrolyte is a potential and inevitable candidate for the evolution of high-performance rechargeable ASSSBs.

For the first time, a simple one-step in situ chemical polymerization technique is used to create a novel molybdenum disulphide/sulphonated carbon quantum dots (CQDs) and polypyrrole (MCP) nanocomposite that is extended for successful use in charge storage supercapacitor (SC) device. By inheriting qualities of excellent electrical conductivity of MoS₂, CQDs and improved pseudocapacitive activity of polypyrrole (PPy), the MCP nanocomposite provides a suitable SC electrode material. 0.6 MCP nanocomposited three-electrode system demonstrates 93.21% retention after 5000 cycles, and a maximum specific capacity of 2253 F/g at 2 mV/s with higher side of energy density as 106.06 Wh/kg along with a considerable power density as 180.28 W/kg. Using MCP as anode and an AC or activated charcoal electrode as cathode, a solid-state asymmetric supercapacitor (ASC) was constructed. The fabricated device supplies a greater value of specific capacitance as 154.09 F/g at 100 mV/s and 175 F/g at 0.1 A/g, also evidenced superior energy density data as 126 Wh/kg along with an appreciable power density of 604.8 W/kg. After charging the ASC for 2 min, the light emitting diode shone for 5 min. The findings underpin that MCP is a potential electrode material that could be utilized as a better alternative in futuristic supercapacitor devices.

In this study, the thermal characterisation of natural rock samples from Zimbabwe for low-temperature industrial thermal energy storage (TES) applications was carried out. Thermal stability, specific heat capacity, thermal diffusivity, thermal conductivity and density were determined. Variations in these parameters were evaluated and their impact on thermal storage performance was analysed. Basalt and dolerite samples from different locations were found to have average specific heat capacities of 826 and 853 J/kg K, respectively, at room temperature. Insignificant variations were observed with differences of 3.4% for basalt and 1.7% for dolerite samples. Also, negligible differences of 0.3% and 0.7% in densities for rocks of the same type but of different origins were obtained for basalt and dolerite samples, respectively. However, significant variations in thermal diffusivity of all the igneous and metamorphic samples were observed with quartzite rock exhibiting the highest value of 2.1 × 10⁻⁶ m²/s, while the values for the other samples range from 0.9 × 10⁻⁶ to 1.6 × 10⁻⁶ m²/s. This implies that the thermal efficiency of sensible TES systems that use different or the same rock types from different locations can be significantly high to be overlooked. Thermo-gravimetric analysis results revealed that the rock samples studied have good thermal stability for low-temperature heat storage applications.

This work is the first attempt to explore the supercapacitor applications of Barium nickelate (BaNiO₃) perovskite nanoparticles. The nanoparticles are synthesized using a simple combustion method and their morphology, elemental composition, and so forth are studied using standard characterization methods such as x-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and so forth. The nanoparticles were found to be hexagonal in shape, with an average particle size of 16 nm, and the elemental analysis confirms the successful synthesis of the BaNiO₃ perovskite nanoparticles. For electrochemical studies, the electrodes are fabricated over a wearable and flexible conductive fabric (CF) substrate. A slurry paste of the synthesized BaNiO₃ nanoparticles is applied over CF and dried overnight, thereby forming a thin film electrode. The fabricated electrode acts as a positive electrode with a high specific capacitance of 508.64 F g⁻¹ at 2.2 A g⁻¹ current density. Upon increasing the current density, the electrode maintains 60% of its specific capacitance and displays 97% cyclic stability over 5000 cycles. The electrochemical impedance spectroscopy (EIS) study indicates excellent conductivity of the electrode, with a bulk resistance of 3.2 Ohms. The electrochemical performance of the fabricated electrode is also compared with various previously reported works and the electrode displays higher specific capacitance and better cyclic stability. These findings suggest that the BaNiO₃ perovskite nanoparticles-based electrode holds promise for utilization as an anode material in supercapacitor applications.

Doping of superfast ionic conductors like NASICON has been shown to boost ionic conductivity and the efficiency of lithium batteries. NASICON-type yttrium and silicon-doped lithium aluminum titanium phosphate (LATP) solid electrolytes have been synthesized via the conventional solid-state method at different sintering temperatures. Their intrinsic physical, chemical, and electrochemical properties are analyzed using x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. Yttrium and silicon co-doped LATP (LAYTSP) powder sintered at 900°C exhibits homogeneous hexagonal morphology and better crystallinity than the pure LATP solid electrolyte synthesized by the same methodology. LAYSTP demonstrated a higher ionic conductivity of 5.98 × 10⁻⁶ S/cm at ambient conditions. Mixing 5%-LiCl with LAYTSP-900°C improved the ionic conductivity significantly up to 1.88 × 10⁻⁴ S/cm. Cell viability testing demonstrated that our cells exhibit long-term stability and are suitable for applications requiring sustained high voltages.

In this study, nanostructures palladium was synthesized using an ultrasonic wave which is innovative, expeditious, and ecologically benign protocol. In the procedure, ultrasonic probe with 150 W was applied to an aqueous solution of Na₂PdCl₄ containing sodium citrate for 1 h at room temperature. The as-prepared palladium nanoparticles were characterized through deployment of XRD, TEM, EDX, and UV-Vis techniques. Moreover, the study extends to take the benefits from palladium nanoparticles to produce a novel carbon-based composite using graphene oxide (Pd-GO) which was characterized by XRD, TEM, EDX, and UV-Vis. The organic-inorganic nanohybrid (Pd-GO) was then applied in a systematic investigation aimed at assessing its ability to enhance the hydrogen storage properties of GO as nano-palladium was incorporated at a ratio of 1 Pd: 100 GO, yielding a significant enhancement (48%) in the storage capabilities of pure GO.