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Lithium–sulfur batteries with high energy density are considered to be one of the most promising candidates for the next‐generation energy storage devices. Electrolyte as the medium for Li+ transportation between the electrodes, also plays a crucial role in inhibiting the dissolution and diffusion of lithium polysulfides in Li–S batteries. The working mechanism of Li–S batteries in different electrolytes is classified into "solid‐liquid‐solid" and "solid‐solid" conversions. Under the "solid‐liquid‐solid" conversion, Li–S batteries would inevitably face the challenges such as "shuttle effect" that lead to poor cycle performance, and under the "solid‐solid" conversion, they would face interface mismatch that limits the utilization of sulfur with low energy density, while both conversion mechanisms cause uncontrollable Li dendrites on anode. According to the conversion mechanism, electrolytes can be divided into ether‐based, ionic liquid‐based, gel polymer electrolytes, and polymer‐based solid‐state electrolytes with "solid‐liquid‐solid" conversion, as well as carbonate‐based electrolytes and oxide/sulfide‐based solid‐state electrolytes with "solid‐solid" conversion. Based on the conversion mechanism of active materials in different electrolytes, the current status on the strategies from multiple perspectives are summarized to improve the electrochemical performance, with the hope to provide a comprehensive guideline toward the development of suitable electrolytes for Li–S batteries. [ABSTRACT FROM AUTHOR]

The functional 2-fluorobenzamide is introduced onto carboxylic multiwalled carbon nanotubes to craft sulfur hosting materials with precisely tailored functional interfaces for Li–S batteries. The semi-ionic C–F bonds and carbonyl functional groups present a synergistic strategy via Li···O and Li···F bonds for anchoring LiPSs, resulting in outstanding electrochemical performance of the sulfur cathode. [Display omitted] • The feasibility of cooperative trapping of lithium polysulfides is demonstrated by strategically designed organic molecules using density functional theory. • Based on theoretical guidance, a series of benzamide-based organic molecules with semi-ionic C-F bonds and carbonyl functional groups were grafted onto carbon nanotubes as sulfur host materials for Li–S batteries. • The semi-ionic C-F bonds and carbonyl functional groups in organic molecules present a synergistic strategy to anchor lithium polysulfides through Li···O and Li···F bonds, resulting in enhanced electrochemical performance. Lithium–sulfur (Li–S) batteries, with promising potential for high energy density, remain compelling candidates for next-generation energy storage systems. However, they still suffer from huge challenges such as severe shuttle effects and sluggish redox kinetics. A strategic approach involves the meticulous design of host materials at the molecular level, emphasizing the construction of efficient sulfiphilic organic molecules as anchoring sites for lithium polysulfides (LiPS). In this study, a series of benzamides (benzamide, 2-fluorobenzamide, and 2,6-difluorobenzamide) are introduced onto carboxylic multiwalled carbon nanotubes (C-CNT) to graft sulfur hosting materials with tailored functional interfaces for Li–S batteries. Through a comparative study, we identify the semi-ionic C−F bond and carbonyl functional group as active centers, presenting a synergistic strategy via Li···O and Li···F bonds for anchoring LiPS. The optimized cathode material of sulfur-based carbon nanotubes grafted with 2-fluorobenzamide exhibits outstanding electrochemical activity, achieving a high reversible capacity of 944.8 mAh/g under a high sulfur loading (5.5 mg cm−2) and low electrolyte usage (8 µL mg−1). Our study underscores the potential of tailoring the molecular structure of host materials to effectively immobilize LiPS for high-performance Li–S batteries. [ABSTRACT FROM AUTHOR]

The CaO/Ca(OH)2 thermochemical energy storage system can store heat through reversible reactions for long term and transport energy for long distance, and thus can solve the mismatching between energy supply and demand. In this study, a one-dimensional model is developed for the physical–chemical–thermal processes during the hydration reaction of CaO/Ca(OH)2 system in an indirect fixed bed reactor, and the corresponding governing equations are solved by the tridiagonal matrix method with self-developed program parallelized by Message Passing Interface. The characteristics and complicated coupling mechanisms of the vapor flow, heat transfer, mass transport and reaction processes are analyzed. Then effects of inlet pressure, convective heat transfer, reactant porosity, reactant permeability and reactor size on the reaction performance are discussed, respectively. It is found that higher inlet pressure, heat transfer coefficient, permeability and porosity can enhance the heat and mass transfer processes, thus accelerating the reaction efficiently. Finally, the reaction performance under different conditions is comprehensively evaluated by four indicators including the reaction time, average power, temperature plateau duration and standard deviation. [ABSTRACT FROM AUTHOR]

Due to environmental concerns, renewable energy sources (RESs) gradually replace conventional power generations. Over the past decade, wind and solar electricity generation have increased from 55 to 275 million MW·h and from 2 to 96 million MW·h, respectively, in the U.S. Recently, FERC order 2222 allows distributed energy resources, including distributed renewable generation and energy storage, to participate in the electricity wholesale market through aggregations. Limited rotating inertia of renewable generation resources results in reduced system inertia, which will increase the rate of change of frequency due to sudden mismatches of generation and demand. During the high visibility national social event, the brightness of LED TV display put simultaneous demand change in power systems. With the development of slim, tightly packaged, and yearly update features of smart TV, the penetration of different LED displays climbed rapidly from 9% to 60% in the U.S. during 2012–2019. In this article, the impact of societal events on frequency stability caused by large viewership on LED TVs are discussed. Increasing RESs penetration and FERC order 2222 are considered in this study. The power demand data of a 55-inch LED TV are collected and analyzed to address the problem. This article discusses the frequency stability issue caused by LED TVs in a low inertia power system. It can help system operators to develop frequency control practices accordingly. [ABSTRACT FROM AUTHOR]

The demand side management (DSM) has been conceived to improve the efficiency and flexibility of the power grids. Currently, different types of DSM programs, such as demand response, the efficiency of power delivery, heating, ventilation, and air conditioning (HVAC) improvements and distributed energy storage, have been developed and implemented by different utility companies. Since DSM is not a one-size-fit-all program, detailed consumers’ consumption data are required to both develop and improve effective DSM programs for different consumers. The rapid expansion of the advanced metering infrastructure in recent years has produced an enormous amount of data which can be utilized by utility companies for the DSM applications. Based upon the consumption characteristics of different types of consumers, various DSM programs can be developed and applied accordingly. This article analyzes and studies the practical smart meter data of commercial consumers from New York City considering the potential of commercial consumers’ participation for DSM applications, and it provides a better understanding of the power consumption pattern of commercial consumers in the urban area. Both utility companies and commercial consumers could benefit from this article to develop and participate in DSM programs, respectively. [ABSTRACT FROM AUTHOR]

• The petal-like NiFeCo-S@NiFeCo-TH ultrathin nanosheets were in situ synthesized on NIF. • The Co2+ exchange reaction plays a vital role in fabricating the ultrathin nanosheets. • The NiFeCo-S@NiFeCo-TH displays rich active sites and short mass diffusion path. • The self-supporting NiFeCo-S@NiFeCo-TH nanosheets show a high energy density. Rationally designing self-supporting heterogeneous nanostructured electrode materials is an effective strategy to enhance electrochemical performance and mechanical strength for asymmetric supercapacitors. Herein, we report a facile synthesis of the self-supporting petal-like NiFeCo-S (Sulfides) @NiFeCo-TH (Ternary Hydroxides) heterogeneous ultrathin nanosheets on nickel iron foam (NIF) using an innovative electro-oxidation, sulfuration and controllable Co2+ exchange process. Petal-like NiFeCo-S@NiFeCo-TH ultrathin nanosheets with the thickness of only 1.8 nm consist of Ni 2 S 3 , FeS, CoNi 2 S 4 , FeCoS 2 and NiFeCo hydroxides nanocrystallines to provide rich interfaces. The unique nanostructured NiFeCo-S@NiFeCo-TH lamellar hybrid delivers the high areal capacity (mass capacity) of 973 µAh cm−2 (174 mAh g−1) at a current density of 10 mA cm−2 and excellent rate capability of 68.3% at a high current density of 100 mA cm−2. More importantly, the assembled NiFeCo-S@NiFeCo-TH/NIF//AC all-solid-state ASC device exhibits a high energy density of 56.3 Wh kg−1 at a power density of 543 W kg−1 and the outstanding cycling stability of 90.1% capacity retention after 4000 charge-discharge cycles. This synthesis strategy exhibits wide application prospect in fabrication of the self-supporting transition metal nanostructured electrodes for energy storage and conversion. [ABSTRACT FROM AUTHOR]

• 3D model of indirect shell-tube reactor coupling physical–chemical-thermal process. • Interaction of reactive transport and heat transfer process of Ca(OH) 2 dehydration. • When HTF inlet velocity increases to 40 m⋅s−1, the reaction time reduced by 46.6%. • Adding tubes in by-pass region improves energy storage amount and reaction rate. • Five possible schemes are proposed to improve the reactor low η store. The Ca(OH) 2 /CaO system is a promising candidate for thermochemical energy storage because of its high energy density, low cost and negligible heat loss. Coupling mechanisms of multiple physiochemical processes still need further investigation and the system performance should be further improved. In this work, for the first time, a three-dimensional numerical model is developed to study the thermochemical energy storage process by Ca(OH) 2 dehydration reaction in a shell-tube reactor. The turbulent heat transfer fluid flow in the shell side, and the steam flow, heat transfer and dehydration reaction in the tube side are comprehensively taken into account. Effects of operation conditions and reactor geometry parameters on the dehydration process are also investigated in detail. Five indicators are proposed to comprehensively evaluate the reactor performance, including reaction time, energy storage density, heat exchange power, heat exchange efficiency and energy storage efficiency. The results reveal that higher inlet temperature and inlet velocity of heat transfer fluid can enhance the heat transfer and accelerate the reaction. Lower porosity, although increases the energy storage density, leads to higher flow resistance and impedes the reaction. With deep understanding of the physiochemical processes, 16 more tubes are properly added in the by-pass flow region, leading to shorter reaction time and higher energy storage amount. The low values of heat exchange efficiency and energy storage efficiency reveal that the input heat cannot be efficiently transferred to the tube side. To improve the energy conversion performance of reactor, additional schemes are discussed including regenerative HTF, optimization of reactor geometry, increase of reactant thermal conductivity, reducing tube-side flow resistance and extending HTF residence time. The numerical model and simulation results in the present work could be helpful for optimizing the shell-tube Ca(OH) 2 /CaO reactor and improving the thermochemical energy storage performance. [ABSTRACT FROM AUTHOR]