Asymmetric supercapacitor comprising a core-shell TiNb2O7@MoS2/C anode and a high voltage ionogel electrolyte

A high peak demand causes the escalating cost of electricity costs for both the utility and end-users. This paper investigates the challenges raised by the high peak demand and the state-of-the-art technologies adopted to reduce the peak demand. The peak shaving technologies can be categorized into four groups. The first category is peaking power plants which include the open-cycle gas turbine (OCGT) power plants and hydroelectric power plants. The second category is the energy storage system (ESS) comprising of the pump hydro storage (PHS), compressed air energy storage (CAES), battery energy storage (BES), flywheel energy storage, thermal energy storage (TES) and hydrogen fuel cell. The third category is the hybrid renewable energy – storage system (HREES) that combines the renewable energy (RE) and energy storage system. The fourth category is the demand-side management (DSM. The advantages and shortfalls of these technologies are highlighted in this paper.

Information/Communication Technologies (ICT) and control has been focal research areas contributing in grid modernization. It enabled the concept of home energy automation solutions by providing control to home assets according to local renewable energy generation and storage systems, providing decentralized control for smart homes also termed as prosumers energy systems. To attain such controls, efficient Demand Side Management (DSM) and Demand Response (DR) approaches are required in energy prosumer units. This paper investigate these efficient approaches by deploying price based DSM as real time Genetic Algorithm based optimal load scheduler. It provides real time control to home appliances according to grid price, renewable energy generation and local energy storage. To develop optimal load scheduler Model Centric Development (MCD) approach is used and simulation environment is established using simulator coupling.

A microgrid (MG) is a discrete energy system consisting of an interconnection of distributed energy sources and loads capable of operating in parallel with or independently from the main power grid. The microgrid concept integrated with renewable energy generation and energy storage systems has gained significant interest recently, triggered by increasing demand for clean, efficient, secure, reliable and sustainable heat and electricity. However, the concept of efficient integration of energy storage systems faces many challenges (e.g., charging, discharging, safety, size, cost, reliability and overall management). Additionally, proper implementation and justification of these technologies in MGs cannot be done without energy management systems, which control various aspects of power management and operation of energy storage systems in microgrids. This review discusses different energy storage technologies that can have high penetration and integration in microgrids. Moreover, their working operations and characteristics are discussed. An overview of the controls of energy management systems for microgrids with distributed energy storage systems is also included in the scope of this review.

The increasing need for energy, the widespread adoption of electric vehicles and renewable energy storage systems, and the search for cost-effective, reliable energy storage options are all factors in the dynamic nature of the global energy landscape and energy storage industry. As more and more people switch to using electric vehicles and other kinds of renewable energy storage, there has been a corresponding increase in demand for LIBs all around the globe. Despite increasing demand, there are geopolitical and supply-chain risks as most LIBs are still manufactured in only a few countries, namely China, Japan, and South Korea. Sodium-ion batteries, also known as SIBs, have recently come to the forefront as a potentially advantageous candidate for the large-scale storage of electric energy due to the potential advantages of widespread availability and low cost of sodium resources. SIB research and development are still at an early stage, and there are few opportunities for their commercialization. SIBs do, however, confront a number of issues that need to be addressed, including as their short cycle life and rate capability, the restricted availability of high-performance materials, and the need for more research and development to maximize their performance and dependability. Nonetheless, tremendous progress has been made recently, and several businesses and research centers across the globe are attempting to enhance SIB technology. The high theoretical specific capacity and quantity of component elements make layered metal oxides suitable cathode materials for SIBs. In order to enhance their electrochemical performance, however, further exploration is required to deal with their drawbacks, such as limited rate capability and voltage fading. As the cathode materials play such a large role in determining the energy density of SIBs, the primary issue in developing high-energy SIBs is discovering cathode materials with plentiful active sites, high reaction potential, unhindered ionic channels, and stable structures. Tailoring the morphology of materials using nanostructure engineering opens up hitherto unimagined possibilities for exploiting the functional features such as enhanced electrode's specific surface area, decreased sodium-ion diffusion distance, and boost in electronic conductivity. This study demonstrates a quaternary 1D layered transition metal oxide-based cathode with a composition of Na0.67Fe0.25Mn0.5Ti0.2V0.05O2 synthesized by a facile sol-gel strategy. From the SEM results, it is seen that 1D spoke like nanorods are evolved with a tiny fraction of 3D hexagonal lattice which is due to the excessive presence of vanadium in the stoichiometry ratio of the composite. Such nanorod framework configuration facilitates large surface area in contact with the electrolyte that is suitable for charge migration and rapid diffusion of sodium ions through short solid-state route. The P2- Na0.67Fe0.25Mn0.5Ti0.2V0.05O2 microstructure, with its high crystallinity and nanorod structure, showed off a high specific capacity and outstanding rate capability which is visible through electrochemical analysis results.

A circular economy world action plan has been assumed to support sustainability and circular product design in the most intensive sectors such as construction, textiles, plastics, and electronics. A transition to a more circular economy is essential to improve the future quality of life. This chapter discusses how the circular economy offers an excellent opportunity to reinvent the economical paradigms, making them more sustainable and competitive. In this scope, energy companies must systematically pursue their transition to affordable, reliable, and more sustainable energy and set ambitious targets in terms of reducing CO 2 emissions. In the following, different energy generation and storage systems are presented and their perspectives and contributions to a sustainable future are discussed. The increasing use of renewable energy generation and energy storage systems brings new perspectives and represents an essential contribution to a sustainable approach. Further, new affordable recycling technologies for raw materials recovery, new ecodesigns, and reutilization by second use are some of the necessary procedures to be considered for an environmentally friendlier and sustainable future.

Carbon aqueous symmetric supercapacitors are attractive supercapacitor devices owing to the low-cost and high conductivity of porous carbons. However, the limited capacitive charge storage process in carbon symmetric capacitors in comparison to pseudocapacitors or asymmetric supercapacitors severely limit the energy density. The only effective strategy to enhance the energy density of carbon aqueous symmetric supercapacitor is to extend the cell voltage beyond the thermodynamic stability of aqueous electrolytes (1.23 V). Also, in recent studies, researchers have focused on preparing high performance carbon electrodes from commercial carbon fiber clothes by activating the surface usually through chemical and electrochemical routes. However, it is still a major challenge to realize a comprehensive electrochemical performance of high capacitances, excellent rate capability, stability and wide operational potential windows in the activated carbon fiber cloth electrodes. Herein, we successfully activated the surface of commercial carbon fiber clothes using a facile-one-step air calcination at 400 oC for 6 hours strategy to realize a remarkable improvement in surface area, porosity and electrochemical performance. The successful activation of the carbon fiber clothes is fully confirmed through BET tests, SEM, TEM, Raman and contact angle measurement tests. Specifically, the activated carbon exhibits a 450-fold increase in specific surface area (615 m2 g-1 for the activated carbon fiber clothes) as well as rich microporosity, excellent conductivity and superhydrophilicity, which would be beneficial in realizing easy electrolyte penetration and excellent capacitive performance. As expected, the activated carbon fiber cloth achieves ultrahigh areal capacitances of 1553 and 1600 mF cm-2 at 1 mA cm-2 in positive and negative potential windows, good rate capability and excellent cycling stability up to 20000 cycles in 1 M Na2SO4 electrolyte compared to a lowly capacitance of 1.53 mF cm-2 for the commercial carbon fiber clothes. Owing to the large overpotential for hydrogen and oxygen evolution, the activated carbon fiber cloth based symmetric supercapacitor is stable in a wide cell voltage of 2.0 V, displaying high volumetric and gravimetric energy densities of 7.62 mWh cm-3 and 18.2 Wh kg-1, respectively. The stability in this wide potential window is again confirmed using float voltage test method. These results not only report one of the best electrochemical performance of activated carbon fiber clothes, it also provides an effective and simple calcination activation method for realizing high capacitances and takes advantage of the wide operating voltage window to achieve high energy density in carbon textile supercapacitors. Importantly, our studies also showed that the electrochemical performances of metal oxides grown on carbon fiber clothes and annealed in air at 400 oC might be over-estimated as that temperature is sufficient to activate the surface of the carbon fibers.

SUMMARYIn the future, renewable energy (RE) generation systems will be constructed and interconnected to the power system by nonutility entities such as generation companies and residential customers. Therefore, generation expansion planning (GEP) should consider the effects of RE generation. The purpose of this paper is to discuss the best GEP from the economic, supply reliability, and environmental aspects considering the penetration of RE generation. For this purpose, this paper proposes a model of a utility's GEP process considering RE generation. The proposed method is based on stochastic dynamic programming (SDP) in which long‐term uncertainties are modeled by geometric Brownian motion (GBM) and the binomial lattice process. The variation of RE generation output due to the weather conditions (short‐term uncertainty) is also considered in the proposed method by means of the net load curve.

Microwave-assisted preparation and improvement mechanism of carbon nanotube@NiMn2O4 core-shell nanocomposite for high performance asymmetric supercapacitors

Airports face unprecedented energy-related challenges amid evolving technological, environmental and operational demands. The Airport-Centric Energy System (ACES) framework provides a novel approach to energy management by transforming airports from energy consumers into energy producers and regional energy hubs. This paper synthesises the conceptual foundation, technological components, implementation strategies and real-world case studies of ACES to provide a comprehensive roadmap for its adoption. ACES integrates renewable energy generation, energy storage, microgrids and district energy systems to enhance sustainability, resiliency and economic performance. The paper identifies key motivators for ACES adoption, including environmental pressures, financial advantages, operational resiliency and social considerations. The study presents a phased implementation model and highlights case studies from airports worldwide that demonstrate the feasibility and benefits of ACES. Barriers to implementation include capital costs, regulatory challenges and location-specific constraints, while opportunities lie in supporting net zero goals, strengthening community relations and diversifying revenue streams. The findings contribute to the emerging discourse on sustainable airport operations and offer practical guidance for airport stakeholders pursuing energy resilience and environmental leadership. This article is also included in The Business & Management Collection which can be accessed at https://hstalks.com/business/.

Integration of renewable energy generation and storage systems for emissions reduction in an islanded campus microgrid

As part of the transition to an energy system with 100% renewable generation, renewable energy power plants must increasingly take over responsibility for system stability. A key element in ensuring system stability is grid forming control of generation and storage units. In Germany, scenarios predict a significant expansion of renewable energy generation and storage systems in distribution networks. Integration of grid-forming systems into distribution networks raises several open questions, among them are power system oscillations and temporary island operation: Grid forming inverters may unintentionally lead to oscillation issues like those found in traditional transmission systems. A study reveals that as the level of virtual inertia in the distribution grid increases, these oscillations may become more pronounced which highlights the importance of implementing effective damping measures. Temporary island operation: In principle, grid-forming inverters enable the stable continued operation of critical sub-grids after a fault-related disconnection from the supply grid. Both disconnection and interception of the grid, as well as resynchronization and reconnection of the sub-grid with active generators and consumers are simulated in a series of laboratory tests and the basic suitability of this technology and the necessary requirements for this application are explained.

Design and synthesis of copper oxide/cobalt-nickel hydroxide core-shell heterostructure material used as cathodes for hybrid supercapacitors

While known for a higher power density than batteries, electrochemical capacitors are limited by their energy density for some energy storage applications. Since the energy density of the device is proportional to the square of operating potential window, an effective way to increase energy density of the device is by increasing the window. Ionic liquid electrolytes are beneficial for this reason since they can theoretically operate at up to 6 V, though experimentally, the value is between 3-4 V, depending on the properties of electrode materials. By employing a novel electrochemical technique to study symmetric supercapacitors with carbon electrodes and ionic liquid electrolytes, we have found one of the possible reasons for the observed smaller operating potential window of ionic liquids in practical applications. We observed that even for a symmetric device, the different properties of the cation and anion results in an asymmetric performance of the two electrodes. However, a solution to this asymmetry is found by mixing two ionic liquids with the same cation, which ultimately results in a higher operating potential window of the device and therefore a higher energy density.1 Onion-like carbon (OLC) was used as the electrode material due to its large (>500 m2/g) outer surface available for ion adsorption and double layer formation, and no internal porosity that could restrict the movement of ions.2 However, electrode materials can also be made from high surface area carbons that contain a network of pores (e.g., activated or carbide-derived carbon) in which ions are adsorbed during charging. Though they boast a large operating potential window, ionic liquids are known to contain large and bulky ions. This can make it difficult to use an ionic liquid on a porous carbon with a range of pore sizes, some being smaller than the ion size, even though the specific surface area of the electrode material measured by gas adsorption is high and therefore the energy storage capability is more impressive. It has also been shown that the capacitance of porous electrodes is maximized when the ion size and pore size are equal.3 In this case, the ion is small enough to fit inside the pores while still large enough to take advantage of the surface area within the pore walls. While materials with a large outer surface allow a more accessible surface for adsorbing large ions, their capacitance is limited by their specific surface area. By designing an electrolyte based on mixed ionic liquids, we can match the ions in the mixture to the multiple pore sizes of the electrode material. Recently, it was found that the capacitance of porous carbon could be increased with the presence of multiple ions in the electrolyte mixture. Imidazolium-based ionic liquids are chosen based on their variable alkyl chain length which alters the cation size and bis(trifluoromethylsulfonyl)- imide (TFSI) is chosen as the anion for all ionic liquids. Different porous carbons with varying pore size distributions are used to illustrate the effect of ionic liquid mixture electrolytes. Finally, it has been shown previously that ionic liquid mixture electrolytes can be used to increase the operating temperature window of a supercapacitor to -50 °C – 100 °C.4 Ionic liquid mixtures have therefore been shown to improve the potential window, the capacitive performance, and the temperature window of supercapacitors, becoming an important area of study in the field of energy storage. 1. Van Aken, K. L., Beidaghi, M. & Gogotsi, Y. Formulation of Ionic-Liquid Electrolyte to Expand the Voltage Window of Supercapacitors. Angew. Chemie 127, 4888–4891 (2015). 2. McDonough, J. K. et al. Influence of the structure of carbon onions on their electrochemical performance in supercapacitor electrodes. Carbon N. Y. 50, 3298–3309 (2012). 3. Lin, R. et al. Solvent effect on the ion adsorption from ionic liquid electrolyte into sub-nanometer carbon pores. Electrochim. Acta 54, 7025–7032 (2009). 4. Lin, R. et al. Capacitive Energy Storage from -50 to 100 C Using an Ionic Liquid Electrolyte. J. Phys. Chem. Lett. 2, 2396–2401 (2011). Figure 1

The manganese oxyborate Mn3(BO3)2 as a high-performance anode for lithium-ion batteries

Charging up Stationary Energy Storage