Energy Storage Technologies Research Articles

Excellent energy storage properties and multi-scale regulation mechanism of Sr(Zr0.5Ti0.5)O3-(Na0.5Bi0.5)0.94Ba0.06TiO3 ceramics

With the rapid advancement of energy storage technologies, dielectric capacitor materials with the outstanding recoverable energy density and power density have garnered significant attention from researchers in the past decades. In this study, (1-x) (Na0.5Bi0.5)0.94Ba0.06TiO3-xSr(Zr0.5Ti0.5)O3 ceramics were prepared via a solid-state reaction method, and the impact of composition on their structure, energy storage performance and stability were investigated. The results revealed that the introduction of Sr(Zr0.5Ti0.5)O3 induced the ferroelectric-relaxor transformation of (Na0.5Bi0.5)0.94Ba0.06TiO3 ceramics, leading to the destruction of the long-range ferroelectric order and the formation of polar nanoregions. In addition, the 0.7(Na0.5Bi0.5)0.94Ba0.06TiO3–0.3Sr(Zr0.5Ti0.5)O3 ceramic exhibited the optimal comprehensive energy storage performance: its recoverable energy storage Wrec attained 8.19 J/cm3 at 650 kV/cm, while the energy storage efficiency η was 85.6 %. Meanwhile, it displayed exceptionally high power density (315.7 MW/cm3) and charge-discharge rate (t0.9 = 50.4 ns). Moreover, this ceramic demonstrated the impressive energy storage performance, in particular, good temperature stability across a wide range of temperatures (20–140 °C), frequency stability (1–200 Hz), and fatigue resistance (1–106 cycles). Finite element analysis showed an enhancement in the breakdown field strength of the ceramics was attributed to the reduction in grain size. First-principles calculations revealed that the band gap increased after adding Sr and Zr elements, and the interactions between the states of O 2p and Ti 3d, Zr 3d, Bi 6p may serve as the microscopic origin of electron energy level polarization and enhanced dielectric performance. Thus, the ceramics have great potential for the application in high-power pulsed electronic systems.

The underground performance analysis of compressed air energy storage in aquifers through field testing

Compressed air energy storage in aquifers (CAESA) has been considered a potential large-scale energy storage technology. However, due to the lack of actual field tests, research on the underground processes is still in the stage of theoretical analysis and requires further understanding. In this study, the first kilometer depth compressed air injection-production field test with multiple flat aquifers is controlled. For all three production rates considered, the minimum pressure drop rate can reach 0.9 MPa/h. An actual wellbore-aquifer-coupled numerical model simulated by T2Well/EOS3 is verified using monitoring data. Due to the limitation imposed by the injection rate, air only flows into the top three sandstone aquifers to build air bubbles. During the production stage, air is first produced from the aquifers and then the air stored in the wellbore is gradually extracted due to the weakened air bubble support effect. Finally, an air-water two-phase occurs and the water level rises in the wellbore. Considering a hypothetical long-term cycle, the designed single aquifer scheme has a better underground performance. A concentrated and larger high air saturation domain can support a stable cycle pressure and above 95% underground efficiency. However, the wellhead pressure drops once water coning happens in the wellbore. With an air bubble replenishment scheme in each cycle, it becomes feasible to maintain stable pressure, ensuring a production pressure difference below 0.94 MPa without water production, over a 100-day cycle in the field. The results provide support for future practical engineering applications.

Hierarchically porous carbon nanosheets derived from Bougainvillea petals with “pores-on-surface” structure for ultrahigh performance Zinc-ions hybrid capacitors

Due to the outstanding electrochemical performance, high safety coefficient, controllable reaction system and low production cost, Zinc-ion hybrid capacitors (ZIHCs) is considered as a new generation of promising energy storage technology, which even seem as a suitable choice for Medical application. However, to produce ideal carbon-base cathode material with low cost and high electrochemical performance still face challenge. Here, we report a ZIHCs’ cathode based on Bougainvillea petal-derived porous carbon nanosheets (Carbonized Bougainvillea activated at 850 °C, CB-3-850). CB-3-850 derived from Bougainvillea petals exhibit extremely an ultrahigh discharge capacity of 239.1 mAh g−1 at 0.5 A g−1 (from 0 V to 1.8 V) and an excellent electrochemical stability at 20 A g−1 (90 %, 10,000 cycles). In addition, ultrahigh energy density (213.4 Wh kg−1) and high power density (14.8 kW kg−1) are realized in CB-3-850. Special “pores-on-surface” structure and ultrathin nanosheet-like morphology of CB-3-850 not only provide a high specific surface area that for more Zn2+ and SO42+ absorbed on its surface but also enable ions across the one nanosheet directly to reach other carbon-sheets units, which realize a fast kinetic process of ions storage and higher capacity. The excellent performance of the Zinc-ion capacitor can be also attributed to N and O doping that strongly interacted with Zn2+ during the charge/discharge process. Finally, natural Bougainvillea petal just contains simple non-metal elements like C, N and O, exhibit high biocompatibility.

Zinc-ion hybrid supercapacitors with hierarchically N-doped porous carbon electrodes and ZnSO4/ZnI2 redox electrolyte exhibit boosted energy density

Zinc-ion hybrid capacitors (ZIHCs) with high energy density is commercial need as energy storing devices, but facile preparation is still a challenge. Herein, we proposed a combined strategy for preparation of ZIHCs with high performance. For this purpose, a nanoemulsion assembly approach with Pluronic F127 as structure-directing agent, 1, 3, 5-trimethylbenzene as pore-expanding agent, polydopamine as carbon and nitrogen source, was used to synthesize hierarchically N-doped porous carbon spheres (N-HNCSs). The optimized sample of N-HNCS-1 exhibited uniform size of 150 nm, hierarchically porous structure, large surface area (705.46 m2 g−1), and N-doping amount of 6.51 %. These properties were beneficial for the transportation of the electrolyte ions resulted in that the N-HNCS-1 electrode displayed superior electrochemical performance with specific capacity of 142 mAh g−1. Furthermore, the Zn//ZnSO4 + ZnI2//N-HNCS-1 ZIHCs achieves an exceptionally high energy density of 347.7 Wh kg−1, which is 3-fold higher than that of Zn//ZnSO4//N-HNCS-1 ZIHCs. To elucidate this outstanding performance, we investigate the mechanisms involved, including Zn2+ deposition/stripping, SO42-/I- adsorption/desorption, Zn4SO4(OH)6⋅0.5 H2O precipitation/dissolution, and redox reactions relating to iodine ions. The incorporation of ZnI2 redox-electrolyte significantly enhanced the energy density by providing prominent pseudocapacitance via the faradaic reaction. Therefore, the high performance of Zn//ZnSO4 + ZnI2//N-HNCS-1 ZIHCs is attributed to the introduction of nitrogen (N) species, advantageous 3D carbonaceous framework, and redox reactions triggered by adding zinc iodide (ZnI2) into the aqueous zinc sulfate (ZnSO4) electrolyte. This groundbreaking research opens up possibilities for the development of high-energy ZIHCs, and advancements in energy storage technology.

Optimizing Power-to-Gas Technology for Efficient Renewable Energy Storage and Integration in Germany: a Review

This study explores the integration of renewable energy sources into the German power grid, with a specific focus on the application of Power-to-Gas (PtG) technology as a solution for energy storage and optimization. Amidst the growing penetration of renewables, characterized by their intermittent nature, the challenge of maintaining a stable and reliable energy supply becomes paramount. This research delves into the use of Polymer Electrolyte Membrane (PEM) electrolysis for hydrogen storage and biological methanation within the PtG process chain, aiming to enhance the efficiency of methane production and the operational performance of trickle-bed reactors. By developing an economically viable approach for PtG technology and suggesting future business models, this work contributes to the identification of the most suitable electrolysis technology for sector coupling and grid integration. The findings indicate that PtG not only offers a promising pathway for the sustainable integration of renewable energies but also underlines the need for novel, application-oriented storage solutions and the optimization of system components for better market penetration and efficiency. This research underscores the pivotal role of PtG technology in bridging the gap between renewable energy production and the existing energy infrastructure, paving the way for a more sustainable and resilient energy system in Germany.

Potential of solar and wind-based green hydrogen production frameworks in African countries

Africa possesses a profusion of renewable energy resources that can address the continent's need for electricity to foster economic development and achieve international objectives for carbon dioxide mitigation. Green hydrogen stands out as promising among the plethora of available energy production, transportation, and storage technologies. The current study offers a general outlook on green hydrogen production utilizing solar and wind energies powering the water electrolyzers. This analysis estimates the electricity production and its production cost, hydrogen production and production cost, carbon dioxide mitigation, and estimation of the levelized cost of hydrogen (LCOH) by 2030 in each African country. The results reveal that hydrogen production from solar energy outweighs that from wind. The minimum and maximum power consumption are 64.26–65.46 kWh/kgH2 for the PV/H2 system and 53.62–64.8 kWh/kgH2 for the WT/H2 system. Moreover, the LCOH ranges from 4.6 to 7.31 $/kg for the PV/H2 system and 5.6 to more than 20 $/kg for the WT/H2 system. Namibia and Egypt have significant LCOH of the PV/H2 system with 4.6 and 4.64 $/kg, while Cape Verde and Djibouti have remarkable LCOH of 5.6 and 6.37 $/kg of the WT/H2 system. The percentage reduction in LCOH is 25.23% for the WT/H2 system and 37% for the PV/H2 system due to adopting the 2030 cost scenario. Moreover, adsorption-based atmospheric water is considered a suitable solution for water supply in arid regions. Finally, the CO2 mitigation ranges from 109.8 to 177.7 kg/m2 for the PV/H2 and 0.1–50.4 kg/m2 for the WT/H2.

Correction: Badea et al. The Energy Storage Technology Revolution to Achieve Climate Neutrality. Energies 2024, 17, 140

In the original publication [...]

Transforming Waste into Wealth: Advanced Carbon-Based Electrodes Derived from Refinery and Coal By-Products for Next-Generation Energy Storage.

This comprehensive review addresses the need for sustainable and efficient energy storage technologies against escalating global energy demand and environmental concerns. It explores the innovative utilization of waste materials from oil refineries and coal processing industries as precursors for carbon-based electrodes in next-generation energy storage systems, including batteries and supercapacitors. These waste-derived carbon materials, such as semi-coke, coal gasification fine ash, coal tar pitch, petroleum coke, and petroleum vacuum residue, offer a promising alternative to conventional electrode materials. They present an optimal balance of high carbon content and enhanced electrochemical properties while promoting environmental sustainability through effectively repurposing waste materials from coal and hydrocarbon industries. This review systematically examines recent advancements in fabricating and applying waste-derived carbon-based electrodes. It delves into the methodologies for converting industrial by-products into high-quality carbon electrodes, with a particular emphasis on carbonization and activation processes tailored to enhance the electrochemical performance of the derived materials. Key findings indicate that while higher carbonization temperatures may impede the development of a porous structure, using KOH as an activating agent has proven effective in developing mesoporous structures conducive to ion transport and storage. Moreover, incorporating heteroatom doping (with elements such as sulfur, potassium, and nitrogen) has shown promise in enhancing surface interactions and facilitating the diffusion process through increased availability of active sites, thereby demonstrating the potential for improved storage capabilities. The electrochemical performance of these waste-derived carbon materials is evaluated across various configurations and electrolytes. Challenges and future directions are identified, highlighting the need for a deeper understanding of the microstructural characteristics that influence electrochemical performance and advocating for interdisciplinary research to achieve precise control over material properties. This review contributes to advancing electrode material technology and promotes environmental sustainability by repurposing industrial waste into valuable resources for energy storage. It underscores the potential of waste-derived carbon materials in sustainably meeting global energy storage demands.

Recent development in the materials and miniaturization of supercapacitors

High‐performing energy storage systems are becoming more and more necessary due to the rapid growth of renewable energy harvesting technology. To keep pace with it, supercapacitors have emerged a promising energy storage technology providing high power density and long cycle life. In an urge to enhance the energy density without sacrificing the power density, enormous research is going on the exploration of high‐performance electrode material. Huge modifications in the present synthesis routes and innovations in the new techniques may attribute to the large‐scale production of potential electrode materials for supercapacitors. This review focuses on the recent advancement carried out for several potential electrode materials for supercapacitors and device miniaturization.

Optimization of Frequency Modulation Energy Storage Configuration in Power Grid Based on Equivalent Full Cycle Model

This paper aims to meet the challenges of large-scale access to renewable energy and increasingly complex power grid structure, and deeply discusses the application value of energy storage configuration optimization scheme in power grid frequency modulation. Based on the equivalent full cycle model and a large number of actual operation data, various energy storage technologies are technically analyzed, and the economic and environmental performance of different energy storage configuration schemes are comprehensively evaluated. On this basis, this paper puts forward a set of efficient and economical energy storage configuration optimization strategies to meet the demand of power grid frequency modulation and promote the wide application of energy storage technology. After an in-depth analysis, it is found that the optimized energy storage configuration scheme is excellent in technology, economy, and environmental protection. Specifically, in terms of technical performance, the optimization scheme has significantly improved key indicators such as energy storage efficiency, capacity and power, and response speed, which can better meet the requirements of power grid frequency modulation. Through the verification of actual operation data, it is found that the overall efficiency of the optimized energy storage configuration scheme is above 55%, which is helpful to the stability and efficiency of power grid frequency modulation. In terms of economic performance, although the initial investment cost of the optimization scheme may be high, it is found that it has good economy through the evaluation of long-term operation benefits. Considering that the energy storage system can reduce the operating cost of the power grid, improve the energy utilization rate, and achieve the optimization of cost-effectiveness in the long run, this scheme is economically feasible and attractive. In terms of environmental performance, the optimization scheme effectively reduces the negative impact on the environment by improving energy storage efficiency, reducing emissions, and optimizing resource utilization. This is not only conducive to the sustainable development of the power grid but also in line with the current global trend of promoting green and low-carbon transformation. To sum up, this paper not only provides an efficient and economical energy storage allocation optimization strategy for power grid frequency modulation but also provides a scientific basis for relevant decision-making departments. By promoting the practical application and development of energy storage technology, this paper is helpful to improve the frequency modulation ability of power grid, optimize energy structure, and reduce environmental pollution, and thus achieve the goal of sustainable energy development. The data results and in-depth analysis of this paper provide strong support for the practical application of energy storage configuration optimization scheme and also provide important reference for the further innovation and development of energy storage technology.

A Case Study of Maritime Hydrogen Energy Development in Jiangsu Province in China

This study aims to develop a systematic review of hydrogen energy storage technologies and maritime applications, intending to present an international perspective on the matter. This study analyses the role of advanced storage methods in enabling renewable energy systems integration in coastal regions, using Jiangsu Province of China as an example. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used as the research method. Data was obtained from research studies over the period 2015–2023. The analysis included a total of 96 papers from Web of Science, Scopus, IEEE Xplore, and ScienceDirect databases. Results show that Europe and East Asia led publications at the intersection of hydrogen storage and marine applications over the past decade. One of the main issues associated with maritime hydrogen adoption found in the dissertation is related to the mismatch between technological readiness levels and commercial maturity. Findings indicate promise for fuel cell integration with ships, ports, offshore wind farms, and other coastal transport sectors. However, the realization of the project depends on infrastructure development, policy support, and viable business models tailored to the marine environment. Focused demonstration projects and public-private collaboration can further progress towards robust hydrogen-based energy storage ecosystems in suitable regions like Jiangsu and beyond.

Jump-Starting Global Grid Decarbonization: US-Dutch Partnerships Energize Utility-Scale Battery Deployment

The United States and the Netherlands heavily invest in renewable energy as part of their individual commitments to net zero emissions by 2050. Weather-dependent fluctuations in wind and solar power, along with limitations in legacy infrastructure and systems, restrict the on-demand use of these renewables and pose substantial bottlenecks to the energy transition. Integration of dynamic energy storage technologies into modernized electrical systems will provide crucial solutions to overcome these challenges. Herein, we profile stakeholder perspectives on the energy transition and present our recommendations for US-Dutch collaboration on utility-scale electrochemical battery solutions to update power grids with robust, accessible, and sustainable carbon-free flexible energy capacity.

Hierarchical multi-dimensional Mn2GeO4 coupled with CNT for long-cycling lithium-ion battery

The escalating demand for renewable and sustainable energy sources has led to a surge in the development of energy storage technologies. Lithium-ion batteries (LIBs), already a well-established technology, play a pivotal role in today’s society. Nevertheless, the limited theoretical specific capacity of graphite-based anode materials currently utilized in LIBs restricts their widespread practical applications. Therefore, in this study, the Mn2GeO4 based anode materials with different morphologies (such as one-dimensional nanowires, two-dimensional nanosheet and three-dimensional irregular nanoparticles) were successfully prepared through facile hydrothermal reaction or calcination. Notably, the experimental results revealed that the two-dimensional Mn2GeO4 nanosheet (MGO-NS) sample exhibited superior electrochemical performance compared to the other two samples. Moreover, the MGO-NS was further modified by carbon nanotubes (CNTs) to form MGO-NS/CNT composite for enhanced stability. Upon conducting electrochemical tests, it was evident that the discharge specific capacity and cycling stability of the composite were significantly improved, holding promise for future energy storage applications.

Comparative techno-economic evaluation of energy storage technology: A multi-time scales scenario-based study in China

Energy storage technology is a crucial means of addressing the increasing demand for flexibility and renewable energy consumption capacity in power systems. This article evaluates the economic performance of China's energy storage technology in the present and near future by analyzing technical and economic data using the levelized cost method. Through a comparative analysis of different energy storage technologies in various time scale scenarios, we identify diverse economically viable options. Sensitivity analysis reveals the possible impact on economic performance under conditions of near-future technological progress. The application analysis reveals that battery energy storage is the most cost-effective choice for durations of <2 h, while thermal energy storage is competitive for durations of 2.3–8 h. Pumped hydro storage and compressed-air energy storage emerges as the superior options for durations exceeding 8 h. This article provides insights into suitable energy storage technologies for China's energy structure development in the present and near future.

Status and Development Perspectives of the Compressed Air Energy Storage (CAES) Technologies—A Literature Review

The potential energy of compressed air represents a multi-application source of power. Historically employed to drive certain manufacturing or transportation systems, it became a source of vehicle propulsion in the late 19th century. During the second half of the 20th century, significant efforts were directed towards harnessing pressurized air for the storage of electrical energy. Today’s systems, which are based on storing the air at a high pressure, are usually recognized as compressed air energy storage (CAES) installations. This paper aims to provide an overview of different technologies that take advantage of the energy accumulated in the compressed air. Particular attention is paid to the CAES installations that are working as electrical energy storage systems (EESs). These systems, developed originally as large capacity (&gt;100 MWe) and fuel-based installations, may soon become fully scalable, highly efficient, and fuel-free electrical energy storage systems. To present this opportunity, a thorough review encompassing previous and up-to-date advancements in their development was carried out. In particular, CAES concepts, such as diabatic (D-CAES), adiabatic (A-CAES), and isothermal (I-CAES), are described in detail. This review also provides the detailed characteristics of the crucial elements of these configurations, including compressors, expanders, air storage chambers, and thermal storage tanks. Knowledge of these components and their role allows us to understand the main challenges behind the further development of the mentioned CAES setups. Apart from the CAES systems that are designed as EES systems, this paper describes other prospective technologies that utilize the energy of pressurized air. Accordingly, compressed air cars and their key elements are explained in detail. Moreover, the technology renowned as wave-driven compressed air energy storage (W-CAES) is described as well, indicating that the utilization of pressurized air represents a viable option for converting ocean energy into electrical power.

Anion substitution-induced CuCoSe hollow nanotubes as multifunctional electrode materials for supercapacitors and overall water splitting

Developing highly efficient non-noble-metal electrode materials for energy storage and conversion is crucial for advancing sustainable and renewable energy. In this study, a facile and effective anion substitution-induced approach was designed to synthesize uniform CuCoSe hollow nanotubes. Impressively, the obtained CuCoSe hollow nanotubes reach an exceptional mass-specific capacitance of 2,853.1F·g−1 at 10 A·g−1, with intriguing rate capability and desirable capacitance retention after 5,000 cycles. The assembled CuCoSe//CuCoSe symmetrical supercapacitor device exhibits a high energy density of 218.9 Wh·kg−1 at a power density of 4,000 kW·kg−1. Furthermore, the CuCoSe hollow nanotubes show exceptional performances in both oxygen and hydrogen evolution reactions, necessitating low overpotentials of 94.4 and 33.4 mV at 10 mA·cm−2. When used as a bifunctional electrocatalyst, the assembled CuCoSe||CuCoSe electrolytic cell affords a low cell voltage of 1.40 V to drive 10 mA·cm−2, significantly superior to other commercial electrolyzers and most reported bifunctional electrocatalysts. Experimental and density functional theory calculations suggest that selenides substituted CuCo-layered double hydroxides can greatly enhance the electrochemical performances. This work will be beneficial for the design of the next generation of energy storage and conversion technologies.

Performance analysis of a compressed air energy storage incorporated with a biomass power generation system

Compressed air energy storage technology is recognized as a promising method to consume renewable energy on a large scale and establish the safe and stable operation of the power grid. To improve the energy efficiency and economic performance of the compressed air energy storage system, this study proposes a design for integrating a compressed air energy storage system with a biomass power generation system. In the energy storage process, the feedwater from the biomass power generation system is used to cool the compressed air in the compressed air energy storage system. In the energy release process, the flue gas from the biomass power generation system is used to heat the compressed air. Besides, the compressed air from the compressed air energy storage system first works in the expander and then goes to the biomass power generation system for combustion. Based on the system simulation, the proposed system is assessed from the energy, exergy, economy, and environment perspectives. The results show that the round-trip efficiency and the energy storage density of the compressed air energy storage subsystem are 84.90 % and 15.91 MJ/m3, respectively. The exergy efficiency of the compressed air energy storage subsystem is 80.46 %, with the highest exergy loss in the throttle valves. The total investment of the compressed air energy storage subsystem is 256.45 k$, and the dynamic payback period and the net present value are 4.20 years and 340.48 k$. Besides, the proposed system’s CO2 emission is 258 kg/GWh. This study provides a new option for enhancing the performance of compressed air energy storage through the system integration.

Optimizing Energy Arbitrage: Benchmark Models for LFP Battery Dynamic Activation Costs in Reactive Balancing Market

This study introduces a novel benchmark model for lithium iron phosphate (LFP) batteries in reactive energy imbalance markets, filling a notable gap by incorporating comprehensive operational parameters and market dynamics that are overlooked by conventional models. Addressing the absence of a holistic benchmark for energy-storage systems in electricity markets, this research focuses on the integration of LFP batteries, considering their unique characteristics and market responsiveness. Regression and regularization techniques, coupled with temporal cross-validation, were employed to ensure model robustness and accuracy in predicting energy trading outcomes. This methodological approach allows for a nuanced analysis of battery degradation, power capacity, energy content, and real-time market prices. The model, validated using Belgium’s system imbalance market data from the 2020–2023 period, incorporates both capital and operational expenditures to assess the economic and operational viability of LFP battery energy-storage systems (BESSs). The findings reveal that considering a broader range of operational parameters in energy arbitrage, beyond just the usual energy prices and round-trip efficiency, significantly influences the cost-effectiveness and performance benchmarking of energy storage solutions. This paper advocates for the strategic use of LFP batteries in energy markets, highlighting their potential to enhance grid stability and energy trading profitability. The proposed benchmark model serves as a critical tool for energy traders, providing a detailed framework for informed decision making in the evolving landscape of energy storage technologies.

Peri‐Xanthenoxanthene‐Based Covalent Organic Frameworks for High‐Performance Aqueous Zn‐Ion Hybrid Supercapacitors

Aqueous zinc‐ion hybrid supercapacitors (Zn‐HSCs) are promising devices for sustainable and efficient energy storage. However, they suffer from a limited energy density compared to lithium‐ion batteries. This limitation can be overcome by developing novel electrode materials, with covalent organic frameworks (COFs) standing out as a particularly intriguing option. Herein, peri‐xanthenoxanthene (PXX) has been integrated for the first time into a COF scaffold to take advantage of its straightforward synthesis, chemical stability, π‐conjugated backbone, and heteroatom content endowing reversible redox reactions at low potentials. Two novel hexagonal COFs have been designed and synthesized by tethering of a PXX‐diamine unit having a C2 symmetry with two distinct tris‐aldehydes acting as C3‐symmetric cornerstones, i.e., triformyl benzene (TFB) and triformylphloroglucinol (Tp), ultimately yielding COF PXX(PhNH2)2‐TFB and COF PXX(PhNH2)2‐Tp, respectively. As cathodes in Zn‐HSCs, COF PXX(PhNH2)2‐Tp exhibits a remarkable specific capacitance, energy, and power densities (237 F g−1, 106.6 Wh kg−1, and 3.0 kW kg−1, respectively), surpassing those of COF PXX(PhNH2)2‐TFB (109 F g−1, 49.1 Wh kg−1, and 0.67 kW kg−1). Importantly, both COFs display outstanding long‐term stability, over 5000 charge/discharge cycles, with capacitance retention &gt;92%. These findings underscore the potential of PXX‐based COFs as high‐performance cathode materials for HSCs, thereby offering a promising new avenue for energy storage technologies.

Tailoring NiCoCu layered double hydroxide with Ag-citrate/polyaniline/functionalized SWCNTs nanocomposites for supercapacitor applications.

Supercapacitors have substantially altered the landscape of sophisticated energy storage devices with their exceptional power density along with prolonged cyclic stability. On the contrary, their energy density remains low, requiring research to compete with conventional battery storage devices. This study addresses the disparities between energy and power densities in energy storage technologies by exploring the integration of layered double hydroxides (LDH) and highly conductive materials to develop an innovative energy storage system. Four electrodes were fabricated via a hydrothermal process using NiCoCu LDH, Ag-citrate, PANI, and f-SWCNTs. The optimal electrode demonstrated exceptional electrochemical properties; at 0.5 A g-1, it possessed specific capacitances of 807 F g-1, twice as high as those of the pure sample. The constructed asymmetric supercapacitor device attained energy densities of 62.15 W h kg-1 and 22.44 W h kg-1, corresponding to power densities of 1275 W kg-1 and 11 900 W kg-1, respectively. Furthermore, it maintained 100% cyclic stability and a coulombic efficiency of 95% for 4000 charge-discharge cycles. The concept of a supercapacitor of the hybrid grade was reinforced by power law investigations, which unveiled b-values in the interval of 0.5 to 1. This research emphasizes the considerable potential of supercapacitor-grade NiCoCu LDH/Ag-citrate-PANI-f-SWCNTs nanocomposites for superior rate performance, robust cycle stability, and enhanced energy storage capacity.