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PbZrO 3 (PZO) possesses a unique antiferroelectric-ferroelectric (AFE-FE) phase transition under an external electric field and engages more attention in understanding and regulating the phase transition behavior. In this work, changing annealing temperature (600–750 °C) and ultralow content (5‰) ions doping are used to optimize the phase transition of PZO films via grain size engineering. As annealing temperature increases, the maximum polarization P max increases but forward/backward switching fields E F / E A reduce accompanied by the average grain size enhances from 622 to 686 nm. Following, 5‰ mol aliovalent ion La3+ or K+ doped PZO-650 films both enhance P max and E F / E A indicating the strengthened antiferroelectricity, and meanwhile the grain size enhances to ∼800 nm. A high discharge density of 31 J/cm3 is achieved for 5‰ mol La-doped PZO films at a low electric field of 1 MV/cm, which is ∼100 % higher than those of pure PZO films at different annealing temperatures. This work compares the phase transition characteristics changes in PZO films by changing annealing temperature and ultra-low content ion doping strategy, which would provide new thinking in grain size-engineered antiferroelectric materials for energy storage applications. [ABSTRACT FROM AUTHOR]

In the context of achieving carbon neutrality, dielectric capacitors have garnered significant attention due to their inherent advantages, including rapid charge and discharge capabilities, high power density, and extended service life. Nevertheless, contemporary lead-free dielectric capacitors encounter challenges such as insufficient energy storage density, suboptimal energy storage efficiency, and inadequate temperature stability. To address these issues, we have chosen the lead-free (Bi 0.5 Na 0.5) 0.65 Sr 0.35 TiO 3 ceramic as the foundational system. Through the addition of Bi(Zn 0.5 Sn 0.5)O 3 for doping modification, this study focuses on optimizing the energy storage characteristics. The results demonstrate an achieved energy storage density of 4.34 J/cm3 and an energy storage efficiency of 84.1% at 358 kV/cm. These findings offer valuable insights for the advancement of lead-free ceramics in the realm of dielectric energy storage. [ABSTRACT FROM AUTHOR]

BiFeO 3 (BF) based ceramics are inspiring great interest in advanced pulsed power applications owing to their giant spontaneous polarization, meanwhile limited by the significant leakage current. In this work, Sr 0.7 Bi 0.2 TiO 3 (SBT) modified 0.7BiFeO 3 -0.3BaTiO 3 (BF-BT) ternary lead-free relaxor ferroelectric ceramics are investigated to elaborate the dielectric performances, including the impedance, relaxor behavior, ferroelectric and energy storage, and strain properties. The substitution of SBT induces a phase transition from an R 3 c to an average pseudo-cubic structure and forms a secondary phase at high dopants. Simultaneously, the resistivity, electrically homogeneous, and band gaps are increased significantly, related to the inhibition of oxygen vacancy formation. Besides, the ferroelectric long-range order is disrupted, which promotes the formation of local defect fields and polar nanoregions. The structural heterogeneity for the higher doped components leads to an increased relaxation behavior with an almost hysteresis-free polarization response to external electric fields. Excellent temperature-insensitive dielectric response and promising dielectric energy storage properties in low electric fields are achieved, respectively. These results indicate that the SBT modification is an effective route in regulating the dielectric performance of bismuth ferrite based relaxors. [ABSTRACT FROM AUTHOR]

Lead-free relaxor ferroelectric energy-storage ceramics based on Bi 0.5 Na 0.5 TiO 3 (BNT) systems are renowned for their exceptional properties, including a high P max (>40 μC/cm2) and Curie temperature (T c ∼ 320 °C). In the pursuit of further enhancing their energy storage characteristics, we have developed a novel series of ceramics, namely (1- x)(Bi 0.5 Na 0.5) 0.7 Sr 0.3 TiO 3 - x Ba 0.94 La 0.04 Zr 0.02 Ti 0.98 O 3 (x = 0, 0.1, 0.2, 0.3 and 0.4), abbreviated as (1- x)BNST- x BLZT, and assessed its structural and performance attributes. With the introduction of Ba 0.94 La 0.04 Zr 0.02 Ti 0.98 O 3 (BLZT), these ceramics retain their characteristic phase structure where tetragonal (T) and rhombohedral (R) phases coexist, effectively disrupting long-range ordered domains and augmenting their energy storage capabilities. Notably, we achieved a remarkable recoverable energy storage density (W rec) of 3.41 J/cm3 and an extraordinarily high energy storage efficiency (ƞ) of 87.33 % in ceramics with x = 0.3 under an electric field of 260 kV/cm. Furthermore, these ceramics exhibit excellent temperature stability (−2 °C ∼ 228 °C), robust cycle stability (106 cycles), a substantial discharge energy density (W d ∼ 0.93 J/cm3), impressive power density (P D ∼ 39.3 MW/cm3), and rapid transient discharge times (t 0.9 ∼ 0.14 μs). In summary, the 0.7BNST-0.3BLZT ceramic demonstrates high power density, rapid charge and discharge rates, and excellent temperature and cyclic stability, positioning it as a promising material for pulse power systems and harsh environments. [ABSTRACT FROM AUTHOR]

The dielectric and energy storage properties of (1- x)(0.7(Bi 0.5 Na 0.5)TiO 3 -0.3(Sr 0.7 Bi 0.2)TiO 3)- x Bi(Mg 0.5 Zr 0.5)O 3 (BNT-SBT- x BMZ) ceramics are systematically investigated, and further modified by using the strategy of doping two kinds of sintering aids, LiF and B 2 O 3 –Bi 2 O 3. The results show that all ceramics exhibit a typical perovskite structure. The doping of sintering aids reduces the sintering temperature effectively to below 1000 °C and obtains the dense microstructure. Meanwhile, the ferroelectric long-range order can be disrupted that facilitates the polarization in nano-regions at high temperatures induced by LiF dopants, which enhance the relaxor behavior and form a dielectric platform together with low dielectric loss in a wide temperature range. In addition, extremely slender polarization-electric field (P - E) hysteresis loops are gained by doping LiF in BNT-SBT- x BMZ ceramics associated with an almost non-polar phase that exhibits linear response. In comparison, little change in shape of P - E loops is observed when adding B 2 O 3 –Bi 2 O 3. As a result, outstanding energy storage performances are achieved in sintering-aids modified ceramics under the relatively low electric fields of 180 kV/cm −210 kV/cm. This work provides the optimized energy storage properties and dielectric stability of BNT-based ceramics at reduced sintering temperatures, and pave the way for the cofiring with base metal electrodes in multilayer ceramic capacitors. [ABSTRACT FROM AUTHOR]

dielectric capacitors are highly desired in advanced high-power electrical systems owing to their fast charge-discharge capabilities, such as electromagnetic devices, high-power microwaves, and hybrid electric vehicles. While the performance of dielectric capacitors is mainly dominated by dielectric materials. (Na 0.5 Bi 0.5)TiO 3 -(Sr 0.7 Bi 0.2)TiO 3 (NBT-SBT) as well-known dielectric ceramics attracted much attention and are widely studied owing to their combining antiferroelectric and relaxor features which achieve high energy density and efficiency. However, few studies report the compositional modification of B-site in NBT-SBT dielectric ceramics. Here, we prepared a series of MgNb 2 O 6 doped NBT-SBT ceramics at B-Sites of the perovskite structure. Their phase structure, microstructure morphology structure, elemental distribution, dielectric and energy storage properties are systemically investigated. The resultant characterization showing minor doping MN into NBT-SBT ceramic decreases the polarization hysteresis generating an outstanding energy storage property. In addition, their energy-density variation of less than 10 % over a wide temperature range of −50 to 150°. The present research offers a route for designing dielectric ceramics with enhanced energy storage performance. • Synthesized pure phase NBT-SBT ceramics with varying MgNb 2 O 6. • Small additions of MgNb 2 O 6 reduced polarization hysteresis while boosting energy storage potential. • Achieved a 1.5 J cm⁻1 energy storage density with stable efficiency (83–95 %) and less than 10 % fluctuation. [ABSTRACT FROM AUTHOR]

[Display omitted] • An assisted liquid-phase plasma electrolysis is applied for synthesis of composite. • The synergy of CNFs, NiCo 2 O 4 and NiCo-LDH improves the electrochemical properties. • The specific capacitance of electrode can reach 1534.7 F/g at 1 A/g. • The ASC device has an energy density of 33.8 Wh/kg at 400 W/kg. • Deposition dynamics of NiCo 2 O 4 /NiCo-LDH/CNFs composites is explored. Nickel cobaltate/NiCo-layered double hydroxides (NiCo 2 O 4 /NiCo-LDH) as energy storage materials offer considerable potential for various applications. However, many of current methods for synthesizing NiCo 2 O 4 /NiCo-LDH suffer from long synthesis times, complex preparation process, and high temperatures and high pressures. In this study, we present a green, simple, and efficient approach known as assisted liquid-phase plasma electrolysis, which realizes the rapid fabrication of ultra-fine NiCo 2 O 4 /NiCo-LDH nanoparticle-decorated electrospun carbon nanofibers (NiCo 2 O 4 /NiCo-LDH/CNFs) composites. Ultra-fine NiCo 2 O 4 /NiCo-LDH nanoparticles (<70 nm) are uniformly deposited on the CNF surface. The CNFs are intertwined to form a highly conductive three-dimensional mesh structure, which synergizes the NiCo 2 O 4 /NiCo-LDH nanoparticles with a high specific capacitance in favor of ion/electron transport efficiency. In addition, the cooperative effect between the two phases of NiCo 2 O 4 and NiCo-LDH further improves the electrochemical properties. The NiCo 2 O 4 /NiCo-LDH/CNFs composites exhibit a high specific capacitance of 1534.7 F/g at 1 A/g and a capacitance retention of 93.9 % after 5000 cycles. An assembled asymmetric supercapacitor using activated carbon and NiCo 2 O 4 /NiCo-LDH/CNFs composites achieves an energy density of 33.8 Wh/kg at a power density of 400 W/kg and a capacitance retention of 93.0 % after 5000 cycles. Notably, two series-connected NiCo 2 O 4 /NiCo-LDH/CNFs ASC supercapacitors can light up an LED bulb, which maintains a certain brightness even after 50 min. Hence, this work provides a new and efficient route for synthesizing carbon-based NiCo 2 O 4 /NiCo-LDH composites for use as advanced energy storage materials. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of efficient and cost-effective electrocatalysts to overcome the intrinsic sluggish kinetics of the oxygen reduction reaction (ORR) in zinc-air batteries is crucial. In this study, we introduce a strategy that integrates a template-assisted synthesis with subsequent thermal treatment to fabricate an active and stable cobalt-based nitrogen-doped carbon electrocatalyst, denoted as Co- N -CNT. The strategy adjusts the disordered architecture of the zeolitic imidazolate framework (ZIF) through the synergistic effect of bimetallic species, restricted the growth of zeolitic imidazolate framework nanoleaves (ZIF-L) using salt templates, and directed the transformation from a two-dimensional blade-like morphology to a three-dimensional multi-tiered composite structure. Notably, the Co- N -CNT-800 sample, synthesized at an optimized pyrolysis temperature of 800 °C, exhibits a half-wave potential of 0.89 V and demonstrates stability with sustained cycling over 21 h, which is comparable to the performance of commercial Pt/C electrocatalysts. Moreover, when employed as the cathode in zinc-air batteries, Co- N -CNT-800 not only surpasses Pt/C in terms of power density but also exhibits long-term charge/discharge stability. This findings offer a viable pathway for the design of active and cost-effective ORR electrocatalysts, holding promise for applications in the electrochemical energy storage and conversion systems. [ABSTRACT FROM AUTHOR]

N, P co-doped MXene has been successfully demonstrated to enhance the performance of lithium-oxygen batteries. The N and P co-doping can increase interlayer distance of MXene and elevate the d-band center of Ti, thereby effectively providing more active sites, strengthening the mass transfer, optimizing the adsorption of reaction intermediates, and accelerating the deposition/decomposition of Li 2 O 2 films. [Display omitted] • N, P co-doped MXene has been successfully demonstrated to enhance the performance of lithium-oxygen batteries. • The N and P co-doping can increase interlayer distance of MXene and elevate the d-band center of Ti. • N, P co-doped MXene can effectively provide more active sites, strengthen the mass transfer, optimize the adsorption of reaction intermediates, and accelerate the deposition/decomposition of Li 2 O 2. The design and fabrication of bifunctional catalysts with high electrocatalytic activity and stability are critical for developing highly reversible Li–O 2 batteries (LOBs). Herein, the N, P co-doped MXene (NP-MXene) is prepared by one-step annealing method and evaluated as bifunctional catalyst for LOBs. The results suggest that the P doping plays a crucial role in increasing interlayer distance of MXene, thereby effectively providing more active sites, fast mass transfer, and ample space for the deposition/decomposition of Li 2 O 2. Moreover, the N doping can significantly elevate the d-band center of Ti, thereby remarkably improving the adsorption of reaction intermediates and accelerating the deposition/decomposition of Li 2 O 2 films. Consequently, the MXene-based LOBs deliver an ultrahigh specific capacity of 13,995 mAh/g at 500 mA g−1, a discharge/charge voltage gap of 0.89 V, and a cycle life up to 523 cycles with a limited capacity of 1000 mAh/g at 500 mA g−1. Impressively, the as-fabricated flexible LOBs with NP-MXene cathode display excellent cycling stability and ability to continuously power LEDs even after bending. Our findings pave the road of heteroatom doped MXenes as next-generation electrodes for high-performance energy storage and conversion systems. [ABSTRACT FROM AUTHOR]

[Display omitted] The selection of highly efficient materials and the construction of advantageous structures are essential for realizing high-performance electrode materials. In this paper, electrode material Cu 2 S/C@NiMnCe-LDH/CF with excellent morphology and high performance has been successfully designed and prepared by simple hydrothermal and calcination techniques. First, ZIF-67 is loaded on the outer layer of Cu 2 S rods to obtain core–shell structured Cu 2 S@ZIF-67 rods, whose ZIF-67 MOF shell is carbonized to obtain Cu 2 S@C rods. Then, NiMnCe-LDH are epitaxially loaded on the outer layer of Cu 2 S@C to obtain Cu 2 S/C@NiMnCe-LDH rods. At a current density of 2 mA cm−2, Cu 2 S/C@NiMnCe-LDH/CF exhibits an area capacitance of 5176.4 mF cm−2. The mass capacitance and the energy density of the Cu 2 S/C@NiMnCe-LDH/CF//AC asymmetric supercapacitor (ASC) reach 150.82F g−1 at a sweep rate of 0.8 A/g and 53.62 Wh kg−1 at a power density of 639.99 W kg−1, respectively. Meanwhile, after 8000 electrochemical cycles, the specific capacitance of Cu 2 S/C@NiMnCe-LDH/CF//AC still has a retention rate of 86.32 %, which proves its excellent cycling stability. These results demonstrate a new strategy for the preparation of novel core–shell structured Cu 2 S/C@NiMnCe-LDH/CF nanocomposite material for electrode materials of energy storage devices with superb performance. [ABSTRACT FROM AUTHOR]

Polymer dielectrics with excellent energy storage properties are crucial for high‐power density electronic equipment in environments such as high temperatures and strong electric fields. They play a critical role in applications including hybrid electric vehicles, electromagnetic launch devices, and photovoltaic power generation. In this paper, the small molecule compound lithium acetate (LiAc), which is low cost and exhibits good thermal stability in high‐temperature environments, was selected and blended with a polyetherimide (PEI) polymer matrix at an ultra‐low loading (≤0.3 vol%). LiAc has a higher electron affinity compared to PEI, which will result in a large trap energy level (Φe). The injected and excited electrons are trapped by strong electrostatic attraction, which suppresses carrier transport, reduces conduction losses, and improves breakdown strength in high‐temperature environments. This composite dielectric exhibits better energy storage properties in high‐temperature environments. The energy density of the 0.2% by volume LiAc/PEI composite dielectric reaches 3.04 J cm−3 at 150°C, maintaining an energy storage efficiency of approximately 90%. The research presented in this paper offers a novel approach to achieving excellent energy storage properties in polymer‐based composite dielectrics operating in high‐temperature environments. [ABSTRACT FROM AUTHOR]

Metal hydrides have captured significant attention for hydrogen storage because of their high energy density and safety. However, the performance of these systems is largely influenced by the design of the storage reactor. In this perspective, a novel compact, lightweight, and effective multi tube MH reactor was designed, fabricated, and experimentally tested. The absorption and desorption behavior of the newly developed Ti 0.9 Zr 0.1 Mn 1.46 V 0.45 Fe 0.09 alloy using the proposed MH reactor for hydrogen storage applications was analysed. At 30 bar supply pressure, the MH reactor absorbed 164.3 g (1.58 wt.%) of hydrogen in 894 s and delivered specific energy at an average rate of 94.7 W/kg MH. Further, the reactor released 153.6 g (1.48 wt.%) of hydrogen in 2246 s, when the desorption temperature was set at 50 °C. Moreover, the parametric study revealed that by raising the supply pressure from 10 bar to 20 bar and 30 bar, the stored capacity was improved by 11 % and 18.9 %, respectively, whereas the absorption time was drastically reduced by 43 % and 61.5 %, respectively. Furthermore, the fabricated reactor achieved gravimetric and volumetric storage densities of 0.75 % and 20.6 kg/m3 of H 2. Also, the MH reactor achieved a maximum hydrogen storage efficiency of 82.3 %. Finally, the comparative results indicated that the MH reactor studied in this work demonstrated a faster hydrogen release rate compared to other medium to large capacity MH reactors reported in the literature. [Display omitted] • Absorption and desorption behavior novel MH reactor were analysed. • The multi tube reactor absorbed 1.56 wt% in 894 s at 30 bar supply pressure. • The reactor desorbed 1.46 wt% in 2246 s at desorption temperature of 50 °C. • The achieved volumetric storage density was 20.6 kg/m3 of H 2. • The MH reactor attained maximum energy storage efficiency of 82.3 %. [ABSTRACT FROM AUTHOR]

Developing high-performance carbon-based materials for environmental and energy-related applications produces solid waste with secondary pollution to the environment at the end of their service lives. It is still challenging to utilize these functional materials in a sustainable manner in different fields. In this study, we demonstrate a cascaded utilization of an Fe3O4@onion-like carbon (Fe3O4@OLC) structure from wastewater adsorbents to a supercapacitor electrode. The structure was formed by carbonizing Fe3O4@oleic acid monodisperse nanoparticles into interconnected Fe3O4@OLCs and subsequent insufficient acid etching. The hollow OLCs in the outside region of the hybrid structure provide high surface area and the encapsulated Fe3O4 nanoparticles in the inside region offer high ferromagnetism. The three-dimensionally interconnected graphitic layers are advantageous for efficient separation and high conductivity. As a result, the maximum saturation adsorption capacity of insufficiently etched interconnected Fe3O4@OLCs can reach up to 90.2 mg g−1 and they can be efficiently separated under a magnetic field. Furthermore, the hybrid structure is thermally transformed into N-doped HOLCs, which are demonstrated to be a high-performance supercapacitor electrode with high specific capacitance and high electrochemical stability. The cascaded utilization of the hybrid structure in this study is meaningful for eco-friendly development of functional materials for environmental and energy storage applications. [ABSTRACT FROM AUTHOR]

Developing highly stable, low-cost, and efficient electrode materials for supercapacitor and oxygen evolution reactions is a challenging issue in energy storage and generation technology to meet the demand for sustainable and clean energy. Herein, cobalt phosphates in comparison with cobalt oxides were synthesized using a successive ionic layer adsorption and reaction (SILAR) method on a nickel foam substrate with different crystallization temperatures, and their supercapacitor and oxygen evolution reaction performances were studied. The nanorod bundles of cobalt phosphate electrodes prepared at 150 °C delivered an excellent specific charge storage capacity of 1512 F g−1 (681 C g−1) at a current density of 5 mA cm−2, which is higher than that of cobalt oxide (1103.9 F g−1 (496 C g−1)). They are highly stable for more than 2000 charge–discharge cycles with a coulombic efficiency of 93%. Furthermore, the same electrodes exhibited enhanced electrocatalytic behaviour for the oxygen evolution reaction (OER) with an overpotential of 359 mV at a current density of 30 mA cm−2, lowest Tafel slope of 60 mV dec−1 and stability of 20 hours. Enhanced reaction kinetics are attributed to the high electrochemical surface area with a Cdl of 594 μF and improved electronic conductivity. The above results indicated that cobalt phosphate is one of the most efficient electrode materials for the OER and supercapacitors. [ABSTRACT FROM AUTHOR]

Efficient and stable persistent phosphors play a crucial role in the fields of energy storage, anti-counterfeiting, and biomedical fields. Here, we present an improved synthetic method for preparing a series of color-tunable LiYGeO 4 :Tb3+ persistent phosphor. The increased Tb3+ concentration in the improved method enhances the persistent luminescent intensity at 20 s by ∼2.96 times. This enhancement is due to the dual roles of Tb3+ as both emitters and trap centers within LiYGeO 4. By simply increasing the doping concentrations, the persistent color can be adjusted from blue to green. LiYGeO 4 :Tb3+ exhibits no loss of persistent luminescent intensity even after exposure to water at 80 °C for 72 h, surpassing the commercial green persistent phosphor. Furthermore, information storage was successful demonstrated by using LiYGeO 4 :Tb3+ with various doping concentrations. This study represents a significant advancement in optimizing the properties of persistent luminescent materials, where dopants simultaneously serve as emitters and trap centers. An improved approach has been developed that significantly enhances the persistent luminescence of LiYGeO 4 :Tb3+. This advancement endows the persistent phosphor with substantial potential for applications in information storage. [Display omitted] [ABSTRACT FROM AUTHOR]

Energy storage technologies play a crucial role in addressing the intermittent characteristics of renewable energy sources, improving the stability of electrical grids, and decreasing the release of greenhouse gas emissions. In this study, we presented nickel indium oxalate (Ni 1-x In x C 2 O 4) as a promising material with potential applications in the field of electrochemical energy storage. The as-prepared Ni-In- oxalate sample was subjected to different physical characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Regarding the electrochemical energy storage capability, the Ni 1-x In x C 2 O 4 electrode material exhibited a specific capacitance of 835 F g−1 (417.5 C g−1) at 1 A g−1. The incorporation of nickel (Ni) into the indium (In) oxalate nanoplates enhances their electrochemical performance. The presence of Ni in the nanoplates generated from substrate, improving the overall conductivity of the material and enhances its electrochemical reactions, thus leading to improved energy storage capabilities. [ABSTRACT FROM AUTHOR]

NaNbO 3 (NN)-based dielectric ceramics for energy storage have garnered significant interest due to their high saturation polarization, low residual polarization, and superior breakdown strength (E b). However, the low recoverable energy storage density (W rec) and efficiency (η) significantly limited their practical application. Herein, BiFeO 3 (BF) was incorporated into NN to optimize the energy storage performance. The NN-BF ceramics exhibited pronounced antiferroelectric (AFE) relaxor phase, alongside grain size reduction and E b enhancement, which contributed to a significant increase of W rec and η. Specially, the optimum W rec of 4.43 J/cm³ and η of 71.51 % were achieved at the composition of 0.9NN-0.1BF. Besides, stable energy storage performance was maintained over a wide temperature range (20–120 °C). These results highlight the potential of NN-BF relaxor AFE ceramics as promising candidates for high-performance energy storage applications. [ABSTRACT FROM AUTHOR]

This study investigates the potential of cerium (Ce) doping to improve the performance of cobalt oxide (Co₃O₄) nanoparticles as battery-type supercapacitor electrodes. Pure Co₃O₄ nanoparticles were synthesized via a solution combustion method and then doped with 2.5 % (Ce-Co 3 O 4) and 5 % Ce (CeO 2 -Co 3 O 4). Comprehensive characterization, including X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FESEM), was used to analyze the impact of Ce doping on the material properties. XRD analysis confirmed the successful incorporation of Ce into the Co₃O₄ structure, with distinct CeO 2 phases forming at higher doping levels. Ce doping resulted in decreased crystallite size and peak intensity, indicating reduced crystallinity and increased defect concentration. Raman spectroscopy corroborated these findings, showing a redshift that suggests weakened metal-oxygen bonds and smaller grain sizes due to Ce³⁺ incorporation. FESEM images demonstrated that Ce doping effectively reduced nanoparticle agglomeration, with 2.5 % doping leading to smaller particles and 5 % doping promoting a 2D flake-like morphology with increased porosity. Nitrogen adsorption-desorption measurements revealed a significant increase in surface area and pore volume for CeO 2 -Co₃O₄, facilitating improved electrolyte diffusion and reduced resistance, thereby enhancing electrochemical performance. Evaluation of the electrochemical properties of undoped and Ce-doped Co₃O₄ materials revealed a battery-like response in a three-electrode configuration. Notably, the CeO 2 -Co 3 O 4 exhibited a superior specific capacity of 603.3 C g−1 at a current density of 1 A g−1, significantly exceeding the values of 368.5 C g−1 and 127.1 C g−1 achieved by Ce-Co 3 O 4 and undoped Co 3 O 4 , respectively. Furthermore, the CeO 2 -doped Co 3 O 4 demonstrated exceptional cyclic stability, retaining 87 % of its initial capacity after undergoing 5000 charge-discharge cycles at a high current density of 10 A g−1. These results suggest that Ce doping is a promising strategy for optimizing Co₃O₄-based battery-type electrode materials, potentially leading to the development of high-performance and cost-effective energy storage systems. [ABSTRACT FROM AUTHOR]

The (1-x)Ba 0.94 Ce 0.04 TiO 3 -xBi(In 1/2 (Li 0.5 Ta 0.5) 1/2)O 3 (BCT-BILT) relaxor ferroelectric ceramic system was explored based on the A-site vacancy design and defect dipole engineering. The impacts of different doping concentrations on the phase composition, dielectric and energy storage performance of the BCT-BILT ceramics were studied and discussed in detail. The pure BCT and 0.95BCT-0.05BILT samples exhibited a mixed crystal structure of tetragonal (T) and pseudo-cubic (PC) phase, while the BCT-BILT samples with x > 0.05 possessed a cubic (C) phase, accompanied by the secondary phases of BaBi 2 Ta 2 O 9 and BaTa 2 O 6. With an increase in the BILT doping concentration, the surface morphologies of the ceramics were continuously modulated, and the dielectric loss had been reduced to 0.001 at 1 kHz, which was beneficial to improve the energy storage properties. Compared to the pure BCT, the breakdown field strength was significantly enhanced owing to the formation of Aurivillius phase BaBi 2 Ta 2 O 9 and the increased dielectric relaxation. Ultimately, the highest energy storage density of W rec = 0.7 J/cm3 and high energy conversion efficiency of η = 95 % was realized at the composition of x = 0.05 under a small electric field of 130 kV/cm. Furthermore, the good temperature stability with the Δ W rec / W rec30°C < 9 % and Δ η / η 30°C < 6.5 % was acquired for the samples with x = 0.20–0.30 in the temperature range of 30–120 °C, owing to the synergistic roles of the defect dipoles, impurities BaBi 2 Ta 2 O 9 , and polar nanoregions (PNRs). The 0.95BCT-0.05BILT ceramic obtains discharge energy density W dis of 0.35 J/cm3 and fast discharge speed t 0.9 of 312 ns at 60 kV/cm, current density C D of 255.4 A/cm2 and power density P D of 10.2 MW/cm3 at 80 kV/cm. This work is of guiding significance for designing and optimizing energy storage performance of lead-free relaxors from the perspective of defect building and engineering. [ABSTRACT FROM AUTHOR]

Polymer materials exhibit vibration damping properties, yet scant research exists on their applicability to submarine tunnels. This study investigates the dynamic characteristics of Polymer Materials Resistant to Seawater Erosion (hereafter referred to as PMRSE) under varying conditions of density, confining pressure, strain rate, and erosion duration through dynamic triaxial tests. The results reveal an increase in material strength with a rise in density; enhanced strength and ductility with increasing confining pressure; and augmented strength and yield stress in correspondence with heightened strain rates. As confining pressure ascends, the equivalent damping ratio λd of PMRSE gradually diminishes. SEM and EDS indicate a porous structure for PMRSE, with a molded surface skin formed post‐manufacturing to thwart seawater erosion. The strain energy storage and energy absorption evaluation of PMRSE demonstrate its excellence as an energy‐absorbing material. Eventually, employing a numerical simulation model for a specific submarine tunnel reveals that the presence of a damping layer absorbs seismic energy and enhances the stress conditions of the secondary lining. PMRSE manifests as a strain‐rate sensitive material unaffected by seawater corrosion, which exhibits deformation characteristics of low yield strength and long yield stage. Accordingly, PMRSE proves suitable for vibration damping in submarine tunnels. [ABSTRACT FROM AUTHOR]

Metallic zinc has emerged as a promising anode material for high‐energy battery systems due to its high theoretical capacity (820 mAh g−1), low redox potential for two‐electron reactions, cost‐effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial‐engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron‐thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+‐ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm2 with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g−1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi‐functional membranes that can advance the development of safe and stable zinc metal batteries. [ABSTRACT FROM AUTHOR]

A hydrogel composed of TEMPO-oxidized cellulose and zinc perchlorate is proposed as an electrolyte for rechargeable Zn-ion battery. The non-flowable solid-like electrolyte has strong shear-thinning behavior, room temperature conductivity of ∼10−1 S cm−1, and stable Zn/electrolyte interphase. The Zn-ion gel-battery with a β-MnO2 cathode delivers over 100 mA h g−1 at 1.5 V allowing safe energy storage. [ABSTRACT FROM AUTHOR]

Due to its unique gravimetric energy density and zero carbon emissions, hydrogen is a top priority for the development of future clean and sustainable energy systems. To satisfy energy demand, underground hydrogen storage (UHS) is being adopted. Among underground hydrogen storage sources, aquifers may be one of the best places for large-scale storage of hydrogen (H 2). However, there is still lacking to understand the operational parameters of UHS, which is essential to achieve better UHS performance. In this study, operational parameters such as hydrogen production time, hydrogen injection rate, hydrogen production rate, frequency and length of cycles, shut-in period, number of wells, and spacing of wells are the focus of numerical simulations. Form the results, some insights are obtained as follows: (1) At higher hydrogen injection rates, H 2 recovery performance declined due to the short contact time between hydrogen and water, as well as lateral expansion of the gas. (2) Optimizing the hydrogen production rate and ensuring sufficient production time were crucial for enhancing hydrogen production performance. (3) Shorter lengths and higher frequencies of storage cycles contributed to an increase in the cumulative hydrogen production volume. Moreover, introducing a shut-in period between the injection and production periods exhibited a detrimental effect on the performance of UHS. (4) In the dual-well configuration, cumulative hydrogen production volume and cumulative recovery efficiency experienced increases of at least 0.51 × 107 m3 and 9.27%, respectively. Concerning well spacing, its impact on the performance of UHS was slight. The effectiveness of UHS in aquifers was confirmed by these results. These understandings provide a certain basis for the optimization of operating parameters. • A comprehensive analysis of operational parameters for optimizing hydrogen storage in an aquifer was performed. • The recovery performance of hydrogen decreased as the injection rate varied. • Boosting hydrogen production rate and ensuring sufficient production time are essential for enhancing performance. • Introducing the shut-in period between the injection and production periods proved to be disadvantageous. • A significant improvement in hydrogen recovery efficiency was observed with an increase in the number of wells. [ABSTRACT FROM AUTHOR]

In the contemporary landscape of technological advancements, the burgeoning demand for portable electronics and flexible wearable devices has necessitated the development of energy storage systems with superior volumetric performance. Tungsten oxide (WO3), known for its high density and theoretical capacitance, is a promising electrode material for supercapacitors. However, low conductivity and poor cycling stability are still the key bottlenecks for its application. Herein, a novel composite comprising hollow porous WO3 spheres (HPWS) derived by template method was electrostatic self-assembled on the surface of the Ti3C2T x nanosheets. The resulting electrodes exhibited ultra-high volumetric capacitance of 1930 F cm−3 at 1 A g−1 and rate capability of 46% at 50 A g−1, attributed to enhanced ion accessibility from microporous structure and electron transport from conductive network of Ti3C2T x even at a high packing density of 3.86 g cm−3. Utilizing HPWS/Ti3C2T x as the negative electrode and porous carbon as the positive electrode, the assembled asymmetric supercapacitor achieved an energy density of 31 Wh kg−1 at a power density of 650 W kg−1 with over 107% capacitance retention after 5000 cycles. This work provides a promising approach for developing next-generation supercapacitors with ultra-high volumetric capacitance. [ABSTRACT FROM AUTHOR]

The space heating in residential buildings during winters account for a considerable amount of conventional or high-grade electrical energy. Therefore, improving the performance of space heating systems with the inclusion of renewable energy sources like solar becomes crucial in order to have better occupant's comfort while reducing energy use. Phase change material (PCM) is one of the best solutions for the storage of renewable thermal energy, especially solar, which are intermittently available. PCM stores energy when surplus energy is available and deliver whenever it is required. It can be integrated with the system for energy storage as well as availing heat at a constant temperature. The present study will try to demonstrate the energy-saving by implementing the local heating with a spiral latent heat thermal energy storage system, when only a particular (local) space heating is of interest. In this work, an experimental, as well as the numerical studies of a dome over a bed were performed. Various heating coil configurations, namely floor coil, roof zig-zag, and roof spiral, were constructed to find the best configuration for the localized space heating. Experiments and simulations with the variable flow rate (0.25, 0.50, and 0.75 m/s) and varying inlet temperatures (55, 60, and 65 °C) of the heat transfer fluid were carried out. It was found that the floor coil heating gives better results as compared with the other two. It was also seen that the effect of mass flow rate and inlet temperature was not that much significant after a limit. A temperature difference of 20 °C was maintained between the space under consideration with the surrounding room. [ABSTRACT FROM AUTHOR]

Lead-free ceramic capacitors are extensively utilized in pulsed power systems for their environmentally friendly characteristics, high power density, and fast charging/discharging rate. However, it remains highly challenging to achieve concurrent improvements in both recoverable energy storage density (W rec) and efficiency (η). In this study, Ta 2 O 5 with a wide bandgap (∼4 eV) was chosen in complex with Mg2+ ions to form Ba(Mg 1/3 Ta 2/3)O 3 as the second phase of a BNT-based solid solution. Combined with phase modulation, a compositional disorder of equipotential sites is formed in chalcogenide crystals, which in turn induces charge disorder generating localized random fields. We have designed and prepared a set of binary (1-x)Bi 0.5 Na 0.5 TiO 3 -xBa(Mg 1/3 Ta 2/3)O 3 (BNT-xBMT) ceramics using a conventional solid-phase method. An ultra-high breakdown field strength (E b) value (245 kV/cm) was attained in 0.80BNT-0.20BMT ceramic, resulting in desirable values of W rec (3.99 J/cm3) and η (92.0 %). These results offer a new strategy for designing high entropy ceramic materials of high performance in the future. [ABSTRACT FROM AUTHOR]

The futuristic technology demands materials exhibiting multifunctional properties. Keeping this in mind, an in-depth investigation and comparison of the dielectric, ferroelectric, piezoelectric, energy storage, electrocaloric, and piezocatalytic properties have been carried out on Ba 0.92 Ca 0.08 Zr 0.09 Ti 0.91 O 3 (BCZT) and Ba 0.92 Ca 0.08 Sn 0.09 Ti 0.91 O 3 (BCST) lead-free compounds synthesized through the conventional solid state reaction method. Further, the Rietveld refinement against the XRD patterns affirmed the coexistence of orthorhombic (Amm2) and tetragonal (P4mm) phases at room temperature for both compounds. While BCZT compound demonstrated remarkable dielectric, piezoelectric, and piezocatalytic characteristics with maximum dielectric constant ( ε m ) ≈ 13304 near the Curie temperature (T c ≈ 105 °C), converse piezoelectric coefficient (d 33 ∗) ≈ 609 p.m. V−1, power density (P d) ≈ 89.71 kW cm−3 at room temperature, and 82.7 % Rhodamine B (RhB) dye degradation capability; on the other hand, BCST compound exceled in superior energy storage density (W r e c ) ≈ 191.8 mJ cm−3 with efficiency η ≈ 73.26 % near room temperature and enhanced electrocaloric properties with adiabatic temperature change (Δ T) ≈ 0.980 K, isothermal entropy change (Δ S) ≈ 1.15 J kg−1K−1 and a higher electrocaloric responsivity (Δ T / Δ E) ≈ 0.49 K mm kV−1. These distinctions arise from the difference in ionic radii, lattice distortion, and the electronic configurations of the dopant ions, leading to a greater polarization change and a lower coercive electric field in the BCST ceramic. The outcome of the present study provides valuable insights for selecting a dopant tailored compound for specific application and underscores the potential of such ceramics in energy storage, piezocatalysis, and the development of advanced solid-state cooling devices for future applications. [ABSTRACT FROM AUTHOR]

Excellent comprehensive energy storage performance is essential to ensure a favorable application prospect for high entropy dielectric capacitors. In this work, the energy storage performance of 0.8(Na 0.5 Li 0.5 NbO 3)-0.2(Sr 0.5 Bi 0.5)(Fe 0.5 Ti 0.25 Zr0.25)O 3 ceramics with high entropy was improved by incorporating various contents of MnO. The results show that with the addition of MnO, the relaxation behavior is enhanced, significantly improving energy storage performance, and a recoverable energy density of 7.93 J/cm³ and energy efficiency of 90.6 % is achieved for [0.8(Na 0.5 Li 0.5 NbO 3)-0.2(Sr 0.5 Bi 0.5)(Fe 0.5 Ti 0.25 Zr0.25)O 3 ]-0.05MnO under a 510 kV/cm electric field. Compared with non-MnO-doped ceramics, the size of the polar nanoregions (PNRs) is significantly reduced. It also shows remarkable stability to temperature and frequency. This study validates that integrating MnO effectively enhances the energy storage performance of high-entropy ceramics. [ABSTRACT FROM AUTHOR]

Global energy crisis imposes immense obstacles leading towards development of innovative devices, and supercapacitors (SCs) are thought to be a viable energy storage technology. The engineering of nanostructured materials with a distinct and consistent morphological design is seen as a better option for various range of electrochemical energy sources. This study reports novel binder-free Ni 3 S 2 /CoS 2 electrode material that acquires higher energy, higher energy density, as well as its simple preparation method, low cost, and earth–abundant resources. The morphological, structural, and textural characteristics resulted in surface area of 46 m2 g−1 of Ni 3 S 2 /CoS 2 that will increase active sites also. The synthesized nanocomposite has particle size of 41.1 nm that leads to enhanced active sites and greater surface area as confirmed through BET analysis. Ni 3 S 2 /CoS 2 nanocomposite has high specific capacity around 828.14 F g−1 at 5 mV s−1 sweep rate using 2 M KOH, a high energy density around 115.01 Wh kg−1, and power density of 1000 Wh kg−1. Ni 3 S 2 /CoS 2 acquires higher ionic conductivity of 5 S m−1, this will enhance the inter-layer transference of electrons, and these results perfectly correlates with EIS, resulting in charge transfer resistance value of 0.9 Ω for nano-composite. These enhanced electrochemical capabilities of Ni 3 S 2 /CoS 2 hold significant potential in practical viability. [ABSTRACT FROM AUTHOR]

Currently, there has been a growing interest in constructing metal oxide composite structures through the in-situ synthesis method, especially for fabricating electrode materials for supercapacitors. This approach offers several advantages, such as improved contact between different materials, enhanced conductivity, efficient ion diffusion, and better overall electrochemical performance. This work investigates the synthesis of zinc manganese oxide and manganese oxyhydroxide (ZnMn 2 O 4 /MnOOH) composite using a solvothermal method. The structure, surface morphology, and composition of the ZnMn 2 O 4 /MnOOH composite were elucidated using standard physicochemical characterization techniques where the presence of ZnMn 2 O 4 and MnOOH phases was confirmed and the ZnMn 2 O 4 /MnOOH nanocomposite behaved as a pseudocapacitive electrode with a notable specific capacitance of 1039.2 F g⁻1 at a current density of 1 A g⁻1. When subjected to a 10-fold increase in current density, the ZnMn 2 O 4 /MnOOH electrode maintained 50 % of its initial capacity, registering 513.4 F g⁻1. Additionally, the electrode showcased excellent cyclic stability, preserving 95 % of its initial capacity after 5000 cycles at 10 A g⁻1. Moreover, the constructed ZnMn 2 O 4 /MnOOH//activated carbon (AC) asymmetric supercapacitor (ASC) device attained a high energy density of 29.45 Wh kg⁻1 at a power density of 1384.5 W kg⁻1. The results confirm that the ZnMn 2 O 4 /MnOOH composite, prepared in a single synthesis step, shows great potential as a phenomenal pseudocapacitive electrode for energy storage applications. [ABSTRACT FROM AUTHOR]

In this study, we investigated the phase structure, Curie temperature, dielectric properties, piezoelectricity, and energy-storage properties of BiFeO 3 (BFO)-modified (Ba 0.95 Ca 0.05) (Ti 0.89 Sn 0.11)O 3 (BCTSO) ceramics using both experimental and theoretical methods. The results indicated that the lattice distortion and chaotic distribution of the local charge increased with the BFO content, resulting in a phase transition and transformation from a ferroelectric to a relaxing ferroelectric. First-principles calculations revealed that the Curie temperature decreased with increasing BFO content, primarily because of an increase in the ground state energy. The variation in the permittivity of the BCTSO- x BFO ceramics with temperature and frequency is affected by the phase structure and Maxwell-Wagner interface polarisation, respectively. The electrical modulus measurements indicated that BCTSO- x BFO exhibited non-Debye-type dielectric relaxation for x = 0.0, 0.1, and 0.5 %, whereas BCTSO- x BFO showed Debye-type dielectric relaxation for x = 0.9%. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable zinc ion batteries (ARZIBs) represent a cheaper and more environmentally friendly alternative to lithium-ion batteries (LIBs) in energy storage systems. Vanadium oxide is one of the most attractive materials to be used as a cathode in ARZIBs because it has multiple oxidation states that grant high specific capacity. This work employed an alternative synthetic route to obtain VO 2 with varied morphology and structural properties utilizing vanadyl acetylacetonate as a precursor by tuning the temperature during two-step solvothermal/hydrothermal treatment. When highly crystalline VO 2 (B) with rod morphology is obtained, the electrode exhibits the best electrochemical response, with the most significant contribution of surface-confined redox processes to the charge stored. The ARZIB assembled with VO 2 rod showed an initial capacity of up to ∼300 mA h g−1 (2.4 mA h cm−2) at 0.1 A g−1, delivering a specific energy of up to 168 W h kg−1 at a specific power of 65 W kg−1. It exhibits outstanding stability after 2000 GCD cycles at 2.5 A g−1. Ex-situ structural and spectroscopic characterization showed that Zn2+ storage causes an expansion and contraction of the lattice without evidence of crystalline phase transformations. [ABSTRACT FROM AUTHOR]

As the world shifts towards renewable energy and more efficient energy storage systems, the demand for advanced materials that can support these technologies has increased. One such promising material class is High Entropy Alloys (HEAs). Unlike conventional alloys, which are typically composed of one or two principal elements, HEAs consist of multiple principal elements in near-equiatomic proportions. Their unique atomic structure, characterized by high configurational entropy, endows them with enhanced stability, tunability, and a high specific surface area—qualities that are highly desirable in supercapacitor applications. HEAs offer significant advantages as supercapacitor electrodes, including increased energy storage capacity, superior electrochemical stability, and the potential for synergistic effects that improve overall performance such as higher energy density, longer cycle life, and greater reliability. FeCoNiCuZn) 3 O 4 has been synthesized by utilizing multiple induction melting process in a quartz tube at 1100 °C , followed by ball milling in order to transform the small pieces into nanostructured powder. The highest specific capacitance obtained is 245.7 F g−1 at 1.5 A g−1 in three electrode measurement system. In addition, plastic biochar was prepared using pyrolysis techniques from plastic wastage. Moreover, it is utilized for supercapacitor application, which shows a maximum specific capacitance of 180 F g−1 at 1 A g−1 for three electrode system. The combing above two electrode materials, the fabricated asymmetric device shows a maximum specific capacitance of 58 F g−1 at 1 A g−1 for 3M KOH electrolyte with maximum specific energy of 23.44 Wh kg−1 at specific power of 1700 W kg−1. [ABSTRACT FROM AUTHOR]

Electric double layer effect in solid electrochemical systems is a key topic in energy storage applications. In this review, we outline recent investigations on the electric double layer effect of solid electrolyte interfaces by utilizing a semiconducting diamond surface as a probe of electrical charges at the solid/solid interfaces. Hall measurements with various solid electrolyte-based transistors evidenced that the electric double-layer effect strongly depends on the properties of the electrolyte and the very thin region from the interface. The unveiled features of the electric double layer at solid electrolyte interfaces are quantitatively discussed from the viewpoint of charge density and charging-discharging rate. Furthermore, applications of the unique switching response of the electric double layer transistors to neuromorphic computing are also demonstrated. [ABSTRACT FROM AUTHOR]

With the rapid development of energy storage devices, lithium–sulfur batteries are considered as one of the promising candidates due to their high energy density (2600 Wh Kg−1) and low cost of sulfur. Despite these advantages, the application of lithium–sulfur batteries is limited by many issues, such as the shuttle effect of polysulfide and slow redox reactions. In this paper, hydrogen-bonded organic frameworks (HOFs) materials are chosen for the first time to improve the performance of sulfur cathodes by exploiting their unique properties. Thanks to the abundant hydrogen bond of HOFs materials, which can interact with lithium polysulfide, this S-HOF composite can inhibit the shuttle of polysulfide and enhance the transformation of polysulfide. As a result, the HOF-S composite has a high initial capacity of 1100 mAh g−1 at 0.1 C and 530 mAh g−1 at 1 C. In this paper, hydrogen-bonded organic frameworks (HOFs) materials are chosen for the first time to improve the performance of sulfur cathodes. In the S-HOF, abundant hydrogen bond sites can interact with lithium polysulfide to inhibit the shuttle of polysulfide and accelerate the redox conversion of polysulfide. Therefore, the S-HOF composite has higher capacity and cycle stability. The initial capacity of the S-HOF composite is 1100 mAh g–1 at 0.1 C and 530 mAh g–1 at 1 C. [ABSTRACT FROM AUTHOR]

This study introduces a new analytical framework that employs the image‐well method to simulate the spatial and temporal temperature distribution in vertical borehole thermal energy storage (BTES) systems. The model accommodates complex boundary shapes and conditions, including insulation, convection, and constant temperature, without requiring iterative solutions at each time step. The model's accuracy and utility are demonstrated through an application to a borehole heat exchanger cluster arranged in an octagonal shape with insulating boundaries, based on a BTES site in Drake Landing (Canada). Model predictions are validated against a finite element model, showing a root‐mean‐square error of 0.012°C. A global sensitivity analysis highlights the influence of thermal parameters on system performance, identifying the heat flux of the borehole heat exchanger as the most sensitive parameter. Overall, this approach combines the advantages of analytical and numerical techniques to provide a clear and efficient tool for evaluating BTES systems, offering significant potential for advancing sustainable energy solutions. [ABSTRACT FROM AUTHOR]

The green energy storage of polyaniline, without major wastages excreted into the environment is effectively demonstrated by using the polyaniline as supercapacitor electrode and the by-product obtained during the synthesis of polyaniline as its electrolyte. This green approach to the energy storage properties of sulphuric acid doped polyaniline (H-PANI) exhibited a substantial improvement in its energy storage, compared to the conventional approach of using an ionically conducting liquid as electrolyte like 1 M H2SO4 (SA), separately. The amelioration of 40.44% was achieved when the by-product obtained as supernatant liquid (SL) was used as electrolyte compared to SA. The H-PANI provided a specific capacity (Q) of 146.4 C g−1, a specific energy (E) of 24.40 W h kg−1 and a specific power (P) of 1.200 kW kg−1 at 1 A g−1 in the presence of SA. The Q of 205.6 C g−1, E of 34.26 W h kg−1 (similar range of E of Pb-acid batteries), P of 1.200 kW kg−1 were achieved in the presence of SL at 1 A g−1 and a high rate capability of 29.18% retention of initial Q up to 25 A g−1 was also achieved. This approach is useful to harvest high energy characters from PANI. [ABSTRACT FROM AUTHOR]

Challenge of achieving high energy density (E) comparable with Li-ion batteries in supercapacitors, with low potential window offering aqueous electrolytes (1.2 V) has been overcome by using the electrode material composed of rGO 3.70%:PANI 51.86%:V2O5 33.33%:SnO2 11.11% (GPVS). The GPVS exhibited different extents of energy storage in the presence of 1 M sulphuric acid (H2SO4) and acidified supernatant liquid (ASL), a green electrolyte. Here, the ASL is the by-product, which is obtained as supernatant liquid after the synthesis of GPVS composites in an in situ synthetic method, and acidified using conc. H2SO4. The energy storage obtained in the presence of ASL is 38% higher than the energy storage obtained in the presence of H2SO4. The GPVS exhibited a remarkable feature of amelioration of energy storage with increase in CV cycles in the presence of H2SO4. The GPVS exhibited an extraordinary cyclic stability up to 41,300 cycles. The energy storage parameters achieved in the presence of H2SO4 after 33,800 cycles are, a specific capacitance (Cs) of 694.44 F g‒1, an E of 138.88 W h kg‒1 (comparable with E of Li-ion batteries) and a power density (P) of 2.1020 kW kg‒1 at 1 A g‒1. The energy storage parameters achieved in the presence of ASL are, a Cs of 212.31 F g‒1, an E of 42.46 W h kg‒1 (comparable with E of Ni–Cd batteries) and a P of 3.1583 kW kg‒1 at 2 A g‒1. It is satisfying that all these high energy characters are achieved with the real two electrodes–supercapacitor cell step up. The green supercapacitors are made by using the by-product, which is obtained as supernatant liquid after the synthesis of GPVS as its electrolytes. [ABSTRACT FROM AUTHOR]

The pursuit of sustainable and efficient energy storage solutions has driven extensive research into advanced electrode materials for pseudocapacitors. In this work, manganese cobalt sulfide (MnCo2S4) and reduced graphene oxide (rGO) were synthesized hydrothermally. The presence of functional groups in crumpled sheet-like rGO having high surface area enhanced the charge storage ability. The existence of multiple oxidation states in MnCo2S4 accounts for the faradic process on the electrode surface. MnCo2S4 and rGO exhibit a specific capacitance of 414 F/g and 588 F/g at the scan rate of 5 mV/s with the faradic dominating behavior in 6 M potassium hydroxide electrolyte. Non-linear charge–discharge curves with plateaus denoted the voltage range for the occurrence of redox reaction. Low charge transfer resistance and solution resistance were observed along with Warburg diffusion resistance in impedance measurements. An asymmetric configuration of electrode containing anode, cathode, separator, and electrolyte was constructed to check the practical relevancy. [ABSTRACT FROM AUTHOR]

Direct current (DC) microgrid has recently gained potential interest since it supports easy integration of distributed generators (DGs) and energy storage devices (ESDs). However, most DGs and ESDs are integrated into the DC bus with the power electronic converter/inverter. Thus, controlling large-scale power electronic-based generators, loads, and ESDs becomes a challenging task. This paper introduces a new control strategy for the DC microgrid to regulate the bus voltage and power sharing among the DGs, ESDs, resistive loads, and constant power loads (CPLs). Each battery's state of charge (SoC) is utilized in the double control loop to determine the charging/discharging speed. Besides, an additional fractional-order proportional-integral voltage compensation loop is introduced to regulate the DC bus voltage. The SoC-based inner loops assist in the automatic balancing of battery charges, while the compensation loop minimizes the DC bus voltage deviation. A detailed small-signal model is derived to design the controller parameter. The optimization approach is applied to the developed model with the objective of reducing the integral square error of the step response. The DC microgrid system with the designed controller is tested with the simulation study. The results depict that the bus voltage deviation is reduced by 63.27% while the SoC balancing is faster for both charging and discharging modes. [ABSTRACT FROM AUTHOR]

Microgrids are designed to utilize renewable energy resources (RER) that are revolutionary choices in reducing the environmental effect while producing electricity. The RER intermittency poses technical and economic challenges for the microgrid systems that can be overcome by utilizing the full potential of hybrid energy storage systems (HESS). A microgrid comprising of a solar photovoltaic panel, wind turbine, lead-acid battery, electrolyzer, fuel cell, and hydrogen (H 2 ) tank is considered for techno-economic feasibility and environmental impact assessment on a grid integration scenario. Mathematical functions are utilized to model the components for estimating annual hourly renewable generation and energy storage behavior. The load consumption model for 50 homes is generated using Gaussian distribution to incorporate the uncertainty. Optimal sizing of the microgrid components is determined using the particle swarm optimization (PSO) algorithm to minimize the upfront installation cost and levelized cost of energy (LCOE). Different energy storage penetration scenarios, e.g., 25%, 50%, 75%, and 100% for the microgrid system, are considered where 100% penetration level stands for maintaining the load demand using the available resources without depending on the grid energy supply. The lowest LCOE is found between 0.06 $/kWh and 0.11 $/kWh, and the highest annual GHG is reduced to half compared to the grid emission. GHG is imposed around 62.14 (tCO 2 e/yr) - 73.57 (tCO 2 e/yr) for Madrid and Seville, respectively. [ABSTRACT FROM AUTHOR]

Due to the depletion of fossil fuels, extensive CO2 emissions, and growing demand for electrochemical energy, it is important to develop further utilization of renewable energy, as well as advanced energy storage techniques. To this end, the optically chargeable supercapacitor, which can convert the photon energy of solar light into electrochemical energy and store it for long‐term usage, attracts extensive investigations. Among these, heterojunction construction was revealed as an effective method to enhance capacity. Recent works have reported the implementations of precipitation in ceramics, where the introduced matrix‐precipitate two‐phase structure is inspiring for constructing heterojunction, whereas it was seldom reported. In this work, Li‐doped NaNbO3 electrode material was prepared by adopting a multi‐step solid reaction to precipitate LiNbO3 and construct LiNbO3/NaNbO3 heterojunctions. The electrochemical measurement demonstrates an enhanced optically chargeable capacity of roughly 85% increase at a scan rate of 1 mV/s and a four‐fold increase at a charging–discharging current density of 1 A/g, as well as outstanding stability by introducing precipitates and constructing heterojunctions. This finding proposes a novel methodology design of heterojunction construction via precipitation to enhance the optically chargeable capacity of supercapacitor electrode materials and, therefore, may open up a potentially new application field for precipitate‐tuned functionality in functional ceramics. [ABSTRACT FROM AUTHOR]

This study proposes a novel strategy to modulate the morphology and electronic structure of MOFs through ligand exchange for high-performance energy storage and conversion devices. The prepared CoNi-TDA/0.2Fc had an oxygen generation reaction (OER) overpotential of 236 mV at 10 mA cm−2 and a significant specific capacitance of 1409 F−1 at 1 A/g, maintaining a capacitance retention of 96.54% after 20,000 cycles. [Display omitted] Rationally designing metal organic frameworks (MOFs) as an ideal dual-function material for water electrolysis and supercapacitors is of great significance for energy storage and conversion. Herein, we successfully synthesized the nanoneedle-like structure CoNi-MOF by partially replacing 2, 5-thiophenedicarboxylic acid (TDA) with 1, 1′-Ferrocenedicarboxylate (Fc). The exchange of Fc ligand can modulate the morphology and electronic structure of CoNi-TDA, thus exposing the abundant active sites and improving the electrical conductivity. The as-prepared CoNi-TDA/0.2Fc exhibited a low overpotential of 236 mV at 10 mA cm−2 for oxygen evolution reaction (OER) and a low Tafel slope of 40.44 mV dec−1. Additionally, CoNi-TDA/0.2Fc demonstrated a notable specific capacitance of 1409 F g−1 at 1 A/g and excellent stability, maintaining a capacitance retention of 96.54 % after 20,000 cycles. The study proposes a new strategy to modulate the morphology and electronic structure of MOFs via the ligand exchange for high-performance energy storage and conversion device. [ABSTRACT FROM AUTHOR]

[Display omitted] The construction of solid-state electrolytes for flexible zinc-air batteries is extremely challenging. A flexible and highly conductive solid electrolyte designed with a "seaweed structure" is reported in this work. Sodium alginate serves as the backbone to form a robust network structure, and the grafted quaternary ammonium groups provide channels for rapid ion transport, achieving excellent flexibility and hydroxide conductivity. The conductivity of the modified electrolyte membrane (QASA) is 5.23 × 10−2 S cm−1 at room temperature and reaches up to 8.51 × 10−2 S cm−1 at 75 °C. In the QASA based battery, bending at any angle is realized, and the power density is up to 57.28 mW cm−2. This work provides a new way to prepare high conductivity, green solid-state zinc-air batteries, and opens up a research line of thought for flexible energy storage materials. [ABSTRACT FROM AUTHOR]

[Display omitted] Affinity and storage capacity for zinc ions of the electrode materials are crucial factors on the properties of zinc ion hybrid capacitors (ZHICs). Wasted pulping liquor with abundant carbohydrates, lignin and inorganic matter served as a unique precursor to produce embedded oxygen-doped hierarchical porous carbon directly through a one-step carbonization process in this investigation. In carbonization process, lignin can serve effectively as the carbon framework, carbohydrates not only act as sacrificial templates but also offer a plentiful oxygen source which can increase the affinity for Zn2+, and sodium-containing inorganic substances plays a role as hard templates to optimize the pore structure. The resulting porous carbon under carbonization temperature of 800 °C shows a high specifical area of 2186 m2g−1 with oxygen content of 4.8 %, which can reduce the adsorption energy of Zn2+ from −0.16 eV to −0.32 eV through electrochemical techniques and density functional theory (DFT) calculations, the incorporation of oxygen was demonstrated to enhance the adsorption and desorption kinetics of Zn2+, suggesting a bright future for application in the domain of energy storage. The resulting ZIHC assembly showcases a notable energy density of 84.6 Wh kg−1 at a power density of 359 W kg−1. Remarkably, even after 10,000 charge and discharge cycles, it exhibits exceptional cycle stability with retaining 86.56 % of its capacity. Consequently, this approach provides fresh insights for exploring the facile and commercial fabrication of biomass-derived cathodes for ZIHCs, thereby propelling the progress of eco-friendly energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous Zn–S batteries (AZSBs) have garnered increasing attention in the energy storage field owing to their high capacity, energy density, and cost effectiveness. Nevertheless, sulfur (S) cathodes face challenges, primarily stemming from sluggish reaction kinetics and the formation of an irreversible byproduct (SO 4 2−) during the charge, hindering the progress of AZSBs. Herein, Te–S bonds within S-based cathodes were introduced to enhance electron and ion transport and facilitate the conversion reaction from zinc sulfide (ZnS) to S. This was achieved by constructing heteroatomic TeS-x@Ketjen black composite cathodes (HM-TeS-x@KB, where x = 36, 9, and 4). The HM-TeS-9@KB electrode exhibits long-term cycling stability, maintaining a capacity decay rate of 0.1 % per cycle over 450 cycles at a current density of 10 A g−1. Crucially, through a combination of experimental data analysis and theoretical calculations, the impact mechanism of Te on the charge and discharge of S active materials within the HM-TeS-9@KB cathode in AZSBs was investigated. The presence of Te–S bonds boost the intrinsic conductivity and wettability of the HM-TeS-9@KB cathode. Furthermore, during the charge, the interaction of preferentially oxidized Te with S atoms within ZnS promotes the oxidation reaction from ZnS to S and suppresses the irreversible side reaction between ZnS and H 2 O. These findings indicate that the heteroatomization of chalcogen S molecules represents a promising approach for enhancing the electrochemical performance of S cathodes in AZSBs. [ABSTRACT FROM AUTHOR]

Aqueous sodium-ion batteries hold practical promise for large-scale energy storage; however, the energy density and lifespan are constrained by the decomposition of anode materials. To address this issue, a Bi-coating is applied to inhibit the localized enrichment of OH– near the NTP surface, effectively curbing its dissolution. Moreover, the Bi-coating on the hybrid anode ensures a higher capacity compared to other NTP-based anodes, attributed to the anion-cation relay mechanism. This study lays the foundation for a potential approach to developing long-lifespan NTP-based anodes and SIBs. [Display omitted] • The OH– hindered Bi-coating was firstly constructed by elaborate design. • The designed Bi-coating can significantly enhance the stability of NTP. • The NTP-based hybrid anode sets a new record for the capacity. Aqueous sodium-ion batteries (ASIBs) show great promise as candidates for large-scale energy storage. However, the potential of ASIB is impeded by the limited availability of suitable anode types and the occurrence of dissolution side reactions linked to hydrogen evolution. In this study, we addressed these challenges by developing a Bi-coating modified anode based on a sodium titanium phosphate (NTP)-carbon fibers (CFs) hybrid electrode (NTP-CFs/Bi). The Bi-coating effectively mitigates the localized enrichment of hydroxyl anion (OH–) near the NTP surface, thus addressing the dissolution issue. Notably, the Bi-coating not only restricts the local abundance of OH– to inhibit dissolution but also ensures a higher capacity compared with other NTP-based anodes. Consequently, the NTP-CFs/Bi anode demonstrates an impressive specific capacity of 216.8 mAh/g at 0.2 mV/s and maintains a 90.7 % capacity retention after 1000 cycles at 6.3 A/g. This achievement sets a new capacity record among NTP-based anodes for sodium storage. Furthermore, when paired with a cathode composed of hydroxy nickel oxide directly grown on Ni foam, we assembled a seawater-based cell exhibiting high energy and power densities, surpassing the most recently reported ASIBs. This groundbreaking work lays the foundation for a potential method to develop long-life NTP-based anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] Hybrid supercapacitors (HSCs) with facile integration and high process compatibility are considered ideal power sources for portable consumer electronics. However, as a crucial component for storing energy, traditional thin-film electrodes exhibit low energy density. Although increasing the thickness of thin films can enhance the energy density of the electrodes, it gives rise to issues such as poor mechanical stability and long electron/ion transport pathways. Constructing a stable three-dimensional (3D) ordered thick electrode is considered the key to addressing the aforementioned contradictions. In this work, a manufacturing process combining lithography and chemical deposition techniques is developed to produce large-area and high-aspect-ratio 3D nickel ordered cylindrical array (NiOCA) current collectors. Positive electrodes loaded with nickel–cobalt bimetallic hydroxide (NiOCA/NiCo-LDH) are constructed by electrodeposition, and HSCs are assembled with NiOCA/nitrogen-doped porous carbon (NiOCA/NPC) as negative electrodes. The HSCs exhibits 55% capacity retention with the current density ranging from 2 to 50 mA cm−2. Moreover, it maintains 98.2% of the initial capacity after long-term cycling of 15,000 cycles at a current density of 10 mA cm−2. The manufacturing process demonstrates customizability and favorable repeatability. It is anticipated to provide innovative concepts for the large-scale production of 3D microarray thick electrodes for high-performance energy storage system. [ABSTRACT FROM AUTHOR]

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This work reports a green synthesis of CuO/NiO nanocomposite with different CuO/NiO ratios. The X-ray diffraction (XRD) confirmed the existence of both CuO and NiO. This was also confirmed by energy dispersive X-ray (EDX). Scanning electron microscopy (SEM) reveals that changing the compositions of the nanocomposites resulted in different surface morphologies with different particle shapes, sizes, and levels of aggregation. Nitrogen adsorption-desorption analysis showed microporous structures with pore size in the range of 1.66-1.75 nm and surface area in the range of 82-513 m2g−1. The supercapacitive activity was examined by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The results display that the 1C3N exhibited the highest capacitive performance of 1072 Fg−1 compared to 760, 716, and 260 Fg−1 for 3C1N, 4 N, and 4 C, respectively. Furthermore, the 1C3N electrode shows a cyclic stability of 72% after 4000 cycles, which makes it a promising candidate for supercapacitive applications. [ABSTRACT FROM AUTHOR]