Excellent Energy Storage Properties Research Articles

High energy density and efficiency of laminated polymeric blend-based composites via introducing ultra-low content micrometer sheets

Polymeric blend-based composites are promising for dielectric capacitor due to the excellent dielectric and energy storage properties. However, the electric displacement difference (Dmax-Dr) and dielectric constant (εr) of the polymeric blend-based composites are incompatible, which further limits the improvement of the available energy densities (Ue). In this study, we propose the solution-processable laminated polymeric blend-based composites to address this challenge. The concurrent enhancement in Dmax-Dr, εr, Ue and charge-discharge efficiency (η) of designed composites is attributed to the synergistic interaction between macroscopic layered interfaces and microscopic interfaces. The laminated polymeric blend-based composites were fabricated by utilizing a blend of 50 wt% poly(vinylidene difluoride)-hexafluoropropylene (P(VDF-HFP)) and linear poly(methyl methacrylate) (PMMA) as the outer layer and P(VDF-HFP)/PMMA incorporated with an ultralow content alumina-modified strontium titanate plates (SrTiO3@Al2O3) the inner layer. As a result, laminated polymeric blend-based composite with the optimized content (0.5 vol%) delivers a maximum Ue of 14.36 J/cm3 due to highest Dmax-Dr of 7.96 μC/cm2, εr of 6.12 (1 kHz), Eb of 400 MV/m, and η of 76.6 %, outperforms those of representative polymer blend-based composites. Specially, laminated polymeric blend-based composite also exhibits the excellent energy storage reliability of different areas. Therefore, this contribution provides a viable approach to promote polymeric blend-based composites for capacitive energy storage.

High-Performance Electro-optical Dual-Mode Color-Changing and Energy Storage Device Based on Mo-Doped WO3 and TiO2/NiO Thin Films.

Under optical and electrical control, a multifunctional electro-optical dual-control color-changing and energy storage device not only realizes fast color conversion but also achieves good energy storage performance. In this work, Mo-doped WO3 (Mo-WO3) films were prepared by a one-step hydrothermal method, among which the 2 at. % Mo-doped WO3 film has the best electrochromic and energy storage performance. Meanwhile, TiO2/NiO composite films were prepared by the hydrothermal method and electrodeposition method. The TiO2/NiO/N719 photoanode was prepared by the dip-dyeing method on the TiO2/NiO composite film. The results show that the TiO2/NiO-10s/N719 composite film has excellent photoelectric conversion and energy storage properties. Finally, choosing Mo-WO3 as the cathode and the TiO2/NiO/N719 film as the anode, a multifunctional electro-optical dual-control Mo-WO3@TiO2/NiO/N719 color-changing and energy storage device was constructed. Under electrical control, it shows a fast color switching rate (the coloring/bleaching time is 4.1/2.9 s), excellent coloration efficiency (62.1 cm2/C), obviously improved area capacitance (90.4 mF/cm2), and excellent cycle stability. Under optical control, it shows a shortened optical response time (the coloring/bleaching is 70.3/158.9 s), excellent coloration efficiency (58.2 cm2/C), better area capacitance (51.1 mF/cm2), and excellent photoelectric conversion efficiency.

Achieving ultra-high energy storage performance in simple systems through minimal element substitution

Dielectric capacitors are essential components of modern advanced electronic devices and power systems based on their ultra-fast charging and discharging speeds and supreme power densities. Nevertheless, how to comprehensively boost their energy storage density and storage efficiency is still an insurmountable challenge. Here, we report a simple micro-chemical polarizability modulation strategy that enables SrTiO3-based dielectric materials to achieve excellent energy storage properties. The energy density and energy efficiency are increased to as high as 76 J∙cm−3 and 72 % from 0.4 J∙cm−3 and 46.7 % of pure STO, respectively, which is the largest value in micro-substitution (less than 3 %). Our results show that the introduction of trace amounts of elements with high ionic polarizabilities (Mn, V) facilitates the increase of chemical disorder and the formation of stable and highly dynamic polar nanoregions (PNRs), which reduces the hysteresis of the polarization switching and improves the polarization at the breakdown field strength, synergistically fostering the energy storage performance. The results of X-ray photoelectron spectroscopy and scanning electron microscopy reveal that the micro-substitution of Mn and V promote the reduction of oxygen vacancies and grain size, improving the breakdown resistance and stability of the capacitor. This present approach is expected to be widely used in the development of high-performance dielectrics.

Self-supported NiCo2O4@Ni1.18S core-shell nanocomposite with impressive electrochemical properties suitable for hybrid supercapacitors

Self-supported NiCo2O4@Ni1.18S core-shell nanocomposite were synthesized on nickel foams by uniform growth Ni1.18S nanosheets encircling NiCo2O4 nanoneedles. Characterization results demonstrate that NiCo2O4@Ni1.18S core-shell nanocomposite have significant advantages in one - and two-dimensional nanostructure coordination structure, with richer REDOX active sites and more energy storage paths. Density functional theory (DFT) calculations results indicate that the surficial adsorption energy with OH− ions is enhanced in NiCo2O4@ Ni1.18S nanocomposite, thereby facilitating the reversible redox reaction kinetics and the electrochemical activity. As a result, self-supported NiCo2O4@Ni1.18S core-shell nanocomposite exhibit excellent energy-storage properties, i.e.: the specific charge capacity of 3158 F g−1 at 1 A g−1, high rate performance of 52.3 % from 1 A g−1 to 5 A g−1, and the 81.25 % capacity retention rate after 5000 cycles. Especially, it should be pointed out that the hybrid supercapacitors assembled from self-supported NiCo2O4@Ni1.18S core-shell nanocomposite and activated carbon present the wide voltage window (0–1.6 V), high energy density of 100.3 Wh kg−1 at power density of 177 W kg−1 and prospective commercial consideration. These facts fully prove the practical feasibility of self-supported NiCo2O4@Ni1.18S core-shell nanocomposite in advanced energy-storage facilities.

Deciphering the relationships among phase boundary, domain structure, and excellent electrical properties of ternary Bi0.5Na0.5TiO3-Bi0.2Sr0.7TiO3-NaNbO3 ferroelectrics

Bi0.5Na0.5TiO3-based ferroelectric ceramics have broad application prospects due to their excellent electrical properties and are considered to be one of the most promising functional materials to supersede lead-based materials. Here, 0.9Bi0.5Na0.5TiO3-0.1Bi0.2Sr0.7TiO3-xNaNbO3 (BNT-BST-xNN) ternary lead-free ferroelectric ceramics were prepared, and the origin of their excellent dielectric properties was investigated in terms of phase boundary and domain structure. The introduction of NN led to a phase transition from the ferroelectric rhombohedral phase (R3c) to the relaxor tetragonal phase (P4bm), and the two phases coexisted in the BNT-BST-xNN ternary solid solution with x ranging from 0.06 to 0.2. Meanwhile, the macroscopic domain of BNT-BST was destroyed and replaced by highly active polar nano-regions (PNRs) of the P4bm phase, leading to an increase in local structural disorder and enhanced relaxor behavior. A dielectric constant (εr) of ∼1765 (150 °C) with Δε/ε150 °C less than 15 % over a broad range from 80 to 328 °C was achieved in the BNT-BST-0.15NN, and an excellent energy storage property (Wrec = 3.3 J/cm3) was obtained under a low electric field (190 kV/cm). More specifically, the relationship among phase boundary, domain structure, and excellent electrical properties was achieved based on Rietveld refinements and the dielectric/ferroelectric characterizations. This work provides a deep insight into the phase evolution and its impact on the electrical properties of the BNT-based relaxor ferroelectrics.

Carbon-intercalated halloysite-based aerogel efficiently encapsulating phase change materials with excellent photothermal conversion and energy storage

Latent heat storage systems based on organic phase change materials (PCMs) are considered to be an efficient solar energy utilization strategy, but leakage vulnerability and insensitivity to sunlight of PCMs limit their further application in energy storage. In this work, a new hierarchical porous aerogel was constructed with the carbon intercalated halloysite nanotubes (CHNTs) as the assembly units for PCMs encapsulation to improve the load weight, stability and sunlight absorption. The CHNTs were first successfully synthesized through intercalation and carbonization, with the aim of increasing their specific surface area and sunlight absorption.Subsequently, the CHNTs/polyvinyl alcohol (PVA) aerogels with 3D honeycomb structure were prepared by self-assembly using a freeze-drying method, which can significantly promote the encapsulation ratio of lauric acid (LA) in the pores of both aerogels and CHNTs. The CHNTs can not only improve compressive strength of the aerogels and shape stability of the composite PCMs, but also enhance light absorption ability of the composites compared to pristine HNTs. As a support material, CHNTs aerogel (CHNP) loaded more than 92 wt% PCM (LA@CHNP) and exhibited an extremely high latent heat capacity (170.9 J/g). The LA@CHNP had good structural and thermal stability in 300 cycles without visible leakage. Besides, solar energy absorption increased from 43 % to 98 %, and the solar-to-thermal energy conversion efficiency increased to 95.88 %, which could be attributed to 3D porousness and carbon nanolayers of the CHNTs. We have successfully synthesized an eco-friendly and facile composite LA@CHNP, which will contribute to the design of advanced composites with excellent solar energy storage properties, and provide a new direction for the application of carbonized materials.

Sputter deposited silver niobate thin films: Pathway towards phase purity

The quest for environmentally sustainable alternatives to lead-based dielectric materials in dielectric capacitors has led research to the exploration of options such as silver niobate (AgNbO3), which has been found to display excellent energy storage properties. Homogeneity and phase-purity of the used thin films are vital for optimal performance of these devices. In this study, a systematic variation of oxygen partial pressure and bias voltage during reactive d.c. magnetron co-sputtering from metallic targets is employed to synthesise AgNbO3 thin films. Structural and chemical composition of the films are investigated using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, elastic recoil detection analysis, and Rutherford backscattering spectrometry. The findings emphasise the necessity of precise parameter control during deposition to avoid the presence of undesirable secondary phases like Ag and Ag2Nb4O11 and to ensure the formation of homogeneous and phase-pure AgNbO3 thin films. The gained insights demonstrate the potential of reactive d.c. magnetron sputtering for the deposition of lead-free AgNbO3 thin films, offering pathways for enhanced environmental compatibility of future dielectric capacitors.

Ag nanowires modified expanded graphite based composite phase change materials with enhanced thermal conductivity, light/electro-to-thermal performances

Phase change materials with excellent thermal energy storage property displayed great potential application in many fields, such as lithium battery thermal management, energy saving building and waste heat utilization. In this paper, a novel composite phase change material of Ag nanowires modified expanded graphite/lauric-myristic-palmitic acid (AgNWs@EG/LMP) with the function of photo/electro-thermal conversion property was prepared which the AgNWs@EG was acted as the matrix material and LMP was the phase change material. The composite exhibited high latent heat of 118.42 J/g at the phase change temperature of 33.62 °C with the LMP supporting ratio of 76.18%. The thermal conductivity of AgNWs@EG/LMP reached 4.23 W/(m∙K) which enhanced 1914% than that of LMP. The photo-thermal conversion efficiency reached 88.01% and the electro-thermal conversion efficiency was 65.4% with an input voltage of 1.5 V. Further results showed the composite AgNWs@EG/LMP possessed good chemical compatibility, good thermal stability and reliability. Therefore, the novel composite of AgNWs@EG/LMP with good thermal property and multi-energy conversion functions will process potential application in energy storage system and thermal management fields.

Enhancing comprehensive energy storage properties in Pb-free relaxor AFE/FE system via heterogeneous structure tuning and defect engineering

Multi-phase NaNbO3 (NN) exhibits high adjustability on the ordering of both polarization and oxygen octahedral tilt, becoming a perfect carrier to design heterogeneous structure for boosting comprehensive energy storage properties. To balance the energy storage density and efficiency, the coexistence of the relaxor antiferroelectric (AFE) with high polarization capability and the relaxor ferroelectrics (RFE) with high efficiency is designed in this work by introducing Sr0.7Bi0.2□0.1Ti0.75Ta0.2□0.05O3 (SBTT) into NaNbO3-BiFeO3. As a result, an outstanding capacitive energy density (Wrec) of 12.25 J cm−3 with a high η of 83 % can be achieved in NN-BF-SBTT ceramic, which can be identified as a novel heterogeneous coexisting structure with the crossover of high polarization capability in relaxor AFE and high efficiency in RFE in terms of high-resolution TEM. Furthermore, grain refinement and the dense structure inhibit the leak current, suppress the concentration of oxygen vacancy defects and raise the activation energy (Ea), thus enhancing the EB. These excellent energy storage properties overcome the trade-offs between the two sets of parameters (Wrec-η, ΔP-EB), offering a refreshing strategy for the development of high-performance ceramic capacitors.

Superior energy storage performance achieved in tungsten bronze SBCN-based ceramics through tape-casting

Simultaneously integrating outstanding energy storage density and good energy storage efficiency in advanced ferroelectrics is crucial to implementing the application of dielectrics in high-power pulse devices. In this work, (Sr0.5Ba0.5)2Ca0.5Nb5-xSbxO15 ceramics were designed and prepared by adopting the B sites substitution engineering together with combining strategies of tape-casting method and two-step sintering process. Benefiting from the refined grain size and high density, the breakdown field of (Sr0.5Ba0.5)2Ca0.5Nb4.8Sb0.2O15 (SBCNS0.2) was promoted to 400 kV/cm. By the substitution of Sb5+ in the B sites, the weaker interaction force of Sb-O bond in BO6 octahedral polar unit induced the occurrence of polar nanoregions (PNRs) at room temperature to strengthen the dielectric relaxation behavior. Then it is noteworthy that SBCNS0.2 ceramics simultaneously obtained excellent recoverable energy density (Wrec, 3.9 J/cm3), energy storage efficiency (η, 90.5 %), power density (PD, 156.0 MW/cm3), and current density (CD, 1356.7 A/cm2). In addition, the SBCNS0.2 ceramics exhibited an ultrafast discharge time (t0.9, 67 ns). These results reveal prospective potential of unfilled tungsten bronze SBCNS0.2 ceramics in power capacitor applications and provide an effective strategy for improving excellent energy storage properties from the perspective of preparation methods.

Controlled preparation of carbon cloth decorated with nanostructured Mn(OH)2/Mn3O4 electrodes for high-performance asymmetric supercapacitors

Environmentally friendly aqueous asymmetric supercapacitors are expected to exhibit excellent energy storage properties, stable performance, and facile production protocols. This study focused on the fabrication and characterisation of an asymmetric supercapacitor (ASC) with a commercial activated carbon (AC) negative electrode and Mn(OH)2/Mn3O4 composite on carbon cloth (hCC) positive electrode. The Mn-based electrode was synthesised using a one-step electrodeposition process. The morphology and crystalline structure of the composite electrode were modified by varying the deposition time of the Mn(OH)2/Mn3O4 nanostructures on carbon cloth substrate which greatly influence the electrochemical performance of the asymmetric systems. The best ASC used the AC electrode and a Mn(OH)2/Mn3O4@hCC electrode prepared using electrodeposition over an optimised time of 3 h. It exhibited a remarkable specific energy density of 40.7 Wh kg−1 at a power density of 100 W kg−1. In addition, this ASC demonstrated stable long-term performance, retaining 88 % of its capacitance after 5000 charge–discharge cycles, showing its great application potential in the field of supercapacitors.

Excellent energy storage properties in ZrO2 toughened Ba0.55Sr0.45TiO3-based relaxor ferroelectric ceramics via multi-scale synergic regulation

Lead-free ceramic capacitors offer ultrahigh power density and ultrafast discharging rates, making them critical energy storage components for advanced pulsed power systems. However, the greatest obstacle to broader applications remains the relatively low energy storage density. In this study, a relaxor ferroelectric ceramic based on (0.6-x)Ba0.55Sr0.45TiO3-0.4Bi0.5Na0.5TiO3-xSrZrO3 ((0.6-x)BST-0.4BNT-xSZ) is prepared using the tape casting method, resulting in an excellent energy density (Wrec ≈ 10.0 J cm−3) and high energy storage efficiency (η ≈ 91 %). The solid solution of linear dielectrics SrZrO3 synergistically regulates both relaxor properties and breakdown strength. The variation of relaxor property was explored utilizing New Glass model and the multi-polarization model, with confirmation provided by piezoresponse force microscopy. Furthermore, the breakdown strength could be attributed to improvements in electric insulation and the widening of the bandgap. As SrZrO3 content increases, the in-situ emergence of the second phase ZrO2, accompanied by a martensitic transformation, not only improves the fracture toughness of ceramics but also serves to elongate the breakdown path. Encouragingly, x = 0.20 ceramics also achieve excellent temperature stability (−95–125 ℃), frequency stability (1–1000 Hz), cycling reliability (1–106 cycles), and great charging-discharging properties. This multiscale synergic regulation strategy plays a guiding role in the screening of high-performance energy storage dielectric materials.

Tailored anion radii of molten-salts systems toward graphite regeneration with excellent energy-storage properties

Graphite, as the typical non-renewable resource, low-cost recycling of graphite from spent lithium-ion batteries (LIBs) enjoys great significance in economic growth and resources reusing. However, the traditional regenerated manners still suffer from the incomplete repairing, especially the inferior isotropy. Herein, assisted by salt melt synthesis (SMS), the effect recycling process to repair spent graphite is successfully developed. Tailored by the melting-boiling points and ionic strength of molten salts, the as-regenerated graphite performed different repaired properties, including interlayer distance, grain size, and crystallinity, leading to a difference in electrochemical performance. As Li-storage anodes, the as-optimized sample displayed an attractive lithium-storage capability of 352 mAh g−1 after 200 loops at 1.0 C. Even at 5.0 C, it could exhibit about 175 mAh g−1. Simultaneously, supported by of detailed kinetic analysis, the evolutionary properties of molten liquid phase could improve interlayer isotropy, thereby enhancing rate performance. Moreover, for repairing spent graphite, the cost of the proposed process is 745.74 $ t−1, and the recycling profit for regenerating graphite is approximately 7200 $ t−1. Given this, this work was expected to offer the effective repairing manners of spent graphite, meanwhile demonstrating the feasibility about the molten salt approach.

Rapid fabrication of binder free nickel cobalt oxide electrodes with dendritic nanostructure for electrochemical energy storage applications

A rapid and facile technique to synthesize nickel cobalt oxide electrodes by photothermal treatment of mixed organometallic precursor solution is reported. Using short and intense pulses of light from a xenon flash lamp, spray coated films are converted into porous nickel cobalt oxide electrodes with dendritic nanostructure. The electrode films fabricated in a few seconds show excellent energy storage properties as supercapacitor electrodes. Specific capacitance of up to 116 Fg−1 and capacitance retention of up to 75 % were observed in samples with low mass loading. Analysis of the cyclic voltammetry (CV) curves shows that capacitance is the dominating charge storage mechanism in these films. To study the effect of varying the mass loading in electrodes, double and triple layered electrodes were also studied. In films with high mass loading, the specific capacitance of the films decreased but areal capacitance continued to increase. A high areal capacitance of up to 243 mFcm−2 is observed in films with high mass loading. CV curve analysis of high mass loading electrodes further shows that in films with higher mass loading, the charge storage mechanism is a mix of capacitance and diffusion processes. The contribution of diffusion increased with increase in the mass loading of the electrodes. This study sheds light into the mechanism of charge storage in electrodes prepared by large-scale-amenable single step process of photonic curing which could be utilized to fabricate electrodes in industrial scale.

High energy-storage density and giant negative electrocaloric effect in PLZS antiferroelectric thick film ceramics prepared via the tape-casting process

Antiferroelectric materials are highly desired for high energy-storage density capacitors and electrocaloric refrigerator in the future due to their excellent energy storage properties and giant negative electrocaloric effect, which have attracted great attention in recent years. In the present work, a highly recoverable energy density (Wrec) and a large reversible adiabatic temperature change (ΔT) were obtained simultaneously in PLZS thick film ceramics (TFCs). A maximum Wrec of 9.84 J·cm−3 with an efficiency of 85.2 % at 440 kV·cm−1, and a negative ΔT of −9.50 °C at 280 kV·cm−1 were obtained. Moreover, the maximum value of electrocaloric strength of 0.98 K·m·MV−1 was achieved for Pb0.97La0.02(Zr0.50Sn0.50)O3 TFCs. These results demonstrate that the PLZS TFCs can be applied potentially for high energy-storage density capacitors and refrigerators.

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.

Ultrahigh energy storage performance in AN-based superparaelectric ceramics

Ceramics capacitors, especially featuring antiferroelectric (AFE) structure, are widely used in pulsed power electronic systems due to distinctive high-power density and external field stability. Lead-free AFE material AgNbO3 has seized substantial research attention owing to its unique temperature driven multi-level phase transitions, and many works have greatly improved the energy storage properties by engineering these temperature-dependent phase boundaries. In this work, an ever-unadopted strategy was proposed to modulate the relaxor structure in AgNbO3 by designing room-temperature (RT) superparaelectric phase via Bi incorporation into AN lattice matrix. Structural analysis shows M phase (space group Pbcm) evolves into O phase (space group Cmcm) with 12 mol.% Bi-substitution, breaking the long-range AFE order into polar nanoregions. Hence, an ultra-high recoverable energy density (7.6 J/cm3) and a high efficiency (79 %) are simultaneously achieved in the Ag0.64Bi0.12NbO3 ceramics under 52.2 kV/mm. Moreover, the excellent energy storage properties are accompanied with good temperature and frequency stability, with the variation of Wrec less than ± 15% (over 25–120 °C) and ± 10% (over 1–200 Hz) under 25 kV/mm, respectively. The novel approach reported herein provides a new guidance for designing AgNbO3-based and other AFE materials for high-performance energy storage applications.

Multistage Porous Carbon Derived from Enzyme-Treated Waste Walnut Green Husk and Polyethylene Glycol for Phase Change Energy Storage.

The thermal storage performance, cost, and stability of phase-change materials (PCMs) are critical factors influencing their application in the field of thermal energy storage. Porous carbon, with its excellent support, thermal conductivity, and energy storage properties, is considered one of the most promising support matrix materials. However, the simple and efficient synthesis of high-performance and highly active bio-based materials under mild conditions still faces challenges. In our work, a novel method for preparing new functional composite phase-change materials based on enzyme treatment technology and using waste walnut green husk biomass and polyethylene glycol as raw materials was developed. The enzymatic treatment method exposes the internal structure of the walnut green husk, followed by the adjustment of the calcination temperature to increase the adsorption sites of the biochar, thereby stabilizing polyethylene glycol (PEG). The porous properties of walnut green husk biochar effectively regulate the phase-change behavior of polyethylene glycol. In the biochar carbonized at 600 °C, the PEG loading reached 72.09%, and the absorption heat of the solid-solid phase-change material (SSPCM) reached 194.76 J g-1. This work not only enriches the application of biomass in heat storage but also demonstrates the broad prospects of SSPCMs in solar thermal utilization.

Bi0.5Na0.5TiO3-based energy storage ceramics with excellent comprehensive performance by constructing dynamic nanoscale domains and high intrinsic breakdown strength

Lead-free ceramic-based dielectric capacitors show huge potential in electrical energy storage in pulsed power systems due to their fast charge/discharge rate, ultrahigh power density and environmental friendliness. However, unsatisfied charge/discharge performance characterized by inferior recoverable energy storage density (Wrec generally <5 J/cm3) has become a key bottleneck to restrict their applications in cutting-edge energy storage devices. In this paper, we focus on simultaneously realizing ultrahigh Wrec and efficiency (ƞ) in eco-friendly Bi0.5Na0.5TiO3 (BNT)-based dielectric ceramics via chemical doping. Interestingly, highly dynamic polar nanoregions (PNRs) and nanodomains are constructed by incorporating Sr0.7Nd0.2TiO3 (SNT) into 0.94BNT-0.06BaTiO3. Of great importance, the resulting relaxor ferroelectrics (RFEs) exhibit high bulk resistivity, submicron grain size and wide band gap due to high level of SNT doping accompanying with 1 at% Nb donor doping. Therefore, excellent energy storage properties with ultrahigh Wrec∼8.08 J/cm3 and ƞ∼92.1% are achieved due to coexistence of large polarization difference (ΔP=Pmax−Pr) and giant dielectric breakdown electric field (Eb∼540 kV/cm). Furthermore, excellent temperature/frequency/cycling stability characterized by ΔWrec < ±4% and Δη < ±2% ensure the energy storage applications of the studied dielectric ceramics over an enormous range of scales.

Samarium-modified PLZST-based antiferroelectric energy storage ceramics for low-temperature sintering in reducing atmosphere

The energy storage properties of pure PLZST-based antiferroelectric ceramics are excellent; however, the high sintering temperature renders them unsuitable for co-firing with copper inner electrodes as MLCC dielectric materials. The proven BASK glass additive was employed in this study to lower the sintering temperature of PLSZT ceramics, while simultaneously doping Sm3+ ions to enhance their sintering performance under reducing atmospheres. The precise evaluation process confirmed that the addition of glass effectively reduced the sintering temperature to 1040 °C. Furthermore, the defect association of Sm3+ doping hindered the formation of oxygen vacancies, facilitated ceramic grain growth, and significantly enhanced insulation resistivity. Consequently, an ultrahigh recoverable energy density (Wrec) of 5.19 J/cm3 with a high energy storage efficiency (η) of 94.5% are achieved at an electric field of 430 kV/cm. Moreover, the AFE ceramics possess excellent discharge energy storage properties with a high discharge energy density (Wd) of 4.26 J/cm3 and a large power density (Pd) of 139 MW/cm3.