Energy Storage Properties Research Articles

Enhanced energy storage performance inBaZrxTi1−xO3 lead-free ferroelectrics near phase transitions

Abstract The present study explores the energy storage properties of BaZrxTi1−xO3 through phase-field modeling, focusing on the impact of composition and temperature on energy storage performance. The obtained results reveal a variety of polarization phases and configurations based on Zr compositions and temperatures. A detailed phase diagram for temperature-composition of BaZrxTi1−xO3 is established, closely aligning with experimental measurements. Variations in Zr content and temperature have a significant impact on the polarization-electric field response, influencing the energy storage properties. Calculations of energy storage properties are derived from the polarization-electric field response. In addition, a thorough diagram is developed to illustrate the discharge energy density of BaZrxTi1−xO3 as a function of temperature and composition. Notably, high discharge energy density is achievable near the Curie temperature, corresponding to the transition from ferroelectric to paraelectric phase. Furthermore, the present study emphasizes the importance of the disparity between maximum and remanent polarization, as well as the electric field-dependent effective permittivity, in determining the discharge energy density.

Nickel Vanadate Cathode Induced In Situ Phase Transition for Improved Zinc Storage by Low Migration Barrier and Zn2+/H+ Co‐Insertion Mechanism

AbstractDesigning cathode materials that exhibit excellent rate performance and extended cycle life is crucial for the commercial viability of aqueous zinc (Zn)‐ion batteries (ZIBs). This report presents a hydrothermal synthesis of stable Ni0.22V2O5·1.22H2O (NVOH) cathode material, demonstrating high‐rate performance and extended cycle life. A successful in situ phase transformation yields Zn3(OH)2V2O7·nH2O (ZVO), which undergoes an irreversible phase transition and exhibits exceptional energy storage properties. The procedure maintains the lattice structure of ZVO and ensures high structural stability throughout the phase transformation. The NVOH cathode material exhibits the discharge capacities of 399 mA h g−1 at a rate of 1 A g−1 after 400 cycles and 303 mA h g−1 at 10 A g−1 after 2000 cycles. Density functional theory calculations indicate that the material is protected by electrostatic forces and exhibits structural stability, with a Zn‐ion migration barrier of 0.32 eV across the host lattice and the electrode–electrolyte interface. Due to these properties, NVOH also exhibits high energy/power densities of 395 Wh kg−1/406 W kg−1 at 0.5 A g−1 and 288 Wh kg−1/8830 W kg−1 at 10 A g−1. Ex situ characterizations indicate structural modifications and irreversible phase changes of NVOH, highlighting the potential of H+ intercalation and in situ phase transitions for high‐performance aqueous ZIBs.

Dielectric and energy storage properties of the g-C3N4/PVDF nanocomposite thick film

Dielectric and energy storage properties of the g-C3N4/PVDF nanocomposite thick film

Improved Energy Storage and Electrocaloric Properties in Sm3+- and Fe3+-Substituted BCZT Ceramics

Improved Energy Storage and Electrocaloric Properties in Sm3+- and Fe3+-Substituted BCZT Ceramics

Energy storaging multifunctional carbon fiber composites based on Nano‐SiO2 reinforced epoxy matrix structural electrolytes

AbstractMultifunctional carbon fiber composite materials capable of storing energy and carrying structural loads have advantages for aerospace structures. In this paper, a structural supercapacitor that consists of an epoxy‐based solid polymer electrolytes (E‐SPEs) and carbon fiber was proposed. To develop an E‐SPEs with better mechanical properties and ionic conductivity, Nano‐SiO2 was introduced into the solid polymer electrolytes. Nano‐SiO2 reinforced E‐SPEs (Nano‐SiO2/E‐SPEs) show improved mechanical properties (Young's modulus [E] = 0.85 GPa) and ionic conductivity (4.99 × 10−4 S cm−1), compared to E‐SPEs without Nano‐SiO2. Structural supercapacitors were further prepared by combining E‐SPEs with carbon fibers. The structural supercapacitor prepared with Nano‐SiO2/E‐SPEs exhibits the higher power and energy density (261.93 W kg−1 and 2.11 Wh kg−1) compared to the structural supercapacitor prepared with E‐SPEs without Nano‐SiO2 (51 W kg−1 and 0.34 Wh kg−1), indicating improved mechanical and energy storage properties for structural supercapacitors after incorporation of Nano‐SiO2. This strategy has great potential in enhancing performance of structural energy storage composite materials for application in next‐generation aerospace vehicles.

Interface‐enhanced polyimide‐based nanocomposites with superior dielectric energy storage properties

Interface‐enhanced polyimide‐based nanocomposites with superior dielectric energy storage properties

Tailoring breakdown strength and energy-storage performance of silicon-integrated lead-free epitaxial BZT thin films through multi-element B-site substitutions

Developing high-temperature dielectric thin films with high-performance energy-storage properties for harsh environment applications has received increased attention. Herein, a multi-element co-doping strategy is proposed to enhance the breakdown strength and energy storage properties of lead-free BaTiO3-based thin films, which were deposited on silicon substrates using pulsed laser deposition. Due to the difference in ionic radii and valence states between the multi-dopants and host Ti-cations, the local lattice distortion and local charged defects are induced, which results in the reduction in the size of polar nanoregions (PNRs) and weakened coupling interactions between these PNRs, thus achieving stronger breakdown strength (EBD). Accordingly, owing to an enhanced EBD of 7.8 MV/cm and a delayed polarization saturation, a superior recoverable energy-storage density (Ur) of 140.8 J/cm3 along with an excellent energy efficiency (η) of 93.2 % were achieved at room temperature in the multi-element doped Ba(Zr0.2Ti0.2Mn0.2Nb0.2Sm0.2)O3 (BZTMNS) thin film. Moreover, the BZTMNS thin film also exhibits an excellent Ur of 102.6 J/cm3, a good η of 86.4 %, and a high EBD of 6.6 MV/cm at an operating temperature of 200 °C. Additionally, a small fluctuation of Ur (-6.1 %) and η (-11.7 %) values can also be observed in BZTMNS thin film in high cycling endurance, up to 1010 cycles, even when operated at an elevated temperature of 200 °C. These findings in the BZTMNS thin film demonstrate a feasible way to design high-temperature capacitors for modern electronic devices for hybrid vehicles and underground oil/gas explorations.

Electrochemical Performance of MoB/Si3N4 Heterojunction as a Potential Anode Material for Li Ion Batteries.

In response to the current policy of high storage capacity, two-dimensional (2D) materials have revealed promising prospects as high-performance electrode materials. MoB, as a type of such material, is widely regarded as an anode candidate for Li-ion batteries due to its large specific surface area and abundant ion diffusion channels; the long-term cycling stability, however, is poor owing to material pulverization during the cycle. Therefore, MoB/Si3N4 heterojunction in this work is proposed as an anode material, with Si3N4 acting as a skeleton, maintaining the stability of the structure, while retaining the high energy storage properties of MoB as well. In addition, a certain built-in electric field is formed between them, which can play a role in regulating charge transfer, improving the ion transport channel, and accelerating the migration rate. Herein, the structural, electronic, and electrochemical properties are systematically investigated by first-principles calculations; the final results indicate that the heterojunction anode material does indeed have built-in electric fields, which promote the anode material to possess excellent electrical conductivity and outstanding electrochemical property. Meanwhile, the introduction of vacancy defects can bolster the diffusion kinetic performance of ion transport and greatly reduce the diffusion energy barrier of Li ions, which is conducive to the realization of rapid charge and discharge for the Li ion battery. Based on the synergistic effect of two single-component materials, the synthesized anode material displays a high theoretical capacity of 461 mAh/g, and the calculated open-circuit voltage is 0.66 V, within the range of the negative electrode criterion of 0-1 V, which can effectively play a role in preventing the formation of Li dendrites; these properties are comparable to other 2D anode materials as well. Given these intriguing properties, the MoB/Si3N4 heterojunction is an exceptional candidate for advanced LIB high-performance anode materials.

How Do the Four Core Factors of High Entropy Affect the Electrochemical Properties of Energy-Storage Materials?

High-entropy materials (HEMs) are extremely popular for electrochemical energy storage nowadays. However, the detailed effects of four core factors of high entropy on the electrochemical properties of HEMs are still unclear. Here, a high-entropy La1/4Ce1/4Pr1/4Nd1/4Nb3O9 (HE-LaNb3O9) oxide is prepared through multiple rare-metal-ion substitution in LaNb3O9, and uses HE-LaNb3O9 as a model material to systematically study the effects of the four core factors of high entropy on electrochemical energy-storage materials. The high-entropy effect lowers the calcination temperature for obtaining pure HE-LaNb3O9. The lattice distortion in HE-LaNb3O9 leads to its decreased unit-cell-volume variations, which benefits its cyclability. Based on the restrained diffusion arising from the lattice distortion, the Li+ diffusivity of HE-LaNb3O9 at room temperature (25°C) is limited, which causes its lowered rate capability. However, the Li+ diffusivity of HE-LaNb3O9 at high temperature (60°C) becomes faster than that of LaNb3O9, which is attributed to the alleviated lattice distortion at the high-temperature, resulting in higher rate capability. The cocktail effects in HE-LaNb3O9 enable its larger electronic conductivity, better electrochemical activity, more intensive Nb5+ ↔ Nb3+ redox reaction, and larger reversible capacity. The insight gained here can provide a guide for the rational design of new HEMs with good energy-storage properties.

Transition Metal-Doped Layered Iron Vanadate (FeV3-xMxO9.2.6H2O, M = Co, Mn, Ni, and Zn) for Enhanced Energy Storage Properties.

With its distinctive multiple electrochemical reaction, iron vanadate (FeV3O9.2.6H2O) is considered as a promising electrode material for energy storage. However, it has a relatively low practical specific capacitance. Therefore, using the low temperature sol-gel synthesis process, transition metal doping was used to enhance the electrochemical performance of layered structured FeV3O9.2.6H2O (FVO). According to this study, FVO doped with transition metals with larger interlayer spacing exhibited superior electrochemical performance than undoped FVO. The Mn-doped FVO electrode showed the highest specific capacitance and retention of 143 Fg-1 and 87%, respectively, while the undoped FVO showed 78 Fg-1 and 54%.

Enhanced comprehensive energy storage properties of lead-free KNN based ceramics through composition optimization strategy

As one of the most potential lead-free dielectric capacitors in pulsed power systems, K0.5Na0.5NbO3 (KNN)-based ceramic possesses comparatively high dielectric breakdown strength (BDS) due to its particular submicron grains. Nonetheless, it is hard to improve both the energy efficiency η and the recoverable energy density Wrec of potassium sodium niobate ceramic at the same time. Herein, a composition optimization strategy is used, Bi(Li0.5Nb0.5)O3 (BLN) as a second component and NaNbO3 (NN) as a third component are introduced into KNN-based ceramic. It is corroborated that BLN content facilitates the growth of polar nano-regions (PNRs), and then strengthens the relaxation behavior, lows the remnant polarization Pr and upgrades the maximum polarization Pmax value of the ceramic. A transition from ferroelectricity to relaxation ferroelectricity occurred and an ultrahigh Wrec of 10.03 J/cm3 with a η of 64.15 % and the BDS of 1140 kV/cm are gained in KNN-0.100BLN-NN ceramic, Wrec of 8.25 J/cm3, η of 71.26 % and the BDS of 840 kV/cm are obtained in KNN-0.075BLN-NN ceramic. Besides, the KNN-0.075BLN-NN ceramic exists not only fine energy storage properties, but also high hardness and good temperature and frequency stability, confirming it’s a feasible material to be applied in pulsed power systems

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.

Pickering emulsions stabilized by cellulose nanofibers with tunable surface properties for thermal energy storage

Cellulose nanofibers (CNFs) have been widely used as a renewable emulsifier to stabilize two immiscible liquids due to their intrinsic amphiphilicity and excellent emulsifying ability. However, it remains challenging to fully understand the effects of carboxylate group content and surface charge density on the emulsifying ability of CNFs and the stability of Pickering emulsion. Herein, carboxymethylated CNFs were extracted from bleached kraft pulp using etherification reaction and high-pressure homogenization, allowing for easy surface charge density and size adjustment by changing sodium chloroacetate content and homogenization cycles. The optimizing CNFs possessed a high Zeta potential (−71.2 mV) and a suitable carboxylate group content (1.81 mmol/g), which enabled CNFs to irreversibly adsorb at the hydrophobic paraffin wax (PW) droplet surface and form interfacial steric barriers, providing large electrostatic repulsion between the PW droplets against coalescence. Thus, the CNF-stabilized PW emulsions could be stored for more than 6 months. Moreover, the phase change enthalpy of the freeze-dried emulsion is as high as 193.7 J/g, which provides the emulsion to reversibly store and release heat. This work provides a comprehensive insight into the interfacial stability mechanism of CNFs as stabilizers and facilitates the potential application in thermal energy storage.

Amorphous NiO nanopyramids with superior electrochromic energy storage properties

In this work, amorphous NiO nanopyramid film has been obtained by using the pulsed magnetron sputtering technique. The uniform amorphous NiO nanostructures exhibit significant electrochromic modulation efficiency in the visible and near-infrared ranges, achieving a high modulation efficiency of 60.73 % at 550 nm and 21.58 % at 1500 nm. It exhibits rapid response time (coloring takes 2.4 s, and bleaching takes 1.0 s) and significant coloring efficiency (43.23 cm2C-1). Moreover, amorphous NiO nanopyramid film displays promising properties of energy storage. The NiO nanopyramid film shows high areal capacitance (7.08 mF/cm2), along with satisfying rate capability. The alteration in the electrode color offers a convenient method for monitoring the quantity of energy stored. Furthermore, the microstructure characteristic, degree of crystallization and electrochemical performance of the NiO film are significantly influenced by both oxygen partial pressure and sputtering time. These findings highlight the potential of employing this bifunctional amorphous NiO nanopyramid film in diverse advanced nanodevices, encompassing electrochromic energy storage applications with superior performance.

Outstanding energy storage properties and dielectric temperature reliability in Na0.35Bi0.35Sr0.3TiO3-based relaxor ferroelectrics through entropy engineering

Outstanding energy storage properties and dielectric temperature reliability in Na0.35Bi0.35Sr0.3TiO3-based relaxor ferroelectrics through entropy engineering

Tailoring phase evolution via high-entropy engineering for superior energy storage properties in (Na0.5Bi0.5)0.75Sr0.25TiO3-based ceramics

High-entropy engineering has garnered significant attention for innovation of dielectric capacitors. However, to meet the demands of the burgeoning market for next-generation advanced capacitors, challenges remain in optimizing the recoverable energy-storage density (Wrec). To address this, a stepwise high-entropy tactic is proposed via integrating four core effects of high-entropy systems with phase transition and energy-storage performance. This technique induces a remarkable Wrec ∼ 7.4 J/cm3 at 400 kV/cm in (Na0.5Bi0.5)0.75Sr0.25Ti1-x(Al1/4Zr1/4Hf1/4Nb1/4)xO3 ceramics (x = 0.00, 0.08, 0.12, 0.16, 0.20). The incorporation of multiple ions with diverse radii and valence states at the B-site enhances the degree of disorder and lattice distortion, contributing to tuning phase evolution and suppressing interfacial polarization, thereby delaying saturation polarization. Furthermore, impressive thermal endurance (30 ∼ 130 ℃), frequency stability (1 ∼ 100 Hz) and a rapid discharge rate t0.9 of ∼ 37.6 ns are also yielded. This work paves the way for the advancement of novel ceramics by tailoring phase transition using a high-entropy strategy.

N-doped porous carbon nanofibers with high specific capacitance and energy density for Zn-ion hybrid supercapacitors

N-doped porous carbon nanofibers have shown a wide application prospect for Zn-ion hybrid supercapacitors (ZHSs), but so far, the affordable synthesis remains a daunting challenge. Using the exfoliated silk nanofibrils (SNFs) as carbon and nitrogen sources, NaCl/KCl as carbonization medium and KOH as active agent, herein, a new variety of N-doped porous carbon nanofibers, SPCN-x, is prepared, involved a sequential ‘SNFs exfoliation’ and ‘mixture pyrolysis’. Results confirm that, with the activation of KOH, porosity structure and specific surface area of the nano-fibriform products are clearly enriched, thus forming a hierarchically porous structure. Typically, SPCN-10 shows a N doping content of 5.6 wt%, pore volume of 0.33 cm3 g−1 and specific surface area of 645 m2 g−1, and presents a great energy storage property as cathode for ZHSs, such as energy density of 70.4 Wh kg−1 and specific capacitance of 197.9 F g−1. Besides, it has excellent durability with a capacitance retention rate of 90.2 % after 10,000 cycles. The electrochemical behavior of SPCN-10 is better than numerous reported ZHS cathodes, which not only highlights our ingenious synthesis, but also ensures a huge potential in large-scale practical application.

Superb energy density in biomass-based nanocomposites with ultralow loadings of nanofillers

Biomass dielectric polymers hold promise in developing renewable and biodegradable capacitive energy storage devices. However, their typical discharged energy density remains relatively low (<20 J/cm3) compared to other existing synthetic polymers derived from petroleum sources. Here a greatly enhanced discharged energy density is reported in diluted cyanoethyl cellulose (CEC) nanocomposites with inclusion of ultralow loadings (0.3%, in volume) of 30-nm-sized TiO2 nanoparticles. Owing to the interfacial polarization introduced by interface, the composite of 0.3% exhibits a large dielectric constant of 29.2 at 1 kHz, which can be described by interphase dielectric model. Meanwhile, the introduction of nanofillers facilitate the formation of deeper traps impeding electrical conduction in CEC, which results in an ultrahigh breakdown strength of 732 MV/m. As a result, a remarkable discharged energy density of 12.7 J/cm3 with a charge-discharge efficiency above 90% is achieved, exceeding current ferroelectric-based and biomass-based nanocomposites. Our work opens a novel route for scalable biomass-based dielectrics with high energy storage properties.

Boosting energy storage properties of BNT-based relaxor ferroelectric ceramics via (Zn1/3Nb2/3)4+ complex ion doping

Boosting energy storage properties of BNT-based relaxor ferroelectric ceramics via (Zn1/3Nb2/3)4+ complex ion doping

Y-Shaped Acceptor-π-Donor-π-Acceptor Configured Anthraquinone-Tethered Phenothiazine Molecular Scaffold for High-Performance Organic Pseudocapacitors.

For the first time acceptor-π-donor-π-acceptor (A-π-D-π-A) based Y-type organic electrode material have been designed and successfully utilized in supercapacitor (SC) application. This Y-type molecular architecture coined as AQ-Im-PTZ-Im-AQ based on anthraquinone (AQ) (A)-imidazole (Im) (π)-phenothiazine (PTZ) (D)-imidazole (Im) (π)-anthraquinone (AQ) (A) in combination with graphite foil (GF). As-fabricated PTZ-Im-AQ/GF and AQ-Im-PTZ-Im-AQ/GF electrode have shown the good energy storage properties in three-electrode supercapacitor system. Moreover, two-electrode symmetric supercapacitor (SSC) device based on AQ-Im-PTZ-Im-AQ/GF electrode exhibited specific capacitance (Csp) of 68.97 F g-1 at 1 A g-1 current density. The specific electron density (ED) of SSC was observed to be 12.06 Wh kg-1 at a specific power density (PD) of 1798.50 W kg-1. The SSC device exhibited 81.62 % of Csp retention after 5000 galvanostatic charge-discharge (GCD) cycles. For real world applications, AQ-Im-PTZ-Im-AQ/GF electrode was tested in symmetric Csp coin cell with applied potential voltage window of -0.4 to 1.0 V was found to be 112.32 F g-1 at 0.5 A g-1. Moreover, it realized high specific capacitance and high energy density of 19.66 Wh kg-1 at 891.94 W kg-1 power density. As a results, AQ-Im-PTZ-Im-AQ/GF make as an attractive electrode material for application in next-generation SCs.