Functional nanostructured materials have attracted great attention over the past several decades owing to their unique physical and chemical properties, while their applications have been proven to ...be advantageous not only in fundamental scientific areas, but also in many technological fields. Spray pyrolysis (SP), which is particularly facile, effective, highly scalable and suitable for on-line continuous production, offers significant potential for the rational design and synthesis of various functional nanostructured materials with tailorable composition and morphology. In this review, we summarize the recent progress in various functional nanostructured materials synthesized by SP and their potential applications in energy storage and conversion. After a brief introduction to the equipment, components, and working principles of the SP technique, we thoroughly describe the guidelines and strategies for designing particles with controlled morphology, composition, and interior architecture, including hollow structures, dense spheres, yolk-shell structures, core-shell structures, nanoplates, nanorods, nanowires, thin films, and various nanocomposites. Thereafter, we demonstrate their suitability for a wide range of energy storage and conversion applications, including electrode materials for rechargeable batteries, supercapacitors, highly active catalysts for hydrogen production, carbon dioxide reduction and fuel cells, and photoelectric materials for solar cells. Finally, the potential advantages and challenges of SP for the preparation of nanostructured materials are particularly emphasized and discussed, and several perspectives on future research and development directions of SP are highlighted. We expect that this continuous, one-pot, and controllable synthetic technology can serve as a reference for preparing various advanced functional materials for broader applications.
A critical challenge in the commercialization of layer‐structured Ni‐rich materials is the fast capacity drop and voltage fading due to the interfacial instability and bulk structural degradation of ...the cathodes during battery operation. Herein, with the guidance of theoretical calculations of migration energy difference between La and Ti from the surface to the inside of LiNi0.8Co0.1Mn0.1O2, for the first time, Ti‐doped and La4NiLiO8‐coated LiNi0.8Co0.1Mn0.1O2 cathodes are rationally designed and prepared, via a simple and convenient dual‐modification strategy of synchronous synthesis and in situ modification. Impressively, the dual modified materials show remarkably improved electrochemical performance and largely suppressed voltage fading, even under exertive operational conditions at elevated temperature and under extended cutoff voltage. Further studies reveal that the nanoscale structural degradation on material surfaces and the appearance of intergranular cracks associated with the inconsistent evolution of structural degradation at the particle level can be effectively suppressed by the synergetic effect of the conductive La4NiLiO8 coating layer and the strong TiO bond. The present work demonstrates that our strategy can simultaneously address the two issues with respect to interfacial instability and bulk structural degradation, and it represents a significant progress in the development of advanced cathode materials for high‐performance lithium‐ion batteries.
Ti‐doped and La4NiLiO8‐coated Ni‐rich layered oxide cathodes are synchronously and in situ synthesized with the guidance of theoretical calculations, which exhibit good surficial stability, fast interfacial kinetic behaviors, suppressed inconsistent structural degradation in combination with markedly improved electrochemical performance. This work opens a new avenue of designing simple modification approaches and advanced cathodes for high‐energy lithium‐ion batteries.
As an emerging solid‐state refrigeration technology with zero‐emission and high energy conversion efficiency, there is a compelling need for ferroelectric materials with giant electrocaloric effects ...(ECEs) at room temperature suitable for refrigeration applications. The complex perovskite antiferroelectric (AFE), PbMg0.5W0.5O3, containing non‐equivalent B‐site ions with a symmetric giant positive and negative ECE near room temperature is presented. At the Curie temperature of 36 °C, the first‐order AFE–paraelectric phase transition gives rise to a large enthalpy change of 3.92 J g−1, more than four times that of BaTiO3. This leads to a significant ECE under the influence of an electric field. The direct electrocaloric characterization shows that the adiabatic temperature change, ΔT, exhibits symmetric peaks with a giant positive maximum of 1.79 K (ΔS = 1.68 J kg−1 K−1) at 36 °C and a negative maximum of −2.02 K (ΔS = −1.93 J kg−1 K−1) at 34 °C. The ultrahigh magnitude of ΔT near room temperature makes PbMg0.5W0.5O3 a superior electrocaloric material far beyond traditional PbZrO3‐based AFEs. The coexistence of symmetric giant positive and negative ΔT to further improve cooling efficiency is expected. In addition, the good reversibility and negligible leakage current should pave the way for practical applications.
In ordered PbB′0.5B″0.5O3 perovskite oxide ceramic‐PbMg0.5W0.5O3, a first‐order antiferroelectric–paraelectric phase transition occurs near room temperature (36 °C), with a large enthalpy change of 3.92 J g−1. The resultant symmetric giant positive (ΔT = 1.79 K, ΔS = 1.68 J kg−1 K−1) and negative electrocaloric effect (ΔT = −2.02 K, ΔS = −1.93 J kg−1 K−1) favors solid‐state ferroelectric refrigeration application.
Two-dimensional (2D) van der Waals (vdW) materials with strong in-plane chemical bonds and weak interaction in the out-of-plane direction have been acknowledged as a basic building block for ...designing dimensional materials in 0D, 1D, 2D and 3D forms. Compared to the explosive research on 2D vdW materials, quasi-one-dimensional (quasi-1D) vdW materials have received rare attention, despite the fact that they also present rich physics in electronics and engineering implications. Herein, quasi-1D MoS2 nanoscrolls are directly fabricated from CVD-grown 2D triangular MoS2 sheets. The formation, stability and electronic properties of quasi-1D MoS2 nanoscrolls are studied experimentally and theoretically. The formation of a nanoscroll always starts from the edge of a triangular MoS2 sheet along its armchair orientation. The electronic properties of MoS2 nanoscrolls are systemically studied with optical spectroscopy and electrical transport together with density-functional theory (DFT) calculations. Surprisingly, the carrier mobility and contact properties of MoS2 nanoscroll based field effect transistors (FETs) are distinct from that of 2D MoS2 sheets. The transition from a 2D semiconductor MoS2 sheet to a 1D metallic MoS2 nanoscroll is successfully achieved. It is expected that this method of fabricating MoS2 nanoscrolls will attract wide interest for 1D transition metal dichalcogenides with novel physical and chemical properties.
Atomically thin two-dimensional (2D) materials have received intense research interest due to their novel properties and promising applications in nanodevices. By using density functional theory ...(DFT) calculations, we investigate catalytic activities of several newly predicted two-dimensional (2D) triphosphides GeP3, SnP3 and InP3 monolayers for hydrogen evolution reaction (HER). The calculation results show that GeP3 and SnP3 monolayers are active catalysts for HER with suitable free energy of hydrogen adsorption in the basal plane. In particular, the Gibbs free energy of hydrogen adsorption (ΔGH*) of GeP3 is 0.024 eV, a value even more favorable compared to the precious-group-metal (PGM) catalyst Pt. Moreover, the 2D GeP3 and SnP3 are intrinsically compatible with the graphene substrate so that the HER performance can be improved via building a hybrid multilayer with graphene sheet. The charge transfer from GeP3 or SnP3 to graphene, estimated to be 0.1278e or 0.2157e, can significantly enhance the electric conductivity and promote the electrocatalytic activity. Although the electronic band structure of GeP3 and SnP3 can be tuned by external strain, we find that the HER performance of GeP3 and SnP3 monolayer is actually insensitive to the external strain, a feature desirable for the catalytic application. The desirable properties for HER with nearly zero Gibbs free energy render 2D GeP3 and SnP3 promising candidates for future application in electrocatalysis.
Lithium (Li) metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries. However, the practical implementation of Li ...anode has been hindered by dendritic growth and volume expansion during cycling, which results in low Coulombic efficiency (CE), short lifespan, and safety hazards. Here, we report a highly stable and dendrite-free Li metal anode by utilizing N-doped hollow porous bowl-like hard carbon/reduced graphene nanosheets (CB@rGO) hybrids as three-dimensional (3D) conductive and lithiophilic scaffold host. The lithiophilic carbon bowl (CB) mainly works as excellent guides during the Li plating process, whereas the rGO layer with high conductivity and mechanical stability maintains the integrity of the composite by confining the volume change in long-range order during cycling. Moreover, the local current density can be reduced due to the 3D conductive framework. Therefore, CB@rGO presents a low lithium metal nucleation overpotential of 18 mV, high CE of 98%, and stable cycling without obvious voltage fluctuation for over 600 cycles at a current density of 1 mA·cm
−2
. Our study not only provides a good CB@rGO host and pre-Lithiated CB@rGO composite anode electrode, but also brings a new strategy of designing 3D electrodes for those active materials suffering from severe volume expansion.
Machine learning (ML) exhibits substantial potential for predicting the properties of solid‐state electrolytes (SSEs). By integrating experimental or/and simulation data within ML frameworks, the ...discovery and development of advanced SSEs can be accelerated, ultimately facilitating their application in high‐end energy storage systems. This review commences with an introduction to the background of SSEs, including their explicit definition, comprehensive classification, intrinsic physical/chemical properties, underlying mechanisms governing their conductivity, challenges, and future developments. An in‐depth explanation of the ML methodology is also elucidated. Subsequently, the key factors that influence the performance of SSEs are summarized, including thermal expansion, modulus, diffusivity, ionic conductivity, reaction energy, migration barrier, band gap, and activation energy. Finally, it is offered perspectives on the design prerequisites for upcoming generations of SSEs, focusing on real‐time property prediction, multi‐property optimization, multiscale modeling, transfer learning, automation and high‐throughput experimentation, and synergistic optimization of full battery, all of which are crucial for accelerating the progress in SSEs. This review aims to guide the design and optimization of novel SSE materials for the practical realization of efficient and reliable SSEs in energy storage technologies.
This review systematically explores recent advancements in machine learning for solid‐state electrolyte properties, focusing on key performance factors such as thermal expansion, modulus, diffusivity, ionic conductivity, reaction energy, migration barrier, band gap, activation energy. It aims to direct future research and guide the selection of optimal solid‐state electrolytes for advanced batteries.
The increasing demand for large-scale electrochemical energy storage, such as lithium ion batteries (LIBs) for electric vehicles and smart grids, requires the development of advanced electrode ...materials. Ti–Nb–O compounds as some of the most promising intercalation-type anode materials have attracted a lot of attention owing to their high theoretical capacity (388–399 mA h g−1) arising from the multiple redox pairs (Ti4+/Ti3+, Nb5+/Nb4+, and Nb4+/Nb3+), high safety, and superior cycling stability. However, their intrinsic low electronic conductivity and slow solid-state ion diffusion lead to unsatisfactory rate performance. To overcome these drawbacks, various efficient strategies have been proposed to improve the performance of Ti–Nb–O compounds, especially TiNb2O7. This Review aims to provide rational understanding of how structural engineering approaches (e.g., dimensional/morphological control, doping/hybridizing with exotic elements/components, carbon coating/compositing, etc.) improve the electrochemical properties of micro/nanostructured TiNb2O7-based anode materials. In addition, other Ti–Nb–O compounds with different compositions as anodes for LIBs and micro/nanostructured TiNb2O7-based anodes for other energy storage systems (sodium-ion batteries, hybrid supercapacitors, and vanadium redox flow batteries) are discussed. Finally, the challenges and opportunities for micro/nanostructured TiNb2O7-related electrode materials for high-performance energy storage applications are highlighted.
Anion and cation substitution is an effective way in modulating electrochemical properties of electrode materials to achieve enhanced performance. Herein, we report our finding in the fabrication of ...advanced binder-free supercapacitor electrodes of hierarchical anion- (phosphorus-) and cation- (zinc- and nickel-) substituted cobalt oxides (denoted as ZnNiCo-P) architectures assembled from nanosheets grown directly on Ni foam. In contrast to the reference Co-P systems, the as-prepared electrode manifests a markedly improved electrochemical performance with a high specific capacity of ~ 958 C g−1 at 1 A g−1 and an outstanding rate capability (787 C g−1 at 20 A g−1) due to its compositional and structural advantages. Density functional theory calculations confirm that the Co species partially replaced by Zn/Ni and O species by P can simultaneously improve the charge transfer behavior and facilitate the OH- adsorption and deprotonation/protonation reaction process. Moreover, an aqueous hybrid supercapacitor based on self-supported ZnNiCo-P nanosheet electrode demonstrates a high energy density of 60.1 Wh kg−1 at a power density of 960 W kg−1, along with a superior cycling performance (89% of initial specific capacitance after 8000 cycles at 10 A g−1 is retained). These findings offer insights into the rational design of transition metal compounds with multi-components and favorable architectures by manipulating the cations and anions of metal compounds for high-performance supercapacitors.
A high-performance mix-metal phosphide nanosheet electrode enables excellent capacity, rate capability, and cycle stability of hybrid supercapacitors. The electrode is composed of hierarchical Zn and Ni co-substituted Co phosphide nanosheet arrays grown on porous Ni foam. Display omitted
•Hierarchical ZnNiCo-P nanosheet arrays grown directly on Ni foam are constructed for the first time.•The resultant binder-free electrodes manifest outstanding electrochemical performances.•The synergetic contribution and structural features together contribute to outstanding electrochemical performance.•The assembled ZnNiCo-P//PPD-rGOs hybrid supercapacitor achieved a high energy density of 60.1 W h kg−1 at a power density of 960 W kg−1.
An improved understanding of the origin of the electrocatalytic activity is of importance to the rational design of highly efficient electrocatalysts for the hydrogen evolution reaction. Here, an ...ambipolar single‐crystal tungsten diselenide (WSe2) semiconductor is employed as a model system where the conductance and carrier of WSe2 can be individually tuned by external electric fields. The field‐tuned electrochemical microcell is fabricated based on the single‐crystal WSe2 and the catalytic activity of the WSe2 microcell is measured versus the external electric field. Results show that WSe2 with electrons serving as the dominant carrier yields much higher activity than WSe2 with holes serving as the dominant carrier even both systems exhibit similar conductance. The catalytic activity enhancement can be characterized by the Tafel slope decrease from 138 to 104 mV per decade, while the electron area concentration increases from 0.64 × 1012 to 1.72 × 1012 cm−2. To further understand the underlying mechanism, the Gibbs free energy and charge distribution for adsorbed hydrogen on WSe2 versus the area charge concentration is systematically computed, which is in line with experiments. This comprehensive study not only sheds light on the mechanism underlying the electrocatalysis processes, but also offers a strategy to achieve higher electrocatalytic activity.
An ambipolar single‐crystal tungsten diselenide (WSe2) semiconductor electrocatalyst is employed as a benchmark system for interfacial model catalysis. By tuning the external electric field, the conductance and carrier of ambipolar WSe2 can be individually modulated. Combining the experimental and theoretical study, it is demonstrated that the electron carrier plays a key role in the hydrogen evolution reaction.
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