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A carbon-free 3D porous metallic Bi aerogel anode for high-rate Na-ion storage was fabricated through a simple dynamic template strategy, showing excellent capability for rapid ion/electron transfer and volume fluctuation.

A rationally designed multifunctional Zn3(BTC)2 coating layer for Zn anodes to achieve dendrite-free aqueous ZIBs with high capacity and long lifespan.

Catalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have garnered great attention as the key character in metal-air batteries. Herein, we developed a superior nonprecious bifunctional oxygen electrocatalyst, fabricated through spatial confinement of Fe/Fe3C nanocrystals in pyridinic N and Fe-Nx rich carbon nanotubes (Fe/Fe3C-N-CNTs). During ORR, the resultant electrocatalyst exhibits positive onset potential of 1.0 V (vs. RHE), large half-wave potentials of 0.88 V (vs. RHE), which is more positive than Pt/C (0.98 V and 0.83 V, respectively). Remarkably, Fe/Fe3C-N-CNTs exhibits outstanding durability and great methanol tolerance, exceeding Pt/C and most reported nonprecious metal-based oxygen reduction electrocatalysts. Moreover, Fe/Fe3C-N-CNTs show a markedly low potential at j =10 mA/cm2, small Tafel slopes and extremely high stability for OER. Impressively, the Fe/Fe3C-N-CNTs-based Zn-air batteries demonstrate high power density of 183 mW/cm2 and robust charge/discharge stability. It is revealed that the spatial confinement effect can impede the aggregation and corrosion of Fe/Fe3C nanocrystals. Meanwhile, Fe/Fe3C and Fe-Nx play synergistic effect on boosting the ORR/OER activity, which provides an important guideline for construction of inexpensive nonprecious metal-carbon hybrid nanomaterials.

Potassium-ion batteries (KIBs) are considered the next powerful potential generation energy storage system because of substantial potassium resource availability and similar characteristics with lithium. Unfortunately, the actual application of KIBs is inferior to that of lithium-ion batteries (LIBs), in which the finite energy density, ordinary circular life, and underdeveloped fabrication technique dominate the key constraints. Various works have recently been directed to growing novel anode electrodes with superior electrochemical capability. Noticeably, metals/metal oxides materials (e.g., Sb, Sn, Zn, SnO2, and MoO2) have been widely investigated as KIBs anodes because of high theoretical capacity, suggesting outstanding promise for high-energy KIBs. In this review, the latest research of metals/metal oxides electrodes for potassium storage is summarized. The major strategies to control the electrochemical property of metals/metal oxides electrodes are discussed. Finally, the future investigation foreground for these anode electrodes has been proposed.

The demand for large energy storage systems is consecutively increasing, which requires low-cost and renewable batteries technologies with sustainable performance. Potassium, as the nearest element to sodium and lithium in the IA group of the periodic table, possesses excellent superiorities in electrochemical energy storage devices. Correspondingly, numerous electrode materials with excellent stability and capability have been developed for rechargeable potassium-ion batteries (KIBs). In this review, recent results of electrode materials concerning different types of electrolytes (organic electrolyte, aqueous electrolyte, and all-solid-state electrolyte) for rechargeable KIBs are summarized. An overall content of ongoing cathode/anode electrode materials utilized in rechargeable KIBs with organic electrolyte is reviewed. The topic focuses on employing organic compounds, Prussian blue analogues, layered oxides, and polyanionic compounds as cathode. In addition, different anode materials such as intercalation compounds, alloy compounds, conversion compounds, and organic compounds were discussed. Furthermore, the current research progress of other potassium-based electrochemical energy storage devices (KEES) with low costs and high specific energy densities, such as potassium-ion hybrid capacitors (KIHCs) and potassium dual-ion batteries (KDIBs), are also summarized. Finally, we pointed out the current challenges and future directions of KEES.

Potassium-ion batteries (PIBs) are attracting increasing attention due to the abundance of K resources, but the sluggish kinetics and inferior cycling stability of anodes still hinder their application. Herein, we present a hybrid 1T/2H phase MoSe2 anode, which shows noticeable pseudocapacitive response and fast kinetics for K storage. Correspondingly, superior electrochemical performances including a high reversible capacity of 440 mA h g-1 after 100 cycles at 0.1 A g-1 and superb rate capacity of 211 mA h g-1 at 20.0 A g-1 are achieved. We believe this work may shed light on the phase engineering of transition metal compounds for rapid charging PIBs.

Activated porous carbons (APCs) are traditionally produced by heat treatment and KOH activation, where the production time can be as long as 2 h, and the produced activated porous carbons suffer from relatively low specific surface area and porosity. In this study, the fast high-temperature shock (HTS) carbonization and HTS-KOH activation method to synthesize activated porous carbons with high specific surface area of ≈843 m

The rational design and synthesis of hybrid-type electrode nanomaterials are significant for their diverse applications, including their potential usage as high-efficiency nanoarchitectures for supercapacitors (SCs) as a class of promising energy-storage systems for powering next-generation electric vehicles and electronic devices. Here, we reported a facile and controllable synthesis of core-shell NiS/Ni3S2@NiWO4 nanoarrays to fabricate a freestanding electrode for hybrid SCs. Impressively, the as-prepared freestanding NiS/Ni3S2@NiWO4 electrode presents an ultrahigh areal capacity of 2032 μA h cm−2 at 5 mA cm−2, and a capacity retention of 63.6% even when the current density increased up to 50 mA cm−2. Remarkably, the NiS/Ni3S2@NiWO4 nanoarray-based hybrid SC delivers a maximum energy density of 1.283 mW h cm−2 at 3.128 mW cm−2 and a maximum power density of 41.105 mW cm−2 at 0.753 mW h cm−2. Furthermore, the hybrid SC exhibits a capacity retention of 89.6% even after continuous 10,000 cycles, proving its superior stability. This study provides a facile pathway to rationally design a variety of core-shell metal nanostructures for high-performance energy storage devices.

Neural network methods have been trained to satisfactorily learn user/product representations from textual reviews. A representation can be considered as a multiaspect attention weight vector. However, in several existing methods, it is assumed that the user representation remains unchanged even when the user interacts with products having diverse characteristics, which leads to inaccurate recommendations. To overcome this limitation, this paper proposes a novel model to capture the varying attention of a user for different products by using a multilayer attention framework. First, two individual hierarchical attention networks are used to encode the users and products to learn the user preferences and product characteristics from review texts. Then, we design an attention network to reflect the adaptive change in the user preferences for each aspect of the targeted product in terms of the rating and review. The results of experiments performed on three public datasets demonstrate that the proposed model notably outperforms the other state-of-the-art baselines, thereby validating the effectiveness of the proposed approach.

Mixed transition-metal oxides (MTMOs) are regarded as advanced electrode materials for sodium-ion batteries (SIBs). In this study, amorphous CoSnO3 nanocubes wrapped by reduced graphene oxide (marked as a-CoSnO3@rGO) are successfully designed via a facile solvothermal method accompanied by a simple calcination process. To examine this design, sodium storage behaviors of a-CoSnO3@rGO nanocomposites are investigated in detail. Compared with the pristine a-CoSnO3, a-CoSnO3@rGO nanocomposite with 25.1 wt% rGO exhibits enhanced electrochemical performance, for instance, it delivers a high specific capacity of 229.9 mAh g−1 after 100 cycles at 50 mA g−1 with a Coulombic efficiency close to 99%, and it is capable of maintaining a specific capacity of 205.7 mAh g−1 even at a high current density of 800 mA g−1. Superior electrochemical performance of a-CoSnO3@rGO is primarily attributed to intrinsic “self-matrices”, rGO-wrapping network, and crystalline texture engineering. Indeed, the unique 3D-rGO-wrapping architecture of a-CoSnO3@rGO manifests compelling advantages, such as developing a high conductive three-dimensional network, facilitating the ion/electron diffusion, accommodating volume change, and strengthening interaction between rGO and a-CoSnO3. It is believed that the proposed strategy may provide new insights to design hybrid anode nano-materials for advanced SIBs.

Potassium-ion batteries (PIBs) are attracting increasing attention due to the abundance of K resources, but the sluggish kinetics and inferior cycling stability of anodes still hinder their application. Herein, we present a hybrid 1T/2H phase MoSe

Earth abundant potassium is a promising alternative to lithium in energy storage systems, but a pivotal limitation of potassium ion batteries KIBs is their relatively low capacity and inferior cycle stability. Here we report the first synthesis of ultrathin metallic V 5 Se 8 nanosheets embedded in porous carbon graphene like V 5 Se 8 C as a superior anode for KIBs, which achieves a high reversible depotassiation capacity along with unprecedented rate performance and outstanding cycling stability a reversible depotassiation capacity of 145 mAh g 1 after 800 cy cles at 4 A g 1 with 82.9 capacity retention . The impressive performances achieved are attributed to the syner gistic contributions of the NiAs type superstructure, ultrathin nanosheet architecture, sufficient accessible active sites, multi dimensional electronic ionic transport pathways and significant pseudocapacitive behaviors. Com bined experimental analysis and first principles calculations reveal fast reaction kinetics, high ionic electronic conductivity and low diffusion barriers of K ion in graphene like V 5 Se 8 C hybrid. Ex situ characterizations con firm that V 5 Se 8 C electrode undergo a reversible phase evolution by the sequential intercalation and conversion reactions with synergistic K storage mechanisms. Furthermore, by coupling with pre treated K 0.5 MnO 2 cathode, the full cell is demonstrated to exhibit large energy density of 160.2 Wh kg 1 with average discharge voltage of 2.2 V and capacity retention of 86 over 200 cycles. These desirable findings demonstrate graphene like V 5 Se 8 C nanosheets hold great practical application in future grid scale energy storage

With the continuous accumulation of social network data, social recommendation has become a widely used recommendation method. Based on the theory of social relationship propagation, mining user relationships in social networks can alleviate the problems of data sparsity and the cold start of recommendation systems. Therefore, integrating social information into recommendation systems is of profound importance. We present an efficient network model for social recommendation. The model is based on the graph neural network. It unifies the attention mechanism and bidirectional LSTM into the same framework and uses a multilayer perceptron. In addition, an embedded propagation method is added to learn the neighbor influences of different depths and extract useful neighbor information for social relationship modeling. We use this method to solve the problem that the current research methods of social recommendation only extract the superficial level of social networks but ignore the importance of the relationship strength of the users at different levels in the recommendation. This model integrates social relationships into user and project interactions, not only capturing the weight of the relationship between different users but also considering the influence of neighbors at different levels on user preferences. Experiments on two public datasets demonstrate that the proposed model is superior to other benchmark methods with respect to mean absolute error and root mean square error and can effectively improve the quality of recommendations.

Heteroatom doping engineering is deemed to be an adoptable strategy to boost the potassium (K) storage performance of carbonaceous materials. The inevitable issue for this strategy lies in the huge volume expansion originated from the large radius of K+. In this study, N/O co-doped porous carbon spheres (PCSs) with high content -C = O are fabricated by a reliable and simple annealing route. Through dual-function engineering for heteroatom doping and pore constructing, the PCSs shows outstanding K+-storage performance with remarkable reversible capacity (389.8 mAh g(-1) at 0.1 A g(-1)), superior rate capability (201.7 mAh g(-1) at 1 A g(-1)), and unprecedented ultralong-term cycling stability (107 mA h g(-1) at 5 A g(-1) after 40,000 cycles with 0.00038% decay per cycle). In-situ Raman analysis uncovers that the PCSs undergoes a reversible adsorption-intercalation hybrid K+-storage mechanism. Specifically, density functional theory calculations and in-situ transmission electron microscopy observations elucidate the possible origins of the high reversible capacity and superb cycling stability by disentangling the synergistic effect of dual-function engineering. The PCSs can be used as the anode for potassium-ion hybrid capacitors (PIHCs) to deliver a high energy/power density. This work opens a new avenue to construct carbonaceous electrode candidates for high-performance PIHCs.

Mixed transition metal sulfides (MTMSs) have been regarded as a potential anode material for sodium-ion batteries (SIBs) due to their high reversible specific capacity. Herein, nanoflower-like few-layered cobalt-tin-based sulfide (F-CoSnS) with a large interlayer spacing is synthesized via a facile route for superior sodium storage. The growth mechanism of this unique F-CoSnS is systematically studied. Such distinctive nanostructured engineering synergistically combines a broad interlayer spacing (∼ 0.85 nm), the functionalities of few (2-3) layers, and the introduction of heterogeneous metal atoms, reducing the ion diffusion energy barrier for high-efficiency intercalation/deintercalation of Na

With the characteristics of high-speed calculation and high-accuracy prediction, artificial intelligence (AI) which also known as machine intelligence, including deep learning, machine learning, etc., have shown great advantages in cross-field applications. In material science field, AI can be used to discover new materials and predict corresponding critical properties. At present, AI has been used in the exploitation of energy conversion materials and other energy-related materials. In this review, we summary the current achievements of AI applications in energy conversions, analyze the advantages and disadvantages of AI techniques in material researches and point out future development prospects.

Energy shortage is a severe challenge nowadays. It has affected the development of new energy sources. Artificial intelligence (AI), such as learning and analyzing, has been widely used for various advantages. It has been successfully applied to predict materials, especially energy storage materials. In this paper, we present a survey of the present status of AI in energy storage materials via capacitors and Li-ion batteries. We picture the comprehensive progress of AI in energy storage materials, including the advantages and disadvantages of material data to support AI. Finally, we provide some ideas to solve those challenges.

In this study, mesoporous ZnCo

The rational design and synthesis of hybrid-type electrode nanomaterials are of significant importance for their diverse applications, including their promising usage as high-efficiency nanoarchitectures for supercapacitors (SCs) as a class of promising energy-storage systems for powering next-generation electric vehicles and electronic devices. Here, we report a regulated synthesis of eutectic structured Ni3S2/NiS nanorods, which is demonstrated to have fantastic electrochemical performance as a freestanding electrode for hybrid SCs. The as-prepared Ni3S2/NiS significantly increases the interfacial atomic activity between Ni3S2 and NiS, which provides more electrochemical active sites and facilitates fast ion diffusion. The Ni3S2/NiS electrode presented superior areal specific capacity of 1330 μA h cm−2 and remains 67.1% of its initial capacity when the current density increased 20 folds. The as-assembled hybrid supercapacitor demonstrated fantastic energy density of 0.567 mWh cm−2@4.251 mW cm−2, and retained at 0.476 mWh cm−2@34.440 mW cm−2 with long durability. This study provides a facile pathway to rationally design a variety of eutectic structured metal compounds for high performance energy storage devices.

A highly electrically conductive film-type current collector is an essential part of batteries. Apart from the metal-based current collectors, lightweight and highly conductive carbon materials such as reduced graphene oxide (RGO) and carbon nanotubes (CNTs) show great potential as current collectors. However, traditional RGO manufacturing usually requires a long time and high energy, which decreases the product yielding rate and manufacturing efficiency. Moreover, the performance of the manufactured RGO needs to be further improved. In this work, CNT and GO are evenly mixed into GO-CNT, which can be directly reduced into RGO-CNT by Joule heating at 2936 K within less than 1 min. The fabricated RGO-CNT achieves a high electrical conductivity of 2750 S cm-1 , and realizes a 106 -fold increase. The assembled flexible aqueous Al-ion battery with RGO-CNT as the current collector exhibits impressive electrochemical performance in terms of superior cycling stability and exceptional rate capability, and excellent mechanical ability regarding the tolerance to mechanical damage such as bending, folding, piercing, and cutting without detrimental consequences.

Functional nanomaterials are playing a crucial role in the emerging field of energy-related devices. Recently, as a novel synthesis method, high-temperature shock (HTS), which is rapid, low cost, eco-friendly, universal, scalable, and controllable, has provided a promising option for the rational design and synthesis of various high-quality nanomaterials. In this report, the HTS technique, including the equipment setup and operating principle, is systematically introduced, and recent progress in the synthesis of nanomaterials for energy storage and conversion applications using this HTS method is summarized. The growth mechanisms of nanoparticles and carbonaceous nanomaterials are thoroughly discussed, followed by the summary of the characteristic advantages of the HTS strategy. A series of nanomaterials prepared by the HTS method, including carbon-based films, metal nanoparticles and compound nanoparticles, show high performance in the diverse applications of storage energy batteries, highly active catalysts, and smart energy devices. Finally, the future perspectives and directions of HTS in nanomanufacturing for broader applications are presented.

The structural instability and sluggish kinetic process of the pristine Na0.75Ni0.2Co0.2Mn0.6O2 (NCM) occurring at a high working voltage result in obvious capacity loss. In this study, Fe3+ doping onto the surface of the P2-type Na0.75Ni0.2Co0.2Mn0.6O2 (NCM) was fulfilled via post-annealing atomic layer deposition (ALD) derived Fe2O3 layer. It indicates that the modified NCM cathode materials exhibit better crystal structure stability and electrochemical behavior than the pristine NCM at wide voltage windows of 2.4–4.5 V and 2.4–4.7 V vs. Na/Na +. Furthermore, the ALD-30C-annealing material shows a higher initial capacity of 107 mA h g−1 at 0.1C (20 mA g−1), and it can reach a reversible capacity of 78 mA h g−1 and Coulombic efficiency of 96.6% after 100 cycles at the cutoff voltage of 4.5 V. Amazingly, combined with reduced graphene oxide (rGO) as an anode material , the ALD-30C-annealing cathode material exhibits notable full cell performance with the specific energy density of 160 Wh kg −1 at the high voltage widows of 2.4–4.5 V after 100 cycles. The designed strategy in this work may be one of the most promising perspectives toward the high performance cathode materials for SIBs .

Polymer-derived silicon carbonitride (SiCN) materials have been synthesized via pyrolyzing from five poly(silylcarbondiimide)s with different contents of carbon (labeled as 1-5#). The morphological and structural measurements show that the SiCN materials are mixtures of nanocrystals of SiC, Si3N4, and graphite. The SiCN materials have been used as anodes for lithium-ion batteries. Among the five polymer-derived SiCN materials, 5#SiCN, derived from dichloromethylvinylsilane and di-n-octyldichlorosilane, has the best cycle stability and a high-rate performance at the low cutoff voltage of 0.01-1.0 V. In lithium-ion half-cells, the specific delithiation capacity of 5#SiCN anode still remains at 826.7 mA h g-1 after 100 charge/discharge cycles; it can even deliver the capacity above 550 mA h g-1 at high current densities of 1.6 and 2 A g-1. In lithium-ion full cells, 5#SiCN anode works well with LiNi0.6Co0.2Mn0.2O2 commercial cathode. The outstanding electrochemical performance of 5#SiCN anode is attributed to two factors: (1) the formation of a stable and compact solid electrolyte interface layer on the anode surface anode, which protects the electrode from cracking during the charge/discharge cycle; and (2) a large amount of carbon component and the less Si3N4 phase in the 5#SiCN structure, which provides an electrochemical reactive and conductive environment in the SiCN structure, benefit the lithiation/delithiation process. In addition, we explore the reason for the capacity fading of these SiCN anodes.

In this study, mesoporous ZnCo2O4/rGO nanocomposites were favorably synthesized via a simple solvothermal technique. As a prospective anode material for sodium-ion batteries, the resulting ZnCo2O4/rGO-II nanocomposite exhibited superior electrochemical sodium storage performance with predominant specific capacity, favorable cyclability and ascendant rate capability. For example, an outstanding discharge capacity of 210.5 mAh g-1 was delivered at a current density of 200 mA g-1. Notably, the nanocomposite could yield a discharge capacity of 101.7 mAh g-1 at a current density of 1000 mA g-1 after 500 loops, which certifies its superior capacity retention and predominant cycling stability. The boosted performance of the anode materials is due to the mutual synergistic effect resulting from a combination of the mesoporous ZnCo2O4 nanospheres and conducting reduced graphene oxide nanosheets.