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Highlights The developmental history of high-entropy materials and the conceptual origin of “high entropy” is comprehensively reviewed. The preparation methods of various high-entropy electrode materials are comprehensively reviewed. The application properties of various high-entropy electrode materials in electrocatalysis and energy storage are comprehensively reviewed, with a prospective outlook on the future development of such materials.

Abstract As machine learning (ML) continues to advance in the field of materials science, the variation in strategies for the same steps of the ML workflow becomes increasingly significant. These details can have a substantial impact on results, yet they have not received the deserved attention. This review aims to explore the various strategies available for each detail within the general workflow of materials ML. Firstly, the general workflow of materials ML will be introduced to help readers gain an understanding of potential details. Subsequently, different strategies of details within each step of the workflow will be presented through state-of-the-art case studies. The potential outcomes associated with choosing different strategies to details will be explored. Following this, suitable strategies for details will be recommended based on distinct application scenarios. Finally, directions for the future development of materials ML concerning details will be proposed. Through these discussions, we aspire to offer a comprehensive understanding of the nuances in details within materials ML. This will serve as valuable reference and guidance for researchers in both materials science and ML.

Abstract Hybrid supercapacitors (HSCs) comprising a battery‐type cathode and capacitive anode have recently become a research hotspot. Nevertheless, the low capacity utilization, poor kinetic behavior, and unstable structure of a single battery‐type oxide cathode restrict the overall performance of the device. Herein, the carbon quantum dots (CQDs) modified NiO/Co3O4 heterostructured flower‐like microspheres are constructed, and enhanced specific capacity, rate capability, and cycling performance are achieved when used as the cathode for HSCs. This is attributed to the fact that the modification of bifunctional CQDs as size regulators and conductive agents and the construction of heterostructure can not only improve the specific surface area and provide more electroactive sites, thereby enhancing the charge storage performance but also regulate the electronic structure and boost the interface charge transfer capability and electronic conductivity, thereby boosting the reaction kinetics and cycle stability. The enhanced electrochemical kinetic behavior is revealed by electrochemical kinetic analyses based on cyclic voltammetry, electrochemical impedance spectroscopy tests and density functional theory calculations. Meanwhile, the electrochemical reaction process and energy storage mechanism are illustrated by ex‐situ X‐ray diffraction and X‐ray photoelectron spectroscopy characterizations. Furthermore, an HSC is further constructed using the CQDs/NiO/Co3O4 heterostructured flower‐like microspheres as the cathode, simultaneously achieving high energy density (40.9 Wh kg−1), high power density (24 kW kg−1), and splendid cyclic stability (94.2% capacity retention after 5000 cycles at 10 A g−1). These synergistic modification strategies of bifunctional CQDs modification and heterostructure design provide a valuable direction for the design and development of HSCs with both high energy density and high power density.

Highlights The robust organic/inorganic hybrid interlayer derived from in situ formed tribofilms were fabricated by using a scalable rolling method. The interlayer facilitates dendrite-free lithium metal anodes by building local de-solvation environments near the interface and inhibiting both dendrite growth and electrolytes corrosion. The symmetrical cell exhibits a remarkable lifespan of 5,600 h (1.0 mA cm-2 and 1.0 mAh cm-2) and 1,350 cycles even at a harsh condition (18.0 mA cm-2 and 3.0 mAh cm-2).

Abstract Although the closed pore structure plays a key role in contributing low-voltage plateau capacity of hard carbon anode for sodium-ion batteries, the formation mechanism of closed pores is still under debate. Here, we employ waste wood-derived hard carbon as a template to systematically establish the formation mechanisms of closed pores and their effect on sodium storage performance. We find that the high crystallinity cellulose in nature wood decomposes to long-range carbon layers as the wall of closed pore, and the amorphous component can hinder the graphitization of carbon layer and induce the crispation of long-range carbon layers. The optimized sample demonstrates a high reversible capacity of 430 mAh g−1 at 20 mA g−1 (plateau capacity of 293 mAh g−1 for the second cycle), as well as good rate and stable cycling performances (85.4% after 400 cycles at 500 mA g−1). Deep insights into the closed pore formation will greatly forward the rational design of hard carbon anode with high capacity.

Abstract A practical high-specific-energy Li metal battery requires thin (≤20 μm) and free-standing Li metal anodes, but the low melting point and strong diffusion creep of lithium metal impede their scalable processing towards thin-thickness and free-standing architecture. In this paper, thin (5 to 50 μm) and free-standing lithium strips were achieved by mechanical rolling, which is determined by the in situ tribochemical reaction between lithium and zinc dialkyldithiophosphate (ZDDP). A friction-induced organic/inorganic hybrid interface (~450 nm) was formed on Li with an ultra-high hardness (0.84 GPa) and Young’s modulus (25.90 GPa), which not only enables the scalable process mechanics of thin lithium strips but also facilitates dendrite-free lithium metal anodes by inhibiting dendrite growth. The rolled lithium anode exhibits a prolonged cycle lifespan and high-rate cycle stability (in excess of more than 1700 cycles even at 18.0 mA cm−2 and 1.5 mA cm−2 at 25 °C). Meanwhile, the LiFePO4 (with single-sided load 10 mg/cm2) ||Li@ZDDP full cell can last over 350 cycles with a high-capacity retention of 82% after the formation cycles at 5 C (1 C = 170 mA/g) and 25 °C. This work provides a scalable approach concerning tribology design for producing practical thin free-standing lithium metal anodes.

Two-dimensional (2D) organic–inorganic hybrid perovskites (OIHPs) have drawn increased attention due to rich physical properties such as ferroelectricity and photovoltaic properties. Nevertheless, it is challenging to discover novel 2D OIHPs within the vast chemical composition space. Herein, a diagrammatic machine learning model was employed to improve this issue. We collected 179 OIHPs with a variety of organic cations and screened out 6 features from 10,622 descriptors. Subsequently, a decision tree model was created to predict the dimensionality of OIHPs, achieving a LOOCV accuracy of 0.94 and a test accuracy of 0.89, respectively. Then, one candidate from a virtual space with 8256 samples was successfully synthesized, which was consistent with the prediction of the model. Finally, three rules were produced by visualization of the tree structure to generally discriminate 2D from non-2D OIHPs. It is believed that the diagrammatic model has reliability in identifying 2D OIHPs and will serve further property studies of OIHPs in the future.

Abstract This review discussed the dilemma of small data faced by materials machine learning. First, we analyzed the limitations brought by small data. Then, the workflow of materials machine learning has been introduced. Next, the methods of dealing with small data were introduced, including data extraction from publications, materials database construction, high-throughput computations and experiments from the data source level; modeling algorithms for small data and imbalanced learning from the algorithm level; active learning and transfer learning from the machine learning strategy level. Finally, the future directions for small data machine learning in materials science were proposed.

Highlights Oxygen-respirable sponge was constructed by carbon dots-assisted synthesis strategy. The hydrophilicity and aerophilicity of Co@C–O–Cs active sites boost oxygen diffusion and the bifunctional oxygen reduction reaction and oxygen evolution reaction activities. Co@C–O–Cs-based Zn-air battery (ZAB) displays excellent specific capacity and stability, and the all-solid-state Co@C–O–Cs-based ZAB exhibits excellent flexibility.

Abstract Carbonaceous materials have been regarded as highly promising anode candidates for potassium storage with their cost‐effectiveness and environmental benignity. However, low specific capacity and difficulty in large‐scale synthesis largely hinder their further development. Herein, a thermal‐induced potassium–carbon alloy phase (KxCy) with the expanded interlayer spacing strategy is first put forward. Through in situ high‐temperature X‐ray diffraction, a K2C2 phase is evoked by thermal energy during the in‐situ carbonization process of carbon quantum dots intermediate derived from potassium‐containing precursors, whereas no lithium or sodium–carbon alloy phase is observed from lithium/sodium‐containing precursors. The as‐obtained ultra‐thin carbon nanosheets achieve adjustable layer spacing, preparation in bulk, delivering reversible potassium storage of 403.4 mAh g−1 at 100 mA g−1 and 161.2 mAh g−1 even at 5.0 A g−1, which is one of the most impressive K‐storage performances reported so far with great potential application. Furthermore, the assembled potassium‐ion hybrid capacitor by combining the impressive CFMs‐900 anode with the three‐dimensional framework‐activated carbon delivers a high energy‐power density of 251.7 Wh kg−1 at 250 W kg−1 with long‐term stability. This study opens a scalable avenue to realize the expanded interlayer spacing, which can be extended to other multicarboxyl potassium salts and can provide approach for the design of high‐performance carbon anode materials for potassium storage.

Abstract Exploring new materials with high stability and capacity is full of challenges in sustainable energy conversion and storage systems. Metal–organic frameworks (MOFs), as a new type of porous material, show the advantages of large specific surface area, high porosity, low density, and adjustable pore size, exhibiting a broad application prospect in the field of electrocatalytic reactions, batteries, particularly in the field of supercapacitors. This comprehensive review outlines the recent progress in synthetic methods and electrochemical performances of MOF materials, as well as their applications in supercapacitors. Additionally, the superiorities of MOFs-related materials are highlighted, while major challenges or opportunities for future research on them for electrochemical supercapacitors have been discussed and displayed, along with extensive experimental experiences.

Abstract Among the solid electrolytes for solid‐state Li batteries, polymer electrolytes are actively explored on the basis of the good interfacial contact and easy making, while it is still constrained by slow ionic transport and low lithium ion transference number. Herein, functional carbon dots‐based Li+ conductor (CD‐Li) is designed to improve the dynamics and selectivity of Li+ transport in polyethylene oxide (PEO) electrolyte. High ionic conductivity (1.0 × 10−4 S/cm, 25 °C) and Li+ transference number (0.60) were successfully achieved within the CD‐Li‐based PEO composite electrolyte, which could be attributed to the enhanced chain movement and the limited motion of anion. Moreover, the characteristics of big volume of individual anions of CD‐Li can provide more free Li+. As well, benefiting from the existence of F atom in the CD‐Li, in‐situ constructed LiF‐containing interfacial layer is in favor of maintaining the interface stability and facilitating the rapid transmission of Li ions. The composite electrolyte with CD‐Li can address the ionic conductivity issues accompanied with strengthening the interfacial stability. The distinctive composite electrolyte realizes the stable cycle performance for Li/LiFePO4 and Li/LiNi0.5Co0.2Mn0.3O2 batteries. The exploration of multifunctional carbon dot fillers provides new ideas for the efficient development of composite electrolytes.

Highlights The chemical process of local oxidation–partial reduction–deep coupling for stibnite reduction of carbon dots (CDs) is revealed by in-situ high-temperature X-ray diffraction. Sb2S3@xCDs anode delivers high initial coulombic efficiency in lithium ion batteries (85.2%) and sodium ion batteries (82.9%), respectively. C–S bond influenced by oxygen-rich carbon matrix can restrain the conversion of sulfur to sulfite, well confirmed by X-ray photoelectron spectroscopy characterization of solid electrolyte interphase layers helped with density functional theory calculations. CDs-induced Sb–O–C bond is proved to effectively regulate the interfacial electronic structure. Abstract The application of Sb2S3 with marvelous theoretical capacity for alkali metal-ion batteries is seriously limited by its poor electrical conductivity and low initial coulombic efficiency (ICE). In this work, natural stibnite modified by carbon dots (Sb2S3@xCDs) is elaborately designed with high ICE. Greatly, chemical processes of local oxidation–partial reduction–deep coupling for stibnite reduction of CDs are clearly demonstrated, confirmed with in situ high-temperature X-ray diffraction. More impressively, the ICE for lithium-ion batteries (LIBs) is enhanced to 85%, through the effect of oxygen-rich carbon matrix on C–S bonds which inhibit the conversion of sulfur to sulfite, well supported by X-ray photoelectron spectroscopy characterization of solid electrolyte interphase layers helped with density functional theory calculations. Not than less, it is found that Sb–O–C bonds existed in the interface effectively promote the electronic conductivity and expedite ion transmission by reducing the bandgap and restraining the slip of the dislocation. As a result, the optimal sample delivers a tremendous reversible capacity of 660 mAh g−1 in LIBs at a high current rate of 5 A g−1. This work provides a new methodology for enhancing the electrochemical energy storage performance of metal sulfides, especially for improving the ICE.

The rapid growth in global electric vehicles (EVs) sales has promoted the development of Co-free, Ni-rich layered cathodes for state-of-the-art high energy-density, inexpensive lithium-ion batteries (LIBs). However, progress in their commercial use has been seriously hampered by exasperating performance deterioration and safety concerns. Herein, a robust single-crystalline, Co-free, Ni-rich LiNi0.95Mn0.05O2 (SC-NM95) cathode is successfully designed using a molten salt-assisted method, and it exhibits better structural stability and cycling durability than those of polycrystalline LiNi0.95Mn0.05O2 (PC-NM95). Notably, the SC-NM95 cathode achieves a high discharge capacity of 218.2 mAh g−1, together with a high energy density of 837.3 ​Wh kg−1 ​at 0.1 C, mainly due to abundant Ni2+/Ni3+ redox. It also presents an outstanding capacity retention (84.4%) after 200 cycles at 1 ​C, because its integrated single-crystalline structure effectively inhibits particle microcracking and surface phase transformation. In contrast, the PC-NM95 cathode suffers from rapid capacity fading owing to the nucleation and propagation of intergranular microcracking during cycling, facilitating aggravated parasitic reactions and rock-salt phase accumulation. This work provides a fundamental strategy for designing high-performance single-crystalline, Co-free, Ni-rich cathode materials and also represents an important breakthrough in developing high-safe, low-cost, and high-energy LIBs.

Highlights Interfacial bonding strategy has been successfully applied to address the high overpotential issue of sacrificial additives, which reduced the decompositon potential of Na2C2O4 from 4.50 to 3.95 V. Ultra-low-dose technique assisted commercial sodium ion capacitor (AC//HC) could deliver a remarkable energy density of 118.2 Wh kg−1 as well as excellent cycle stability. In-depth decomposition mechanism of sacrificial compound and the relative influence after pre-metallation were revealed by advanced in situ and ex situ characterization approaches. Abstract Sacrificial pre-metallation strategy could compensate for the irreversible consumption of metal ions and reduce the potential of anode, thereby elevating the cycle performance as well as open-circuit voltage for full metal ion capacitors (MICs). However, suffered from massive-dosage abuse, exorbitant decomposition potential, and side effects of decomposition residue, the wide application of sacrificial approach was restricted. Herein, assisted with density functional theory calculations, strongly coupled interface (M–O–C, M = Li/Na/K) and electron donating group have been put forward to regulate the band gap and highest occupied molecular orbital level of metal oxalate (M2C2O4), reducing polarization phenomenon and Gibbs free energy required for decomposition, which eventually decrease the practical decomposition potential from 4.50 to 3.95 V. Remarkably, full sodium ion capacitors constituted of commercial materials (activated carbon//hard carbon) could deliver a prominent energy density of 118.2 Wh kg−1 as well as excellent cycle stability under an ultra-low dosage pre-sodiation reagent of 15–30 wt% (far less than currently 100 wt%). Noteworthily, decomposition mechanism of sacrificial compound and the relative influence on the system of MICs after pre-metallation were initially revealed by in situ differential electrochemical mass spectrometry, offering in-depth insights for comprehending the function of cathode additives. In addition, this breakthrough has been successfully utilized in high performance lithium/potassium ion capacitors with Li2C2O4/K2C2O4 as pre-metallation reagent, which will convincingly promote the commercialization of MICs.

Perovskite materials have been one of the most important research objects in materials science due to their excellent photoelectric properties as well as correspondingly complex structures. Machine learning (ML) methods have been playing an important role in the design and discovery of perovskite materials, while feature selection as a dimensionality reduction method has occupied a crucial position in the ML workflow. In this review, we introduced the recent advances in the applications of feature selection in perovskite materials. First, the development tendency of publications about ML in perovskite materials was analyzed, and the ML workflow for materials was summarized. Then the commonly used feature selection methods were briefly introduced, and the applications of feature selection in inorganic perovskites, hybrid organic-inorganic perovskites (HOIPs), and double perovskites (DPs) were reviewed. Finally, we put forward some directions for the future development of feature selection in machine learning for perovskite material design.

Abstract The uncontrollable dendrite growth and complex interfacial reactions are still challenging issues hindering the practical applications of lithium (Li) metal anode. A variety of materials are widely studied to regulate the surface properties of Li metal anode except for the lithiophobic materials. This study shows that a double lithiophobic sandwich structure can induce uniform Li deposition to suppress Li dendrite growth at the nucleating stage. A hexagonal boron nitride (h‐BN) particle layer on Cu foil (h‐BN@Cu) is prepared as the research target to intensely explore the fundamental role of the lithiophobic h‐BN layer on the diffusion and nucleation behavior of Li on the Cu surface. The h‐BN layer makes the h‐BN@Cu interface possess lower adsorption energy and more substantial charge transfer, leading to the “h‐BN‐Li‐Cu” sandwich deposition mode. Theoretical calculations, in situ monitoring, and experimental tests confirm the relevance between uniform Li deposition and the h‐BN@Cu interface structure. The h‐BN@Cu anode enables a significantly improved lifespan (over 550 h) compared to the Cu anode and enhanced cycling stability when assembled in whole cells with LiFePO4 (LFP) cathode. This discovery provides a new insight into h‐BN and other lithiophobic materials as a protective layer to improve the Li deposition behavior.

Zinc affinity plays a key role in the zinc plating and stripping processes but its internal mechanism is still unclear. Here, the authors report a protective layer with controllable zinc affinity by adjusting the crystal orientation to suppress the dendrite growth on the zinc anode interface.

Abstract The lack of methods to modulate intrinsic textures of carbon cathode has seriously hindered the revelation of in-depth relationship between inherent natures and capacitive behaviors, limiting the advancement of lithium ion capacitors (LICs). Here, an orientated-designed pore size distribution (range from 0.5 to 200 nm) and graphitization engineering strategy of carbon materials through regulating molar ratios of Zn/Co ions has been proposed, which provides an effective platform to deeply evaluate the capacitive behaviors of carbon cathode. Significantly, after the systematical analysis cooperating with experimental result and density functional theory calculation, it is uncovered that the size of solvated PF6 − ion is about 1.5 nm. Moreover, the capacitive behaviors of carbon cathode could be enhanced attributed to the controlled pore size of 1.5–3 nm. Triggered with synergistic effect of graphitization and appropriate pore size distribution, optimized carbon cathode (Zn90Co10-APC) displays excellent capacitive performances with a reversible specific capacity of ~ 50 mAh g−1 at a current density of 5 A g−1. Furthermore, the assembly pre-lithiated graphite (PLG)//Zn90Co10-APC LIC could deliver a large energy density of 108 Wh kg−1 and a high power density of 150,000 W kg−1 as well as excellent long-term ability with 10,000 cycles. This elaborate work might shed light on the intensive understanding of the improved capacitive behavior in LiPF6 electrolyte and provide a feasible principle for elaborate fabrication of carbon cathodes for LIC systems.

Abstract Carbon quantum dots (CQDs) as a new class of emerging materials have gradually drawn researchers’ concern in recent years. In this work, the graphitic CQDs are prepared through a scalable approach, achieving a high yield with more than 50%. The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials, manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity. Moreover, the nitrogen-doped reduced graphene oxide (N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO. A novel alkaline aqueous battery assembled by these materials displays a specific energy (50.2 Wh kg−1), ultrahigh specific power (9.7 kW kg−1) and excellent cycling performance with 91.5% of capacity retention at 3 A g−1 for 5000 cycles. The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.

Abstract Background To investigate the status of anti-tuberculosis treatment in critically ill patients, and to explore the value of APACHE-II score in guiding anti-tuberculosis treatment. Methods This analysis included critically ill patients with tuberculosis. The utility of APACHE-II score for predicting drug withdrawal was evaluated using receiver operating characteristic (ROC) curve analysis. Results Among 320 patients enrolled (58 ± 22 years; 256 males), 147 (45.9%) had drugs withdrawn. The drug withdrawal group had higher APACHE-II score (median [interquartile range]: 21 [3–52] vs. 17 [4–42] points), higher CD4%, lower hemoglobin level, higher rates of chronic obstructive pulmonary disease (COPD) and chronic renal failure, and lower rate of extrapulmonary tuberculosis (P 18 (odds ratio [95% confidence interval]: 2.099 [1.321–3.334], P 18 points might predict patient tolerance of anti-tuberculosis treatment.

An electrochemical collision method is utilized to compare the sodium de-insertion process in particles of quarternary sodium-containing layered metal oxides NaxTMO2 (TM = Fe, Mn, Ni, Cu) in the O3 phase and the P2 phase. The electrochemical behavior of the two types of materials is found to be different. The diffusion of Na+ inside an individual particle occurs more readily in O3-type oxides than in P2-type oxides, which is contrary to the conventional wisdom that P2-type oxides usually provide higher Na-ion conductivity than their O3 analogs. These results provide a more detailed analytical perspective for assessing battery materials.

Abstract Given the inherent features of open tunnel‐like pyrochlore crystal frameworks and pentavalent antimony species, polyantimonic acid (PAA) is an appealing conversion/alloying‐type anode material with fast solid‐phase ionic diffusion and multielectron reactions for lithium‐ion batteries. Yet, enhancing the electronic conductivity and structural stability are two key issues in exploiting high‐rate and long‐life PAA‐based electrodes. Herein, these challenges are addressed by engineering a novel multidimensional integrated architecture, which consists of 0D Mn‐substituted PAA nanocrystals embedded in 1D tubular graphene scrolls that are co‐assembled with 2D N‐doped graphene sheets. The integrated advantages of each subunit synergistically establish a robust and conductive 3D electrode framework with omnidirectional electron/ion transport network. Computational simulations combined with experiments reveal that the partial‐substitution of H3O+ by Mn2+ into the tunnel sites of PAA can regulate its electronic structure to narrow the bandgap with increased intrinsic electronic conductivity and reduce the Li+ diffusion barrier. All above merits enable improved reaction kinetics, adaptive volume expansion, and relieved dissolution of active Mn2+/Sb5+ species in the electrode materials, thus exhibiting ultrahigh rate capacity (238 mAh g−1 at 30.0 A g−1), superfast‐charging capability (fully charged with 56% initial capacity for ≈17 s at 80.0 A g−1) and durable cycling performance (over 1000 cycles).

Tuning hierarchical pore structure of carbon materials is an effective way to achieve high energy density under high power density of carbon-based supercapacitors. However, at present, most of methods for regulating pores of carbon materials are too complicated to be achieved. In this work, a durian shell derived porous carbon (DSPC) with abundant porous is prepared through chemical activation as a defect strategy. Hierarchical porous structure can largely enhance the transfer rate of electron/ion. Furthermore, DSPC with multiple porous structure exhibits excellent properties when utilized as electrode materials for electric double layer capacitors (EDLCs), delivering a specific capacitance of 321 F g−1 at 0.5 A g−1 in aqueous electrolyte. Remarkably, a high energy density of 27.7 Wh kg−1 is obtained at 675 W kg−1 in an organic two-electrode device. And large capacity can be remained even at high charge/discharge rate. Significantly, hierarchical porous structure allows efficient ion diffusion and charge transfer, resulting in a prominent cycling stability. This work is looking forward to providing a promising strategy to prepare hierarchical porous carbon-based materials for supercapacitors with ultrafast electron/ion transport.

Abstract Lithium metal is the most ideal anode for next‐generation lithium‐ion batteries. However, the formation of lithium dendrites and the continuous consumption of electrolyte during cycling lead to a serious safety problems. Developing stable lithium metal anode with uniform lithium deposition is highly desirable. Herein, a nitrogen plasma strengthening strategy is proposed for copper oxide nanosheet–decorated Cu foil as an advanced current collector, and deep insights into the plasma regulating mechanism are elaborated. The plasma‐treated electrode can maintain a high coulombic efficiency of 99.6% for 500 cycles. The symmetric cell using the lithium‐plated electrode can be cycled for more than 600 h with a low‐voltage hysteresis (23.1 mV), which is much better than those of electrodes without plasma treatment. It is well confirmed that this plasma‐induced nitrogen doping method can provide sufficient active sites for lithium nucleation to enhance the stability of lithium deposition on copper oxide nanosheets decorated on Cu foil and improve the electrical conductivity to greatly reduce the overpotential of the lithium nucleation, which can be extended to other modified current collectors for stable lithium metal anode.

Restricted by the dissatisfied capacity of traditional materials, lithium-ion batteries (LIBs) still suffer from the low energy-density. The pursuing of natural electrode resources with high lithium-storage capability has triggered a plenty of activities. Through the hydro-refining process of raw molybdenite ore, containing crushing–grinding, flotation, exfoliation, and gradient centrifugation, 2D molybdenum disulfide (MoS2) with high purity is massively obtained. The effective tailoring process further induce various sizes (5, 2, 1 and 90 nm) of sheets, accompanying with the increasing of active sites and defects. Utilized as LIB anodes, size-tuning could serve crucial roles on the electrochemical properties. Among them, MoS2-1 μm delivers an initial charge capacity of 904 mAh g−1, reaching up to 1,337 mAh g−1 over 125 loops at 0.1 A g−1. Even at 5.0 A g−1, a considerable capacity of 682 mAh g−1 is remained. Detailedly analyzing kinetic origins reveals that size-controlling would bring about lowered charge transfer resistance and quicken ions diffusion. The work is anticipated to shed light on the effect of different MoS2 sheet sizes on Li-capacity ability and provides a promising strategy for the commercial-scale production of natural mineral as high-capacity anodes.

Abstract Different dimensions of carbon materials with various features have captured numerous interests due to their applications on the tremendous fields. Restricted by the raw materials and devices, the controlling of their morphology is a major challenge. Utilizing the catalytic features of the intermediates from the low‐cost salts and polymerization of 0D carbon quantum dots (CQDs), 0D CQDs are expected to self‐assemble into 1/2/3D carbon structures with the assistance of temperature‐induced intermediates (e.g., ZnO, Ni, and Cu) from the salts (ZnCl2, NiCl2, and CuCl). The formation mechanisms are illustrated as follows: 1) the “orient induction” to evoke “vine style” growth mechanism of ZnO; 2) the “dissolution–precipitation” of Ni; and 3) the “surface adsorption self‐limited” of Cu. Subsequently, the degree of graphitization, interlayer distance, and special surface area are investigated in detail. 1D structure from 700 °C as anode displays a high Na‐storage capacity of 301.2 mAh g−1 at 0.1 A g−1 after 200 cycles and 107 mAh g−1 at 5.0 A g−1 after 5000 cycles. Quantitative kinetics analysis confirms the fundamentals of the enhanced rate capacity and the potential region of Na‐insertion/extraction. This elaborate work opens up an avenue toward the design of carbon with multidimensions and in‐depth understanding of their sodium‐storage features.

In this paper, a graphene decorated SiC nanomaterial (graphene@SiC) fabricated via a facile adiabatic process was physicochemically characterised, then applied as a supercapacitor material and as an anode within a Li-ion battery (LIB). The reported graphene@SiC nanomaterial demonstrated excellent supercapacitative behaviour with a relatively high power density and specific capacitance of 4800 W·kg−1 and 394 F·g−1, respectively. In terms of its capabilities as an anode within an LIB, the layered-graphene overwhelms the Li-intercalation, which is reflected in the obtained specific capacity of 150 mAh·g−1, with a columbic efficiency of ~99% (after 450 cycles) at a current of 100 mA·g−1.

Cubic copper hexacyanoferrate (CuHCF) nanoparticles prepared via electrolytic deposition are presented with their morphology and crystalline structure characterized with SEM and XRD. The advantage of this methodology is that it allows the fabrication of uniform cubic nanoparticles with permeable structures onto the desired underlying electrode substrate. It was observed that the CuHCF film acts as a permeable membrane for cations such as K+, Na+, Li+, and NH4+ with a selection order of K+> Li+>NH4+> Na+. Furthermore, the analytical utility of these cubic-like CuHCF morphologies supported on a glassy carbon electrode was evaluated towards the electrochemical oxidation of hydrazine which was found to exhibit a linear response over the range 66 𝜇M to 17 mM with a detection limit corresponding to 16.5 𝜇M.

This paper studies the single-index varyingcoefficient quantile model with missing covariates at random. Firstly, some estimators of index parameters and their corresponding linkage function are given by using the inverse probability weighting method for missing data in two cases including parameter estimation and non-parametric estimation for the single-index varying-coefficient quantile regression model. In particular, the latter case focuses on the study of both known and unknown probability functions. Secondly, the established estimators are proved to be asymptotic normal under some suitable regularity conditions. Finally, the simulation studies are conducted to demonstrate the finite sample performance of the proposed method. [ABSTRACT FROM AUTHOR]