Hard carbon is the most promising anode material for sodium-ion batteries, yet its complex disordered structure has long obscured the actual sodium-ion storage behaviors. This review focuses on the critical structure-performance correlation that governs electrochemical performance. It examines how key microstructural features-including pseudo-graphitic domains, interlayer spacing, defects, heteroatom doping, and multi-scale pore architecture-collectively determine sloping/plateau capacities, initial Coulombic efficiency, and rate capability. The review highlights recent advances in decoupling these complex relationships through advanced characterization, predictive descriptors, and machine learning. Looking into the future, it is necessary to shift from empirical optimization methods toward quantifiable and predictable design principles for developing high-performance hard carbon anodes.
Amid the global energy transition, aqueous zinc-ion batteries (AZIBs) have gained prominence as safe, low-cost, and resource-abundant candidates for grid-scale storage. However, their Zn anodes suffer from dendritic growth, hydrogen evolution reaction (HER), and corrosion/passivation, which severely limit cycling life and performance. Constructing an artificial protective layer at the interface offers an effective solution to these issues. This review first explains the formation mechanisms of dendrites, HER, and corrosion/passivation, as well as their mutually reinforcing vicious cycle. It then systematically examines the design principles, working mechanisms, and performance enhancements enabled by coatings based on conventional materials (e.g., carbon materials), composites, and emerging materials such as MXenes. These layers improve anode reversibility and stability by acting as physical barriers, homogenizing electric fields and ion flux, and guiding uniform Zn nucleation through zincophilic sites. Finally, the review outlines current challenges and future directions, highlighting the need for deeper mechanistic insight via in-situ characterization and theoretical calculations, the development of multifunctional synergistic systems, and the integration of machine learning, among others, to advance practical high-performance AZIBs.
Achieving thick electrodes concurrent with efficient ion and electron transport remains a critical bottleneck in enhancing the areal energy density of micro-supercapacitors (MSCs). Herein, a quasi-solid-state MSC with bicontinuous thick electrodes is constructed, in which an asymmetric geometry composed of nickel hexacyanoferrate (NiHCF) and activated carbon (AC) is employed. This electrode architecture provides both continuous electron pathways and interconnected porosity, supporting high mass loading simultaneously with fast transport dynamics. The resulting NiHCF//AC MSCs show a wide potential window of 1.6 V, a superior areal capacitance up to 1826 mF cm-2 at 1 mA cm-2, a notable energy density of 649 mu Wh cm-2, and excellent cycling stability (90.2% retention of the initial capacitance after 2000 cycles). Moreover, the MSCs demonstrate excellent mechanical toughness and can be integrated into series-parallel configurations for tunable output. This work mitigates the trade-off between mass loading and charge transport, offering a feasible route toward highenergy-density, flexible, and scalable micro-energy storage systems.
Friction and wear, long regarded as unavoidable penalties in mechanical systems, consume nearly a quarter of global primary energy. Metallic components in engines, turbines, and bearings therefore present both the greatest challenge and the greatest opportunity for efficiency gains. This mini-review surveys how heterostructured (HS) metals—encompassing gradient, laminate, and nanotwinned (NT) architectures—enable adaptive and self-stabilizing responses under diverse tribological conditions. Through engineered gradients in strength, periodic stacking of layers with distinct mechanical responses, and the incorporation of dense nano-twin populations, HS metals redistribute contact stresses, promote compatible heterogeneous plasticity, and delay the onset of surface degradation, leading to substantial reductions in friction and wear. Building on these mechanistic insights, we discuss a full-scaling tribological framework that links architectural descriptors (such as gradient depth and slope, laminate period, interface character, and twin spacing) to operational variables (such as contact radius, Hertzian stress, sliding velocity, and lubrication condition) and to friction–wear responses from nano- to macro-scales. Looking ahead, we highlight opportunities to integrate operando characterization, multi-scale simulations, and data-driven design to construct quantitative “design maps” for the tribological performance of HS metals. The convergence of heterostructure design with advanced fabrication routes is expected to yield microstructures that are not only strong and wear-resistant but also adaptive and robust under service-relevant conditions, pointing toward low-energy, long-life metallic friction interfaces.
Hard carbon is widely regarded as one of the most commercially promising anode materials for sodium-ion batteries. Nevertheless, its practical application remains challenged by limited reversible capacity and sluggish sodium storage kinetics. Herein, a strategy is proposed to modify N doped hard carbon by introducing Co to construct CoNx sites (Co-NC). In Co-NC, the CoNx sites provide sufficient active sites for Na storage, leading to an enhanced reversible capacity of 422.8 mAh g-1 at 0.05 C. Meanwhile, Co-NC exhibits excellent initial Coulombic efficiency, rate capability and cycling stability. Multiple characterization results confirm that the CoNx sites facilitate the formation of a solid electrolyte interphase enriched in inorganic components, which can accelerate ion transport kinetics at the electrode electrolyte interface. Furthermore, in situ and ex situ analyses were conducted to elucidate the structural evolution of Co-NC across different sodium storage stages, as well as the dynamic evolution pathway of the CoNx sites. This work offers a viable strategy to concurrently enhance the capacity and kinetic performance of hard carbon anodes.
With the growing demand for high-energy-density and long-lifespan lithium-ion batteries (LIBs), silicon/graphite composites have emerged as promising anode materials, as they synergize the ultrahigh capacity of silicon (Si) and the structural stability of carbon. To address the intrinsic volume variation issue of silicon, this work demonstrates a scalable and environmentally benign synthesis of micron-sized porous silicon/graphite composites (NGT-pSi/C) via the integration of FeCl3-etched spherical porous silicon (pSi) and waste-derived natural graphite tailings (NGT). The as-prepared NGT-pSi/C features a watermelon-like multi-core-shell architecture. The pores in pSi effectively accommodate the large volume expansion during cycling. Meanwhile, the upcycled NGT form a conductive layer to disperse mechanical stress, and the glucose-derived carbon layer constructs a conductive network. This waste-to-wealth approach enables the conversion of industrial byproducts into highperformance LIB anode materials. Comprehensive physicochemical and electrochemical characterizations reveal that abundant pores and continuous conductive networks in NGT-pSi/C synergistically mitigate Si pulverization, suppress interfacial degradation and enhance charge transfer kinetics. The NGT-pSi/C anode delivers exceptional cycling stability (591.2 mAh g-1 after 400 cycles at 0.5 A g-1) and superior rate capability. Furthermore, full cells paired with NCA90 (LiNi0.9Co0.05Al0.05O2) cathodes maintain 72.6% of their initial capacity after 800 cycles. The corresponding pouch cell exhibits a high discharge capacity of 0.7 Ah and retains 74.43% capacity after 500 cycles. This practical strategy achieves a cost-performance synergy. Overall, by using near-zero-cost graphite waste and adopting a non-acidic etching process, this work establishes a sustainable and economically viable pathway for the scalable production of high-performance Si-based anodes.
To circumvent the cost constraints and scarcity of noble-metal oxygen evolution reaction (OER) catalysts, this work pioneers an electrolyte-regulation strategy for boosting nickel phosphide (Ni2P) performance. Introducing a trace amount of Co2+ (40 & micro;L 1 M CoSO4) into the alkaline KOH electrolyte significantly enhances the surface adsorption kinetics and reactivity of Ni2P. The optimized system achieves a reduction in overpotential to 363.9 mV, a decrease in Tafel slope to 109.6 mV dec-1, and a smaller charge transfer resistance. Mechanism research reveals that a dynamic "oxidation-adsorption-reconstruction" process is driven by electrical oxidation. Specifically, Co2+ undergoes an oxidation reaction and is adsorbed on the material surface, leading to the in-situ formation of an epitaxial CoOOH/NiOOH heterointerface. This simultaneously increases active-site density, optimizes OH* adsorption energy, and accelerates interfacial electron transfer. This electrolyte-catalyst synergy strategy redefines efficient OER electrocatalyst design, shifting focus from complex material engineering to intelligent interfacial microenvironment control.
Superalloys are extensively utilized in the aerospace and energy industries due to their outstanding high-temperature strength, thermal stability, and corrosion resistance. However, the rapidly growing demands for higher thrust-to-weight ratios and elevated turbine inlet temperatures in advanced engines have posed significant challenges to current hot-section component materials. Ceramics, with their inherent high hardness and melting points, are promising reinforcement candidates. Incorporating ceramics into superalloys enables the design of composites that overcomes the intrinsic limitations of conventional alloys. The newly-developed laser powder bed fusion (LPBF) technique provides great potential for fabricating such composites with tailored structures and properties. However, porosity and cracking frequently arise during LPBF due to complex multi-field interactions, thus degrading their service performance. This review systematically summarized advances in LPBF-fabricated ceramic-reinforced superalloys. The key coupling relationships between ceramic particle characteristics, LPBF process parameters, and high-temperature service performance are systematically clarified. The metallurgical process, microstructure evolution, and precipitation behavior of superalloy composites are comprehensively scrutinized. The initiation and propagation mechanisms of metallurgical defects in these composites are explicitly analyzed and elucidated. Furthermore, the mechanical properties of the composite materials and their underlying strengthening mechanisms are thoroughly addressed. Finally, the bottleneck problems associated with ceramic-reinforced superalloy composites fabricated by LPBF are synthesized, and future perspectives are proposed.
Because of their exceptional safety and thermal stability, all-solid-state sodium batteries are viable next-generation energy storage technologies, while borohydride-based solid electrolytes have garnered considerable interest for their favorable electrochemical stability. Nevertheless, the poor room-temperature ionic conductivity of Na2B12H12 continues to be a significant obstacle that restricts its usefulness. To address this issue, this work proposes a simple mechanochemical compositing strategy. By introducing boron nitride (BN) as a multifunctional interfacial modifier, the ionic conduction performance is significantly enhanced. The Na2B12H12/BN composite electrolyte is prepared via high-energy ball milling. Structural characterizations reveal that the incorporation of BN induces a mechanochemistry-driven phase and structural transformation in Na2B12H12 and creates abundant heterointerfaces. Electrochemical measurements show that the optimized composite electrolyte achieves a high room-temperature ionic conductivity of 2.2 & times; 10-4 S cm-1, almost an order of magnitude higher than that of ball-milled pristine Na2B12H12, with a reduced activation energy of 0.31 eV. Furthermore, the electrolyte exhibits excellent stability against a Na-Sn alloy, enabling symmetric cells to cycle stably for over 800 h. An all-solid-state sodium battery assembled with Na3V2(PO4)3 as the cathode and a Na-Sn alloy as the anode demonstrates outstanding cycling stability (80% capacity retention after 100 cycles at 0.5 C) and rate capability. This work offers new insights for the creation of sophisticated all-solid-state sodium batteries by rationalizing the design of high-performance borohydride-based solid electrolytes through interfacial engineering using inert nanomaterials.
Photoreduction of carbon dioxide (CO2) into useful carbon-based fuels is a promising strategy for reducing excessive CO2 emissions and addressing the global energy crisis. However, developing photocatalysts that achieve nearly 100% carbon monoxide (CO) selectivity while maintaining a high production rate remains a great challenge. Herein, a U-L-Fe metal-organic framework (MOF)-based photocatalyst was successfully synthesized by a mixed-ligand strategy followed by light-induced deposition. As a result, U-L-Fe exhibits a high CO production rate of 9.50mmolg−1 h−1 with a remarkable selectivity of nearly 100% under visible light, surpassing those of previously reported metal-organic framework MOF-based catalysts. In situ Fourier transform infrared (FTIR) spectroscopy identifies *COOH and *CO species as crucial intermediates in the photoreduction of CO2 to CO. This work provides valuable insights for designing highly efficient MOF-based catalysts for CO2 conversion and offers practical strategies for optimizing their activity.
The presence of γ′ phase establishes Co-based alloys as promising candidates for next-generation superalloys, stimulating intense research interest in the development of γ/γ′ Co-based superalloys. Although elucidating the intrinsic elasticity of γ′ phase is crucial for designing novel γ/γ′ superalloys, acquiring a large amount of elastic data of multicomponent γ′ remains a bottleneck. In this study, we proposed an interpretable strategy for predicting the elastic properties of γ′ phase in multicomponent Co-based alloys using density functional theory (DFT) and machine learning (ML) methods. A 1,674-sample elastic dataset was first constructed via high-throughput DFT calculations. By utilizing this dataset, a predictive model with strong interpretability was successfully trained in terms of sure independence screening and sparsifying operator (SISSO) techniques. The accuracy of the well-trained 2D model for bulk modulus (B) reached 87% while that for shear modulus (G) and Young’s modulus (E) exceeded 95%, respectively. The SHapley Additive exPlanations (SHAP) analysis revealed mechanisms: part of compositions, mixing enthalpy, valence electron concentration, and electronegativity yield significantly effect on the mechanical properties, in which Co elevation, Cr reduction, valence electron concentration (VEC) > 8, and standard deviation of VEC (DVEC) lowering enhance G and E values; smaller DVEC/Atom (Average atomic radius), larger average bulk modulus (Bulk), and Fe > Ni enhance B values. Using the well-trained and low-cost predictive model, we predicted the mechanical properties of γ′ phases across 151,796 samples in the unknown compositional space. The statistical analysis revealed that W, Fe, Mo, Nb, Ti, Ta, V, and Ni play dominant strengthening roles. Excluding W and Fe, promising candidate systems include Al-free Co-Mo-Ni-Nb/Ta/V and Al-containing Co-Al-Mo-Cr/Nb/Ta/V alloys. These systems warrant further research to advance the optimization of novel γ/γ′ Co-based superalloys.
Aqueous zinc (Zn) batteries (AZBs) possessing low cost and high safety offer a prominent solution for large-scale energy storage. However, the application of AZBs is still plagued by the corrosion of Zn electrode due to hydrogen evolution reactions (HERs) in aqueous electrolytes. Herein, the combination of H2O-polar molecule and H2O-anion interactions is proposed as an efficient approach to alter the solvation structure of aqueous electrolyte for stable AZBs. Using dimethyl sulfoxide (DMSO) with a high polarity as a model molecule, its interaction with H2O can weaken the Zn2+-H2O interaction in Zn2+ solvation sheath, thereby suppressing HERs while at the expense of Zn2+ mobility. By fixing the DMSO content at a compromising value to balance the Zn2+ transport and HER suppression, a supplementary H2O-anion interaction is further experienced in the solvation structure by using bis(fluorosulfonyl)imide anion (FSI-), where the interaction between FSI- and the bipolar H2O molecules enables additional force to reduce the H2O number of the Zn2+ solvation sheath. Based on the combined H2ODMSO and H2O-FSI- interactions, the HERs and Zn corrosions are significantly suppressed for stable AZBs.
Lithium-ion batteries (LIBs) exhibit significant performance deterioration in low-temperature environments. Key challenges include severely hindered lithium-ion transport kinetics, substantial capacity loss, and inadequate charging capability, which collectively limit their application in electric vehicles, aerospace, and deep-sea exploration. This study demonstrates the development of a Sn/P/LiNi0.8Mn0.1Co0.1O2 composite anode via ball milling of Sn, P and LiNi0.8Mn0.1Co0.1O2 (abbreviated as T8), which achieves exceptional high-rate capability and stable cycling performance for lithium storage under low-temperature conditions. The composite anode delivers a reversible capacity of 660mAh g−1 after 150 cycles at 0.5Ag−1 under −10 °C and maintains 680mAh g−1 after 50 cycles at −30°C, even with conventional electrolytes. The incorporation of T8 cathode material facilitates in-situ formation of amorphous Sn-O-P oxides and Li3P, enhancing ionic conductivity, pre-lithiation, and reaction kinetics. Transition metals from T8 act as catalytic sites, reducing charge-transfer resistance and enabling high-rate performance (e.g., 480mAh g−1 at 15Ag−1 in full cells). This work provides a sustainable strategy for designing advanced anode materials with superior low-temperature resilience and high capacity for next-generation LIBs.
Tin (Sn) stands as a promising anode for sodium-ion batteries due to its high theoretical capacity, yet it suffers from severe volume changes during cycling. This work develops a novel SnAl-Cu6Sn5 composite through a rational dealloying strategy, featuring a unique 3D continuous bimodal porous structure that effectively mitigates mechanical stress during Na+ insertion/extraction. The incorporated Cu and Al components act as the bimetallic conductive network and thus benefit the electron transfer. Remarkably, the anode delivers an initial capacity of 432.6 mAh g-1 at 1 A g-1 and retains 291.4 mAh g-1 after 1000 cycles with the capacity retention of 67.4%. Furthermore, the Na3V2(PO4)3//SnAl-Cu6Sn5 full cell demonstrated excellent rate performance and cycling stability, maintaining 96.7% of its initial capacity after 100 cycles at 1 C. These findings provide important methodological guidance for the application of tin-based materials as high performance anodes in sodium-ion batteries.
Characterized by exceptionally high heating rate, low sintering temperature, and remarkable process flexibility, spark plasma sintering (SPS) is an efficient near-net-shape powder metallurgy technology that is highly suitable for manufacturing porous titanium alloys intended for biomedical implants. This review comprehensively outlines the fundamental requirements of pore structure and mechanical properties for biomedical implant materials, and elaborates on the principles and advantages of SPS for preparing porous titanium biomaterials. The methods for fabricating porous titanium alloys by SPS are critically discussed. Furthermore, the key process parameters and the performance of SPS-prepared porous titanium and its alloys are summarized. Finally, this review delineates the prevailing challenges and future research orientations for SPS-fabricated biomedical porous titanium alloy implant materials.
To address the challenges of coarse columnar grains and solidification cracks in 6061 Al alloy (AA6061) through laser powder-bed fusion (L-PBF), this study proposes an in-situ co-modification strategy by using Ni-induced eutectic reaction and Ti-induced peritectic reaction, resulting in the development of high-performance and crack-free AA6061 based alloys. The in-situ fabrication mechanism, microstructures and mechanical properties of the as-built AA6061-Ni-Ti alloys are investigated systematically. As a result, Ti could in-situ form cubic Al3Ti precipitates with low lattice mismatch, acting as heterogeneous nucleation sites to refine grains and promote columnar-to-equiaxed transition. Simultaneously, Ni enriches at grain boundaries to form a continuous network, narrowing the solidification temperature range and suppressing end-of-solidification cracks. The modified alloy achieves a high yield strength (YS) of 413.95 +/- 13.37 MPa, ultimate tensile strength (UTS) of 427.77 +/- 2.57 MPa and elongation (EL) of 6.40% +/- 0.16%, exhibiting superior strength-ductility synergy compared to other L-PBF Al-Si and Al-Mg alloys. Fracture analysis confirms a shift from cleavage fracture (unmodified) to dimple fracture with an average dimple size of similar to 3.45 & micro;m. This work demonstrates that the dual phases co-modification by combining eutectic and peritectic reaction could effectively enhance laser absorptivity, eliminate un-melted powders, and optimize microstructures for high-performance Al alloys via L-PBF.
The incorporation of conductive supports is crucial for achieving superior electrocatalytic performance in transition metal sulfide(TMS)systems.However,the influence of conductive supports with different dimensions remains insufficiently explored.Hereby,quasi-1D graphene nanoribbons(GNRs)and 2D Ti3C2Tx-MXene are for the first time simultaneously introduced to construct a novel 3D Co9S8/GNRs/Ti3C2Tx ternary composite via a simple annealing process.Systematic characterizations reveal that the GNRs/Ti3C2Tx composite support endows the ternary composite with superior properties,including a unique 3D architecture,improved Co9S8 dis-persibility,increased structural defects,and higher conductivity when compared to its binary counterparts.These advantages collectively contribute to significantly enhanced oxygen evolution reaction(OER)perfor-mance.Consequently,the Co9S8/GNRs/Ti3C2Tx catalyst delivers an overpotential of 285 mV at 10 cm-2 and a Tafel slope of 78 mV dec-1,surpassing other comparative catalysts and approaching the performance of com-mercial RuO2 catalyst.Additionally,it exhibits remarkable stability,with a negligible overpotential increase of only 2 mV during a 24 h durability test.When employed as an anode catalyst in water-splitting devices,the Co9S8/GNRs/Ti3C2Tx catalyst requires a low overpotential of 343 mV,manifesting substantial potential for water electrolysis.This work not only reports an excellent OER catalyst,but also offers a valuable strategy for designing high-performance ternary composites for energy-related reactions.
Through phase-field crystal simulations, we systematically investigate the effects of grain misorientation angle θ on phase transformation kinetics and defect evolution mechanisms. The results reveal a significant dependence of phase transformation pathways and energy relaxation behavior on θ. For θ was 0°–5°, the phase transformation process exhibits a two-stage characteristic, where dislocation annihilation induced by incoherent interfaces dominates the later stage of energy relaxation; consequently, the rate of energy stabilization lags significantly behind that of phase transformation. At θ was 5°, pinned dislocations form stable structures at subgrain boundaries, resulting in a local maximum in the system's free energy. For θ was 5°–8°, the phase transformation demonstrated multi-stage, spatially selective evolution: the upper and lower phase boundaries (parallel to the X-axis) undergo preferential structural reorganization, while the left and right phase boundaries (parallel to the Y-axis) exhibit delayed transformation due to high migration energy barriers. This study further elucidates the inherent non-synchronicity between the completion of phase transformation and energy stabilization. In systems with 0°–5°, energy relaxation is governed by dislocation migration kinetics; conversely, systems with 5°–8° achieve co-stabilization of structure and energy through defect annihilation at phase boundaries. This study’s defect-interface interaction model offers a theoretical basis for precisely controlling microstructural evolution during phase transformations.
Shear spinning is an important method for metal shell forming. However, due to the poor plasticity of magnesium alloy, limited research exists on its spinning forming. Understanding the microstructure evolution of magnesium alloy during shear spinning is the key to realizing its controllable spinning forming. In this work, the microstructure, mechanical properties and fracture behavior of Mg-5Zn-1Gd-1Y-1Mn (ZGWM5111) alloy formed by shear spinning were investigated, and the dynamic recrystallization behavior and texture evolution during shear spinning were clarified. The results show that compared with the traditional plastic deformation, the thickness reduction of ZGWM5111 alloy in shear spinning is very small, and the microstructure can be changed significantly only by shear stress. The shear stress of the alloy varies during the spinning process, influencing both the recrystallization driving force and subgrain mobility. This leads to an evolution in the recrystallization mechanism, progressing from twin-induced to continuous, and ultimately to discontinuous dynamic recrystallization. Different from the existing research on magnesium alloys, the recrystallization grains of ZGWM5111 alloy are continuously refined during the spinning process, and the basal texture strength is also continuously enhanced. In addition, the mechanical properties of ZGWM5111 alloy were significantly improved after shear spinning, especially the elongation was doubled compared with that before spinning, which changes the fracture mode from brittle fracture to ductile-brittle mixed fracture.
To avoid the wear failure of hot parts at 1000 °C, a ZrB2-reinforced CoNiCrAlY coating was prepared using step-fashion mechanical alloying and high-velocity oxygen-fuel (HVOF) spraying. With CoNiCrAlY and CoNiCrAlY-Al2O3 coatings as controls, the microstructure, mechanical properties, and tribological performance at 1000 °C of the CoNiCrAlY-ZrB2 coatings with different ZrB2 contents (10–25wt%) were investigated. Compared with the CoNiCrAlY coating, the incorporation of either Al2O3 or ZrB2 can improve the hardness, elastic modulus, and wear resistance of the coatings. However, the pinning effect of Al2O3 disrupts the oxide film integrity, leading to a debris accumulation on the CoNiCrAlY-10wt%Al2O3 coating with a wear rate of 68.61×10−14 m3 (N m)−1. In contrast, ZrB2 promotes the formation of a protective oxide film composed of ZrO2, (Co,Ni)Cr2O4, Cr2O3, and Al2O3, resulting in a lower wear rate of 8.95×10−14 m3 (N m)−1 for CoNiCrAlY-10wt%ZrB2 coating. As the ZrB2 content increases, the mechanical properties and wear resistance further improve. The CoNiCrAlY-20wt%ZrB2 coating exhibits minimized COF (0.40) and wear rate (2.34×10−14 m3 (N m)−1), demonstrating promising potential as a protective coating of hot parts.
