Xiang Zhang

Conventional chemical functionalization strategies intended to enhance graphene/Cu interfacial bonding often compromise the intrinsic properties of graphene. Here, we integrate ball milling with in situ synthesis to embed 1D carbon nanotubes (CNTs) into multilayer graphene, replacing chemical interfacial modification with a physical meshing interface—1D undulating‐structural graphene (CNTs@Gr), which preserves graphene integrity and ameliorate Gr–Cu matrix coupling. The Cu matrix composite possessing optimized interface structure, which is associated with the CNT content and outer diameter, achieves exceptional strength‐ductility synergy, displaying a yield strength of 301 MPa and an ultimate tensile strength of 341 MPa, as well as a remarkable elongation‐to‐failure of 17.8% for 0.25CNTs(m)@Gr/Cu composite. Meanwhile, the CNTs@Gr facilitates dislocation pile‐up, graphene‐induced crack deflection and CNTs crack‐bridging, dominating the stable plastics deformation. Furthermore, by circumventing the detrimental impacts inherent to conventional interface modification strategies, the structurally intact graphene and contamination‐free interface effectively preserve the material's electrical conductivity, which remains at a high level of 90.7% IACS. This work unlocks the reinforcing potential of interface engineering and opens a novel avenue for improving mechanical properties and electrical conductivity.

Hard carbon materials are promising candidates for advancing large-scale energy storage in sodium-ion batteries. However, a fundamental trade-off often exists between sodium storage sites and fast diffusion kinetics in hard carbon. Herein, we overturn this long-standing constraint through a machine learning design paradigm and low-temperature thermal-force coupling carbonization that enables the microstructure in hard carbon of both abundant sodium storage sites and rapid Na ⁺ diffusion. Benefiting from this low-temperature construction, the sodium-ion pouch cell exhibits a high specific energy (based on the entire cell) of 208.1 Wh kg ⁻¹ at 1.5-4.3 V. Besides, the required carbonization temperature reduces from 1300 °C to 900 °C, leading to an energy consumption reduction of 49.7% and a carbon emission reduction of 47.5%. This work not only provides a double-field regulation strategy to prepare high-performance hard carbon under low temperature, but also contributes a viable pathway toward sustainable sodium-ion batteries.

Oxygen has been regarded as a detrimental impurity in titanium alloys, as it triggers embrittlement and compromises ductility. Recent research advancements, however, have revolutionized this perception, revealing oxygen as a powerful microstructural architect capable of mediating phase transformations and deformation mechanisms to achieve strength–ductility combinations. This review systematically summarizes the pivotal roles of oxygen across various phases, including α, β, α′, α″, ω, and face‐centered cubic (FCC) phases. The underlying strengthening mechanisms and the oxygen embrittlement mechanisms were further analyzed, covering the strengthening theoretical models, interfacial segregation behaviors, and oxygen shuffling mechanism. These mechanistic insights are essential for understanding the evolution of dislocation configurations, twinning behaviors, and phase transformation dynamics. To harness oxygen's strengthening potential while mitigating its adverse effects, potential innovative strategies, including compositional, microstructural, and process design approaches, are proposed, which span from the atom‐scale to the micro‐scale. By integrating multiscale computational simulations, advanced in situ characterization, and the challenge of controlling oxygen uptake, this work provides a comprehensive framework for the intelligent design of next‐generation oxygen‐containing titanium alloys with exceptional mechanical properties.

Na ₂ S, as the terminal discharge product of room‐temperature sodium–sulfur (Na–S) batteries, is electronically and ionically insulating. When it deposits as a compact film on the cathode, the cathode will become passivated, hindering electron transport and inhibiting further sulfur conversion reactions. Existing catalyst strategies promote the formation of Na ₂ S thermodynamically by enhancing polysulfide adsorption, but this does not address the kinetics passivation issue. Here, we adopt the exchange current density ( j ₀ ) as a kinetic descriptor of the Na ₂ S nucleation mode. Finite‐element simulations reveal that increasing j ₀ drives the nucleation pathway from progressive to instantaneous nucleation. The deposit morphology then evolves from a compact passivating film to uniformly dispersed nanoparticles, and ion and electron transport channels are preserved. This pathway prevents Na ₂ S aggregation and electrode passivation, maintaining electrochemical activity at deep discharge. Guided by this kinetic insight, nitrogen‐doped porous carbon‐supported V single‐atom catalysts (NPC‐V SACs) with high apparent j ₀ were fabricated, and instantaneous Na ₂ S nucleation was achieved on their surfaces. The resulting Na–S battery retains 976.3 mAh g ⁻¹ after 200 cycles at 0.2 A g ⁻¹ , with a decay rate of only 0.08% per cycle. This work establishes a kinetic design perspective for regulating Na ₂ S nucleation in durable Na–S batteries.

Na ₂ S, as the terminal discharge product of room‐temperature sodium–sulfur (Na–S) batteries, is electronically and ionically insulating. When it deposits as a compact film on the cathode, the cathode will become passivated, hindering electron transport and inhibiting further sulfur conversion reactions. Existing catalyst strategies promote the formation of Na ₂ S thermodynamically by enhancing polysulfide adsorption, but this does not address the kinetics passivation issue. Here, we adopt the exchange current density ( j ₀ ) as a kinetic descriptor of the Na ₂ S nucleation mode. Finite‐element simulations reveal that increasing j ₀ drives the nucleation pathway from progressive to instantaneous nucleation. The deposit morphology then evolves from a compact passivating film to uniformly dispersed nanoparticles, and ion and electron transport channels are preserved. This pathway prevents Na ₂ S aggregation and electrode passivation, maintaining electrochemical activity at deep discharge. Guided by this kinetic insight, nitrogen‐doped porous carbon‐supported V single‐atom catalysts (NPC‐V SACs) with high apparent j ₀ were fabricated, and instantaneous Na ₂ S nucleation was achieved on their surfaces. The resulting Na–S battery retains 976.3 mAh g ⁻¹ after 200 cycles at 0.2 A g ⁻¹ , with a decay rate of only 0.08% per cycle. This work establishes a kinetic design perspective for regulating Na ₂ S nucleation in durable Na–S batteries.

The rapid development of additive manufacturing (AM) offers unprecedented design freedom for high-performance aluminum alloys, yet process optimization remains challenging due to the complex interdependencies between processing parameters and mechanical properties. Here, we present an integrated machine learning (ML) framework coupling predictive modeling with genetic algorithm (GA) optimization to accelerate the discovery of optimal processing conditions for laser powder bed fusion (LPBF) of aluminum alloys based on a 2024 Al alloy with Ti and B addition. Leveraging a comprehensive experimental data set, this work established a high-accuracy predictive model (Light Gradient Boosting Machine, LGBM) that predicts mechanical properties from composition and process parameters. The GA-guided optimization identified optimal parameters that yielded exceptional mechanical performance with a tensile strength of 505 MPa and a fracture elongation of 8.5%, surpassing all entries in the training data set. Microstructural analysis revealed that in situ-formed TiB₂ nanoparticles promoted heterogeneous nucleation, resulting in ultrafine equiaxed grains. The strengthening mechanisms were attributed to grain boundary strengthening from the refined microstructure and dislocation strengthening arising from the high density of geometrically necessary dislocations (GNDs) generated by thermal mismatch under rapid solidification conditions, as well as dislocation bypassing of second-phase particles. This work demonstrates that ML-driven optimization can effectively navigate the high-dimensional parameter space of AM, offering a process-property modeling workflow for accelerating the design of high-performance, customized Al alloys.

MoAlB, a MAB phase, exhibits significant potential as a reinforcement material for copper matrix composites due to its exceptional overall properties. However, its application is limited by the tendency to decompose at elevated temperatures during processing, leading to fragmentation and a reduction in the copper matrix's electrical conductivity. Addressing this challenge, this study successfully prepared two-dimensional (2D) MoAlB nanosheets (NSs) via viscous-solvent-assisted ball milling. Subsequently, these nanosheets were employed as reinforcement to fabricate MoAlB NSs/Cu composites through an impregnation-reduction-sintering route. Characterization of the resulting composite revealed a limited interfacial reaction between the 2D MoAlB NSs and the copper matrix, leading to the formation of a distinctive gradient interface structure. The gradient interface consists of a Cu/MoB atomic-scale composite transition zone and a Mo₂AlB₂/Cu semicoherent interface. This reaction-limited and robust interface synergistically activates multiple strengthening mechanisms, including significant grain refinement, efficient load transfer, and dislocation strengthening. Moreover, this structure effectively mitigates solute atom electron scattering in the copper matrix by constraining Al atom diffusion to the interfacial regions. Consequently, the 0.5 wt % MoAlB NSs/Cu composite achieved a notable balance of mechanical and electrical properties: a tensile strength of 333.3 MPa, which represents a significant improvement over pure Cu (255.1 MPa) and the 0.5 wt % MoAlB/Cu composite (268 MPa), combined with an elongation of 15.5% and an electrical conductivity of 92.6% IACS. Additionally, the composites demonstrated superior resistance to high-temperature softening, retaining high hardness even after annealing at 900 °C. These findings present a new design strategy for creating next-generation high-performance metal matrix composites.