Chengzhi Hu

The fast‐charging capability of phase‐separating graphite electrodes is largely constrained by heterogeneous reaction kinetics and sluggish mass transport at both the particle and electrode scales, which increase the risk of parasitic lithium plating and associated safety concerns. A deeper mechanistic understanding of the interplay among phase‐separation dynamics, electrode microstructure, and lithium‐plating propensity is therefore essential for guiding the rational design of advanced electrode architectures and fast‐charging protocols. Here, we combine operando optical microscopy with three‐dimensional microstructure‐resolved phase‐field modeling to resolve the interplay between phase separation and lithium plating. Microscopy captures stages evolution, phase mode transitions and structural dynamics across the particle population and at the single‐particle level, which is driven by the slow interfacial reactions. Non‐equilibrium phase‐field simulations elucidate the kinetic control mechanisms governing phase transitions as the current varies. Importantly, a new mechanism of lithium plating associated with interfacial ohmic resistance is identified. Based on these insights, we evaluate particle‐size‐distribution design and use thermal activation as a mechanistic probe to resolve how temperature alters phase‐separation pathways and lithium‐plating behavior. These results may serve as a foundation for improving the physical understanding and driving optimization of fast charging protocols for lithium‐ion batteries.

The fin-felt composite device with a self-sustaining moisture cycle reduces temperature by 41.6 °C, increases waste-heat-driven power generation by over 70%, and enables micro-fan driving and continuous lithium-battery power supply.

The complex composition of lubricating base oils makes it difficult to analyze the influence of specific molecular structure on lubricating performance. To achieve this target, nine kinds of poly α-olefin molecules with different structure characteristics were designed, which prepared the lubricant models. Molecular dynamic simulation was used to analyze the tribological performance under pressure of 500 MPa, temperature 353 K, and shear velocity of 20 m/s; the volume compression and shear stress of lubricant films were obtained. Molecular volume, adsorption energies, radius of gyration, and mean square displacement were used to analyze the relationship between molecular structure and lubricant performance. Results show that the characteristic of the Iso and Mid type have the best friction reduction performance. The molecules of the Iso structure have the highest oil film thickness and the best load-bearing performance. The radius of gyration increases with the shear simulation for most of the molecules. The adsorption energy of End is the highest, and the Mid is the smallest. Among the nine molecules, C20Iso shows excellent performance both in load-bearing and friction reduction, which provides a reference for the molecular design of high-performance lubricant base oils.

Innovative DRF films combine sodium alginate-CaCl ₂ /PVA for dual desorption-radiation cooling, achieving 9 °C steady-state cooling and 18% heat transfer boost. The system maintains 96% efficiency after cycles and reduces PV temperature by 3.5 °C.

Phase change hydrogels (PCHs), used in multiple engineering scenarios, have been developed to overcome leakage, structural instability, and low thermal conductivity of solid–liquid phase-change materials.

Changing the wettability and surface texturing have a significant impact on lubrication. In this study, the researchers used the molecular dynamics method to investigate how adjusting the interaction between alkanes and the wall affects oil film morphology and frictional properties under boundary lubrication. The findings revealed that the bearing capacity was influenced by both the morphology of the oil film and the strength of solid–liquid adsorption. In cases where the walls had weak wettability, the alkanes formed clusters to effectively separate the walls, while in cases where the walls had strong wettability, the oil film spread and formed a strong adsorption film. The super oleophilic textured surface could enhance the oil film adsorption capacity and replenish the oil film to the friction area in time, and the super oleophobic smooth surface could further reduce the friction coefficient. Therefore, a composite surface consisting of a super oleophilic textured surface and a super oleophobic smooth surface can be designed to enhance the bearing capacity of the oil film and reduce friction.

MoS₂ exhibited excellent bearing capacity, and a large-area of MoS₂ coated on the asperity surface could effectively prevent asperity contact, reduce friction coefficient and wear.

The heat transfer performance is improved as surface temperature increases, but the rise of surface temperature increases the flow resistance when solid–liquid interaction is weak but decreases the flow resistance when solid–liquid interaction is strong.

The service life of catalysts is a key aspect limiting the commercial development of proton exchange membrane fuel cells (PEMFCs). In this paper, a one-dimensional degradation model of a Pt-Co alloy catalyst in the cathode catalytic layer (CCL) of a PEMFC is proposed, which can track the catalyst size evolution in real time and demonstrate the catalyst degradation during operation. The results show that severe dissolution of particles near the CCL/membrane leads to uneven aging of the Pt-Co alloy catalyst along the CCL thickness direction. When the upper potential limit (UPL) is less than 0.95 V, it does not affect the catalyst significantly; however, a slight change may cause great harm to the catalyst performance and service life after UPL > 0.95 V. In addition, it is found that operating temperature increases the Pt mass loss on the carbon support near the CCL/membrane side, while it has little effect on the remaining Pt mass on the carbon support near the CCL/GDL side. These uncovered degradation mechanisms of Pt-Co alloy provide guidance for its application in PEMFCs.

Nanofluids for heat transfer application suffer from inevitable pump power consumption and adhesion effect with interface during flow. The hydrophobic treatment for heat transfer surface may be one of the most prospective strategies to achieve heat transfer enhancement and flow resistance reduction. However, the limitations of hydrophobic treatment technique and process make it difficult to fabricate desirable large size and high curvature hydrophobic surface. Herein, a facile displacement reaction method is applied to prepare the lath-like silver crystals and micro-nano gaps in the inner surface of copper tube with assistance of benzoic acid dispersant. The result shows that the convective heat transfer coefficient increases to 18.1% and the Darcy friction factor decreases to 4.9% at the volume concentration of 2.0% when SiO ₂ /DI-water (deionized water) nanofluids flow through the hydrophobic surface. The hydrophobic surface-assisted strategy may provide an effective scheme for wide applications of nanofluids in heat exchange equipment.