University Of Jinan

Compared to traditional electrodes, binder-free electrodes have attracted extensive attention due to their high energy density. However, the absence of binders results in weak connection between the active material and the current collector, which can cause active materials to detach from the collector, especially in alloy-type electrode such as Sb with severe volume change. Herein, we report an electrochemically inactive Ag₃Ga film as a bonding layer between Sb film and stainless steel mesh (ssm). The bonding strength is further enhanced by annealing at 400 °C, during which Sb film alloyed with Ag₃Ga to form GaSb film (GaSb@Ag₃Ga-400). As for anode of sodium ion batteries (SIBs), the GaSb@Ag₃Ga-400 electrode operated in 0.01-0.75 V (vs. Na⁺/Na) exhibits excellent cycling stability (245.9 mAh g^-1 after 400 cycles at 1 A g^-1) and satisfactory rate capability (205.3 mAh g^-1 at 3 A g^-1). The sodium storage kinetics of GaSb@Ag₃Ga-400 electrode was further characterized by cyclic voltammetry at different scan rates and galvanostatic intermittent titration technique. More importantly, the alloying/dealloying storage mechanism of GaSb@Ag₃Ga-400 electrode was revealed by in situ X-ray diffraction analysis. The present work presents the significant potential of Ag₃Ga film as a robust bonding layer for binder-free electrode with long-term cycling stability and offers available insights for the development of other binder-free electrodes.

Transition metal sulfides (TMS) have emerged as promising electrocatalysts for overall water splitting (OWS), owing to their cost-effectiveness, inherent abundant active sites and tunable electronic structures. However, several issues, e.g., high overpotentials originating from the sluggish water dissociation, shielding of active sites and mass transfer resistance, as well as the modest long-duration electrocatalytic stability, are still enormous challenges. For this, the superwetting leafy Fe-doped nickel sulfide/cobalt sulfide nanoarrays on nickel foam (NF) (denoted as Fe-NiS/Co_2.67S₄/NF) are successfully designed and fabricated by the template-involved avenue. The interfacial electron re-arrangement of NiS/Co_2.67S₄ induced by Fe doping optimizes the charge density distribution near the d-band center, promoting the adsorption-desorption of reaction intermediates. Additionally, the unique leafy architecture exhibits superhydrophilic sur-/interfaces, enabling efficient electrolyte penetration and accelerated bubble release during in-situ gas generation. Thereby, the advantages validated by comprehensive physical experiments and theoretical calculations endow Fe-NiS/Co_2.67S₄/NF with superior electrocatalytic performance in both hydrogen evolution reaction and oxygen evolution reaction, along with remarkable operational stability during high-current-density overall water electrolysis (1000 h at 500 mA cm^-2). This work, besides the well-established reliable methodology for TMS nanoarrays, offers in-depth insights into catalytic optimization of electrocatalysts for high-efficiency OWS.

This study proposes a flexible sensing system for simultaneously measuring mandibular movement trajectories and bite force during mastication. The system employs a dual-mode sensing mechanism: the triboelectric module realizes non-contact detection of movement trajectories, while the ionic supercapacitor module achieves contact-based quantitative monitoring of bite force. The triboelectric unit delivers a peak voltage of 0.2 V, with signal attenuation below 5% after 10,000 s of continuous cycling, enabling stable capture of dynamic occlusion trajectories. The ionic unit exhibits a high sensitivity of 4.97 kPa^-1 in the pressure range of 10-40 kPa, with a response time of 1 s and a recovery time of 1.6 s. It also shows signal drift below 10% after 1000 cycles, allowing reliable monitoring of bite force. By integrating machine learning, a dental health recognition model is constructed, achieving 99.25% accuracy in occlusal trajectory identification. This high-performance flexible system accurately captures mandibular movement and bite force, enabling full reconstruction of occlusal relationships and providing essential data support for the diagnosis and treatment of oral diseases.