Jingshu Hui

Aqueous zinc‐ion batteries are severely hindered by interfacial side reactions including dendrite growth and by‐product accumulation, primarily caused by local pH fluctuations at the Zn/electrolyte interface. Here, we propose a dynamic interfacial pH‐buffering strategy using glycine (Gly), which simultaneously anchors onto the Zn surface and regulates proton transfer through its reversible acid–base equilibria. In situ pH mapping with an ultramicroelectrode probe directly confirms that Gly effectively suppresses interfacial alkalization and maintains a stable interfacial environment during Zn plating/stripping. Benefiting from this local buffering effect, the Gly‐containing electrolyte achieves a Coulombic efficiency (CE) of 99.5% in Zn||Cu cells, stable cycling over 1000 h in symmetric cells, and durable cycling for 2000 cycles in Zn||NaV ₃ O ₈ full cells. This work establishes interfacial pH stabilization as an important design criterion for electrolyte‐additive engineering in aqueous Zn batteries.

Dual-disk electrodes with low RG values and narrow gaps were fabricated reproducibly by combining a thick-wall nanopipette template with tip forging.

Reference electrodes are essential for meaningful electrochemical measurements but face significant challenges in miniaturization and long-term stable potential. Conventional commercial reference electrodes, which rely on ion migration across porous frits, suffer from electrolyte leakage, potential drift, and limited scalability to micro dimensions. Quasi-reference electrodes lack a thermodynamically defined interface, exhibiting polarization-sensitive potentials that drift with experimental conditions, compromising their reliability for rigorous quantitative analysis. Therefore, a miniaturized reference electrode capable of stable potential output is critical for techniques like scanning electrochemical cell microscopy (SECCM), where accuracy and spatial resolution depend on electrode robustness. Herein, we report a facile and reproducible strategy to fabricate a nanopipette reference electrode (NPRE) leveraging nanoscale ion transport. This architecture replaces conventional glass bodies and fritted junctions with a monolithic pulled capillary structure, integrating a nanoscale terminal pore that inherently minimizes electrolyte leakage. The NPRE demonstrates excellent potential stability (>24 h) in both aqueous and organic media, underscoring its robustness across distinct chemical environments. Successful integration of NPRE with SECCM enables precise nanoscale electrochemical measurements, effectively overcoming the inherent limitations of conventional systems and providing an ideal platform for high-resolution studies in complex physiological or materials environments.

Dopamine is a key neurotransmitter crucial for learning, memory, emotion, sleep, and motor control. Its imbalance is linked to disorders such as Parkinson's disease and depression. To address the limitations of costly and specialized dopamine detection methods, this study developed an electrochemical sensor using copper oxide (CuO) and 3 mol% cobalt doped CuO (Co‐doped CuO) composite with multiwalled carbon nanotubes (MWCNT). Both materials were synthesized via solution combustion, yielding single‐phase nanoparticles under 100 nm. Cyclic voltammetry (CV) showed dopamine oxidation at 0.75 V for concentrations ranging from 0.1 to 100 μM. The Co‐doped CuO/MWCNT composite exhibited enhanced electrocatalytic activity compared to undoped CuO/MWCNT, confirmed by CV and chronoamperometry. The Co‐doped sensor demonstrated high sensitivity (65.001 μA⋅μM ⁻¹ ⋅cm ⁻² ), significantly higher than the 57.297 μA⋅μM ⁻¹ ⋅cm ⁻² observed for the undoped CuO‐based electrode. A low detection limit is 0.0285 μM, and strong selectivity against interfering neurotransmitters like acetylcholine and serotonin. This innovative electrochemical method advances our understanding of CuO/MWCNT composites and offers a practical and effective solution for dopamine detection.

Redox-active colloids (RACs) represent a novel class of energy carriers that exchange electrical energy upon contact. Understanding contact-mediated electron transfer dynamics in RACs offers insights into physical contact events in colloidal suspensions and enables quantification of electrical energy transport in nonconjugated polymers. Redox-based electron transport was directly observed in monolayers of micron-sized RACs containing ethyl-viologen side groups via fluorescence microscopy through an unexpected nonlinear electrofluorochromism that is quantitatively coupled to the redox state of the colloid. Via imaging studies, using this electrofluorochromism, the apparent charge transfer diffusion coefficient D _CT of the RAC was easily determined. The visualization of energy transport within suspensions of redox-active colloids was also demonstrated. Our work elucidates fundamental mechanisms of energy transport in colloidal systems, informs the development of next-generation redox flow batteries, and may inspire new designs of smart active soft matter including conductive polymers for applications ranging from electrochemical sensors and organic electronics to colloidal robotics.

Flexible aqueous zinc-ion batteries (AZIBs) are considered one of the most attractive flexible devices owing to their high theoretical capacity, low cost, and high security. However, the formation of Zn dendrites and the poor flexibility of the Zn material greatly impede the application of wearable AZIBs. Herein, by transferring graphene onto the surface of polyethylene terephthalate-indium tin oxide (PET-ITO-G), a substrate combining excellent flexibility and dendrite suppression ability was prepared. Meanwhile, a quantitative in situ strain application system was proposed to investigate the electrochemical and morphological characteristics of flexible Zn anode interface. The plating/stripping performance of the Zn|PET-ITO-G flexible device was demonstrated under various strains. Subsequent analysis indicated that the origin of its high stability under static bending strain came from the formation of densely packed Zn (101) upon cycling. In addition, PET-ITO-G could quickly recover to Zn (002) after the strain was relieved. A failure model of strain-modulated Zn deposition was proposed based on the formation of surface cracks and distorted surface current distribution. This work identified the main factors that constrained the long cycling life of a flexible metal anode and provided a feasible approach for a systematic study on the influence of in situ strain on flexible batteries.

Cathode-electrolyte interphase (CEI) is critical for inhibiting the cathode degradation to maintain cell life. However, the evolution of the CEI is still unclear due to its complex and slow dynamic process. Here we used scanning electrochemical microscopy (SECM) for in situ investigation of CEI formation process on LiFePO₄ cathode. Feedback images and probe scan curves showed a heterogeneous passivation that was gently generated on the LiFePO₄ particles during both charging and discharging. Besides, a LiFePO₄ composited electrode was also used to investigate the CEI formation to simulate the condition of real battery system. The composited cathode does not show obvious CEI formation within first two cycles. The SECM results between the pristine LiFePO₄ particles and the composited LiFePO₄ indicated the dynamic accumulation of CEI, which is influenced by the ability to charge transfer kinetics of cathode materials. This approach provided a feasible consideration for the connections between the dynamic evolution of the CEI and changes in charge transfer capability of cathode during cycling.

An accurate assessment of the electrodeposition mechanism is essential for evaluating the electrochemical stability and reversibility of the metal anodes. Multiple strategies aimed at uniform Zn deposition have been extensively reported, yet it is challenging to clarify the Zn crystal growth regularity and activity due to the obscured physicochemical properties of as-deposited Zn. Herein, we present a protocol for elucidating the controlled epitaxial growth process of Zn crystals and quantifying their surface electrochemical activity using scanning electrochemical microscopy. We find that the early-stage epitaxy tends to form a stacked-multilayer structure accompanied by intermittent rotation. The site-dependent kinetics and morphology correlation reveal a distinct evolution path at early and final stages. Our exploration advances the understanding of the Zn growth mechanism and facilitates the realization of the interface kinetics of metal batteries in situ.