Zhenxing Zhang

Solid state conversion electrodes are promising for aqueous energy storage but are frequently constrained by sluggish interfacial kinetics, leading to a persistent energy‐power trade‐off and underutilized capacity at high rates. Here we propose a chemical mediation strategy in which dissolved [Fe(CN) ₆ ] ⁴⁻ /[Fe(CN) ₆ ] ³⁻ couples continuously regenerate an interfacial oxidant to chemically drive the α‐Co(OH) ₂ to CoOOH conversion, thereby rewriting the rate limiting solid state electrochemical step into an electrochemical‐chemical cascade at the electrode/electrolyte interface. Electrochemical analyses and spectroscopy corroborate the spontaneous oxidative phase transformation and the mediator enabled pathway reconstruction beyond simple solid–liquid capacity superposition. To make this capacity boosting strategy practically efficient, we further tune the initial redox composition of the mediator couple to suppress shuttle driven self‐discharge while maintaining fast interfacial conversion kinetics, as quantified by multi‐potential‐step measurement (MPSM) and visualized by in situ Raman mapping. Consequently, the redox‐enhanced alkaline Zn‐Co battery exhibits a remarkable areal capacity of 0.98 mAh cm ⁻² (a 96% enhancement), while simultaneously retaining a high energy density of 0.92 mWh cm ⁻² and an ultrahigh‐power density of 75 mW cm ⁻² . This work highlights a functional electrolyte design route to unlock deep solid state conversion capacity under high‐power operation in aqueous batteries.

The bulk topological band crossings near the Fermi level (Pd ₃ Sn) optimize the adsorption of hydrogen intermediates, significantly enhancing HER performance.

Planar micro‐supercapacitors (MSCs) are emerging as crucial power sources within the realm of microelectronics technology, yet their development is hindered by limitations such as low energy density and significant self‐discharge issues frequently found in dual‐layer MSCs. Recently, water‐in‐salt electrolytes are identified as viable alternatives, offering an expansive voltage range compared to traditional electrolytes and opening new avenues for improved performance. Moreover, redox electrolytes add further enhancements by providing pseudocapacitive benefits. A promising strategy involves using a bipolar redox mediator in water‐in‐salt electrolytes to enhance energy storage capability. Herein, this study introduces symmetric polypyrrole‐based MSCs utilizing redox ZnI ₂ and ZnCl ₂ water‐in‐salt electrolytes (ReWISE). The assembled MSCs exhibit a capacity of 316 mAh cm ⁻³ , an energy density of 351.4 mWh cm ⁻³ , and a power density of 2 W cm ⁻³ , surpassing the performance of conventional carbon‐based MSCs. These MSCs reveal impressive durability, with the device maintaining 76.3% of its initial capacity after 10,000 charging cycles and ensuring the stability of the voltage platform for consistent power output. These findings emphasize the immense potential of ReWISE for advancing MSCs technology, offering a significant leap forward in creating high‐performance, energy‐dense solutions necessary for modern microelectronics.

The shuttle effect and sluggish reaction kinetics of soluble lithium polysulfides (LiPSs) significantly impede the practical application of lithium‐sulfur (Li‐S) batteries. Topological semimetals (TSMs) offer a promising solution to these challenges due to their unique topological surface states. This study synthesizes reduced graphene oxide (rGO)‐loaded Pd₃Sn TSMs (Pd₃Sn@rGO) that are prepared by the NaBH₄ reduction method. The obtained Pd₃Sn@rGO composite has a notably stronger adsorption capability for LiPSs than pure rGO verified by adsorption experiments and density functional theory (DFT) calculations. The topological surface states of Pd₃Sn facilitate the acceptance of electrons from Li₂S₆ during the adsorption process, thereby enhancing adsorption and accelerating redox reactions. Furthermore, Li₂S deposition experiments confirm the effective catalytic role of Pd₃Sn@rGO in the nucleation process of Li₂S. Consequently, Li‐S batteries with Pd₃Sn@rGO modified separators showcase exceptional rate performance across various current densities along with impressive cycling stability (decay rate of 0.0598% per cycle at 1C). This work highlights the capability of Pd₃Sn in catalyzing sulfur redox reactions and underscores the potential of other TSM electrocatalysts in enhancing the performance of Li‐S batteries.