ABSTRACT Measuring low‐frequency or infrasound acoustic signals plays a crucial role in the monitoring of natural disasters, structural health, and predictive maintenance of critical energy structures. Smart sound sensing systems often consist of linear sound sensors coupled to a separate processing unit, nonlinearly transforming the signal to solve the given task. However, nonlinear sensors have seen increased scientific interest in fields like reservoir computing, with the goal of minimizing power consumption by implementing the signal processing in the sensor itself. Here, the use of an organic electrochemical transistor based on conductive polymeric fibers embedded inside a free‐standing solidified gel membrane as a robust, highly sensitive, and nonlinear low‐frequency sound sensor is demonstrated. The slow dynamics of the device allow sensing in the low‐frequency and infrasound regime with a cutoff‐frequency at around with power consumptions below . Our work further demonstrates that the introduction of a gating mechanism increases sensitivity, nonlinearity, and stability compared to a previously introduced linear two‐terminal sensors. As a demonstration, we show that a three‐terminal device contains sufficient information to classify spoken digits from ten classes, using in‐software reservoir computing.
ABSTRACT Topotactic phase‐transition (TPT) oxide memristors contain ordered 1D oxygen‐vacancy channels (OVCs) that enable anisotropic oxygen‐ion migration and reversible brownmillerite/perovskite transition, offering a materials platform for neuromorphic computing. However, the lack of spatially predefined oxygen‐ion migration sites in conventional TPT films promotes stochastic perovskite SrFeO 3 conductive filament (CF) growth, compromising the response stability and state distinguishability required for reliable temporal signal processing. Here, a single‐component self‐assembled SrFeO x memristor with alternating vertical and horizontal superlattice‐like OVC regions is reported. Structural characterization, density functional theory calculations, and kinetic Monte Carlo simulations indicate that this intrinsic self‐assembled architecture directs oxygen‐ion migration through vertical channels while horizontal regions restrict stray out‐of‐plane transport, promoting localized CF growth. The device combines forming‐free bipolar switching, an ON/OFF ratio of ∼4.4 × 10 3 , low cycle‐to‐cycle (C2C) variation with CV(V SET )/CV(V RESET ) of 3.2%/0.6%, 16‐state retention over 10 4 s, and endurance up to 10 7 pulse cycles. Reproducible device‐to‐device (D2D) switching is obtained across 32 cells, with D2D CV(V SET )/CV(V RESET ) values of 10.1%/5.9%. Finally, the device's short‐term memory transforms temporal inputs into distinguishable states that a fixed linear readout decodes with 84.59% accuracy on a temporal classification task. This work highlights intrinsic OVC‐orientation engineering as a materials‐level strategy toward reliable single‐component TPT memristors.
ABSTRACT Rechargeable Na‐Cl 2 batteries have emerged as a promising alternative and supplement for lithium‐ion batteries due to their ultra‐high energy density. Nevertheless, developing satisfactory cathode materials to facilitate the complex solid, liquid, and gas three‐phase conversion process during charge‐discharge cycling remains a significant challenge. Herein, we propose a three‐dimensional ordered macroporous Prussian blue analog (3DOM PBA) fabricated via a stepwise vacuum impregnation template strategy, which can serve as an ideal cathode material for rechargeable Na‐Cl 2 batteries. The hierarchically ordered porous structure arranging from micropores to macropores can provide appropriated channels for ions transfer, Cl 2 storage, and NaCl crystal deposition. Moreover, customizable metal site doping not only optimize the electronic and ionic conductivity but also provide efficient adsorption and in‐situ catalytic conversion sites for Cl 2 /Cl − , thereby effectively increasing the reversible reaction kinetics and long‐term cycling stability. As a result, the assembled Na‐Cl 2 battery delivers a reversible capacity of 2000 mAh g − 1 and stable cycling life of 2500 cycles at 15 000 mA g − 1 , which can still maintain reversible charge‐discharge behavior even at 30 000 mA g − 1 , much superior to the reported results. This study provides new insights for developing high‐performance electrode materials for rechargeable Na‐Cl 2 batteries.
ABSTRACT Spin‐charge interconversion mediated by spin‐orbit interaction represents a central concept in modern spintronics. The efficiency of spin‐charge interconversion is conventionally estimated from the Berry curvature of Bloch states within the linear‐response regime. Besides the linear regime, recent studies have uncovered nonlinear spin‐charge conversion arising from higher‐order electric‐field terms in noncentrosymmetric materials with nontrivial spin textures. Hence, harnessing and controlling such nonlinear responses promise opportunities for designable and reconfigurable nonlinear spintronic devices. Here, we report the nonlinear planar Hall effect in topological semimetal SrIrO 3 (001) thin film, enabled by inversion‐symmetry breaking at the interface. Furthermore, systematic transport measurements reveal robust second‐order electrical transport that can be dynamically and reversibly tuned by ionic‐liquid gating. This tunability originates from gating‐induced structural reconstruction, valence‐state modulation, and oxygen‐vacancy formation, which modify the interfacial inversion‐symmetry breaking and consequently reshape the band structure. These findings establish an effective electrical route for controlling nonlinear planar Hall responses through ionic engineering of spin texture in momentum space and provide a promising platform for reconfigurable nonlinear spintronic applications.
ABSTRACT Lithium dendrite formation in solid‐state lithium metal batteries originates not only from mechanical failure but also from spatially heterogeneous interfacial electrostatic fields that induce localized Li + accumulation. However, existing electrolyte designs mainly regulate mechanical strength or chemical interfacial reactions, while dynamic regulation of interfacial electrostatic disorder remains unexplored. Here, we introduce an interfacial potential homogenization enabled by polarization‐mediated regulation. A molecularly entangled PEO/polyurethane/MOF‐177 electrolyte is constructed, where polar polymer networks and MOF polarization domains cooperatively redistribute local electric‐field fluctuations. This electrostatic regulation homogenizes Li + flux, lowers migration barriers, and suppresses preferential lithium nucleation. Consequently, CPEZ exhibits an ionic conductivity of 1.9 × 10 −3 S cm −1 and a Li + transference number of 0.71, both measured at 60°C. The Li/CPEZ/Li cell cycles stably for 9000 h at 0.1 mAh cm −2 . The Li/CPEZ/LFP retains 90 % capacity after 5000 at 1 C, while Li/CPEZ/LFP retains 85% capacity after 500 cycles at 100°C and cycles stably for 150 cycles at −15°C. This work establishes electrostatic regulation via polar interactions as a transferable design principle for durable, wide‐temperature solid‐state lithium metal batteries.
