The rapid advancements in flexible electronics, artificial intelligence (AI), and the Internet of Things (IoT) have made the safe and friendly interaction between humans and machines a significant area of focus. The combination of AI with flexible sensing technology is shown to enhance data processing capabilities, enabling the development of intelligent sensory systems that can analyze and interpret complex sensory data. This review article discusses the integration of artificial intelligence (AI) with flexible sensing technologies to create advanced human-machine interaction (HMI) systems. The design and development of functional materials and innovative structures for building flexible sensor systems are discussed, which are essential for creating intelligent sensory systems that can mimic human senses. This review also explored the applications of intelligent perception systems in various domains, such as visual, auditory, speech, olfactory, gustatory, and tactile perception, demonstrating the potential of these systems in enhancing human-computer interaction. The author emphasizes the challenges and future opportunities in developing AI-driven smart flexible sensor systems, leading to smarter systems capable of environmental ”self-awareness” and opening new avenues in the era of an intelligent society.

Li/Mn-rich layered oxide (LMR) cathode active materials offer remarkably high specific discharge capacity (>250 mAh g-1) stemming from both cationic and anionic redox. The latter necessitates harsh charging conditions to high cathode potentials (>4.5 V vs. Li|Li+), which is accompanied by lattice oxygen release, phase transformation, voltage fade, and transition metal (TM) dissolution. In cells with graphite anode, TM dissolution is particularly detrimental as it initiates electrode crosstalk. Lithium difluorophosphate (LiDFP) is known for its pivotal role in suppressing electrode crosstalk through TM scavenging. In LMR || graphite cells charged to an upper cut-off voltage (UCV) of 4.5 V, effective TM scavenging effects of LiDFP is observed. In contrast, in cells with an UCV of 4.7 V, the scavenging effects is limited due to more severe TM dissolution compared an UCV of 4.5 V. Worth noting, the low solubility limit of the TM scavenging agents, e.g., PO43- and PO3F2-, which are the decomposition products of LiDFP, cannot scavenge additional TMs, even when higher LiDFP concentration are added to the electrolyte and can even worsen the performance.

Supercapacitors hold great promise as energy storage devices due to their rapid charge-discharge rates and exceptional durability. However, their low energy density has constrained their practical applications. In this study, we synthesize carbon-nanotubes@MnO2-nanosheets core-shell nanotube arrays on carbon cloth to enhance the volumetric capacitance of supercapacitors. Our method utilizes radially grown ZnO nanowires as sacrificial supports to fabricate carbon-nanotube-supported MnO2 structures. The resulting electrode exhibits a high specific capacitance of 0.52 F cm⁻² at 2 mV s⁻¹ and demonstrates excellent rate performance, maintaining a capacitance of 0.25 F cm⁻² at a high scan rate of 100 mV s⁻¹. The asymmetric solid-state supercapacitor, constructed using this composite and paired with a carbon electrode, displays outstanding electrochemical performance, including a voltage window of up to 1.8 V, a high volumetric energy density of 2.85 mWh cm⁻³, and a power density of 453.8 mW cm⁻³. These findings provide valuable insights for the development of next-generation energy storage devices, capable of meeting the growing demands for portable and flexible electronics.

Zinc-ion secondary batteries hold exciting potential due to their outstanding charge-discharge performance, high power and energy density, cost-effectiveness, safety, and eco-friendliness. Metallic zinc, with its superior conductivity, low equilibrium potential, high theoretical specific capacity, and affordability, is an ideal anode material for aqueous secondary batteries. However, the use of conventional aqueous electrolytes often results in problems like dissolution of cathode active materials, decomposition of aqueous solvents, and issues related to dendrite growth, corrosion, and passivation. These challenges limit the reversible capacity and lifespan of zinc-ion secondary batteries. By optimizing and adjusting factors like electrolyte, morphology, and surface modifications of the zinc anode, these battery performances can be enhanced. This article reviews recent progress in anode materials for aqueous zinc-ion secondary batteries, including metal zinc anodes, composite zinc anodes, and zinc alloys. Additionally, it provides a summary and future outlook on the challenges encountered during the implementation and application of the emerging rechargeable zinc battery technology.

This work reports the development of a MoS2@MWCNTs core–shell heterostructure synthesized through an optimized hydrothermal process, designed to enhance the oxygen evolution reaction (OER) efficiency in alkaline water electrolysis. By employing continuous tumbling during synthesis, a uniform and precise thickness of MoS2 was grown on the MWCNTs, striking a balance between maximal catalytic activity at the MoS2 edges, and leveraging the high electrical conductivity of the MWCNTs. The resulting MoS2@MWCNTs catalyst exhibited outstanding electrocatalytic performance for OER, with low overpotential of 285 mV at current density of 10 mA·cm−2, Tafel slope of 42 mV·dec−1, and exceptional durability, maintaining stable operation over 900 hours. Furthermore, the catalyst demonstrated robust performance under dynamic and unstable operating conditions, highlighting its potential for real-world applications in green hydrogen production. This study showcases the successful application of a core–shell structure for OER catalysis, while contributing to the advancement of sustainable energy technologies by providing a cost-effective and efficient solution for hydrogen production through water electrolysis.

Chemical looping gasification (CLG) is a clean and efficient technology that uses oxygen carriers (OCs) to convert carbon energy. Industrial waste phosphogypsum (PG) as raw material for OCs has been proven to be a feasible strategy. Single PG for the preparation of OCs has certain limitations; however, two or more types of elements to modified PG has not been applied in biomass CLG process. In this work, PG was used as carrier and modified with iron and cerium for syngas production through CLG. The PG prepared OCs significantly reduce the costs and improve the utilization rate of solid waste. The reaction conditions of the OCs for syngas production were investigated in a batch fluidized bed. Experimental results show that the best syngas performance is achieved when the PG content is 20 wt.%, Fe/Ce = 2:1, gasification temperature of 800 °C and steam injection rate = 40 μL/min. Multiple redox manifest that the additives of Fe2O3 and CeO2 in the prepared PG carriers increase reaction activity and its stability can be kept at a high level. Finally, the reaction mechanism of modified PG used in biomass CLG was analyzed by combining various characterization methods and density functional theory (DFT) simulations. The possible mechanism suggests that variations of syngas are affected by the calcium roles and valence change of iron. This research provides an effective pathway for the conversion of biomass and the utilization of solid waste PG.

Thick electrode, with its feasibility and cost-effectiveness, has attracted significant attention as a promising approach to maximize the energy density of lithium-ion batteries (LIBs). Through raising the mass loading of active materials without altering the fundamental chemical attributes, thick electrodes can boost the energy density of the batteries effectively. Nevertheless, as the thickness of the electrode increases, the ionic conductivity of the electrode decreases, leading to abominable polarization in the thickness direction, which severely hampers the practical application of a thick electrode. This work proposes a novel porous gradient design of high-performance thick electrodes for LIBs. By constructing a porous structure that serves as a fast transport pathway for lithium (Li) ions, the ion transport kinetics within thick electrodes are significantly enhanced. Meanwhile, a particle size gradient design is incorporated to further mitigate polarization effects within the electrode, leading to substantial improvements in reaction homogeneity and material utilization. Employing this strategy, we have fabricated a porous gradient nanocellulose-carbon-nanotube based thick electrode, which exhibits an impressive capacity retention of 86.7% at a high mass loading of LiCoO2 (LCO) active material (20 mg cm⁻²) and a high current density of 5 mA cm⁻².

This study explores the synthesis of high-entropy alloy (HEA) nanoparticles with core-shell structures using hydrogen reduction-assisted ultrasonic spray pyrolysis (USP). The focus is on synthesizing nanoparticles with transition metal based CoCuFeNi and CoCuFeNiZn HEA shells over iron oxide cores. The USP method enabled precise control over particle composition and morphology, resulting in spherical nanoparticles with complex core-shell configurations. The first synthesized particles with a CoCuFeNi shell over an Fe3O4 core (Fe3O4@CoCuFeNi) exhibited an average grain size of 144.9 nm. Subsequent synthesis involving the addition of Zn resulted in a CoCuFeNiZn shell over an FeO core (FeO@CoCuFeNiZn). The addition of Zn not only contributed to the shell composition but also modified the type of iron oxide core from Fe3O4 to FeO, increasing the grain size of the nanospheres to an average diameter of 224.4 nm. Electrocatalytic testing showed that Fe3O4@CoCuFeNi exhibited outstanding oxygen evolution reaction (OER) activity in 1 M KOH alkaline media. These nanospheres required overpotentials of 306 mV at 10 mA cm², with a Tafel slope of 61.5 mV dec⁻¹. Meanwhile, FeO@CoCuFeNiZn demonstrated a higher overpotential of 378 mV at 10 mA cm² and a Tafel slope of 65.4 mV dec⁻¹, underlining the influence of zinc addition on catalytic activity. Compared to some other HEAs and commercial IrO2 electrocatalysts, both core-shell nanosphere variants show improved charge transfer and reaction kinetics, underscoring their potential as cost-effective and highly efficient electrocatalysts for sustainable water electrolysis.

The limited space in urban areas often presents a challenge for harnessing renewable energy, particularly solar energy. However, this obstacle can be overcome by using building facades to generate energy. The global energy consumption significantly affected by building, contributing significantly demand and greenhouse gases. These buildings require energy (electrical & thermal) for various processes. Photovoltaic/thermal (PV/T) systems can offer a solution by producing both electrical and thermal energies, simultaneously. The circulating working fluid within the system will reduce the surface temperatures of PV panels and subsequently improving the electrical efficiency. Integrating PV/T systems into building facades, known as building-integrated PV/T (BIPV/T) systems, enables efficient production of energy, enhancing the overall energy consumption of buildings. The aim of the current review is to provide an outline of BIPV/T systems; explaining how they work, their classification, the benefits of their utilization in buildings, and techniques for energy enhancement in buildings. The primary objective of this review is to offer researchers up-to-date information on BIPV/T systems available in the literature. It includes recent published technological advancements in BIPV/T systems, focuses on the cited works and their key areas of interest, and provide readers with a comprehensive and systematic overview of the topic rather than an exhaustive analysis of BIPV/T systems.

Water electrolysis using renewable electricity is a promising strategy for high-purity hydrogen production. To realize the practical application of water electrolysis, an electrocatalyst with high redox properties and low cost is essential for enhancing the sluggish oxygen evolution reaction (OER). Herein, we fabricated Fe-doped nickel oxalate (Fe-NiC2O4) directly grown on Ni foam as an efficient electrocatalyst for the alkaline OER using a facile one-step hydrothermal method. Fe-NiC2O4 served as a precursor for obtaining highly active Fe-NiOOH via in-situ electrochemical oxidation. Consequently, 0.75Fe-NiOOH was demonstrated to be the optimal electrocatalyst, exhibiting outstanding OER activity with a low overpotential of 220 mV at a current density of 100 mA cm−2 and a Tafel slope of 20.5 mV dec-1. Furthermore, Fe-NiOOH maintained its OER activity without performance decay during long-term electrochemical measurements, owing to the phase transformation from NiOOH to γ-NiOOH. These performances significantly surpass those of recently reported transition metal-based electrocatalysts.

In this study, a framework for predicting the gas-sensitive properties of gas-sensitive materials by combining machine learning and density functional theory (DFT) has been proposed. The framework rapidly predicts the gas response of materials by establishing relationships between multi-source physical parameters and gas-sensitive properties. In order to prove its effectiveness, the perovskite Cs3Cu2I5 has been selected as the representative material. The physical parameters before and after the adsorption of various gases have been calculated using DFT, and then a machine learning model has been trained based on these parameters. Previous studies have shown that a single physical parameter alone is not enough to accurately predict the gas sensitivity of materials. Therefore, a variety of physical parameters have been selected for machine learning, and the final machine learning model achieved 92% accuracy in predicting gas sensitivity. It is important to note that although there have been no previous reports on the response of Cs3Cu2I5 to hydrogen sulfide, the resulting model predicts the gas response of H2S, which is subsequently confirmed experimentally. This method not only enhances the understanding of the gas sensing mechanism, but also has a universal nature, making it suitable for the development of various new gas-sensitive materials.

Triboelectric nanogenerators (TENGs) are emerging as new technologies to harvest electrical power from mechanical energy. With the distinctive working mechanism of triboelectric nanogenerators, they attract particular interest in healthcare monitoring, wearable electronics, and deformable energy harvesting, which raise the requirement for highly conformable devices with substantial energy outputs. Here, a simple, low-cost strategy for fabricating stretchable triboelectric nanogenerators with ultra-high electrical output is developed. The TENG is prepared using PTFE micron particles (PP-TENG), contributing a different electrostatic induction process compared to TENG based on dielectric films, which was associated with the dynamics of particle motions in PP-TENG. The generator achieved an impressive voltage output at 1000 V with current of 25 µA over a contact area of 40×20 mm2. Additionally, the TENG exhibits excellent durability with a stretching strain of 500%, and the electrical output performance does not show any significant degradation even after 3000 cycles at a strain of 400%. The unique design of the device provides high conformability and can be used as a self-powered sensor for human motion detections.

A touch sensor is an essential component in meeting the growing demand for human-machine interfaces. These sensors have been developed in wearable, attachable, and even implantable forms to acquire a wide range of information from humans. To be applied to the human body, sensors are required to be biocompatible and not restrict the natural movement of the body. Ionic materials are a promising candidate for soft touch sensors due to their outstanding properties, which include high stretchability, transparency, ionic conductivity, and biocompatibility. Here, this review discusses the unique features of soft ionic touch position sensors, focusing on the ionic material and its key role in the sensor. The touch sensing mechanisms include piezocapacitive, piezoresistive, surface capacitive, piezoelectric, and triboelectric and triboresistive sensing. This review analyzes the implementation hurdles and future research directions of the soft ionic touch sensors for the transformative potential.

Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers. Typically, a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties. Here, we systematically investigated 26 dimeric MX2-type compounds (where M represents a metal and X represents a non-metal element) to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations. A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX2, due to the much weakened bonds manifested by the shallow potential well, smaller interatomic force constants, and higher atomic displacement parameters. Based on these findings, we propose two ionic compounds, BaAs and BaSe2, to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X2 dimers, while still maintaining the large lattice anharmonicity. The combined superior electrical and thermal properties of BaSe2 lead to a high n-type thermoelectric ZT value of 2.3 at 500 K. This work clarifies the structural origin of the heat transport properties in dimeric MX2-type compounds and provides an insightful strategy for developing promising thermoelectric materials.

The growing demand for flexible, lightweight, and highly processable electronic devices makes high-functional conducting polymers such as poly (3,4-ethylene dioxythiophene): polystyrene sulfonate (PEDOT:PSS) an attractive alternative to conventional inorganic materials. However, considerable improvements are necessary to make conducting polymers a commercially viable choice. This study explores nanopatterning, as an effective strategy for enhancing polymer functionality, which results in substantial improvements in mechanical, thermal, optical, and electrical properties. Nanopatterned conducting polymers with manipulated electrical properties can be utilized in various fields, including thermoelectrics (TE). Introducing nanopatterning into thermoelectric polymers is challenging due to intricate technical hurdles and the necessity for individually manipulating the TE parameters such as electrical conductivity, Seebeck coefficient, and thermal conductivity. Here, enhanced TE performance is achieved by imposing array nanopatterns on PEDOT:PSS free-standing films using direct electron beam irradiation. Through nanopatterning, selective and independent control of electric and thermal transport in PEDOT:PSS was achieved. The e-beam irradiation transformed PEDOT:PSS from a highly-ordered quinoid to an amorphous benzoid structure, leading to a remarkable reduction in the thermal conductivity by 70% of that of the non-patterned PEDOT:PSS, without a significant reduction in electrical conductivity. Consequently, the thermoelectric figure of merit was enhanced by 60% compared to non-patterned PEDOT:PSS. The proposed nanopatterning methodology demonstrates a skillful approach to precisely manipulate the thermoelectric parameters, thereby improving the thermoelectric performance of conducting polymers, and promising utilization in cutting-edge electronic applications.

A heteronuclear dual transition metal atom catalyst is a promising strategy to solve and relieve the increasing energy and environment crisis. However, the role of each atom still does not efficiently differentiate due to the high activity but low detectivity of each transition metal in the synergistic catalytic process when considering the influence of heteronuclear induced atomic difference for each transition metal atom, thus seriously hindering intrinsic mechanism finding. Herein, we proposed coordinate environment vary induced heterogenization of homonuclear dual transition metal, which inherits the advantage of heteronuclear transition metal atom catalyst but also controls the variable of the two atoms to explore the underlying mechanism. Based on this proposal, employing density functional theory study and machine learning, 23 kinds of homonuclear transition metals are doping in four asymmetric C3N for heterogenization to evaluate the underlying catalytic mechanism. Our results demonstrate that five catalysts exhibit excellent catalytic performance with a low limiting potential of -0.28 to -0.48 V. In the meantime, a new mechanism, ‘capture-charge distribution-recapture-charge redistribution’, is developed for both side-on and end-on configuration. More importantly, the pronate site of the first hydrogenation is identified based on this mechanism. Our work not only initially makes a deep understanding of the transition dual metal-based heteronuclear catalyst indirectly but also broadens the development of complicated homonuclear dual atom catalysts in the future.

Thermoelectric materials, capable of converting temperature gradients into electrical power, have been traditionally limited by a trade-off between thermopower and electrical conductivity. This study introduces a novel, broadly applicable approach that enhances both the spin-driven thermopower and the thermoelectric figure-of-merit (zT) without compromising electrical conductivity, using temperature-driven spin crossover. Our approach, supported by both theoretical and experimental evidence, is demonstrated through a case study of chromium doped-manganese telluride, but is not confined to this material and can be extended to other magnetic materials. By introducing dopants to create a high crystal field and exploiting the entropy changes associated with temperature-driven spin crossover, we achieved a significant increase in thermopower, by approximately 136 μV/K, representing more than a 200% enhancement at elevated temperatures within the paramagnetic domain. Our exploration of the bipolar semiconducting nature of these materials reveals that suppressing bipolar magnon/paramagnon-drag thermopower is key to understanding and utilizing spin crossover-driven thermopower. These findings, validated by inelastic neutron scattering, X-ray photoemission spectroscopy, thermal transport, and energy conversion measurements, shed light on crucial material design parameters. We provide a comprehensive framework that analyzes the interplay between spin entropy, hopping transport, and magnon/paramagnon lifetimes, paving the way for the development of high-performance spin-driven thermoelectric materials.

The development of cost-effective, highly efficient, and durable electrocatalysts has been a paramount pursuit for advancing the hydrogen evolution reaction (HER). Herein, a simplified synthesis protocol was designed to achieve a self-standing electrode, composed of activated carbon paper embedded with Ru single-atom catalysts and Ru nanoclusters (ACP/RuSAC+C) via acid activation, immersion, and high-temperature pyrolysis. Ab initio molecular dynamics (AIMD) calculations are employed to gain a more profound understanding of the impact of acid activation on carbon paper. Furthermore, the coexistence states of the Ru atoms are confirmed via aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). Experimental measurements and theoretical calculations reveal that introducing a Ru single atom site adjacent to the Ru nanoclusters induces a synergistic effect, tuning the electronic structure and thereby significantly enhancing their catalytic performance. Notably, the ACP/RuSAC+C exhibits a remarkable turnover frequency (TOF) of 18 s-1 and an exceptional mass activity (MA) of 2.2 A mg-1, surpassing the performance of conventional Pt electrodes. The self-standing electrode, featuring harmoniously coexisting Ru states, stands out as a prospective choice for advancing HER catalysts, enhancing energy efficiency, productivity, and selectivity.