Metal–air batteries are an appealing option for energy storage, boasting a high energy density and environmental sustainability. Researchers focus on the catalyst design to solve the problem of sluggish cathode reaction kinetic. However, in some cases, where thermodynamic regulation is required, the role of catalysts is limited. Based on catalysts changing reaction kinetics, external fields can change the thermodynamic parameters of the reaction, further reduce overpotential, and accelerate the reaction rate. By selecting appropriate external fields and adjusting controllable variables, greater flexibility and potential are provided for reaction control. This paper reviews the basic principles by which several external fields influence metal–air batteries. Additionally, some design strategies of photoelectrode materials, the similarities and differences of different magnetic field effects, and some research progress of the ultrasonic field, stress field, and microwave field are systematically summarized. Multifield coupling can also interact and produce additive effects. Furthermore, introducing external fields will also bring about the problem of aggravated side reactions. This paper proposes some research methods to explore the specific reaction mechanism of external field assistance in more depth. The primary objective is to furnish theoretical direction for enhancing the performance of external field-supported metal–air batteries, thereby advancing their development.

As for the high sustainable solar hydrogen production via water splitting, transition metal doping on an oxide photoanode in photoelectrochemical (PEC) cells has been recognized as an effective approach. However, conventional thermal-diffusion-mediated doping strategies face the challenge of resolving sluggish catalytic kinetics for oxygen evolution reaction (OER) and its practical utilization for the synthesis of photoanode films. Herein, we introduce facile ultrafast flame-boosted doping of Mo into a BiVO₄ (FL MoBVO) film for 20 s to achieve an efficient PEC OER. Mo elements in a low-valence state (i.e., Mo^6–δ) and Mo⁶⁺ are successfully doped into the photoanode, which manipulate the energy band structure, facilitating the downward shift of band edges and promoting the surface catalytic kinetics. Consequently, the flame-boosted Mo-doping results in superior PEC performance in a mild environment with neutral electrolyte without introducing any other additives or co-catalysts, where the photocurrent density at 1.23 V_RHE under 1 sun illumination in pH 7 is outstandingly enhanced, over 9-fold higher than that of a pristine BiVO₄. The flame-boosted doping induces significantly enhanced photoexcited charge transport and catalytic reaction kinetics performances simultaneously. Our report provides the effective strategy boosting both the thermodynamic and kinetic charge migration properties for sustainable materials.

Tactile sensors are a potential solution for material identification. However, current potential tactile sensors for material identification are pressed, expensive, and applications-confined. Here we report a clamped-on pyroelectric tactile sensor on the basis of a ferroelectric Bi_0.5Na_0.5TiO₃ material to identify different film materials. The fabricated device exhibits different heat absorption capacities while in contact with different materials, leading to a different temperature change in the ferroelectric material under the same illumination. As a result, the device can recognize different materials by comparing the pyroelectric charge via integrating the obtained current under the same irradiation of 365 nm light-emitting diode. The clamped-on pyroelectric tactile sensor can identify six individual materials with a high accuracy of 98.8% and a fast response of 40 ms. All of the above processes can be accomplished with an intelligent material identification system. The device provides a new solution for material identification and lays a foundation for smart factories and laboratories.

Flexible sensors exhibit the properties of excellent shape adaptability and deformation ability, which have been applied for environmental monitoring, medical diagnostics, food safety, smart systems, and human–computer interaction. Cellulose-based hydrogels are ideal materials for the fabrication of flexible sensors due to their unique three-dimensional structure, renewability, ease of processing, biodegradability, modifiability, and good mechanical properties. This paper comprehensively reviews recent advances of cellulose-based hydrogels in the construction of flexible sensor applications. The characteristics, mechanisms, and advantages of cellulose-based hydrogels prepared by physical cross-linking, chemical cross-linking are respectively analyzed and summarized in detail. The focus then turns to the research and development in cellulose-based hydrogel sensors, including physical sensing (pressure/strain, humidity/temperature, and optical sensing), chemical sensing (chromium, copper, and mercury ion sensing, toxic gas sensing, nitrite sensing), and biosensing (glucose, antibody, and cellular sensing). Additionally, the limitations of cellulose-based hydrogels in sensors, along with key challenges and future directions, are discussed. It is anticipated that this review will furnish invaluable insight for the advancement of novel green, flexible sensors and facilitate the integration of cellulose-based hydrogels as a fundamental component in the development of multifunctional sensing technologies, thereby expediting the design of innovative materials in the near future.

Semitransparent perovskite solar cells (PSCs) hold great potential for applications in aesthetic building facades and top-illuminated tandem devices. Indium tin oxide is currently the frequently used top transparent contact, which would degrade the underlying perovskites during sputter process. Here, we report low-temperature, scalable solution-processed silver nanowires (AgNWs) as top window electrodes for fabricating efficient and stable semitransparent PSCs. As a decisive step, an impermeable SnO₂ thin film deposited by atomic layer deposition (ALD) is applied to prevent chemical reactions between AgNWs and halides of perovskites. In parallel, the molecular absorption of propylenediamine iodine (PDADI) on perovskite surface, instead of forming two-dimensional (2D) perovskite capping layer, is found to effectively passivate the perovskite surface, which simultaneously leads to remarkably enhanced thermal stability, thus affording the processing window for ALD-SnO₂ deposition. Eventually, the prepared semitransparent PSCs with a bandgap of 1.71 eV achieve a champion efficiency of 17.5%, being the highest efficiency for semitransparent PSCs with AgNWs top contacts. On these bases, we constructed a four-terminal perovskite/copper indium gallium diselenide (CIGS) tandem cell, giving a state-of-the-art efficiency of 26.85%.

Polymer-derived SiOC materials are widely regarded as a new generation of anodes owing to their high specific capacity, low discharge platform, tunable chemical/structural composition, and good structural stability. However, tailoring the structure of SiOC to improve its electrochemical performance while simultaneously achieving elemental doping remains a challenge. Besides, the lithium storage mechanism and the structural evolution process of SiOC are still not fully understood due to its complex structure. In this study, a hollow porous SiOCN (Hp-SiOCN) featuring abundant oxygen defects is successfully prepared, achieving both the creation of a hollow porous structure and nitrogen element doping in one step, finally enhancing the structural stability and improving the lithium storage kinetics of Hp-SiOCN. In addition, the formation of a fully reversible structural unit, SiO₃C—N, through the chemical interaction between N and Si/C, showcases a strong lithium adsorption capacity. Taking advantage of these combined benefits, the as-prepared Hp-SiOCN electrode delivers a reversible specific capacity of 412 mAh g^–1 (93% capacity retention) after 500 cycles at 1.0 A g^–1 and exhibited only 4% electrode expansion. This work offers valuable mechanistic insights into the synergistic optimization of elemental doping and structural design in SiOC, paving the way for advanced developments in battery technology.

Anode-free sodium batteries (AFSBs) have attracted increasing attention for their high energy density. However, they suffer from rapid capacity decline resulting from sodium dendrite growth at the sodium/host interface and irreversible side reactions at the electrolyte/sodium interface. Herein, a GaInSn-coated Cu foil (G-Cu), prepared by a simple brush coating method, was applied as the sodiophilic current collector to regulate sodium nucleation behavior. In addition, a nonexpendable functional electrolyte additive, hexamethyldisiloxane (HMDSO), was introduced, which could be absorbed on the sodium surface and serve as a protective layer against corrosion side reactions at the electrolyte/sodium interface. It is interesting to note that this additive barely participated in forming the solid electrolyte interphase. The synergetic effects of sodiophilic interface design and electrolyte regulation enable reversible sodium plating and stripping. Ultimately, the AFSB assembled using G-Cu and HMDSO electrolyte with a highly loaded Na₃V₂(PO₄)₃ cathode (≈12.5 mg cm^–2) delivers a discharge capacity of 84.5 mAh g^–1 after 200 cycles with a high capacity retention of 87.6%, significantly extending its operation lifespan.

Tailoring atomically dispersed single-atom catalyst (Fe-SAC) holding well-defined coordination structure (Fe-N₄) along with precise control over morphology is a critical challenge. Herein, we propose a novel acid-amine coupling reaction between metal-chelated ionic liquid ([1-(3-aminopropyl) 3-methylimidazolium tetrachloroferrate(III)] [APIM]⁺[FeCl₄]^–) and carboxylic groups of carbon allotropes (C = GO, CNT, CNF, and vX-72) to precisely immobilize Fe-N_x sites. Out of designed single-atom catalyst (IL-Fe-SAC-C), Fe-N₄ on graphene (IL-Fe-SAC-Gr) delivered superior oxygen reduction reaction (ORR) activity by holding higher halfwave potential of 0.882 V versus RHE in 1.0 M KOH akin to Pt/C (0.878 V vs. RHE) and surpassing recently reported M–N–C catalysts with superior ethanol tolerance. Thanks to higher graphitization degree, enhanced surface characteristics, and richness in high-density Fe-N₄ sites of IL-Fe-SAC-Gr confirmed by XPS, X-ray absorption spectroscopy (XAS), and HAADF analysis. The IL-Fe-SAC-Gr catalyst-coated cathode on testing in flexible direct ethanol fuel cells (f-DEFC) delivered higher peak power density of 18 m W cm^–2 by outperforming Pt/C-based cathode by 3.5 times as a result of excellent ethanol tolerance. Further, the developed f-DEFC successfully powered the Internet of Things (IoT)-based health monitoring system. This method demonstrates novel strategy to tailor high-performance single-atom (Fe-SAC-C) sites on desired morphologies to meet specific application requirements with feasibility and versatility.

In light of cost-effectiveness, high volumetric capacity, and abundant supplies on Earth of aluminum metal, the rechargeable aluminum battery (RAB) represents a cutting-edge alternative for energy storage devices. RABs have achieved significant progress as a result of tireless efforts; however, challenges like as expensive ionic liquid electrolytes, a restricted voltage window of aqueous electrolytes, corroded anode, and rapid capacity degradation limit their practical applications. In terms of increasing RAB mileage, electrode materials can be regarded as the foundation of battery performance. Metal-organic frameworks (MOFs), which have customizable topologies, multiple active sites, and various metal centers and ligands, are promising electrode materials. Herein, for the first time, we deliver in detail the recent advancement of MOFs in RABs. The relationship on structure-properties-performance of MOFs is thoroughly discussed. MOF and MOF-derived electrode materials are first summarized. In aluminum sulfur/selenium batteries, MOF can serve as a host to capture the sulfides or selenides. Furthermore, the MOF as catalysts for aluminum-air batteries are provided. Then we focused on the challenges and opportunities that RABs would face in the future, and some prospects are presented. We believe this account will facilitate the exploration of MOFs in RABs and give more inspiration for discovering advanced RABs.

Sustainable power sources for outdoor wearable electronics are essential for the continuous operation of wearable devices. However, the current lack of engineering design that can harvest energy regardless of weather conditions presents a significant challenge. In this regard, this study introduces a wearable, breathable all-weather usable dual energy harvester (AWuDEH) that can seamlessly generate electrical energy regardless of weather conditions. In this study, the AWuDEH integrated with the thermoelectric generator and the droplet-based electricity generator is demonstrated. The AWuDEH, especially engineered with a bi-functional top substrate for radiative cooling and electrification, achieves sustainable energy harvesting outdoors, thereby addressing the conventional challenge associated with the necessity for separate energy harvesters tailored to outdoor usage contingent on weather conditions. The device reaches a maximum power output of 14.6 µW cm^–2 under simulated sunny conditions and generates a much more enhanced thermoelectric power of 74.78 µW cm^–2 and a droplet-based electric power of 256.25 mW m^–2 in rainy conditions. As proof, this study developed self-powered wearable electronics capable of acquiring physiological signals in simulated outdoor scenarios. This study presents a promising advancement in wearable technology, offering a potent solution for sustainable energy harvesting independent of weather conditions.