Atomically Dispersed Fe–N₄ and Ni–N₄ Independent Sites Enable Bidirectional Sulfur Redox Electrocatalysis

Single-atom catalysts (SACs) with high atom utilization and outstanding catalytic selectivity are useful for improving battery performance. Herein, atomically dispersed Ni–N4 and Fe–N4 dual sites coanchored on porous hollow carbon nanocages (Ni–Fe–NC) are fabricated and deployed as the sulfur host for Li–S battery. The hollow and conductive carbon matrix promotes electron transfer and also accommodates volume fluctuation during cycling. Notably, the high d band center of Fe in Fe–N4 site demonstrates strong polysulfide affinity, leading to an accelerated sulfur reduction reaction. Meanwhile, Li2S on the Ni–N4 site delivers a metallic property with high S 2p electron density of states around the Femi energy level, enabling a low sulfur evolution reaction barrier. The dual catalytic effect on Ni–Fe–NC endows sulfur cathode high energy density, prolonged lifespan, and low polarization

Stretchable and Self-Powered Temperature–Pressure Dual Sensing Ionic Skins Based on Thermogalvanic Hydrogels

Tactile sensors with both temperature- and pressure-responsive capabilities are critical to enabling future smart artificial intelligence. These sensors can mimic haptic functions of human skin and inevitably suffer from tensile deformation during operation. However, almost all actual multifunctional tactile sensors are either nonstretchable or the sensing signals interfere with each other when stretched. Herein, we propose a stretchable and self-powered temperature–pressure dual functional sensor based on thermogalvanic hydrogels. The sensor operates properly under stretching, which relies on the thermogalvanic effect and constant elastic modulus of hydrogels. The thermogalvanic hydrogel elastomer exhibits an equivalent Seebeck coefficient of −1.21 mV K–1 and a pressure sensitivity of 0.056 kPa–1. Combined with unit array integration, the multifunctional sensor can be used for accurately recording tactile information on human skin and spatial perception. This work provides a conceptual framework and systematic design for stretchable artificial skin, interactive wearables, and smart robots

Ultrathin Smart Energy-Storage Devices for Skin-Interfaced Wearable Electronics

The emergence of on-skin electronics with functions in human–machine interfaces and on-body sensing calls for the development of smart flexible batteries with high performance. Electrochromic energy-storage devices provide a visual indication of the capacity through a real-time change in color without any additional power supply. In this study, dual-function battery and supercapacitor devices for skin-interfaced wearable electronics are developed by a simple and scalable transfer printing method, featuring a thickness of less than 50 μm. Supercapacitive and battery-type devices with areal capacities of 113.4 mF cm–2 and 6.1 μAh cm–2, respectively, are achieved by assembling electrochromic cathodes, hydrogel film electrolyte, and zinc anode. The high flexibility of the ultrathin energy devices endows them with good conformity on arbitrarily shaped surfaces, including elastic human skin, further enhancing the capability of intrinsically non-stretchable thin-film electronics. Our results provide a pathway for the development of versatile electronic skins and next-generation wearable electronics

Ultrathin Smart Energy-Storage Devices for Skin-Interfaced Wearable Electronics

The emergence of on-skin electronics with functions in human–machine interfaces and on-body sensing calls for the development of smart flexible batteries with high performance. Electrochromic energy-storage devices provide a visual indication of the capacity through a real-time change in color without any additional power supply. In this study, dual-function battery and supercapacitor devices for skin-interfaced wearable electronics are developed by a simple and scalable transfer printing method, featuring a thickness of less than 50 μm. Supercapacitive and battery-type devices with areal capacities of 113.4 mF cm–2 and 6.1 μAh cm–2, respectively, are achieved by assembling electrochromic cathodes, hydrogel film electrolyte, and zinc anode. The high flexibility of the ultrathin energy devices endows them with good conformity on arbitrarily shaped surfaces, including elastic human skin, further enhancing the capability of intrinsically non-stretchable thin-film electronics. Our results provide a pathway for the development of versatile electronic skins and next-generation wearable electronics

Robust and Low-Cost Flame-Treated Wood for High-Performance Solar Steam Generation

Solar-enabled steam generation has attracted increasing interest in recent years because of its potential applications in power generation, desalination, and wastewater treatment, among others. Recent studies have reported many strategies for promoting the efficiency of steam generation by employing absorbers based on carbon materials or plasmonic metal nanoparticles with well-defined pores. In this work, we report that natural wood can be utilized as an ideal solar absorber after a simple flame treatment. With ultrahigh solar absorbance (∼99%), low thermal conductivity (0.33 W m^–1 K^–1), and good hydrophilicity, the flame-treated wood can localize the solar heating at the evaporation surface and enable a solar-thermal efficiency of ∼72% under a solar intensity of 1 kW m^–2, and it thus represents a renewable, scalable, low-cost, and robust material for solar steam applications

Ultrathin Smart Energy-Storage Devices for Skin-Interfaced Wearable Electronics

The emergence of on-skin electronics with functions in human–machine interfaces and on-body sensing calls for the development of smart flexible batteries with high performance. Electrochromic energy-storage devices provide a visual indication of the capacity through a real-time change in color without any additional power supply. In this study, dual-function battery and supercapacitor devices for skin-interfaced wearable electronics are developed by a simple and scalable transfer printing method, featuring a thickness of less than 50 μm. Supercapacitive and battery-type devices with areal capacities of 113.4 mF cm–2 and 6.1 μAh cm–2, respectively, are achieved by assembling electrochromic cathodes, hydrogel film electrolyte, and zinc anode. The high flexibility of the ultrathin energy devices endows them with good conformity on arbitrarily shaped surfaces, including elastic human skin, further enhancing the capability of intrinsically non-stretchable thin-film electronics. Our results provide a pathway for the development of versatile electronic skins and next-generation wearable electronics

Ultrathin Smart Energy-Storage Devices for Skin-Interfaced Wearable Electronics

The emergence of on-skin electronics with functions in human–machine interfaces and on-body sensing calls for the development of smart flexible batteries with high performance. Electrochromic energy-storage devices provide a visual indication of the capacity through a real-time change in color without any additional power supply. In this study, dual-function battery and supercapacitor devices for skin-interfaced wearable electronics are developed by a simple and scalable transfer printing method, featuring a thickness of less than 50 μm. Supercapacitive and battery-type devices with areal capacities of 113.4 mF cm–2 and 6.1 μAh cm–2, respectively, are achieved by assembling electrochromic cathodes, hydrogel film electrolyte, and zinc anode. The high flexibility of the ultrathin energy devices endows them with good conformity on arbitrarily shaped surfaces, including elastic human skin, further enhancing the capability of intrinsically non-stretchable thin-film electronics. Our results provide a pathway for the development of versatile electronic skins and next-generation wearable electronics

Low-Cost High-Performance Solid-State Asymmetric Supercapacitors Based on MnO₂ Nanowires and Fe₂O₃ Nanotubes

A low-cost high-performance solid-state flexible asymmetric supercapacitor (ASC) with α-MnO₂ nanowires and amorphous Fe₂O₃ nanotubes grown on flexible carbon fabric is first designed and fabricated. The assembled novel flexible ASC device with an extended operating voltage window of 1.6 V exhibits excellent performance such as a high energy density of 0.55 mWh/cm³ and good rate capability. The ASC devices can find numerous applications as effective power sources, such as powering color-switchable sun glasses and smart windows

Hydrogenated ZnO Core–Shell Nanocables for Flexible Supercapacitors and Self-Powered Systems

Although MnO₂ is a promising material for supercapacitors (SCs) due to its excellent electrochemical performance and natural abundance, its wide application is limited by poor electrical conductivity. Inspired by our results that the electrochemical activity and electrical conductivity of ZnO nanowires were greatly improved after hydrogenation, we designed and fabricated hydrogenated single-crystal ZnO@amorphous ZnO-doped MnO₂ core–shell nanocables (HZM) on carbon cloth as SC electrodes, showing excellent performance such as areal capacitance of 138.7 mF/cm² and specific capacitance of 1260.9 F/g. Highly flexible all-solid-state SCs were subsequently assembled with these novel HZM electrodes using polyvinyl alcohol/LiCl electrolyte. The working devices achieved very high total areal capacitance of 26 mF/cm² and retained 87.5% of the original capacitance even after 10 000 charge/discharge cycles. An integrated power pack incorporating series-wound SCs and dye-sensitized solar cells was demonstrated for stand-alone self-powered systems

Hydrogenated ZnO Core–Shell Nanocables for Flexible Supercapacitors and Self-Powered Systems

Although MnO₂ is a promising material for supercapacitors (SCs) due to its excellent electrochemical performance and natural abundance, its wide application is limited by poor electrical conductivity. Inspired by our results that the electrochemical activity and electrical conductivity of ZnO nanowires were greatly improved after hydrogenation, we designed and fabricated hydrogenated single-crystal ZnO@amorphous ZnO-doped MnO₂ core–shell nanocables (HZM) on carbon cloth as SC electrodes, showing excellent performance such as areal capacitance of 138.7 mF/cm² and specific capacitance of 1260.9 F/g. Highly flexible all-solid-state SCs were subsequently assembled with these novel HZM electrodes using polyvinyl alcohol/LiCl electrolyte. The working devices achieved very high total areal capacitance of 26 mF/cm² and retained 87.5% of the original capacitance even after 10 000 charge/discharge cycles. An integrated power pack incorporating series-wound SCs and dye-sensitized solar cells was demonstrated for stand-alone self-powered systems