Nano Energy最新文献

The 2D/3D heterojunction structure emerges as a viable approach for enhancing the efficiency and stability of perovskite photovoltaics. However, the formation of an accumulative low-dimensional 2D perovskite (n=1) cladding layer often impedes carrier transport due to the insulating nature and high quantum confinement, and there is a paucity of detailed understanding regarding its surface phase control. This study introduces a Dion-Jacobson (DJ) phase 2D perovskite, employing decane-1,10-diammonium diiodide (DDADI) to interface with 3D perovskite, leveraging long-chain diammonium cations for structural stability and defect passivation on the 3D FAPbI₃ perovskite surface. In addition, a novel PbI₂-assisted phase control (PAPC) technique is proposed to mitigate the quantum confinement effects of the 2D layer, especially reducing the formation of the highly confined insulating n=1 phase. X-ray scattering analysis confirms the method's efficacy in promoting the formation of an n=2 phase, facilitating cascading HOMO levels and improving hole carrier transport. The optimized 2D/3D perovskite solar cell (PSC) achieve an exemplary efficiency of 25.16 %, with a notable open-circuit voltage of 1.192 V, and retain 92.9 % of its initial efficiency after 1000 hours in a nitrogen atmosphere, signifying a strategic advancement in 2D/3D PSC construction.

The evolving landscape of intelligent devices and toys demands seamless interaction, exceptional performance, and visually captivating features. Triboelectric nanogenerators (TENGs) offer an eco-friendly solution for generating electrical energy in smart toys and devices. This research introduces high-power and stretchable triboelectric layers in various colors tailored for toys and wearable gadgets. Combination of the silicone rubber with the ceramic powders, not only improved mechanical properties, but also provided vibrant colors. This process enhanced the fracture strain and the toughness, and reduced the Young's modulus, so stretchability and overall quality were increased. The best composite, the green layer, demonstrated outstanding attributes such as a power density of 6.5 W/m², a fracture strain of 385 %, a toughness of 1.86 Mj/m³, and a Young's modulus of 0.20 MPa. The green TENG, a sandwich format with an EGaIn electrode, was used for effective monitoring of human body movements. Additionally, a highly efficient machine learning model has been developed for identifying human motions with a remarkable accuracy of 98 %. The study highlighted the considerable power density, voltage, and current exhibited by the colorful TENGs. By integrating these TENGs into circuitry, an engaging toy was created that produces musical notes and displays corresponding pattern on a computer screen when a colorful array was pressed. These colorful nanogenerators hold significant promise for battery-free toys and wearable electronics.

Two-dimensional (2D) piezoelectric nanogenerators (PENGs) have great potential in capturing weak physiological signals on the body surface due to their superior flexibility and high sensitivity. However, there are few reports on utilizing 2D PENG to capture physiological signals for identifying human health status, and to conduct clinical trials. Here, we reported an intelligent cardiovascular disease diagnosis system that integrates a self-powered pulse sensor based on 2D Bi₂O₂Se PENG and deep learning (DL) technology to accurately identify nine common cardiovascular diseases. The significant piezoelectricity of Bi₂O₂Se nanosheets prepared by chemical vapor deposition was experimentally validated via piezoresponse force microscopy. The open-circuit voltage (V_OC) and short-circuit current (I_SC) of the 2D PENG can reach 60 mV and 2 nA under 0.6 % strain, respectively. The 2D PENG attached to the skin can sense the three characteristic peaks of pulse signals in different body statuses, and then extract some predictive indicators reflecting cardiovascular diseases. Clinical trials show that the intelligent cardiovascular disease diagnosis system can accurately identify nine common diseases with a recognition accuracy of 93.75 %. Our study indicates that 2D PENG has an enormous potential for long-term non-invasive health monitoring, and provides a new strategy for early diagnosis of cardiovascular diseases.

Although soft mechano-electrochemical energy harvesters have attracted considerable attention as wearable sensors, they face challenges, including low output performance, high Young’s modulus and low energy-conversion efficiency. To address these limitations, we introduce a novel design featuring macroscopically coiled and microscopically buckled fibres to improve the mechano-electrochemical energy-harvesting capability, thereby maximising capacitance change and affording higher electrical output. The harvester achieved a gravimetric peak current density of 121 A/kg and a peak power density of 16 W/kg. Moreover, the harvester showed enhanced stretchability under a strain of over 400 %, low Young’s modulus of 0.2 MPa and an energy conversion efficiency of 0.33 %. Furthermore, when implanted in a pig’s bladder, it showed minimal impact during expansion and contraction thanks to its softness and provided real-time electrical output in response to static and dynamic volume changes.

The harnessing of vibrational energy is becoming increasingly pivotal in the development of intelligent rail transit systems. The integration of emerging technologies such as triboelectric nanogenerators (TENGs), electromagnetic generators (EMGs), or hybrid generators has become crucial for fault detection and energy harvesting in rail transit. This paper introduces a self-powered fault detection system (SPFDS). SPFDS combines multiple compact rotating Triboelectric-Electromagnetic Nanosensor (TENS) nodes with a deep learning-based diagnostic module to transform vibrational energy generated during train operations into electrical power and accurately identifies five distinct train bogie fault conditions. Simulations and experiments have shown that the TENS nodes, with a root mean square power of 0.21 W and a power density of 1595.7 W/m³, can efficiently detect various bogie faults. Additionally, their power output is adequate to support commercial sensors and Bluetooth modules. Through hyperparameter optimization, the diagnostic module utilizing multi-TENS nodes achieves an average diagnostic accuracy of 99.38 % for the five fault modes of freight train bogies. Implementing multiple TENS nodes in SPFDS enhances fault detection accuracy by an average of 32 % compared to a single TENS node, with a peak increase of 128 %. The multi-node TENS configuration and SPFDS's self-powered detection capabilities represent an innovative approach to complex fault detection, significantly contributing to the advancement of vibration energy harvesting and the development of distributed self-powered sensor network technologies for smart transportation.

The combination of triboelectric nanogenerator (TENG) and wood-based materials offers a sustainable strategy for energy harvesting. The main challenge in realizing wood-based TENG is to increase the polarizabilities of wood. Herein, we introduce the first instance of a transparent wood-based triboelectric nanogenerator (TW-TENG), which synergistically incorporates superior triboelectric properties, optical properties, and aesthetic of wood. Addressing the challenges of weak polarizability and opacity inherent in natural wood, we propose a functionalized modification approach involving delignification and impregnation with UV-curable resin. In this study, leveraging delignification and the strong electron-donating groups within the UV-curable resin, the electrical output performance of TW-TENG is improved by 6.5 times compared to that of natural wood, and maintains stability over 10,000 operational cycles. Moreover, the matching refractive index between the UV-curable resin and the wood substrate offers TW-TENG with high transparency, achieving an optical transmittance of up to 88.8 %, exhibiting the unique aesthetic value of transparent wood. Furthermore, we demonstrate the potential applications of TW-TENG in energy harvesting, sensor technologies, smart decorative materials, smart home systems, and beyond, exemplified through its utilization in electrical output generation by pressing, capacitor charging and discharging, and self-powered multiplexed sensing smart target shooter.

Interface engineering has a critical impact on the performances of organic solar cells (OSCs). And cathode interface layer (CIL) with thickness insensitivity is urgently pursued to improve the possibility of industrialization of OSCs. N-type self-doping has been proven effective in increasing electron mobility. Here, four novel n-type small molecule electrolytes (SMEs) with diverse counter anions (CAs), PDIN-BF₄, PDIN-BPh₄, PDIN-BPhF₄, and PDIN-BIm₄ were synthesized and employed as cathode interface layers (CILs). Among them, PDIN-BIm₄-based OSCs with PM6:Y6 active layer achieved the most glorious electron mobility and thickness insensitivity with a power conversion efficiency (PCE) of 16.98 % due to outstanding self-doping effect and interfacial regulation ability. However, the multi-F atoms on PDIN-BPhF₄ may prevent self-doping progress and impede electron transport, thus leading to a low PCE of 11.53 %. Meanwhile, the PDIN-BIm₄-based device can maintain over 80 % of the optimal PCE with a thickness of 43 nm or storing in a glove box for 600 h. In addition, PM6: BTP-eC9-based device with PDIN-BIm₄ CIL acquired a PCE of 17.82 %, highlighting the broad applicability of PDIN-BIm₄. Our work demonstrates that the introduction of CAs into n-type organic materials helps promote the progress of efficient and stable OSCs.

Sodium-ion batteries (SIBs) have advantages in high sodium resources, providing powerful supplement to the current energy storage system. However, the lack of low-cost and high-performance anode materials still limits its practical application. Herein, a soft carbon anode derived from petroleum coke was successfully synthesized by engineering its composition and microstructure through resin and sodium phosphate compositing with optimal heat treatment process, delivering significant merits over existing composite anode in term of price density, initial Coulombic efficiency (ICE) and carbon yield. Resin helps to increase micropores and inhibit graphitization. Na₃PO₄ contributes to expand layer spacing and increase reversible groups, meanwhile facilitates the cross-linking of graphite microcrystalline and provides additional sodium supplement with improved ICE and conductivity. Through the synergistic effect by the additives, the optimized sample (P-ONH-1200) exhibits a superior reversible charge specific capacity of 311.9 mAh g⁻¹ with high cycling stability, ICE (90.7 %) in SIBs, and high carbon yield (70 %). It also gains rate performance of 209.7 mAh g⁻¹ at 4 C with 98 % retention after 1000 cycles. The full cell with Na₃V₂(PO₄)₃ (NVP) cathode at 1.05 N/P ratio exhibits an excellent stability with a capacity retention of 70 % after 500 cycles at 1 C. It provides a model reference for the microstructure regulation of petroleum coke and a revenue for preparation high-performance soft carbon anode for SIBs.

With the unremitting demand for renewable energy sources, triboelectric nanogenerators as efficient micro-energy, particularly wind-energy harvesting devices, have garnered increased attention. This study introduces an innovative wind flutter-driven triboelectric nanogenerator (WF-TENG). It employs an on-demand integrated design of a "mortise and tenon" microstructure and is assembled in a "negative-positive-negative" configuration mimicking a "corrugated paper" macrostructure, effectively converting wind energy into electrical energy. The porous crosslinked ethyl cellulose/polyethyleneimine positive friction layer and the bionic rose-petal-like fluorinated ethylene propylene negative friction layer are assembled to form a miniaturized "mortise and tenon" structure, which greatly improves the charge transfer efficiency. Surprisingly, due to the collaborative structural design on micro-/macro-scale, WF-TENG elevates the breakthrough power density of WF-TENG to 455.932 mW cm⁻². Further, the integrated-equipped bladeless wind tunnel generator, assembled with the WF-TENG array, utilizes airflow disturbances to produce high-frequency flutter-driven frictional motions. This system outputs up to 7.5 kV at a startup wind speed of 7.9 m s⁻¹ and maintains stable performance for 60 days. Application experiment substantiates the ample electrical energy collected by the bladeless wind tunnel generator for powering an indoor formaldehyde purifier demonstrates a high formaldehyde purification rate of 94 %, providing new insights for the design and applications of novel micro-energy harvesting devices.

Solar water evaporation is vital for addressing global water scarcity, particularly in regions with limited freshwater. Through the utilization of photothermal materials, solar water evaporation harnesses solar radiation to generate heat, which in turn accelerates the evaporation of water, producing clean drinking water. Subsequently, the vapor is condensed to produce fresh water, offering a sustainable solution to water scarcity. This research field has garnered immense scientific interest, with over six thousand publications. Reported solar absorber evaporation rates exceed 100 kg m⁻² h⁻¹ under one sun irradiation, far surpassing the theoretical limit of 1.47 kg m⁻² h⁻¹ achievable on two-dimensional absorber surfaces, assuming constant latent heat at 2444 J g⁻¹. This review addresses this significant discrepancy in theoretical and practical values. A cut-off of 3 kg m⁻² h⁻¹ (under one sun irradiation) is considered to narrow focus, facilitating analysis of high-rate evaporators. Critical challenges and factors contributing to high evaporation rates are discussed, providing comprehensive insights into field advancements.