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In order to cope with the increasingly serious problem of energy shortage, supercapacitors have been developed as a clean and renewable energy source, and the supercapacitors with excellent energy density and long cycle life are imperative. Here, by employing a facile liquid–liquid (L-L) interfacial method at room temperature (RT), a set of two-dimensional (2D) metal complex nanosheets N1-N3 have been synthesized by the facile coordination between Co²⁺ ion and 2,3,6,7,10,11-hexaiminotriphenylene (HITP). Given the layered superstructure with well-ordered nanopores, the N1-N3 electrodes displayed excellent capacities of 4751.9, 5770.9 and 6075.2 F g⁻¹ at 1 A g⁻¹, and a good cyclic stability with 92.1% capacity retention after 1000 cycles for the N3 electrode. The asymmetric supercapacitor device with N3 as the positive electrode delivers a maximum energy density of 238.2 Wh kg⁻¹ at a power density of 1610.1 W kg⁻¹ and an excellent cycling stability with a capacitance retention of 109.1% after 5000 cycles. This is the best electroactive bottom-up metal complex nanosheet reported so far for use in supercapacitor, which greatly expands the applicability of this 2D nanomaterial in energy device applications.

MoS₂ as a typical layered transition metal dichalcogenide (LTMD) has attracted considerable attention to work as sodium host materials for sodium-ion batteries (SIBs). However, it suffers from low semiconducting behavior and high Na⁺ diffusion barriers. Herein, intercalation of N-doped amorphous carbon (NAC) into each interlayer of the tiny MoS₂ nanosheets embedded on rGO conductive network is achieved, resulting in formation of rGO@MoS₂/NAC hierarchy with interoverlapped MoS₂/NAC superlattices for high-performance SIBs. Attributed to intercalation of NAC, the resulting MoS₂/NAC superlattices with wide MoS₂ interlayer of 1.02 nm facilitates rapid Na⁺ insertion/extraction and accelerates reaction kinetics. Theoretical calculations uncover that the MoS₂/NAC superlattices are beneficial for enhanced electron transport, decreased Na⁺ diffusion barrier and improved Na⁺ adsorption energy. The rGO@MoS₂/NAC anode presents significantly improved high-rate capabilities of 228, 207, and 166 mAh g⁻¹ at 20, 30, and 50 A g⁻¹, respectively, compared with two control samples of pristine MoS₂ and MoS₂/NAC counterparts. Excellent long-term cyclability over 10 000 cycles with extremely low capacity decay is demonstrated at high current densities of 20 and 50 A g⁻¹. Sodium-ion full cells based on the rGO@MoS₂/NAC anode are also demonstrated, yielding decent cycling stability of 200 cycles at 5C. Our work provides a novel interlayer strategy to regulate electron/Na⁺ transport for fast-charging SIBs.

Developing efficient electrocatalysts with low-cost for the urea oxidation reaction (UOR) is a significant challenge in energy-saving H₂ production owing to its lower thermodynamic potential. Heteroatom incorporation strategy has been proven to boost electrocatalytic activity by altering electronic structures and revealing more active sites on catalysts. Herein, nickel hydroxide nanosheets with various vanadium incorporation (V_x-Ni(OH)₂) were developed through a facile hydrothermal approach. By optimizing the incorporated vanadium contents, V₆-Ni(OH)₂ catalyst exhibited easily accessible active sites and enhanced charge transfer with structural advantages, then assembled as the working electrode for urea-assisted H₂ production. Consequently, V₆-Ni(OH)₂ catalyst demonstrated superior UOR activity compared with other incorporated samples with an overpotential of 1.33 V and a Tafel slope of 28.3 mV dec⁻¹. Theoretical calculations revealed that the improved UOR activity was attributed to the potential determining step of V-Ni(OH)₂, which exhibited lower energy in comparison with the pristine Ni(OH)₂ and increased electronic states density near the Fermi level. Both experimental and theoretical calculations confirmed vanadium incorporation on Ni(OH)₂ could modify the electronic structure of Ni(III) species, improving electrical conductivity, and optimizing the adsorption energy for key reaction intermediates. Furthermore, the crucial contribution of vanadium incorporation with optimized electronic structures to the high UOR activity of Ni(OH)₂ is demonstrated.

Three-dimensional (3D) current collectors (CCs) have emerged as an effective strategy to inhibit dendrites and ensure the safety of lithium (Li) metal anodes. However, existing 3D CCs are generally too heavy (typically tens of mg cm⁻²) or too thick (tens to hundreds of micrometers), making large-scale production and further application challenging. Additionally, the use of single-component 3D CCs, whether electrically active or inert, only exhibits limited effects on stabilizing Li anodes. Here, we present a scalable screen-printing technique for the synthesis of ultralight (~0.4 mg cm⁻²) and ultrathin (~0.54 μm) SiO₂ grids on Cu foil to regulate both the vertical electric field and Li-ion concentration by forming an electrically active/inert dual-function architecture. This technology breaks the limitations of traditional 3D CCs in material/fabrication costs, weight, thickness and especially, scalability for large-scale fabrication. By using this dual-function architecture, our Cu@SiO₂-grid CCs (~8.31 mg cm⁻²), which are even lighter than the original Cu-foil CCs (~8.85 mg cm⁻²), realize an ultra-smooth anode surface without Li dendrites, and thus leads to an ultra-long cyclic life of over 1500 h at 1 mA cm⁻². The assembled Li metal batteries demonstrate excellent capacity retention of ~80% over 400 cycles at 1 C and ~ 76% over 250 cycles at 5 C, which highlight the promising 3D CCs for practical applications.

Global trends toward green energy have empowered the extensive application of high-performance energy storage systems. With the worldwide spread of electric vehicles (EVs), lithium-ion batteries (LIBs) capable of fast-charging have become increasingly important. Nonetheless, state-of-the-art LIBs have failed to satisfy the demands of prospective customers, including rapid charging, extended cycle life, and high energy density. Addressing these challenges through innovations in material science and other advanced battery technologies is essential for meeting the growing demands of prospective customers. Besides the choice of active materials, electrolyte formulation has a significant impact on the fast-charging performance and cycle life of LIBs over a wide range of temperatures. The liquid electrolyte is typically composed of lithium salts to provide an ion source, solvents to carry Li⁺ ions, and functional additives to build a stable solid electrolyte interphase (SEI). To enable the fast movement of Li⁺ ions, the liquid electrolytes should have low viscosity and high ionic conductivity. Meanwhile, SEI layers must be thin, uniform and ionically conductive. Furthermore, the low binding energy of the solvent facilitates desolvation of the solvation sheath, enabling fast Li⁺ ion transport to the anode during fast charging. This review provides the latest insights into rapid Li⁺ ion transport during fast charging, focusing on ensuring a deeper understanding of liquid electrolyte chemistry. The involvement of existing electrolyte mechanisms in materials discovery will develop electrolyte engineering techniques to improve the fast-charging performance of batteries over a wide temperature range and will also facilitate the development of EV-adoptable advanced electrodes.

The human body continuously generates ambient mechanical energy through diverse movements, such as walking and cycling, which can be harvested via various renewable energy harvesting mechanisms. Triboelectric Nanogenerator (TENG) stands out as one of the most promising emerging renewable energy harvesting technologies for wearable applications due to its ability to harness various forms of mechanical energies, including vibrations, pressure, and rotations, and convert them into electricity. However, their application is limited due to challenges in achieving performance, flexibility, low power consumption, and durability. Here, we present a robust and high-performance self-powered system integrated into cotton fabric by incorporating a textile-based triboelectric nanogenerator (T-TENG) based on 2D materials, addressing both energy harvesting and storage. The proposed system extracts significant ambient mechanical energy from human body movements and stores it in a textile supercapacitor (T-Supercap). The integration of 2D materials (graphene and MoS₂) in fabrication enhances the performance of T-TENG significantly, as demonstrated by a record-high open-circuit voltage of 1068 V and a power density of 14.64 W/m² under a force of 22 N. The developed T-TENG in this study effectively powers 200+ LEDs and a miniature watch while also charging the T-Supercap with 4-5 N force for efficient miniature electronics operation. Integrated as a step counter within a sock, the T-TENG serves as a self-powered step counter sensor. This work establishes a promising platform for wearable electronic textiles, contributing significantly to the advancement of sustainable and autonomous self-powered wearable technologies.

This illustration depicts the precise carbon coating of a cost-effective SiO₂ primary particle using different organic materials to create a highly electronic conductive material. This development enhances high-energy-density lithium-ion battery systems, making them ideal for electric vehicle applications by improving performance, and affordability.

In the rapidly advancing field of information technology, passive sensors with the exemption of external power input can serve as intelligent instruments for end-node data acquisition. 3D perovskites have been recognized as a superior optoelectronic material but suffering from notorious instability due to their “soft lattice” nature. Replacing by their 2D counterparts in these photo-sensing applications can boost the reliability level. However, traditional fabrication for 2D perovskite relay on wet chemistry methods, exhibiting complication, and inefficiency in making high-quality films for device integration. This study unveils a new solid–solid conversion routing toward a direct transformation from 3D orientated films into 2D highly crystalline configuration, based on a spontaneous lattice regulation mechanism through an amine steam treatment. The resultant 2D film exhibits greater orientational micromorphology and a distinct monochromatic narrowband light sensing behavior after integration into a self-powered photodetector. This method on perovskite conversion bears the promise of advanced future-manufacturing for high-performance photonic sensing.

The cover image of the publication eom2.12453 showed how lignin, a bio-polymer material, significantly enhances the sensitivity of MXene composite as a 2D materials chemiresistive sensor for molecular gas detection. This study also demonstrated a hybridized MXene composite flexible chemiresistive sensor, which paves the way for new solid-state sensing platforms for curvature structures.