EcoMat最新文献

Lithium-ion composite solid electrolyte membranes embedded with Li_1.3Al_0.3Ti_1.7P₃O₁₂ and poly(vinylidene fluoride) are prepared using a facile casting method. Furthermore, we added LiI as an active agent for decomposing the anode product. The synergy resulted in a high conductivity of 7.4 mS·cm⁻¹ and lithium-ion mobility of 0.59 and a reduction of the overpotential to 0.86 V for lithium–oxygen batteries (LOBs). The membrane has enhanced Young's modulus of 6.6 GPa that effectively blocked the lithium dendrite growth during the battery operation and puncturing to the membrane led to a significant LOB cycle life of 542 cycles. Meanwhile, Li|Li symmetrical battery overpotential maintained at 42 mV after 470 h of operation.

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.

Metal–organic frameworks (MOFs) are a class of promising nanomaterials for atmospheric water harvesting (AWH), especially in arid remote areas. However, several challenges are still faced for practical applications because of the dissatisfied water adsorption/desorption properties in terms of the capability, kinetics, and stability. Herein, we report the facile synthesis of a nano-sized octahedral nitrogen-modified MOF-801 that exhibits superior solar-powered AWH performance using a custom-made device, with a state-of-the-art water harvesting ability up to $��4.64��L_{�H_2�O�}��{{\mathrm{kg}}_{\text{MOFs}}}^{�-�1�}�$ from air upon 12-h test under a relative humidity (RH) of 30% and simulated sunlight irradiation. The nitrogen-modified MOF-801 with rapid sorption–desorption kinetics, uptakes $��0.29��g_{�H_2�O�}��{g_{\text{MOFs}}}^{�-�1�}�$ of water at 30% RH within 30 min and releases 90% of the captured water within 10 min under 1-sun illumination. The success relies on N-doping-induced mixed-linkers in the form of 2,3-diaminobutanedioic acid and fumaric acid in the unique pore structures of the MOFs for rapid and high-capacity water capture. The N-doped MOF-801 with water uptake capacity, fast adsorption kinetics, and cycle stability sheds light on the practical use of MOFs for effective solar-powered water harvesting from droughty air.

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.