Search

Increasing the electrochemical stability window and working temperature range of supercapacitor aqueous electrolyte is the major task in order to advance aqueous electrolyte-based supercapacitors. Here, a supramolecular induced new electrolyte of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) in dimethyl sulfoxide (DMSO) and water co-solvent system is proposed. Adjusting the coordination structure among LiTFSI, DMSO, and water in the electrolyte via supramolecular interactions results in its high ionic conductivity, low viscosity, wide electrochemical stability window, and large working temperature range. The new electrolyte-based supercapacitors can work in 2.40 V working potential and 130 °C working-temperature range from −40 to 90 °C. The devices exhibit good electrochemical performances, especially the energy density over 21 Wh kg−1, which is much higher than that with traditional aqueous electrolytes (

An efficient exfoliation strategy is developed to exfoliate spent electrode materials with robust interlayer interactions into atomically thin nanosheets for high performance in OER electrocatalysis.

Understanding the electrokinetic conversion efficiency in a nanochannel is vital for designing energy storage and conversion devices. In this paper, an analytical electrokinetic energy conversion efficiency in a nanochannel is obtained based on the linear electrokinetic response. The analytical result shows that the conversion efficiency has a maximum with the increasing of the nanochannel pore radius. Numerical solutions based on the Poisson-Nernst-Planck (PNP) and Navier-Stokes (NS) equations are used to confirm the analytical expressions. Besides, the influences of the pore radius and surface roughness on the conversion efficiency in nanochannels are also studied by the numerical calculations. In particular, the influences of the surface roughness on the fluid flow, streaming current and streaming potential are examined. The results show that the large bumps and grooves representing the roughness can hinder the fluid flows and ion transports in the nanochannels. The maximum efficiency in a smooth nanochannel is higher than that in a rough channel. However, the small bumps and grooves can increase the surface area of the channel, which is beneficial to improving the conversion efficiency in some cases. This research can provide theoretical guidance to design electrokinetic energy conversion devices.

Strongly hydrogen-bonded compounds such as 1,3,5-triamino-2,4,6‑trinitrobenzene (TATB, an important insensitive high explosive) have excellent stability, but poor solubilities to limit their recrystallization, purification and recycling. In this study, core-shell clusters based on symmetrical tetra-n-alkylammonium [TTA]

Lithium-ion battery packs are made by many batteries, and the difficulty in heat transfer can cause many safety issues. It is important to evaluate thermal performance of a battery pack in designing process. Here, a multiscale method combining a pseudo-two-dimensional model of individual battery and three-dimensional computational fluid dynamics is employed to describe heat generation and transfer in a battery pack. The effect of battery arrangement on the thermal performance of battery packs is investigated. We discuss the air-cooling effect of the pack with four battery arrangements which include one square arrangement, one stagger arrangement and two trapezoid arrangements. In addition, the air-cooling strategy is studied by observing temperature distribution of the battery pack. It is found that the square arrangement is the structure with the best air-cooling effect, and the cooling effect is best when the cold air inlet is at the top of the battery pack. We hope that this work can provide theoretical guidance for thermal management of lithium-ion battery packs.

MoS2 coating is an effective way to suppress the growth of lithium dendrites, but the study of the layer spacing effect is still lacking. In this work, the diffusion and adsorption of lithium ions on the MoS2 were studied by multiscale simulations. The transport of lithium ions on the MoS2 was investigated by a continuum method, which shows that the smaller layer spacing of 1 nm can enhance the ion diffusion. The QDFT method was used to study the lithium ions transport on 1T- and 2H- MoS2 with layer spacing of 0.65 nm - 1.15 nm. Results indicate that lithium dendrites are more difficult to grow on 2H- MoS2. For both types of MoS2, enlarged layer spacing can reduce lithium dendrites growth and 0.75 nm is the most suitable interlayer distance for MoS2 expanding. We hope our results can provide guidance to the synthesis of dendrite-free lithium metal batteries.

In building engineering, building waterproofing technology is a comprehensive and highly applied engineering science and technology. It is an important part of construction technology. It is important to improve the function of building use and production, quality of life and improve the living environment. Waterproof engineering is a systematic project, which involves the waterproof material, waterproof engineering design, construction technology, the management of the building and other aspects. The task of building waterproofing project is to synthesize all the above factors, to carry out all-round evaluation, select the high-performance waterproof material to meet the requirements, and carry out reliable, durable, reasonable and economical waterproof function engineering design, careful organization, careful construction, maintenance management system to meet the buildings and structures of the waterproof durability, to achieve high quality waterproofi ng and good comprehensive benefi ts. At the same time, waterproof engineering is a demanding professional technology, so the construction of specialization is to ensure that the quality of roof waterproofi ng works the key, if construction operation is not serious, the technology is not enough, and the consequences will inevitably lead to failure of waterproofing works. Quality of waterproofing works the overall quality requirements of building waterproofi ng works are: impermeable to leakage, to ensure smooth drainage, so that the building has a good waterproof and use function. The quality of building waterproofi ng works is superior to waterproofi ng material, waterproof design, waterproof construction and maintenance management.