Potassium-ion batteries are a promising alternative to lithium-ion batteries. However, it is challenging to achieve fast charging/discharging and long cycle life with the current electrode materials ...because of the sluggish potassiation kinetics. Here we report a soft carbon anode, namely highly nitrogen-doped carbon nanofibers, with superior rate capability and cyclability. The anode delivers reversible capacities of 248 mAh g
at 25 mA g
and 101 mAh g
at 20 A g
, and retains 146 mAh g
at 2 A g
after 4000 cycles. Surface-dominated K-storage is verified by quantitative kinetics analysis and theoretical investigation. A full cell coupling the anode and Prussian blue cathode delivers a reversible capacity of 195 mAh g
at 0.2 A g
. Considering the cost-effectiveness and material sustainability, our work may shed some light on searching for K-storage materials with high performance.
When external pressure drives an electrolyte solution in a capillary tube with a charged inner surface, we obtain a streaming potential/current. This effect is also manifested when water flows ...through the microchannels of a tree, which is driven by capillary pressure and natural evaporation. Thus, by making use of natural evaporation, we took advantage of the anisotropic three-dimensional wood structures to fabricate nanogenerators drawing electricity from the streaming potential/current. As a result, direct current can be harvested continuously, simply through a piece of wood. A 300 mV open-circuit voltage and a 10 μA short-circuit current (I SC) were recorded from a single device, which surpassed the I SC values of most previous works by an order. By connecting five wood nanogenerators in series, a calculator can be completely functional, as a demonstration for practical application.
Potassium‐ion batteries (KIBs) in organic electrolytes hold great promise as an electrochemical energy storage technology owing to the abundance of potassium, close redox potential to lithium, and ...similar electrochemistry with lithium system. Although carbon materials have been studied as KIB anodes, investigations on KIB cathodes have been scarcely reported. A comprehensive study on potassium Prussian blue K0.220FeFe(CN)60.805⋅4.01H2O nanoparticles as a potential cathode material is for the first time reported. The cathode exhibits a high discharge voltage of 3.1–3.4 V, a high reversible capacity of 73.2 mAh g−1, and great cyclability at both low and high rates with a very small capacity decay rate of ≈0.09% per cycle. Electrochemical reaction mechanism analysis identifies the carbon‐coordinated FeIII/FeII couple as redox‐active site and proves structural stability of the cathode during charge/discharge. Furthermore, for the first time, a KIB full‐cell is presented by coupling the nanoparticles with commercial carbon materials. The full‐cell delivers a capacity of 68.5 mAh g−1 at 100 mA g−1 and retains 93.4% of the capacity after 50 cycles. Considering the low cost and material sustainability as well as the great electrochemical performances, this work may pave the way toward more studies on KIB cathodes and trigger future attention on rechargeable KIBs.
Potassium Prussian blue nanoparticles are reported as a potential cathode material for potassium‐ion batteries. The cathode exhibits high reversible capacity, excellent cyclability, and great rate capability. Electrochemical mechanism analysis reveals the active‐redox site and proves the structural stability during charge/discharge. Pairing with commercially available carbon materials, a potassium‐ion battery full cell is demonstrated for the first time.
The next‐generation smart grid for the storage and delivery of renewable energy urgently needs to develop a low‐cost and rechargeable energy storage technology beyond lithium‐ion batteries (LIBs). ...Owing to the abundance of potassium (K) resources and the similar electrochemical performance to that of LIBs, potassium‐ion batteries (PIBs) have been attracted considerable interest in recent years, and significant progress has been achieved concerning the discovery of high‐performance electrode materials for PIBs. This review especially summarizes the latest research progress regarding anode materials for PIBs, including carbon materials, organic materials, alloys, metal‐based compounds, and other new types of compounds. The reversible K‐ion storage principle and the electrochemical performance (i.e., capacity, potential, rate capability, and cyclability) of these developed anode materials are summarized. Furthermore, the challenges and the corresponding effective strategies to enhance the battery performance of the anode materials are highlighted. Finally, prospects of the future development of high‐performance anode materials for PIBs are discussed.
This review mainly summarizes the latest achievements on the anode materials of potassium‐ion batteries, including carbon materials, metal‐based chalcogenides and oxides, alloying materials, and organic materials. The effective strategies to enhance electrochemical performance are also highlighted.
Accurate identification of potential interactions between drugs and protein targets is a critical step to accelerate drug discovery. Despite many relative experimental researches have been done in ...the past decades, detecting drug-target interactions (DTIs) remains to be extremely resource-intensive and time-consuming. Therefore, many computational approaches have been developed for predicting drug-target associations on a large scale.
In this paper, we proposed an deep learning-based method to predict DTIs only using the information of drug structures and protein sequences. The final results showed that our method can achieve good performance with the accuracies up to 92.0%, 90.0%, 92.0% and 90.7% for the target families of enzymes, ion channels, GPCRs and nuclear receptors of our created dataset, respectively. Another dataset derived from DrugBank was used to further assess the generalization of the model, which yielded an accuracy of 0.9015 and an AUC value of 0.9557.
It was elucidated that our model shows improved performance in comparison with other state-of-the-art computational methods on the common benchmark datasets. Experimental results demonstrated that our model successfully extracted more nuanced yet useful features, and therefore can be used as a practical tool to discover new drugs.
http://deeplearner.ahu.edu.cn/web/CnnDTI.htm.
•The spreading and solidification of supercooled gallium droplets during impact was investigated.•The impact process of supercooled gallium droplet and the solidified patterns were ...observed.•Influence of the dimensionless parameters, substrate materials, and substrate temperatures was analyzed.•The guidelines for predicting the size of gallium droplet after impact and ensuring its solidification were summarized.
The spreading and solidification of supercooled gallium droplets during impact affects the application of gallium-based liquid metals during 3D printing and spray coating. In this study, the impact process of supercooled gallium droplets was observed, and the influence of the dimensionless parameters, substrate materials, and substrate temperatures on the spreading and solidification of supercooled gallium droplets was analyzed. It was observed that the supercooled gallium droplets retracted slightly during the impact process and were likely to undergo solidification due to impact. The maximum spreading factor of the supercooled gallium droplet during impact was proportional to We1/2 (square root of the Weber number). The substrate material and substrate temperature less affected the maximum spreading factor, whereas they have a significant effect in determining whether the droplets solidify. The guidelines controlling the maximum spreading factor and the solidification of supercooled gallium droplets have been outlined in this study.
•l-Aspartate family amino acids (AFAAs) are important in human and animal diet.•Five-word strain breeding strategy “enter, flow, moderate, block, exit” are proposed.•Genetic modifications in central ...metabolic pathways for AFAAs production.•Metabolic pathways of AFAAs and derivatives and regulations involved.•Metabolic engineering in AFAAs metabolic pathways based on different strategies.
The l-aspartate amino acids (AFAAs) are constituted of l-aspartate, l-lysine, l-methionine, l-threonine and l-isoleucine. Except for l-aspartate, AFAAs are essential amino acids that cannot be synthesized by humans and most farm animals, and thus possess wide applications in food, animal feed, pharmaceutical and cosmetics industries. To date, a number of amino acids, including AFAAs have been industrially produced by microbial fermentation. However, the overall metabolic and regulatory mechanisms of the synthesis of AFAAs and the recent progress on strain construction have rarely been reviewed. Aiming to promote the establishment of strains of Corynebacterium glutamicum and Escherichia coli, the two industrial amino acids producing bacteria, that are capable of producing high titers of AFAAs and derivatives, this paper systematically summarizes the current progress on metabolic engineering manipulations in both central metabolic pathways and AFAA synthesis pathways based on the category of the five-word strain breeding strategies: enter, flow, moderate, block and exit.
•This work reduced the supercooling of gallium by adding nucleating agents.•TeO2, CaO, MgO, iron, and copper particles were selected as nucleating agents and compared.•The nucleating agent that has ...similar lattice content with α-Ga and relatively good wettability with gallium shows better performance in reducing the supercooling of gallium.•The influence of thermal history and the size of nucleating agent on the supercooling of gallium were investigated. The proportion of nucleating agents in the mixture was optimized.
Gallium, a typical room temperature liquid metal, has high thermal conductivity and large volume fusion enthalpy. These characteristics make it a promising phase change material (PCM). However, the significant supercooling of gallium has obstructed its wide application. Adding nucleating agents is a commonly adopted method to reduce supercooling, while the study of nucleating agents for liquid metal is rarely reported so far. In this paper, the influences of the thermal history and the particle size of nucleating agents on the supercooling of gallium were systematically investigated. After that, several particles, such as TeO2, CaO, MgO, iron, and copper were selected as nucleating agents for experiments. The lattice constant was found as one of the most important parameters when selecting nucleating agents. In addition, a more favorable wettability of the nucleating agents with gallium also contributed to the restraint of supercooling. The experimental result showed that the addition of TeO2, whose lattice constant appears as the most similar to that of α-Ga, had the best effect for reducing the supercooling of gallium. The largest reduction of supercooling occurred when 0.5 wt.% TeO2 was added, and more additions resulted in particle agglomeration and a lower nucleation effect. This paper provides important routes for the selection of nucleating agents for gallium, which will benefit for future applications of liquid metal in building heat storage, thermal comfort maintenance and thermal management.
Bismuth (Bi) has been considered as a promising alloying-type anode for potassium-ion batteries (PIBs), owing to its high theoretical capacity and suitable working voltage plateaus. However, Bi ...suffers from dramatic volume fluctuation and significant pulverization during the discharge/charge processes, resulting in fast capacity decay. Herein, we synthesize Bi nanoparticles confined in carbonaceous nanospheres (denoted as Bi@C) for PIBs by first utilizing BiOCl nanoflakes as a hard template and a Bi precursor. The construction of the loose structure buffers the mechanical stresses resulting from the volume expansion of Bi during the alloying reaction and avoids the fracture of the electrode structure, thus improving the cycling performance. Moreover, the carbonaceous layers increase the electronic conductivity and disperse the Bi nanoparticles, enhancing the charge transportation and ionic diffusion, which further promotes the rate capability of Bi@C. It exhibits a superior capacity (389 mAh g–1 at 100 mA g–1 after 100 cycles), excellent cycling stability (206 mAh g–1 at 500 mA g–1 over 1000 cycles), and an improved rate capability (182 mAh g–1 at 2.0 A g–1). This work provides a new structuring strategy in alloying materials for boosting reversible and stable potassium-ion storage.
Many organisms produce stunning optical displays based on structural color instead of pigmentation. This structural or photonic color is achieved through the interaction of light with intricate ...micro-/nano-structures, which are "grown" from strong, sustainable biological materials such as chitin, keratin, and cellulose. In contrast, current synthetic structural colored materials are usually brittle, inert, and produced via energy-intensive processes, posing significant challenges to their practical uses. Inspired by the brilliantly colored peacock feathers which selectively grow keratin-based photonic structures with different photonic bandgaps, we develop a self-growing photonic composite system in which the photonic bandgaps and hence the coloration can be easily tuned. This is achieved via the selective growth of the polymer matrix with polymerizable compounds as feeding materials in a silica nanosphere-polymer composite system, thus effectively modulating the photonic bandgaps without compromising nanostructural order. Such strategy not only allows the material system to continuously vary its colors and patterns in an on-demand manner, but also endows it with many appealing properties, including flexibility, toughness, self-healing ability, and reshaping capability. As this innovative self-growing method is simple, inexpensive, versatile, and scalable, we foresee its significant potential in meeting many emerging requirements for various applications of structural color materials.
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