Batteries powering next‐generation flexible and wearable electronic devices require superior mechanical bendability and foldability. Herein, a self‐standing hybrid nanoarchitecture constructed by ...ultralong MnO2 nanowires and graphene nanosheets as an advanced and lightweight cathodes for flexible and foldable zinc‐ion batteries (ZIBs) is designed and fabricated. The new‐designed batteries exhibit not only a high energy density of 436 Wh kg−1 based on the total cathode mass but also good 2000‐cycling durability. More importantly, the shape‐deformable ZIBs can be operated without any capacity loss under both bent and folded circumstances. The foldable ZIBs with high energy density and long lifetime hold great promise for smart and wearable electronics.
A freestanding MnO2/graphene hybrid membrane is fabricated to construct highly flexible and foldable zinc‐ion batteries that delivers an unprecedented high energy density of 436 Wh kg−1 based on the total cathode mass and long lifetime over 2000 cycles.
Rechargeable zinc-ion batteries based on Zn/MnO2 in neutral aqueous electrolytes are promising for grid-scale energy storage applications owing to their favorable merits of high safety, low cost and ...environmental benignity. However, MnO2 cathodes are subjected to the challenging issues of poor cyclability and low rate capability. Herein, we report a facile chemical method for the preparation of mesoporous MnO2 flower-like nanospheres with the layered framework stabilized by hydrated Zn2+ pillars. The MnO2 cathode could deliver a reversible specific capacity of 358 mA h g−1 at 0.3 A g−1 after 100 cycles, a high rate capacity of 124 mA h g−1 at 3.0 A g−1, and excellent operating stability over 2000 cycles. Structural and morphological investigations demonstrate an energy storage mechanism of co-insertion/extraction of H+ and Zn2+ accompanied by deposition/dissolution of zinc sulfate hydroxide hydrate flakes on the electrode surface. The superior electrochemical performance makes the zinc ion stabilized MnO2 promising for high capacity and long lifespan zinc-ion batteries.
Supercapacitors have emerged as one of the most attractive electrochemical storage systems with unique characteristics featuring high power delivery and long-term cycling stability. Manganese oxides ...(MnO2) have particularly received increasing attention owing to their high specific capacitance, low cost, natural abundance, and environmental benignity. Nanoscale MnO2 structures should incorporate highly porous and electrically conductive materials to form hybrid or composite nanostructures in order to maximize their capabilities and electrochemical performance. The rapid development of MnO2-based nanocomposites for high-performance supercapacitors in recent years has been reviewed in terms of the charge storage mechanism, materials science, and smart cell assembly. This review article aims to summarize the latest progress in MnO2-based nanocomposite electrodes to provide guidance for the design, manufacturing, and assembly of high-performance supercapacitors. The review starts with the discussion of charge storage mechanisms of MnO2-based materials. Subsequent emphasis is placed on the significant progress of MnO2-based heterogeneous nanocomposites, followed by the development of asymmetric supercapacitors assembled with the MnO2-based nanocomposites. Finally, perspectives and challenging issues regarding the rational design and synthesis of MnO2-based nanocomposites for high-performance supercapacitors are discussed.
Hierarchically porous carbon nanomaterials with well‐defined architecture can afford a promising platform for effectively addressing energy and environmental concerns. Herein, a totally green and ...straightforward synthesis strategy for the fabrication of hierarchically porous carbon nanotubes (HPCNTs) by a simple carbonization treatment without any assistance of soft/hard templates and activation procedures is demonstrated. A high specific surface area of 1419 m2 g−1 and hierarchical micro‐/meso‐/macroporosity can be achieved for the HPCNTs. The unique porous architecture enables the HPCNTs serving as excellent electrode/host materials for high‐performance supercapacitors and Li–sulfur batteries. The design strategy may pave a new avenue for the rational synthesis of hierarchically porous carbon nanostructures for high‐efficient energy storage applications.
A green synthesis strategy is demonstrated herein for the preparation of high‐surface‐area and nitrogen‐enriched hierarchically porous carbon nanotubes without hard/soft templating assistance and activation procedures. The carbon nanostructures provide excellent energy storage platform for high‐performance supercapacitors and Li–S batteries.
Rechargeable aqueous Zn metal batteries hold exciting promise for next-generation grid-scale energy storage owing to their virtues of low cost, high safety, and eco-benignity. However, the ...detrimental corrosion and dendrite issues of metallic Zn anodes severely slow down the commercialization pace. Herein, we propose a universal and versatile metal–organic complex interphase strategy for navigating fast and uniform Zn deposition toward long-life Zn metal batteries. The in situ complexing of metal-phytic acid interphases could construct a zincophilic interface that kinetically homogenizes the nucleation and growth of Zn. Additionally, the functional interlayer could serve as robust armor to safeguard the Zn anode from corrosion. An ultrastable Zn anode is obtained with substantially improved Coulombic efficiency of 99.9% over 800 cycles and an extended cycling lifetime of a superhigh cumulative plated capacity of 4.25 Ah cm −2 . Practical feasibilities based on the modified Zn anodes are demonstrated in Zn//MnO 2 full cells. This work paves a fresh pathway for rational design of metal–organic complex interphases toward high-performance aqueous Zn metal batteries and beyond.
Formamidinium–lead triiodide (FAPbI3) perovskite is considered as one of the most promising perovskite materials for high‐performance photodetectors because of its narrow bandgap and superior thermal ...stability. Nevertheless, to realize efficient carrier transport and highly performing photodetectors, it imposes the requirement of fabricating α‐FAPbI3 with pure phase, preferred crystal orientation, large grain size, and passivated interface, which still remains challenging. Here, a facile strategy based on additive engineering to obtain pure‐phase FAPbI3 perovskite films by introducing N‐(2‐aminoethyl) acetamide into perovskite precursors is reported. The formation of chemical bond and hydrogen bond between N‐(2‐aminoethyl) acetamide and perovskite reduces the potential barrier in the phase‐transition process from an intermediate yellow phase to a final black phase, passivates the defects of the film, and leads to a high‐quality and phase‐pure α‐FAPbI3 perovskite. A self‐powered photodetector based on the as‐fabricated FAPbI3 film exhibits a maximum responsivity of 0.48 A W−1 at 700 nm with a peak external quantum efficiency of 95% at 440 nm. Moreover, the optimized device remains 83% of the initial performance after 576 h storage at ambient condition. This work provides a simple and feasible scheme for the preparation of high‐quality phase‐pure α‐FAPbI3 perovskite and associated devices.
A facile strategy to obtain phase‐pure α‐FAPbI3 perovskite films by introducing N‐(2‐aminoethyl) acetamide into perovskite precursors is reported. The additive reduces the potential barrier in the phase transition process, passivates the defects of the film, and leads to a high‐quality and phase‐pure α‐FAPbI3 perovskite. The resultant self‐powered photodetector based on the as‐fabricated FAPbI3 film exhibits superior performance.
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Rechargeable aqueous zinc-ion batteries (ZIBs) are considered to be one of the most promising energy storage devices for grid-scale applications due to their high safety, ...eco-friendliness, and low cost. In recent years, enormous efforts have been devoted to developing a great number of high-efficient cathodes, anodes, and electrolytes for improving the electrochemical properties of aqueous ZIBs. However, the as-documented ZIBs and their associated energy storage mechanisms are still in infancy and need to be further investigated for real practice. To expedite the development of ZIBs, this review will offer a comprehensive summary and a detailed discussion of the significant progress and breakthroughs. A brief overview of the battery configuration and various energy storage mechanisms are first introduced. The following emphasis will be mainly dedicated to discussing different design strategies regarding cathodes, anodes, and electrolytes, aiming to provide insightful design principles for future research activities from a fundamental perspective. Finally, the current challenges of developing high-performance ZIBs and their opportunities for practical viability are discussed.
A central player in brain computationA small subgroup of nerve cells plays a central role in information processing in the brain. Hu et al. review our present knowledge about the specific makeup of ...these neurons. Specifically, the individual properties of the molecules, their distribution within the cell, and the anatomy of the cells themselves are described. This information helps to explain why these neurons are so important for the function of microcircuits in the brain, as well as the behavior of the organism. This detailed level of understanding will become relevant as these cells become future targets for the treatment of neurological diseases.Science, this issue p. 10.1126/science.1255263
The present-day lithium ion batteries represent a brilliant electrochemical energy storage technology that has established a dominant niche in portable electronics, yet loses the potentiality in ...applications that demand increasing energy density such as electric vehicles. Lithium–sulfur (Li–S) batteries are considered as an alternative candidate owing to its ultrahigh energy density, low cost, natural abundance, and eco-friendliness. However, the paramount challenges to become a viable technology include inferior utilization of active materials, short cycle life, and low Coulombic efficiency, which are closely associated with the structural designs of sulfur cathodes. Significant progresses and breakthroughs have been made in the most recent years towards the successful modification of the sulfur cathodes for high-performance Li–S batteries. Among them, nanostructured carbons have been demonstrated to be particularly effective to address the critical hurdles mentioned above. To promote the advancement of this exciting field, this article herein will discuss the progresses of the sulfur cathodes with an emphasis on the advanced engineering of nanostructured carbons to improve specific capacity and Coulombic efficiency, high-rate capability, and cycling retention. The review article primarily covers “inside” and “outside” design strategies on cathodes by developing carbon–sulfur composites and novel cell configurations, respectively. Discussion will be detailed to correlate synthesis principles and characteristics of nanostructured carbons with electrochemical performance.
The advanced engineering of carbon nanostructures for lithium–sulfur technology has been reviewed in terms of inside and outside modifications of sulfur cathodes. Display omitted
•The recent progress of advanced engineering carbon nanostructures for Li–S batteries has been reviewed.•Nanocarbons are summarized in terms of nanocomposite and cell configuration for inside and outside modifications of sulfur cathodes.•The correlation between physicochemical characteristics of nanocarbon and cell performance is present.•Perspectives on optimization of carbon nanostructures and prospect of Li–S technology are proposed.
Water electrolysis has been considered as a sustainable way for producing renewable energy of hydrogen. However, this process requires a low-cost and high-efficient hydrogen evolution reaction (HER) ...catalyst to improve the overall reaction efficiency. Molybdenum (Mo)-based electrocatalysts are regarded as the promising candidates to replace the benchmark but expensive Pt-based HER catalysts, due to their high activity and stability in a wide pH range. In this review, we present a comprehensive and critical summary on the recent progress in the Mo-based electrodes for HER, including molybdenum alloys, molybdenum sulfides, molybdenum selenides, molybdenum carbides, molybdenum phosphides, molybdenum borides, molybdenum nitrides, and molybdenum oxides. Particular attention is mainly focused on the synthetic methods of Mo-based materials, the strategies for increasing the catalytic activity, and the relationship between structure/composition and electrocatalytic performance. Finally, the future development and perspectives of Mo-based electrocatalysts toward high HER performance are proposed.
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