Zinc Anode for Mild Aqueous Zinc-Ion Batteries: Challenges, Strategies, and Perspectives

The rapid advance of mild aqueous zinc-ion batteries(ZIBs)is driving the development of the energy storage system market.But the thorny issues of Zn anodes,mainly including dendrite growth,hydrogen evolution,and corrosion,severely reduce the performance of ZIBs.To commercialize ZIBs,researchers must overcome formidable challenges.Research about mild aqueous ZIBs is still developing.Various technical and scientific obstacles to designing Zn anodes with high stripping efficiency and long cycling life have not been resolved.Moreover,the performance of Zn anodes is a complex scientific issue determined by various parameters,most of which are often ignored,failing to achieve the maximum performance of the cell.This review proposes a comprehensive overview of existing Zn anode issues and the corresponding strategies,frontiers,and development trends to deeply comprehend the essence and inner connection of degradation mechanism and performance.First,the formation mechanism of dendrite growth,hydrogen evolution,corrosion,and their influence on the anode are analyzed.Furthermore,various strategies for constructing stable Zn anodes are summarized and discussed in detail from multiple perspectives.These strategies are mainly divided into interface modification,structural anode,alloying anode,intercalation anode,liquid electrolyte,non-liquid electrolyte,separator design,and other strategies.Finally,research directions and prospects are put forward for Zn anodes.This contribution highlights the latest developments and provides new insights into the advanced Zn anode for future research.

CNT@MnO_(2) composite ink toward a flexible 3D printed micro-zinc-ion battery

Flexible energy storage devices have played a significant role in multiscenario applications,while flexible zinc-ion batteries(ZIBs),as an essential branch,have developed rapidly in recent years.Three-dimensional(3D)printing is an extremely advanced technology to design and modify the structure of batteries and provides unlimited possibilities for the diversified development of energy storage equipment.Herein,by utilizing 3D printing technology,carbon nanotube(CNT)is coated by MnO_(2) to form a flexible CNT@MnO_(2) ink as a cathode for flexible aqueous micro-ZIBs for the first time and zinc powder ink is used as an anode due to its high flexibility and bendability.The Zn//CNT@MnO_(2) flexible battery shows a stable capacity of 63μAh cm^(−2) at 0.4mA cm^(−2).When the battery is bent in different states,the maximum capacity loss compared with the initial value is only 2.72%,indicating its stability.This study shows the potential of 3D printing technology in the development of flexible manganese-based ZIBs.

Cuprous Chloride Nanocubes Grown on Copper Foil for Pseudocapacitor Electrodes

In this paper, for the first time, we report the synthesis of nanoscale cuprous chloride(Cu Cl) cubic structure by a facile hydrothermal route. A possible mechanism for the growth of those nanostructures is proposed based on the experimental results. It is discovered that the existence of HCl could affect the surface of Cu Cl nanocubes. This unique cube-like nanostructure with rough surface significantly enhances the electroactive surface areas of Cu Cl, leading to a high special capacitance of 376 m F cm-2at the current density of 1.0 m A cm-2. There is still a good reversibility with cycling efficiency of 88.8 % after 2,000 cycles, demonstrating its excellent long-term cycling stability and might be the promising candidates as the excellent electrode material.

Hierarchical Semiconductor Oxide Photocatalyst:A Case of the SnO_2 Microflower

Hierarchically assembled SnO_2 microflowers were synthesized by a facile hydrothermal process.Field emission scanning electron microscope results showed these hierarchical nanostructures were built from two dimensional nanosheets with the thicknesses of about 50 nm. Photoluminescence spectrum of the asobtained products demonstrated a strong visual emission peak at 564 nm. The photochemical measurement results indicated that the as-prepared sample exhibits excellent photocatalytic performance. These three dimensional SnO_2 hierarchical nanostructures may have potential applications in waste water purification.

Emerging rechargeable aqueous magnesium ion battery

Recently,aqueous rechargeable batteries have played an essential role in developing renewable energy due to the merits of low cost,high security,and high energy density.Among various aqueous-based batteries,aqueous magnesium ion batteries(AMIBs)have rich reserves and high theoretical specific capacity(3833 mAh cm3).However,for future industrialization,AMIBs still face many scientific issues to be solved,such as the slow diffusion of magnesium ions in the material structure,the desolvation penalty at electrode-electrolyte interfaces,the cost of water-in-salt electrolyte,the low voltage of traditional aqueous electrolyte,etc.And yet a comprehensive summary of the components of AMIBs is lacking in the research community.This review mainly introduces the exploration and development of AMIB systems and related components.We conduct an in-depth study of the cathode materials appropriate for magnesium ion batteries from their crystal structures,focusing primarily on layered structures,spinel structures,tunnel structures,and three-dimensional framework structures.We also investigate the anode materials,ranging from inorganic materials to organic materials,as well as the electrolyte materials(from the traditional electrolyte to water-in-salt electrolyte).Finally,some perspectives on ensuing optimization design for future research efforts in the AMIBs field are summarized.

Synthesis and application of green solvent dispersed organic semiconducting nanoparticles

Organic photovoltaic semiconductors have made significant progress and have promising application prospects after decades of development.When compared with traditional semiconductors,the solution method for preparing photovoltaic semiconductors shows the advantages of low cost and convenient preparation.However,because of the extremely poor solubility of the polymers used to prepare semiconductors,toxic solvents must be used when using the solution method,which has significant negative effects on the environment and operators and severely limits its development prospects.Organic nanoparticles(NPs),on the other hand,can avoid these issues.Because NPs are typically water or alcohol-based,no toxic solvents are used.Furthermore,NPs have been used in organic solar cells,hydrogen catalysis,organic light-emitting diodes,and other fields after nearly two decades of development,and their preparation methods have been developed.We describe the preparation,optimization,and application of NPs in photovoltaic semiconductors in this review.

Development and application of blade-coating technique in organic solar cells

Due to the characteristics of lower material waste,higher crystallinity,roll-to-roll compatibility,and high-throughput continuous processing,blade-coating has been widely applied in the preparation of large-area organic solar cells.In this paper,the technique of blade-coating is introduced,including the effects of blading speed,substrate temperature,and other technological innovations during the process of blade-coating.Besides,the recent progress of blade-coating in organic solar cells is summarized and the active layer prepared by a blade-coating method is introduced in detail,including materials,processing methods,solvents,and additives.The interface layer and electrodes prepared by the blade-coating method are also discussed.Finally,some perspectives on the blade-coating method are proposed.In the foreseeable future,blade-coating will become the core of batch production of large-area organic solar cells,so as to make organic solar cells more competitive.