【作者】 李明；

【导师】 韩春华；

【作者基本信息】 武汉理工大学 ， 材料科学与工程， 2019， 硕士

【摘要】 随着环境恶化,社会发展,以及可穿戴电子设备的涌现,设计具有高能量/功率密度,长久耐用性,低成本和良好安全性的柔性可穿戴能量存储装置受到越来越多的关注。尽管在过去的几十年中,研究者们在研究柔性碱金属离子电池（Li⁺,Na⁺,K⁺）方面做出了相当大的努力。然而,相对较高的生产成本以及有机电解液所带来的一系列问题,限制了它们进一步发展和应用。因此,为了更好的发展柔性储能器件,在保证电化学性能的前提下提升其在使用过程中的安全性和电化学性能,降低生产成本是广大研究者的目标。得益于价格低廉,安全性高,环境友好等优势,水系储能体系逐渐成为研究热点。另外,水系电解质往往具有更快速的离子传输速度,这也导致其展现出更好的倍率性能。在水系储能体系中,水系锌基电池由于其独特的高输出电压优势,825 mAh g^-1的高理论容量,被认为是解决碱金属离子电池和超级电容器之间储能困境的有力候选者。但是,两个关键问题严重阻碍了它们的发展。一个是锌枝晶的形成和生长,这大大缩短了锌基电池的循环寿命。另一个是直接使用锌片作为负极,降低了能量密度并限制了它们在柔性储能装置中的应用。本课题通过精心设计纳米结构的策略,从正负极两个角度同时入手,在解决锌枝晶的同时,提升正极材料的电化学性能,并最终应用于柔性电池。主要思路和研究结果如下:（1）本课题首先在碳布上生长三维核壳结构ZnO@C阵列作为骨架,之后通过电化学沉积法,在骨架上均匀进行锌沉积,最终合成柔性ZnO@C-Zn作为Zn-Co电池负极。（2）在碳布上通过简单的水热法构筑Co（CO₃）_0.5（OH）_x·0.11H₂O@CoMoO₄分级异质树枝状的正极材料。所制备的电极在1 mA cm^-2的电流密度下,可以提供超高的面积比容量0.72 mAh cm^-2。即使在64 mA cm^-2的高电流密度下,容量仍然保持0.42 mAh cm^-2,容量保持率可达67.6%。（3）进一步基于PVA凝胶电解质,本课题组装了纤维状柔性器件,展现出优异的电化学性能和柔韧性。可以为一系列电子设备供能,展现出巨大的实际应用潜力。更多还原

【Abstract】 With the deteriorating environmental conditions and the huge demand for renewable energy,as well as the growing pursuit of portable electronic products,flexible and wearable energy storage with high energy/power density,long-term durability,low cost and good safety devices are receiving more and more attention.In the past few decades,researchers have made considerable efforts to develop alkali metal ion batteries（Li⁺,Na⁺,K⁺）.However,a series of intrinsic problems with alkali metal ion batteries,such as the increase in the price of alkali metal（in particular for lithium salts）,the toxicity and flammability of organic electrolytes,severely limit their further widespread use.In particular,high safety is a more important consideration when applied as a flexible energy storage device to wearable electronic devices（such as skin sensors）that may be exposed to the skin.In order to better develop flexible energy storage devices,the safety and electrochemical performance of the flexible energy storage devices under the premise of ensuring their electrochemical performance are pursued.Aqueous electrolytes are usually used in flexible supercapacitors,which is a potential replacement for flammable alkali metal ion batteries because of its safety and cost effectiveness,but their relatively low energy density is far from being adequate for a wide range of applications.Zinc-based batteries are considered to be a powerful candidate for solving the energy storage dilemma between alkali metal ion batteries and supercapacitors due to their unique high output voltage advantages,high theoretical capacity(825 mAh g^-1),eco-friendliness and low cost.The aqueous electrolyte used can provide higher ionic conductivity and better safety than organic electrolytes,thus resulting in higher rate performance.However,two key issues have seriously hampered their widespread application.One is the formation and growth of zinc dendrites,which greatly shortens the cycle life of zinc-based batteries（usually less than 500 cycles）and has an important impact on the cycle performance,rate performance and safety of the battery.The other is the use of high weight zinc foil as negative electrodes in conventional zinc-based batteries,reducing energy density and limiting their use in flexible energy storage devices.Therefore,it is our research goal to develop a more stable anode material to avoid zinc dendrite while increasing the reversible capacity of the cathode material and finally apply it to the field of flexible energy storage.This project aims to explore a viable method for manufacturing cost-effective,dendritic,high-safety,flexible zinc-based batteries through careful design of nanostructures.The electrochemical properties are improved by optimizing anode and cathode at the same time.The main ideas and research results of this topic are as follows:（1）This reasearch first grow a three-dimensional core-shell ZnO@C array as a skeleton on carbon cloth,and then uniformly deposit zinc on the skeleton by electrochemical deposition,and finally synthesize flexible ZnO@C-Zn anode of Zn-Co battery.（2）The high-perforamnce Co（CO₃）_0.5（OH）_x·0.11H₂O@CoMoO₄ nanowire grow on carbon cloth by a simple hydrothermal method.The prepared electrode can provide an ultra-high area specific capacity of 0.72 mAh cm^-22 at a current density of 1mA cm^-2(0.36 A g^-1).Even at a high current density of 64 mA cm^-2(23.02 A g^-1),the capacity remains at 0.42 mAh cm^-2(152.2 mAh g^-1)and the capacity retention rate is67.6%.（3）Further based on the PVA gel electrolyte,the subject assembled a fibrous flexible device exhibiting excellent electrochemical performance and flexibility.It can power a range of electronic devices and demonstrates tremendous potential for practical applications.更多还原