【作者】 陈哲；

【导师】 黄燕；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2020， 硕士

【摘要】 商业锂离子电池因其有机系溶剂存在着燃烧与爆炸的安全隐患。针对目前柔性可穿戴器件所需的绝对安全性能要求,本文开发了一款具有本征安全性的高能量密度水系锌离子电池。为实现器件与储能单元的适配性,将水系锌离子电池进行了柔性化制备,获得了与耗能单元同等甚至更加优异的抗破坏性和形变能力。通过增大电池的输出电压,提高了电池器件的能量密度与功率密度表现。为实现柔性、高电压、水系锌离子电池的功能集成,本文从电池的三个部分,即正极材料、电解质、负极材料进行实验探究。通过循环伏安与恒电流充放电测试对正极材料与负极材料,电极材料与电解质的匹配性进行研究,根据测试结果选择最佳的电池结构组成,最大化地实现全电池的高电压性能。同时,在电池的电解质中引入水凝胶载体,制备成半固态的高电压柔性水系锌离子电池,解决液态电池的封装难题。采用电化学工作站与蓝电电池测试系统对柔性全电池的电压、容量、循环与倍率性能进行综合评估,并且将所制备的柔性电池在模拟的严苛使用条件下进行容量保持率测试,用以表征其对外部环境的耐受能力。正极采用高温共沉淀法合成了铁氰化锌、铁氰化铁、铁氰化亚铁、铁氰化铜、铁氰化镍、铁氰化钴、铁氰化锰七种普鲁士蓝类似物活性物质,通过控制变量的实验方法进行性能筛选,最终确定铁氰化锌为锌离子传输介质的最佳材料组成。基于提高材料利用率和柔性化的目的,运用了原位电沉积的方法制备了三维形貌的锌电极,并在不同沉积环境中对比得出最佳的负极制备方式。在上述体系中对双三氟甲烷磺酸锌、硫酸锌和醋酸锌三种电解质进行匹配性研究与浓度优化,得出1 M双三氟甲烷磺酸锌的电压与容量水平最高。进一步探究硫酸钾和醋酸钾添加剂对电池电化学性能的影响,再次验证单一电解质的性能优势。将电解质与明胶接枝聚丙烯酰胺水凝胶载体进行原位复合,与铁氰化锌正极和柔性锌负极以三明治结构组装,实现全电池的柔性制备。组装的柔性水系锌离子电池在200 m A g^-1电流密度下展现出1.9 V和1.8 V的高充放电电压,并展现极为少见的稳定电压平台和0.1 V的超小充放电压降。此外,该电池还具有2000 m A g^-1下的高倍率性能和260次的长循环性能,基于活性物质质量的能量密度和功率密度分别达到120 Wh kg^-1和3700 W kg^-1。为验证柔性电池的本征安全优势,在锤击、缝纫、打孔和浸泡破坏条件下进行性能测试,容量测试均呈现出较高的保持水平,表明柔性水系锌离子电池在以上严苛条件下具备优异的安全性。更多还原

【Abstract】 Commercial lithium-ion batteries have potential risks of combustion and explosion due to their organic solvents.In view of the absolute safety requirements of current flexible wearable devices,a high-energy density aqueous zinc ion battery with intrinsic safety was developed.For realizing the adaptability of the device and the energy storage system,the aqueous zinc-ion battery was flexibly prepared to obtain the same or even better resistance to damage and deformation than the energy-consuming unit.By increasing the output voltage of the battery,the energy density and power density are significantly improved.In order to achieve the functional integration of flexibility,high-voltage,aqueous zinc-ion batteries,this work conducted experimental exploration from cathode,electrolyte,and anode material of the battery.Through cyclic voltammetry and galvanostatic charge and discharge tests,the matching between cathode and anode,electrode and electrolyte was studied.According to the test results,the best battery structure composition was selected to maximize the high voltage performance of the whole battery.At the same time,a hydrogel carrier is introduced into the electrolyte to prepare a quasi-solid high voltage flexible aqueous zinc ion battery to solve the encapsulation problem of the liquid battery.The electrochemical test systems were employed to evaluate the voltage,capacity,cycle and rate performance of the flexible battery.The capacity retention rate was tested under the simulated severe service conditions to characterize its tolerance to the external environment.Seven kinds of Prussian blue analogues were synthesized by high temperature coprecipitation method,including zinc hexacyanoferrate,ferric cyanide,ferrous cyanide,copper ferricyanide,nickel ferrocyanide,cobalt ferrocyanide and manganese ferrocyanide.The performance of the compounds was screened by controlling the variables.Finally,zinc ferricyanide was determined as the best material composition of zinc ion transport medium.In order to improve the material utilization and flexibility,the zinc electrode with three-dimensional morphology was prepared by in-situ electrodeposition method,and the best preparation method of anode was obtained by comparing in different deposition environment.In the above system,the matching and concentration optimization of zinc bis（trifluoromethanesulfonate）,zinc sulfate and zinc acetate were carried out.The results showed that the voltage and capacity of1 M zinc bis（trifluoromethanesulfonate）were the highest.The effects of potassium sulfate and potassium acetate additives on the electrochemical performance of the battery were further explored,and the performance advantages of single electrolyte were verified again.The electrolyte and gelatin grafted polyacrylamide hydrogel carrier were synthesized in situ,and assembled with sandwich structure of zinc cyanide cathode and zinc anode to achieve the flexible preparation of the whole battery.The assembled flexible aqueous zinc ion batteries exhibit high charge discharge voltages of 1.9 V and 1.8 V at 200 m A g^-1 current density,as well as extremely rare stable voltage platform and small charge discharge voltage drop of 0.1 V.In addition,the battery also has a high rate performance at 2000 m A g^-1 and a long cycle performance of 260 cycles.The energy density and power density based on the mass of active substance reach 120 Wh kg^-1 and 3700 W kg^-1,respectively.To verify the intrinsic safety advantages of flexible battery,the performance test was carried out under hammering,sewing,drilling and soaking conditions.The capacity showed a high level of maintenance,indicating that the flexible aqueous zinc ion battery has excellent safety under the above harsh conditions.更多还原