【作者】 李宇；

【导师】 兰孝征；

【作者基本信息】 山东农业大学 ， 化学工程（专业学位）， 2024， 硕士

【摘要】 随着大规模储能系统的日益增长,传统液态电解质因其电解质易燃、有毒而至使安全性能差,这不仅对人们的生命和财产安全造成严重威胁,而且也无法满足锂离子电池对高能量密度的要求。引入固态电解质,组成全固态电解质系统,成为解决上述安全问题的优秀方案之一。有机离子型塑性晶体（OIPCs）作为一种新型固态电解质,因其有可塑性、热稳定性高、电化学窗口宽、化学结构可以进行多种修饰等优良性能而备受人们关注。但已发现的有机离子塑性晶体种类有限、纯品电导率较低、离子电导率与其关键影响因素如相变（热能驱动）、离子动力学等之间的联系尚不清晰,因此,揭示有机离子塑性晶体离子传导机理,提高有机离子塑性晶体的离子电导率,使其更好地应用于全固态电池,是一个亟需突破的难题。本实验以有机离子塑晶的化学结构及相行为为基础,合成离子电导率较高的有机离子塑性晶体,通过变温DSC、变温XRD、电化学阻抗谱,测量塑晶及功能离子掺杂样品相变温度、相变焓、离子电导率,探讨塑晶离子电导率与相变、构晶离子动力学之间的关系,根据这些实验数据判断离子传导的途径和提高离子电导率的方法。主要研究内容及结果如下:（1）自主设计并完善了电导率测量装置。制作了一种压力可调宽温区固态电解质电导率变温测试微型装置,通过调节长螺栓来调节固态电解质电导率测试模具内部压力大小,具有气密性,可以在惰性气氛条件下测量0～120°C固态电解质离子电导率,为研究有机离子塑晶的离子传导性能提供准确数据。（2）有机离子塑性晶体四乙基铵高氯酸盐([N₂₂₂₂]Cl O₄)以及掺杂Li⁺、Cl^-和F^-后的DSC曲线显示出不同的热行为;变温XRD显示,[N₂₂₂₂]Cl O₄在进入高温相后,转变为立方相;掺杂不同浓度的Li Cl O₄、[N₂₂₂₂]F、[N₂₂₂₂]Cl后电导率都有不同程度的提高,其中,掺杂[N₂₂₂₂]F的混合物电导率比掺杂Li⁺和Cl^-的混合物的电导率明显提高,与纯[N₂₂₂₂]Cl O₄相比提高了约33倍。（3）对有机离子塑晶左旋奎宁醇盐酸盐（（+）-[3-OH-QH]Cl）、奎宁环盐酸盐（[HQ]Cl）分别掺杂不同浓度的Li BF₄,以及将两种结构相近的有机离子盐进行掺杂并掺入不同浓度的Li BF₄,研究结果表明,（+）-[3-OH-QH]Cl和[HQ]Cl分别在64°C和67°C左右存在一个固-固相变,掺杂不同浓度的Li BF₄后,相变温度与相变焓随浓度的增加而减小,两种有机离子盐掺杂并掺入Li BF₄后没有明显的相变峰;变温XRD显示（+）-[3-OH-QH]Cl和[HQ]Cl在高温相转变为立方结构;掺杂Li BF₄后两种有机离子盐的电导率分别有不同程度的提升,当把两种有机离子盐与不同浓度的Li BF₄掺杂在一起后离子电导率没有很大提高。更多还原

【Abstract】 With the increasing development of large-scale energy storage systems,traditional liquid electrolytes have poor safety performance due to their flammable and toxic electrolytes,which not only poses a serious threat to people’s life and property safety,but also fails to meet the requirements of lithium-ion batteries for high energy density.The introduction of solid electrolyte to form an all-solid-state electrolyte system has become one of the excellent solutions to the above safety problems.Organic ionic plastic crystals（OIPCs）,as a new type of solid electrolyte,have attracted much attention due to their excellent properties such as plasticity,high thermal stability,wide electrochemical window,and chemical structure that can be modified.However,the types of organic ionic plastic crystals have been found to be limited,the conductivity of pure products is low,and the relationship between ionic conductivity and its key influencing factors such as phase transition（thermal energy driving）and ion dynamics is not clear.Therefore,it is an urgent challenge to reveal the ionic conduction mechanism of organic ionic plastic crystals and to improve the ionic conductivity of organic ionic plastic crystals for their better application in all-solid-state batteries.In this experiment,based on the chemical structure and phase behavior of organic ion plastic crystals,organic ion plastic crystals with high ionic conductivity were synthesized.The phase transition temperature,phase transition enthalpy and ionic conductivity of plastic crystals and functional ion doped samples were measured by variable temperature DSC,variable temperature XRD and electrochemical impedance spectroscopy.The relationship between the ionic conductivity of plastic crystals and the kinetics of phase transition and crystal structure was discussed.According to these experimental data,the way of ion conduction and the method of improving ionic conductivity were judged.The main research contents and results are as follows:（1）Self-designed and improved conductivity measurement device.A micro-device for temperature-dependent test of solid electrolyte conductivity in a wide temperature range with adjustable pressure was fabricated.The internal pressure of the solid electrolyte conductivity test mold was adjusted by adjusting the long bolt.It has air tightness and can measure the solid ion conductivity of 0 to120°C under the condition of inert atmosphere,which provides accurate data for studying the ion conductivity of organic ion plastic crystal.（2）The DSC curves of organic ionic plastic crystalline tetraethylammonium perchlorate([N₂₂₂₂]Cl O₄)and after doping with Li⁺,Cl^-,and F^-show different thermal behaviors;variable temperature XRD shows that[N₂₂₂₂]Cl O₄ transforms into a cubic phase after entering the high-temperature phase;The conductivity was increased to different degrees after doping with different concentrations of Li Cl O₄,[N₂₂₂₂]F and[N₂₂₂₂]Cl.Among them,the conductivity of the[N₂₂₂₂]F-doped mixtures was significantly higher than that of the mixtures doped with Li⁺and Cl^-,and it was increased by a factor of about 33 as compared with that of the pure[N₂₂₂₂]Cl O₄.（3）The organic ionic plastic crystals quinuclidinol hydrochloride（（+）-[3-OH-QH]Cl）and quinuclidinium chloride（[HQ]Cl）were doped with different concentrations of Li BF₄,and the two organic ionic salts with similar structures were doped and doped with different concentrations of Li BF₄.The results of the study showed that（+）-[3-OH-QH]Cl and[HQ]Cl existed a solid-solid phase transition around 64°C and 67°C,The phase transition temperature and enthalpy of the phase transition decreased with the increase of concentration after doping with different concentrations of Li BF₄,and there was no obvious phase transition peak after the two organic ionic salts were doped and doped with Li BF₄;Variable temperature XRD showed that（+）-[3-OH-QH]Cl and[HQ]Cl were transformed into cubic structure at high temperature.The conductivity of the two organic ionic salts has different degrees of improvement after doping Li BF₄.When the two organic ionic salts are doped with different concentrations of Li BF₄,the ionic conductivity is not greatly improved.更多还原