【作者】 红霞；

【导师】 阿拉腾宝力格；

【作者基本信息】 内蒙古师范大学 ， 物理学， 2024， 硕士

【摘要】 9,10-蒽醌(AQ)凭借其理论比容量高、原料充裕、结构具备可设计性、氧化还原活性较高、电化学可逆性较强以及环境友好等诸多优势,在二次电池储能研究领域中,作为低成本、高能量密度的电极活性材料而备受瞩目。然而,蒽醌易于溶解于常用的有机电解液之中,致使以蒽醌作为正极材料的二次电池产生容量衰减严重、使用寿命短、循环可逆性欠佳、倍率性能差等问题。基于此,本硕士论文择取七种卤化蒽醌衍生物当作活性材料,经由与乙炔黑、石墨以及聚偏氟乙烯复合来制备出有机正极材料,进一步构建3032式锂离子电池,而后对电池的充放电特性、循环稳定性、倍率性能以及阻抗性能展开了深入探析,旨在为开发高容量且高稳定性的锂离子电池有机正极材料提供切实有效的实验数据和理论依据。其主要内容如下:1.选用蒽醌以及单卤化蒽醌衍生物(1-氯蒽醌、1-溴蒽醌、2-氯蒽醌和2-溴蒽醌),通过X射线衍射分析和扫描电子显微镜对晶体结构和微观形貌进行了表征。结果显示,在蒽醌骨架上引入单卤素功能团能够有效降低材料的尺寸及结晶度。相较于蒽醌,1-溴蒽醌、2-氯蒽醌和2-溴蒽醌与乙炔黑、石墨以及聚偏氟乙烯复合而成的正极材料,在锂硫电解液中表现出更优异的稳定性。在进行的50次充放电循环性能测试中,它们也展现出了更好的容量保持率。此外,单卤素的引入使蒽醌正极锂离子电池获得了更高的放电平台电压值和更低的电荷转移电阻。2.选用双卤化蒽醌衍生物(1,5-二氯蒽醌和1,5-二溴蒽醌),通过X射线衍射分析和扫描电子显微镜,对晶体结构及微观形貌进行了表征。结果表明,在蒽醌骨架的1,5位置引入双卤素功能团,可降低材料的尺寸和结晶度。与蒽醌以及1,5-二氯蒽醌相比,1,5-二溴蒽醌与乙炔黑、石墨和聚偏氟乙烯复合而成的正极材料,在锂硫电解液中展现出更为出色的稳定性。在进行的50次充放电循环性能测试中,1,5-二溴蒽醌表现出所有卤化蒽醌衍生物中最高的容量保持率(94.5%)。此外,双卤素的引入使蒽醌正极锂离子电池获得了更高的放电平台电压值和更低的电荷转移电阻。其中,1,5-二氯蒽醌正极所获得的放电平台电压值是所有卤化蒽醌衍生物中最高的(2.40 V)。3.选用四卤化蒽醌衍生物(1,4,5,8-四氯蒽醌),通过扫描电子显微镜对比单氯蒽醌、双氯蒽醌和四氯蒽醌的微观形貌。结果表明,在蒽醌骨架1,4,5,8四个位置对称引入氯原子,结晶颗粒尺寸与蒽醌相似。1,4,5,8-四氯蒽醌正极锂离子电池在进行的50次充放电循环性能测试中的容量保持率为32.6%,在充放电测试中的出平台电压为2.16 V,均与蒽醌正极锂离子电池相似,表明1,4,5,8-四氯蒽醌作为锂离子电池正极材料不具备长期稳定性和电化学稳定性。更多还原

【Abstract】 Anthraquinone(AQ),with its high theoretical capacity,abundant raw materials,designable structure,high redox activity,strong electrochemical reversibility,and environmental friendliness,has attracted significant attention as a low-cost,high-energy-density electrode active material for secondary battery energy storage research.However,AQ is prone to dissolve in commonly used organic electrolytes,leading to severe capacity fading,short service life,poor cycling reversibility,and inferior rate performance in secondary batteries using AQ as the cathode material.Based on this,the master’s thesis selected seven halogenated anthraquinone derivatives as active materials,prepared organic cathode materials by compounding them with acetylene black,graphite,and polyvinylidene fluoride,and further constructed 3032-type lithium-ion batteries.An in-depth analysis of the battery’s charge-discharge characteristics,cycling stability,rate performance,and impedance performance was conducted,aiming to provide practical experimental data and theoretical basis for the development of high-capacity and high-stability organic cathode materials for lithium-ion batteries.The main contents are as follows:1.Anthraquinone and monohalogenated anthraquinone derivatives(1-chloroanthraquinone,1-bromoanthraquinone,2-chloroanthraquinone,and2-bromoanthraquinone)were selected,and their crystal structures and micro-morphologies were characterized by X-ray diffraction analysis and scanning electron microscopy.The results showed that introducing a monohalogen functional group on the anthraquinone framework effectively reduced the material’s size and crystallinity.Compared with AQ,the cathode materials prepared by compounding 1-bromoanthraquinone,2-chloroanthraquinone,and 2-bromoanthraquinone with acetylene black,graphite,and polyvinylidene fluoride exhibited better stability in lithium-sulfur electrolyte.In the 50 charge-discharge cycling performance tests conducted,they also showed better capacity retention.In addition,the introduction of a monohalogen increased the discharge platform voltage value and reduced the charge transfer resistance of the AQ cathode lithium-ion battery.2.Dihalogenated anthraquinone derivatives(1,5-dichloranthraquinone and1,5-dibromoanthraquinone)were selected,and their crystal structures and micro-morphologies were characterized by X-ray diffraction analysis and scanning electron microscopy.The results indicated that introducing dihalogen functional groups at the 1,5 positions of the anthraquinone framework reduced the material’s size and crystallinity.Compared with AQ and 1,5-dichloranthraquinone,the cathode material prepared by compounding1,5-dibromoanthraquinone with acetylene black,graphite,and polyvinylidene fluoride showed more excellent stability in lithium-sulfur electrolyte.In the50 charge-discharge cycling performance tests conducted,1,5-dibromo-anthraquinone demonstrated the highest capacity retention(94.5%)among all halogenated anthraquinone derivatives.Moreover,the introduction of dihalogens increased the discharge platform voltage value and reduced the charge transfer resistance of the AQ cathode lithium-ion battery.Among them,the discharge platform voltage value obtained by the1,5-dichloranthraquinone cathode was the highest among all halogenated anthraquinone derivatives(2.40 V).3.Tetrahalogenated anthraquinone derivatives(1,4,5,8-tetrachloro-anthraquinone)were selected,and the micro-morphologies of monochloro-anthraquinone,dichloroanthraquinone,and tetrachloroanthraquinone were compared by scanning electron microscopy.The results showed that symmetrically introducing chlorine atoms at the 1,4,5,8 positions of the anthraquinone framework resulted in crystalline particle sizes similar to those of anthraquinone.The capacity retention of the1,4,5,8-tetrachloro-anthraquinone cathode lithium-ion battery after 50charge-discharge cycling performance tests was 32.6%,and the platform voltage in the charge-discharge test was 2.16 V,both similar to those of the anthraquinone cathode lithium-ion battery,indicating that1,4,5,8-tetrachloroanthraquinone does not possess long-term stability and electrochemical stability as a cathode material for lithium-ion batteries.更多还原