铵根离子预嵌入对二氧化锰正极材料放电行为的影响  

Effect of pre-embedding of ammonium ion on discharching behavior of manganese dioxide for cathode materials

作　　者：胡德计 刘吉源 刘兴江[2,3] 徐强[2] HU De-ji;LIU Ji-yuan;LIU Xing-jiang;XU Qiang(School of Information,Tianjin University of Commerce,Tianjin 300134,China;School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;Tianjin Institute of Power Sources,Tianjin 300384,China)

机构地区：[1]天津商业大学信息学院,天津300134 [2]天津大学化工学院,天津300350 [3]中国电子科技集团公司,天津300384

出　　处：《中国有色金属学报》2023年第9期2948-2956,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(21975180)。

摘　　要：为了缓解锰基正极材料在水系锌离子电池充放电过程中引起的结构塌陷,预嵌入分子和离子是一种有效的解决手段。通过简单的水热法,将与锌离子半径相近的铵根离子(NH_(4)^(+))预嵌入α-MnO_(2)材料中,制备了一种水系锌离子电池正极材料(NMnO_(2))。铵根离子的预嵌入稳固了锰基材料的宿主结构,降低了电化学过程中的电荷转移势垒,进而提高了正极材料的反应动力学。结果表明:所组装的锌离子电池在电流密度0.5 A/g下的初始比容量达到304.1 mA·h/g,充放电循环1000次后容量保持率为77.7%;在1 A/g下的电流密度下初始比容量为183.5 mA·h/g,经过2000次循环后,电池比容量仍然达到138.7 mA·h/g,容量保持率为75.5%。此外,等效模拟电路的计算和CV曲线测试结果表明,扩散作用和赝电容行为的共同作用机制有效地提升了锌离子电池的倍率性能。To alleviate the structural collapse of manganese-based cathode materials caused by the charging and discharging process of aqueous Zn-ion batteries,pre-embedding molecules and ions is an effective means to solve the problem.An cathode material(NMnO_(2))was prepared by a simple hydrothermal method by pre-embedding ammonium ion(NH_(4)^(+)),which has a similar radius to zinc ion,intoα-MnO_(2)material.The pre-embedding of ammonium ions solidifies the host structure of the manganese-based materials and improves the charge transfer process during electrochemistry,which in turn improves the reaction kinetics of the cathode.The results show that the assembled zinc ion battery can contribute a high specific capacity of 304.1 mA∙h/g at 0.5 A/g with a capacity retention rate of 77.7%after 1000 cycles.The initial specific capacity at a current density of 1 A/g is 183.5 mA∙h/g,and after 2000 charge/discharge cycles it can still contribute a specific capacity of 138.7 mA∙h/g with a capacity retention of 75.5%.In addition,the data fitting of CV curves also proves the joint mechanism of diffusion control and pseudocapacitance behavior of the battery.

关 键 词：预嵌入 水热法 锌离子电池 电荷转移过程 宿主结构 

分 类 号：TQ448.21[化学工程—化学肥料工业]