钙钒青铜/碳纳米管复合材料的制备及电化学性能  

Preparation and Electrochemical Properties of Calcium Bronze/Carbon Nanotubes Composites

作　　者：刘建 杜海会 孙田将 年庆舜 李海霞[1] 陶占良[1] LIU Jian;DU Haihui;SUN Tianjiang;NIAN Qingshun;LI Haixia;TAO Zhanliang(Key Laboratory of Advanced Energy Materials Chemistry,Ministry of Education,College of Chemistry,Nankai University,Tianjin 300071,China)

机构地区：[1]南开大学化学学院先进能源材料化学教育部重点实验室

出　　处：《高等学校化学学报》2019年第12期2526-2533,共8页Chemical Journal of Chinese Universities

基　　金：国家重点研究发展计划项目(批准号:2016YFB0901500);国家自然科学基金(批准号:51771094,21571148);天津市自然科学基金(批准号:18JCZDJC31500)资助~~

摘　　要：采用水热法制备了具有二维层状结构的钙钒青铜(CaxV2O5·n H2O,CVO)水系锌离子电池钒基正极材料,并通过调控前驱体溶液中碳纳米管的含量,得到3种钙钒青铜/碳纳米管复合材料(CVO@CNTs).利用X射线衍射、热重分析、扫描电子显微镜和透射电子显微镜等对材料进行了表征.结果表明,所制备的CVO呈纳米带形貌,长约十几微米,宽约几百纳米,选区电子衍射测试表明所得材料为单晶结构.循环伏安测试结果表明,CVO和CVO@CNTs均具有多个氧化还原峰,储锌机制包括赝电容行为和电池行为.在放电倍率1C (1C=300 m A/g)测试条件下,CVO纳米带比容量稳定在210. 1 m A·h/g;与CNTs复合后,CVO@CNTs复合材料的电荷转移阻抗降低,在相同测试条件下表现出更高的比容量和优异的倍率性能.其中,CVO@CNTs-40表现出最高的比容量,在1C倍率测试条件下的比容量可达274. 3 m A·h/g,即使在20C的测试条件下放电比容量仍可达85. 2 m A·h/g,且循环1000次后容量保持率能达到92%.A new layered material,calcium bronze( CaxV2O5· n H2O,CVO) nanoribbons as cathode materials of aqueous zinc ion batteries( AZIBs) was prepared by hydrothermal method. Three kinds of calcium bronze@ carbon nanotubes composites( CVO@ CNTs) were synthesized by adjusting the content of CNTs in the precursor solution. The synthesized CVO had a fine nanobelts structure with a length of about 10 μm and a width of several hundred nanometers. Selected area electron diffraction( SAED) spectrum showed that CVO was single crystal. The CV test revealed that the CVO had multiple redox peaks,corresponding to different stages of zinc ion insertion/desertion. The zinc storage mechanism includes pseudocapacitive behavior and battery behavior. When applied as the cathode material of AZIBs,the specific capacity of CVO was stable at 210. 1 m A·h/g at a current rate of 1 C( 1 C = 300 m A/g). The addition of CNTs could decrease the charge transfer impedance of CVO@ CNTs composites. More importantly,the one-dimensional CTNs twisted between the nanoribbons could effectively avoid the stack of nanoribbons,increase the contact area between active materials and electrolyte,and improve the utilization of active materials. Therefore,CVO@ CNTs composites exhibited a higher capacity at the same test condition. Among them,CVO@ CNTs-40 exhibited a highest specific capacity of 274. 3 m A·h/g at a current rate of 1 C. What’s more,this cathode material delivered a high rate capability and high capacity retention of more than 92% over 1000 cycles,at a current rate of 20 C.

关 键 词：水系锌离子电池 正极材料 钙钒青铜 碳纳米管 水热反应 

分 类 号：O646[理学—物理化学] O611.6[理学—化学]