机械驱动生成自支撑的流苏状镍钴磷酸盐电极及其在超级电容器中的应用  

Mechanical force-driven growth of free-standing tassels-like nickel cobalt phosphate electrode for high-performance supercapacitor

作　　者：冯含芳 徐进 王乐辰 曹晋玮 李华阳 朱光 Hanfang Feng;Jin Xu;Lechen Wang;Jinwei Cao;Huayang Li;Guang Zhu(3D Manufacturing Innovation Center,Yongjiang Laboratory,Ningbo 315202,China;New Materials Institute,Department of Mechanical,Materials and Manufacturing Engineering,University of Nottingham Ningbo China,Ningbo 315100,China)

机构地区：[1]3D Manufacturing Innovation Center,Yongjiang Laboratory,Ningbo 315202,China [2]New Materials Institute,Department of Mechanical,Materials and Manufacturing Engineering,University of Nottingham Ningbo China,Ningbo 315100,China

出　　处：《Science China Materials》2024年第8期2671-2682,共12页中国科学（材料科学）（英文版）

基　　金：supported by Ningbo Municipal 3315 Talent Scheme by Ningbo Science and Technology Bureau;Zhejiang Provincial Natural Science Foundation of China(LQ23F010016 and LR19F010001)。

摘　　要：过渡金属磷酸盐(TMPs)虽然具有优异的理论比容量和良好的晶体结构,但由于层间结构严重堆积导致的低比电容和倍率性能阻碍了其实际应用.本文首次采用水热搅拌法制备了由超薄纳米片组成的流苏状镍钴磷酸盐(NCP)电极.超薄纳米片可以同时提供大的比表面积、超多的活性位点和畅通的离子传输路径.制备的Ni_(2)C(PO_(4))_(2)(NCP-2)电极在2mA cm^(−2)下的比电容为2518mC cm^(−2)(1007Cg-1),在50mAcm^(−2)时的电容保持率为76.7%,优于先前报道的其他TMPs电极.根据密度泛函理论(DFT)计算结果,NCP-2电极表现出更高的电导率和更强的OH-吸附能.此外,以NCP-2和石墨烯水凝胶分别作为正负极组装成的混合超级电容器(HSC)具有高能量密度和高功率密度.充满电后,HSC可以点亮发光二极管(LED)灯5分钟以上.此外,该电极可与鞋垫形摩擦纳米发电机结合,以收集和储存人类行走时的机械能.此外,还可将其用作柔性压阻传感器的电源.本水热搅拌法可以扩展到其他电活性材料的制备.Although transition metal phosphates(TMPs)possess superb theoretical capacity and favorable crystalline structure,their practical applications are still hindered by the low capacity and inferior rate performance caused by the severely stacked layer structures.Herein,the free-standing tassels-like nickel cobalt phosphate(NCP)electrode composed of ultrathin nanosheets is firstly prepared via a facile hydrothermal stirring method.The ultrathin nanosheets can provide large surface area,tremendous exposed active sites,and effortless ion penetration path at the same time.The as-prepared Ni_(2)Co(PO_(4))_(2)(NCP-2)electrode demonstrates a maximum specific capacity of 2518 mC cm^(−2)(1007 C g−1)at 2 mA cm^(−2)with 76.7%capacity retention at 50 mA cm^(−2),outperforming the other previously reported TMP electrodes.According to the density functional theory calculation results,the bimetallic NCP-2 electrode exhibits a higher conductivity and stronger adsorption capacity of OH−compared with the monometallic Ni3(PO_(4))_(2)(NP)electrode.Moreover,hybrid supercapacitors(HSCs)with NCP-2 and graphene hydrogel(GH)as the positive and negative electrodes,respectively,deliver a high energy density of 46.25 W h kg−1 and a highpower density of 9579 W kg−1.After being fully charged,the HSC can illuminate the light-emitting diode light for more than 5 min.Furthermore,when the HSC is integrated with an insole shaped triboelectric nanogenerator,it can be used to harvest and store the mechanical energy from human walking.Finally,the HSC can also serve as the voltage source for flexible piezoresistive sensors.Thus,this hydrothermal stirring method can be extended to prepare other electroactive materials with unique nanostructures for high-performance supercapacitors.

关 键 词：混合超级电容器 比电容 压阻传感器 机械驱动 摩擦纳米发电机 层间结构 搅拌法 正负极 

分 类 号：O646[理学—物理化学] TM53[理学—化学]