General formation of Prussian blue analogue microtubes for high-performance Na-ion hybrid supercapacitors  

类普鲁士蓝空心微米管的通用性制备及其作为高性能非对称超级电容器的研究

作　　者：Xuemin Yin Hejun Li Ruimei Yuan Leilei Zhang Jinhua Lu 殷学民;李贺军;袁瑞梅;张磊磊;卢锦花(State Key Laboratory of Solidification Processing,C/C Composites Research Center,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]State Key Laboratory of Solidification Processing,C/C Composites Research Center,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Science China Materials》2020年第5期739-747,共9页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(51821091 and 51872233);the Natural Science Foundation of Shaanxi Province(2018JM5044)。

摘　　要：One-dimensional(1D)hollow-structured nanomaterials with desirable compositions have aroused huge attention in the field of electrochemical energy storage.In the present study,1D hierarchical cobalt hexacyanoferrate(CoHCF)microtubes were initially fabricated using a facile self-templated method with the electrospun polyacrylonitrile(PAN)-cobalt acetate(Co(Ac)2)as templates.After the chemical reaction was performed between the templates and a potassium ferricyanide solution,the core-shell PANCo(Ac)2@CoHCF nanofibers were successfully fabricated.Subsequently,the CoHCF microtubes were finally obtained via the selective dissolution of the PAN-Co(Ac)2 cores.Benefiting from the unique structural characteristic,the CoHCF microtubes electrode exhibited prominent electrochemical characteristics in Na2SO4 aqueous electrolyte,including a high specific capacitance of 281.8 F g^-1(at 1 A g^-1),and good rate capability as well as long cycling stability(93%capacitance retention after 5000 cycles).The hybrid supercapacitor assembled with CoHCF microtubes and activated carbon(AC)as the positive and negative electrodes,respectively,exhibited a high energy density of 43.89 W h kg^-1,a power density of 27.78 k W kg^-1,as well as a long cycle life.Note that this versatile self-templated synthetic strategy could be extended to fabricate other 1D hollow Prussian blue(PB)or its analogues(PBA)with controllable composition,which have a potential application in a range of fields.在电化学储能领域,具有可控组成的一维空心结构纳米材料引起了人们的极大关注.本文以静电纺丝制备的聚丙烯腈(PAN)-醋酸钴(Co(Ac)2)纳米纤维为模板,首次采用简易的自模板法制备了一维铁氰化钴(CoHCF)空心微米管.PAN-Co(Ac)2纳米纤维模板与铁氰化钾溶液反应,合成了核壳结构的PAN-Co(Ac)2@CoHCF纳米纤维;随后,选择性溶解去除PAN-Co(Ac)2芯部,从而得到CoHCF空心微米管.得益于其独特的结构优势,CoHCF空心微米管电极在Na2SO4电解液中表现出优异的电化学性能,如高比电容(281.8 F g^-1@1 A g^-1),良好的速率性能和长时间循环稳定性(5000次循环后电容保持率为93%).由CoHCF为正极和活性炭(AC)为负极组装的非对称超级电容器,具有43.9 W h kg^-1的高能量密度、20 k W kg^-1的功率密度以及长的循环寿命.更重要的是,这种通用性的自模板合成策略可以推广到其他组成可控的一维空心普鲁士蓝(PB)及其类似物(PBA)材料,因而在很多领域具有广泛的应用前景.

关 键 词：ELECTROSPINNING MICROTUBES cobalt hexacyanoferrate hollow structures hybrid SUPERCAPACITORS 

分 类 号：TM53[电气工程—电器] TB383.1[一般工业技术—材料科学与工程]