Mesoporous NiCo_2O_4 nanoneedles@MnO_2 nanoparticles grown on nickel foam for electrode used in high-performance supercapacitors  

作　　者：Yanmei Li Jingjing Pan Jinzhu Wu Tingfeng Yi Ying Xie 

机构地区：[1]School of Chemistry and Chemical Engineering, Anhui University of Technology [2]School of Resources and Materials, Northeastern University at Qinhuangdao [3]Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University

出　　处：《Journal of Energy Chemistry》2019年第4期167-177,共11页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (nos. 51774002 and 21773060);Anhui Provincial Science Fund for Excellent Young Scholars (no. gxyqZD2016066)

摘　　要：Mesoporous NiCo_2O_4@MnO_2 nanoneedle arrays as electrode materials for supercapacitor grown on a conductive nickel foam were prepared by a facile hydrothermal route. The interconnected mesoporous structure of the NiCo_2O_4 nanoneedle arrays provides a large specific surface area for charge storage.The electrochemically active MnO_2 nanoparticles covered on the surface of NiCo_2O_4 nanoneedle result in a favorable synergistic storage effect because of charge redistribution at the NiCo_2O_4|MnO_2 interface,which reduces the interfacial polarization and facilitates ion diffusion. The initial specific capacitance of NiCo_2O_4@MnO_2(S2) is 1001 F g^(-1) at current density of 15 A g^(-1). The capacity retention of S2 is about87.4% after 4000 cycles, and the specific capacitance of S2 electrode only decreases from 1001 F g^(-1) to736 F g^(-1) even after 10,000 cycles. The first-principles calculations show that a chemical bonding between the NiCo_2O_4 and MnO_2 is not only helpful for stabilizing the composites but also leads to a charge redistribution at the interface, which may lead to a smaller interfacial polarization and thus beneficial for the interfacial capacity. The excellent electrochemical performance of NiCo_2O_4@MnO_2 composites(S2)can be ascribed to the high surface area, unique architecture, MnO_2 nanoparticle modification, reduced charge transfer resistance and stable interface between NiCo_2O_4 and MnO_2. The simple material synthesis and architectural design strategy provides new insights in opportunities to exhibit promising potential for practical application in energy storage.Mesoporous NiCo_2O_4@MnO_2 nanoneedle arrays as electrode materials for supercapacitor grown on a conductive nickel foam were prepared by a facile hydrothermal route. The interconnected mesoporous structure of the NiCo_2O_4 nanoneedle arrays provides a large specific surface area for charge storage.The electrochemically active MnO_2 nanoparticles covered on the surface of NiCo_2O_4 nanoneedle result in a favorable synergistic storage effect because of charge redistribution at the NiCo_2O_4|MnO_2 interface,which reduces the interfacial polarization and facilitates ion diffusion. The initial specific capacitance of NiCo_2O_4@MnO_2(S2) is 1001 F g^(-1) at current density of 15 A g^(-1). The capacity retention of S2 is about87.4% after 4000 cycles, and the specific capacitance of S2 electrode only decreases from 1001 F g^(-1) to736 F g^(-1) even after 10,000 cycles. The first-principles calculations show that a chemical bonding between the NiCo_2O_4 and MnO_2 is not only helpful for stabilizing the composites but also leads to a charge redistribution at the interface, which may lead to a smaller interfacial polarization and thus beneficial for the interfacial capacity. The excellent electrochemical performance of NiCo_2O_4@MnO_2 composites(S2)can be ascribed to the high surface area, unique architecture, MnO_2 nanoparticle modification, reduced charge transfer resistance and stable interface between NiCo_2O_4 and MnO_2. The simple material synthesis and architectural design strategy provides new insights in opportunities to exhibit promising potential for practical application in energy storage.

关 键 词：SUPERCAPACITOR FIRST-PRINCIPLES calculations Electrochemical performance SYNERGISTIC effect NiCo2O4 

分 类 号：O4[理学—物理]