The increasing demand for portable electronic devices and hybrid electric vehicles stimulates the develop- ment of supercapacitors as an advanced energy storage system. Here, we demonstrate a binder-free nickel hydrox...The increasing demand for portable electronic devices and hybrid electric vehicles stimulates the develop- ment of supercapacitors as an advanced energy storage system. Here, we demonstrate a binder-free nickel hydroxide@nano- porous gold/Ni foam （Ni（OH）2@NPG/Ni foam） electrode for high-performance supercapacitors, which is prepared by a facile three-step fabrication route including electrodeposition of Au-Sn alloy on Ni foam, chemical dealloying of Sn and electrodepostion of Ni（OH）2 on NPG/Ni foam. Such Ni（OH）2@NPG/Ni foam electrode is composed of a thin layer of conformable Ni（OH）2 nanoflakes supported on three-di- mensional （3D） hierarchically porous NPG/Ni foam substrate. The resulting Ni（OH）2@NPG/Ni foam electrode can offer highways for both electron transfer and ion transport and lead to an excellent electrochemical performance with an ultrahigh specific capacitance of 3,380 F g-1 at a current density of 2 A g-1. Even when the current density was increased to 50 A g-1, it still retained a high capacitance of 1,927 F g-1. The promising performance of the Ni（OH）2@NPG/Ni foam elec- trode is mainly ascribed to the 3D hierarchical porosity and the highly conductive network on the NPG/Ni foam composite current collector, as well as the conformal electrodeposition of Ni（OH）2 active material on the NPG/Ni foam, which induces the formation of interconnected porosity both on the top surface and on the inner surface of the electrode. This in- spiring electrochemical performance would make the as-de- signed electrode material become one of the most promising candidates for future electrochemical energy storage systems.展开更多
Novel three-dimensional （3D） concentration-gradient Ni-Co hydroxide nanostructures （3DCGNC） have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigat...Novel three-dimensional （3D） concentration-gradient Ni-Co hydroxide nanostructures （3DCGNC） have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigated as binder- and conductor-free electrode for supercapacitors. Based on a three- electrode electrochemical characterization technique, the obtained 3DCGNC electrodes demonstrated a high specific capacitance of 1,760 F·g^-1 and a remarkable rate capability whereby more than 62.5% capacitance was retained when the current density was raised from 1 to 100 A·g^-1. More importantly, asymmetric supercapacitors were assembled by using the obtained 3DCGNC as the cathode and Ketjenblack as a conventional activated carbon anode. The fabricated asymmetric supercapacitors exhibited very promising electrochemical performances with an excellent combination of high energy density of 103.0 Wh·kg^-1 at a power density of 3.0 kW·kg^-1, and excellent rate capability-energy densities of about 70.4 and 26.0 Wh·kg^-1 were achieved when the average power densities were increased to 26.2 and 133.4 kW·kg^-1, respectively. Moreover, an extremely stable cycling life with only 2.7% capacitance loss after 20,000 cycles at a current density of 5 A·g^-1 was achieved, which compares very well with the traditional doublelayer supercapacitors.展开更多
基金financially supported by the National Natural Science Foundation of China (21673051,51604086)the Guangdong Science and Technology Department (2016A010104015)+4 种基金the Pearl River Scholar Funded Scheme of Guangdong Province Universities and Colleges (2015)the Science and Technology Program of Guangzhou (201604030037)the 'One-hundred Talents plan' (220418056)the 'One-hundred Young Talents plan' (220413126)the Youth Foundation (252151038) of Guangdong University of Technology
文摘The increasing demand for portable electronic devices and hybrid electric vehicles stimulates the develop- ment of supercapacitors as an advanced energy storage system. Here, we demonstrate a binder-free nickel hydroxide@nano- porous gold/Ni foam （Ni（OH）2@NPG/Ni foam） electrode for high-performance supercapacitors, which is prepared by a facile three-step fabrication route including electrodeposition of Au-Sn alloy on Ni foam, chemical dealloying of Sn and electrodepostion of Ni（OH）2 on NPG/Ni foam. Such Ni（OH）2@NPG/Ni foam electrode is composed of a thin layer of conformable Ni（OH）2 nanoflakes supported on three-di- mensional （3D） hierarchically porous NPG/Ni foam substrate. The resulting Ni（OH）2@NPG/Ni foam electrode can offer highways for both electron transfer and ion transport and lead to an excellent electrochemical performance with an ultrahigh specific capacitance of 3,380 F g-1 at a current density of 2 A g-1. Even when the current density was increased to 50 A g-1, it still retained a high capacitance of 1,927 F g-1. The promising performance of the Ni（OH）2@NPG/Ni foam elec- trode is mainly ascribed to the 3D hierarchical porosity and the highly conductive network on the NPG/Ni foam composite current collector, as well as the conformal electrodeposition of Ni（OH）2 active material on the NPG/Ni foam, which induces the formation of interconnected porosity both on the top surface and on the inner surface of the electrode. This in- spiring electrochemical performance would make the as-de- signed electrode material become one of the most promising candidates for future electrochemical energy storage systems.
基金This work was supported by the National Natural Science Foundation of China （No. 21001117）, the Shenzhen Peacock Plan （No. KQCX20140522150815065）, and the Starting-Up Funds of South University of Science and Technology of China （SUSTC） through the Talent Plan of the Shenzhen Government. H. T. L. acknowledges the support from a Key Project of the Hunan Provincial Science and Technology Plan （No. 2014FJ2007）.
文摘Novel three-dimensional （3D） concentration-gradient Ni-Co hydroxide nanostructures （3DCGNC） have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigated as binder- and conductor-free electrode for supercapacitors. Based on a three- electrode electrochemical characterization technique, the obtained 3DCGNC electrodes demonstrated a high specific capacitance of 1,760 F·g^-1 and a remarkable rate capability whereby more than 62.5% capacitance was retained when the current density was raised from 1 to 100 A·g^-1. More importantly, asymmetric supercapacitors were assembled by using the obtained 3DCGNC as the cathode and Ketjenblack as a conventional activated carbon anode. The fabricated asymmetric supercapacitors exhibited very promising electrochemical performances with an excellent combination of high energy density of 103.0 Wh·kg^-1 at a power density of 3.0 kW·kg^-1, and excellent rate capability-energy densities of about 70.4 and 26.0 Wh·kg^-1 were achieved when the average power densities were increased to 26.2 and 133.4 kW·kg^-1, respectively. Moreover, an extremely stable cycling life with only 2.7% capacitance loss after 20,000 cycles at a current density of 5 A·g^-1 was achieved, which compares very well with the traditional doublelayer supercapacitors.
