Self-assembly of nickel phosphate-based nanotubes into two-dimensional crumpled sheet-like architectures for high-performance asymmetric supercapacitors
Self-assembly of nickel phosphate-based nanotubes into two-dimensional crumpled sheet-like architectures for high-performance asymmetric supercapacitors
复制标题
DOI：
10.1016/j.nanoen.2019.104270
复制
发表时间：
2020-01-01
期刊：
影响因子：
17.6
通讯作者：
Yamauchi, Yusuke
中科院分区：
文献类型：
--
作者：
Septiani, Ni Luh Wulan;Kaneti, Yusuf Valentino;Yamauchi, Yusuke
本工作首次采用磷酸辅助溶剂热法，以甘油镍颗粒为牺牲模板，成功地将非晶态磷酸镍纳米管自组装成二维皱缩的片状结构。自解构-自编织机制被认为是由甘油酸镍模板形成这种纳米管组装的皱折片状结构的原因。以纳米管组装的非晶态二维磷酸镍(NiHPI-500)为正极，以活性碳(AC)为负极组装的非对称超级电容器(ASC)器件在功率密度为362W kg(-1)、1443W kg(-1)和2838W kg(-1)时的能量密度分别为50W h kg(-1)、40W h kg(-1)和32W h kg(-1)。此外，在7242W kg(-1)的高功率密度下，该ASC器件可以保持令人印象深刻的18W h kg t的能量密度。此外，NiHPI-500//AC ASC也表现出良好的长期稳定性，在10Ag-1的大电流密度下，5000次循环后的高容量保持率为100%。这种优异的电化学性能归功于独特的纳米管组装的2D结构、纳米管之间良好的互连性以及由此产生的大比表面积，这些结构可以为氧化还原反应提供许多活性中心，便于电解质离子的有效传输和扩散，从而使活性材料得到更有效的利用。这些结果表明，纳米管组装的2D磷酸镍纳米结构在超级电容器应用中具有很大的潜力。
This work demonstrates the successful self-assembly of amorphous nickel phosphate-based nanotubes into two-dimensional (2D) crumpled sheet-like architectures for the first time by employing nickel glycerate particles as sacrificial templates through a two-step phosphoric acid-assisted solvothermal method. A "self-deconstruction-self-weaving" mechanism is believed to be responsible for the formation of such nanotube-assembled crumpled sheet-like architectures from the nickel glycerate template. The asymmetric supercapacitor (ASC) device assembled using nanotube-assembled amorphous 2D nickel phosphate (NiHPi-500) as the positive electrode and activated carbon (AC) as the negative electrode exhibits high energy densities of 50 W h kg(-1), 40 W h kg(-1), and 32 W h kg(-1) at power densities of 362 W kg(-1), 1443 W kg(-1), and 2838 W kg(-1), respectively. Furthermore, this ASC device can retain an impressive energy density of 18 W h kg t at high power density of 7242W kg(-1). In addition, the NiHPi-500//AC ASC also displays good long-term stability with a high capacitance retention of 100% after 5000 cycles at a high current density of 10 Ag-1. The excellent electrochemical performance is attributed to the unique nanotube-assembled 2D architectures, the good interconnectivity between the nanotubes, and the large surface area arising from such structures which can provide many active sites for the redox reactions and facility effective transport and diffusion of the electrolyte ions, leading to more efficient utilization of the active material. These results indicate the promising potential of nanotube-assembled 2D nickel phosphate nanoarchitectures for supercapacitor applications.