A robust hierarchical microcapsule for efficient supercapacitors exhibiting an ultrahigh current density of 300 A g(-1)
A robust hierarchical microcapsule for efficient supercapacitors exhibiting an ultrahigh current density of 300 A g(-1)
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一种用于高效超级电容器的坚固的分层微胶囊，具有 300 A g(-1) 的超高电流密度
DOI：
10.1039/c8ta00255j
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发表时间：
2018
影响因子：
11.9
通讯作者：
Gao Lian
中科院分区：
文献类型：
--
作者：
Yang Cheng;Shi Minjie;Song Xuefeng;Zhao Xiaofeng;Zhao Liping;Liu Jing;Zhang Peng;Gao Lian
提出了一种独特的三维分层微胶囊结构（NiSx@NCV），该结构是通过原位纳米空间限制热解策略将n掺杂碳囊包封双nisx （α-NiS/NiS2）纳米粒子实现的。NiSx@NCV在1 a g−1时具有1600 F g−1的高赝电容和令人印象深刻的速率性能（电容保持率为84.5%，从1到25 a g−1）。利用这种有趣的结构，制备了一种高性能的不对称超级电容器（ASCs），分别使用3D NiSx@NCV微胶囊和纳米多孔碳（NPC）作为正极和负极。值得注意的是，所制备的ASCs在1ag−1下具有135.06 F g−1的能力，在32ag−1下具有出色的速率能力。更重要的是，即使在32 ~ 300 a g−1的电流密度下，仍能保持87%的高电容保持率，这表明NiSx@NCV//NPC ASCs具有超高速率性能。此外，NiSx@NCV//NPC ASCs在功率密度为800 W kg - 1时，能量密度为48.02 W h kg - 1，即使在超高功率密度为240 kW kg - 1时，能量密度仍保持在30 W h kg - 1。这是由于双nisx纳米颗粒的丰富的氧化还原反应和界面效应，n掺杂碳囊泡的丰富活性位点和高导电性。
A unique three dimensional (3D) hierarchical microcapsule structure (NiSx@NCV) has been put forward, which is realized by the ensemble of N-doped carbon vesicles encapsulating dual-NiSx (α-NiS/NiS2) nanoparticles via an in situ nanospace-confined pyrolysis strategy. The NiSx@NCV shows a high pseudocapacitance of 1600 F g−1 at 1 A g−1 and impressive rate performance (a capacitance retention ratio of 84.5%, from 1 to 25 A g−1). Benefiting from this intriguing configuration, a kind of high performance asymmetric supercapacitor (ASCs) has been fabricated, using 3D NiSx@NCV microcapsules and nanoporous carbon (NPC) as positive and negative electrodes, respectively. Remarkably, the fabricated ASCs achieve a capability of 135.06 F g−1 at 1 A g−1 and exhibit an outstanding rate capability at 32 A g−1. More importantly, a high capacitance retention ratio of 87% is still achieved even at current densities from 32 to 300 A g−1, which exhibits well the ultrahigh rate performance of the NiSx@NCV//NPC ASCs. In addition, the NiSx@NCV//NPC ASCs deliver an attractive energy density of 48.02 W h kg−1 at a power density of 800 W kg−1, and still maintain 30 W h kg−1 even at an ultrahigh power density of 240 kW kg−1. This is attributed to the rich redox reaction and interface effect of dual-NiSx nanoparticles, abundant active sites and high electrical conductivity from N-doped carbon vesicles.