Li Xiaoyu, Han Dong, Gong Zhiqiang, Wang Zhenbo
College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
College of New Energy, China University of Petroleum (East China), Qingdao 266580, China.
Nanomaterials (Basel). 2021 Oct 14;11(10):2715. doi: 10.3390/nano11102715.
In the aim to go beyond the performance tradeoffs of classic electric double-layer capacitance and pseudo-capacitance, composites made out of carbon and pseudo-capacitive materials have been a hot-spot strategy. In this paper, a nest-like MnO nanowire/hierarchical porous carbon (HPC) composite (MPC) was successfully fabricated by a controllable in situ chemical co-precipitation method from oily sludge waste. Due to the advantages of high surface area and fast charge transfer for HPC as well as the large pseudo-capacitance for MnO nanowires, the as-prepared MPC has good capacitance performance with a specific capacitance of 437.9 F g at 0.5 A g, favorable rate capability of 79.2% retention at 20 A g, and long-term cycle stability of 78.5% retention after 5000 cycles at 5 A g. Meanwhile, an asymmetric supercapacitor (ASC) was assembled using MPC as the cathode while HPC was the anode, which exhibits a superior energy density of 58.67 W h kg at the corresponding power density of 498.8 W kg. These extraordinary electrochemical properties highlight the prospect of our waste-derived composites electrode material to replace conventional electrode materials for a high-performance supercapacitor.
为了超越传统双电层电容和赝电容的性能权衡，由碳和赝电容材料制成的复合材料一直是一种热门策略。本文通过可控的原位化学共沉淀法，成功地从含油污泥废料中制备了一种巢状MnO纳米线/分级多孔碳（HPC）复合材料（MPC）。由于HPC具有高表面积和快速电荷转移的优点，以及MnO纳米线具有大的赝电容，所制备的MPC具有良好的电容性能，在0.5 A g时比电容为437.9 F g，在20 A g时具有79.2%的良好倍率性能保持率，在5 A g下5000次循环后具有78.5%的长期循环稳定性。同时，以MPC为正极、HPC为负极组装了一种不对称超级电容器（ASC），在相应的498.8 W kg功率密度下，其能量密度高达58.67 W h kg。这些优异的电化学性能突出了我们由废料衍生的复合材料电极材料取代传统电极材料用于高性能超级电容器的前景。
