Ma Xueying, Feng Hanfang, Yan Tianxiang, Zhang Li, Liu Xuying, Cao Shaokui
School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China.
Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, People's Republic of China.
Dalton Trans. 2021 Oct 5;50(38):13276-13285. doi: 10.1039/d1dt01744f.
A monolithic supercapacitor electrode of a KNiCoPO·HO-graphene composite hydrogel supported on Ni foam (KNCP-GH/NF) is first prepared by a one-step hydrothermal method, which achieves notable improvements in the electrode surface area and mass-loading of active materials. The KNCP-GH/NF electrode enjoys a hierarchical open-porous structure, where the KNCP-GH composite hydrogel fills in the voids in NF and the porous graphene hydrogel (GH) simultaneously provides a large support surface for growing active KNCP nanoflowers. Accordingly, the KNCP-GH/NF electrode exhibits a strikingly high capacity of 3240 mC cm (876 C g) at 2 mA cm and a satisfactory rate performance with 78.3% retention at 100 mA cm. Further, an all-solid-state asymmetric supercapacitor, constituted by using KNCP-GH/NF and FeP/GH/NF as the cathode and anode, respectively, and PVA-KOH as the solid-state gel electrolyte, delivers a high energy density of 69.2 W h kg (3.9 mW h cm) and a power density of 13 229 W kg (720 mW h cm) as well as notable cyclability with 81.2% capacity retention after 10 000 charge/discharge cycles. These attractive performances suggest a promising potential for a hierarchically structured KNCP-GH/NF electrode for the high-performance energy storage application.
首先通过一步水热法制备了一种负载在泡沫镍上的KNiCoPO·HO-石墨烯复合水凝胶的整体式超级电容器电极（KNCP-GH/NF），该方法显著提高了电极表面积和活性材料的质量负载。KNCP-GH/NF电极具有分级开孔结构，其中KNCP-GH复合水凝胶填充在NF的空隙中，多孔石墨烯水凝胶（GH）同时为生长活性KNCP纳米花提供了大的支撑表面。因此，KNCP-GH/NF电极在2 mA cm时表现出惊人的3240 mC cm（876 C g）高容量以及令人满意的倍率性能，在100 mA cm时保持率为78.3%。此外，一种全固态非对称超级电容器，分别使用KNCP-GH/NF和FeP/GH/NF作为阴极和阳极，以及PVA-KOH作为固态凝胶电解质，具有69.2 W h kg（3.9 mW h cm）的高能量密度和13 229 W kg（720 mW h cm）的功率密度，并且在10000次充放电循环后具有显著的循环稳定性，容量保持率为81.2%。这些吸引人的性能表明，具有分级结构的KNCP-GH/NF电极在高性能储能应用方面具有广阔的前景。
