Abstract The supercapacitor (SC) based on nickel cobalt layered double hydroxide (NiCo-LDH) has aroused great interest in the field of energy storage. However, the agglomeration and low electrical conductivity are unfavorable for electrochemical performance. Herein, Ag nanowires (Ag NWs) was first dip-coated on nickel foam (NF) to form a conductive substrate, on which the NiCo-LDH nanosheet array in-situ grew to construct an efficient three-dimensional (3D) self-supported hierarchical structure NiCo-LDH/Ag NWs/NF electrode. The presence of Ag NWs inhibits aggregation of LDH nanosheets and accelerates the electron transfer. Electrochemical studies exhibit that NiCo-LDH/Ag/NF hybrid electrode possesses the higher specific capacitance of 2920.6 F g−1 at a current density of 5 A g−1 and excellent cycling stability (89.8% after 2000 cycles) compared with the electrode without Ag NWs. The asymmetric supercapacitor (ASC) with the NiCo-LDH/Ag/NF heterostructure as the positive electrode and active carbon (AC) as the negative electrode displays a high energy density of 42.9 Wh kg−1 at a power density of 800 W kg−1. When two aqueous ASCs were assembled in series and charged for only 1 min, the stored energy was capable of powering two green light-emitting-diodes (LEDs) for more than 3 min, indicating NiCo-LDH/Ag/NF electrode material shows great potential application in supercapacitor.

中文翻译：

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用于高性能超级电容器的自支撑超薄NiCo-LDH纳米片阵列/Ag纳米线无粘合剂复合电极

摘要 基于镍钴层状双氢氧化物（NiCo-LDH）的超级电容器（SC）引起了储能领域的极大兴趣。然而，团聚和低电导率不利于电化学性能。在此，首先将银纳米线（Ag NWs）浸涂在镍泡沫（NF）上以形成导电基材，在导电基材上原位生长 NiCo-LDH 纳米片阵列以构建有效的三维（3D）自支撑分层结构 NiCo-LDH/Ag NWs/NF 电极。Ag NWs 的存在抑制了 LDH 纳米片的聚集并加速了电子转移。电化学研究表明，NiCo-LDH/Ag/NF 混合电极在 5 A g-1 的电流密度下具有 2920.6 F g-1 的较高比电容和优异的循环稳定性（89. 8%（2000 次循环后）与没有 Ag NW 的电极相比。以NiCo-LDH/Ag/NF异质结构为正极、活性炭（AC）为负极的非对称超级电容器（ASC）在800 W kg-的功率密度下显示出42.9 Wh kg-1的高能量密度1. 当两个水性 ASC 串联组装并仅充电 1 分钟时，储存的能量能够为两个绿色发光二极管 (LED) 供电 3 分钟以上，表明 NiCo-LDH/Ag/NF 电极材料表现出良好的性能在超级电容器中的潜在应用。