鎳－鈷層狀雙金屬氫氧化物應用於高性能超級電容

Nickel-Cobalt Layered Double Hydroxide for High-Performance Supercapacitor

本研究採用兩步驟電沉積法製備高性能超級電容器電極。首先，在含有Ni2+離子以及碳化矽（SiC）奈米粉末的電解液下建構三維互聯多孔結構鎳框架（3D-Ni/SiC）。該製程構築出嵌入SiC奈米顆粒的導電多孔基底，從而提升其導電性與電化學雙層電容。第二步，在含有Co2+與Ni2+的電解液環境下原位合成鎳-鈷層狀雙氫氧化物（Ni-Co LDH）奈米片，形成NiCo 3D-Ni/SiC複合材料。透過在三維多孔框架中集成擬電容型Ni-Co LDH奈米片與電雙層型SiC，形成了具有協同效應的多尺度結構，顯著增強表面活性面積並暴露大量電活性位點，從而促進高效的法拉第氧化還原反應。製備的NiCo 3D-Ni/SiC電極表現出優異的電化學性能，在1 mA/cm2電流密度下面積電容高達1512 mF/cm2，並具有優異的倍率性能。此外，採用此複合組裝的對稱超級電容器裝置已成功為商用發光二極體（LED）供電，彰顯了其在實際儲能應用中的巨大潛力。

In this study, a two-step electrodeposition method was employed to fabricate high- performance supercapacitor electrodes. In the first step, a three-dimensional interconnected porous nickel framework embedded with silicon carbide (SiC) nanoparticles (3D-Ni/SiC) was constructed in an electrolyte containing Ni²⁺ions and SiC nanopowders. This process produced a conductive porous substrate with uniformly embedded SiC nanoparticles, thereby enhancing electrical conductivity and electrochemical double-layer capacitance. In the second step, nickel–cobalt layered double hydroxide (Ni-Co LDH) nanosheets were in situ synthesized on the 3DNi/ SiC framework in an electrolyte containing both Co²⁺and Ni²⁺ions, forming the NiCo 3DNi/ SiC composite. The integration of pseudocapacitive Ni-Co LDH nanosheets and double-layer capacitive SiC within the 3D porous framework created a synergistic multiscale structure, which significantly increased the active surface area and exposed abundant electroactive sites, thereby facilitating efficient Faradaic redox reactions. The as-prepared NiCo 3D-Ni/SiC electrode exhibited outstanding electrochemical performance, delivering a high areal capacitance of 1512 mF/cm2 at a current density of 1 mA/cm2, along with excellent rate capability. Furthermore, a symmetric supercapacitor device assembled from this composite successfully powered commercial light-emitting diodes (LEDs), demonstrating its great potential for practical energy storage applications.