One-step growth of NiCoAl layered double hydroxides microspheres toward high energy density supercapacitors.

Layered double hydroxides (LDHs) are a class of 2D structure anionic clays with tunable structure, which has high theoretic faradaic capacitance. However, self-aggregation of LDHs nanosheet usually restricts their energy storage performances. Microspheres materials possess high specific surface area and structure stability, which provide a promising method to address the issue of aggregation in LDHs nanosheet. In this work, we present the one-step fabrication of NiCoAl-LDH microspheres with well-dispersed morphology and high electrochemically active surface area. The fabricated Ni 1 Co 2 Al 1 -LDH microspheres present specific capacitance of 451 F g−1 at current density of 5 A g−1, which is 1.92 times higher than that of conventional lamellar Ni 1 Co 2 Al 1 -LDH. Based on the Ni 1 Co 2 Al 1 -LDH microspheres, an all-solid-state asymmetric supercapacitor device was fabricated, giving high energy density, power density and long term cycling stability. This one-step growth of NiCoAl-LDH microspheres method has potential applications in large-scale manufacture of energy storage materials. Image 1 • Self-aggregation of LDHs nanosheet restricts their energy storage performances. • LDHs microspheres materials draw lots of attention due to the high specific surface area and structure stability. • NiCoAl-LDH microspheres were prepared by one-step growth method. • This one-step growth method has potential applications in large-scale manufacture. [ABSTRACT FROM AUTHOR]