Synthesis of Two-Dimensional Sr-Doped LaNiO₃ Nanosheets with Improved Electrochemical Performance for Energy Storage

Designing a novel, efficient, and cost-effective nanostructure with the advantage of robust morphology and outstanding conductivity is highly promising for the electrode materials of high-performance electrochemical storage device. In this paper, a series of honeycombed perovskite-type Sr-doped LaNiO₃ nanosheets with abundant porous structure were successfully synthesized by accurately controlling the Sr-doped content. The study showed that the optimal LSNO-0.4 (La_0.6Sr_0.4NiO_3-δ) electrode exhibited excellent electrochemical performance, which showed a high capacity of 115.88 mAh g^-1 at 0.6 A g^-1. Furthermore, a hybrid supercapacitor device (LSNO//AC) based on LSNO-0.4 composites and activated carbon (AC) showed a high energy density of 17.94 W h kg^-1, a high power density of 1600 W kg^-1, and an outstanding long-term stability with 104.4% capacity retention after 16,000 cycles, showing an excellent electrochemical performance and a promising application as an electrode for energy storage.