In Situ Generated Ni₃Si₂O₅(OH)₄ on Mesoporous Heteroatom-Enriched Carbon Derived from Natural Bamboo Leaves for High-Performance Supercapacitors

Hybrids consisting of mesoporous carbon and uniform sized, regular morphology and even distributed metal silicate have been a challenge, although they are a potential promising material for electrochemical supercapacitor. In this work, we have synthesized a hybridized supercapacitor electrode of layered nickel silicate Ni3Si2O5(OH)4 nanoparticles on the porous carbon derived from calcined natural bamboo leaves (C-SiO2). The good combination of C-SiO2 and in situ generated layered nickel silicate, which turned out to be an outstanding electrode, demonstrates high specific surface area, multiporous structure, good electrical conductivity, and prominent electrochemical performance. For instance, the obtained C-NiSi-3 showed 132.4 F g–1 at a current density of 0.5 A g–1 and significantly maintained 100% after 10000 cycles. Furthermore, a flexible all-solid-state asymmetric supercapacitor device was assembled by C-NiSi-3 and Ni(OH)2. The device was suited to various bending angles and achieved a high capacitance (693.8 F cm–2 at the current density of 4 mA cm–2) and an energy density of 30.0 Wh kg–1. The results presented in this work reveal that the C-NiSi material is a promising candidate for fabricating supercapacitors with high performance, bending mechanical properties, and relatively low cost.