Laser rapid synthesis of ultra-small Ni nanoparticles embedded graphene for high-performance supercapacitors

Conductive carriers embedded with ultra-small metal nanoparticles have great potential in energy conversion and storage, but it is still a challenge to develop large-scale, cost-effective and rapid fabrication methods. Herein, we demonstrated that the precursors of graphene oxide and nickel salt can be easily transformed into ultra-small Ni nanoparticles (515 nm) anchored on reduced graphene oxide (RGO@Ni) via a simple laser instantaneous heating method. Without the need for a binder, the prepared RGO@Ni-based electrode material can be directly patterned into a micro energy storage device. As a potential application of the prepared RGO@Ni with this unique structure, we evaluated its electrochemical performance. Considering the synergistic effect of the surface oxide layer of ultra-small Ni nanoparticles and RGO, the RGO@Ni based electrodes exhibit high areal specific capacitance exceeding 51.5 mF cm-2. This is much greater than that of pure RGO electrode materials. This work gives a fast and effective strategy for the rapid preparation of RGO@Ni composite materials and the elevation of capacitor performance.