Pulsed laser deposition of the porous nickel oxide thin film at room temperature for high-rate pseudocapacitive energy storage

This work reports the pulsed laser reactive deposition of the NiO thin film by ablating nickel targets in low-pressure O2 atmosphere at room temperature. The electrode exhibits a porous structure, which facilitates ion transport in the electrode/electrolyte. When applied as an electrode, the porous NiO film exhibits the high specific capacitance (835 F g− 1 at 1 A g− 1). Meanwhile, the film exhibits a superb rate capability. At a very high current density of 40 A g− 1 there is more than 59% retention in the capacitance relative to 1 A g− 1. Furthermore, the excellent cycling performance (94% capacitance retention after 1000 cycles) is achieved for the film electrode. These results demonstrate that pulsed laser deposition (PLD) is a very promising technique for making the film electrodes for applications in electrochemical energy storage.

► Laser ablated nickel atoms and ions react with O2 to form NiO thin film.
► The electrode exhibits a porous structure and demonstrates a respectable specific capacitance of 835 F g− 1.
► The NiO film structure exhibits a superb rate capability.
► The excellent cycling performance (without degradation after 1000 cycles) is achieved.