Ni@NiO core/shell dendrites for ultra-long cycle life electrochemical energy storage

Abstract

A dendritic Ni@NiO core/shell electrode (DNE) is successfully fabricated by electrodeposition in a Ni-free electrolyte, with a Ni anode providing Ni ions through dissolution and diffusion. The unique structure is ideal for electrochemical energy storage since the dendrites provide a large surface area for easy electrolyte infiltration; the metal core improves the electrode conductivity with a shortened ion diffusion path, and the metal oxide shell is active for faradaic charge storage. As a result, the synthesized DNE demonstrates a high specific capacitance of 1930 F g À1 and a high areal capacitance of 1.35 F cm À2 , with super-long cycle stability. The gravimetric capacitance of the DNE hardly shows any decay after 70 000 cycles at a scan rate of 100 mV s À1 . It was also demonstrated that our electrodeposition method in a source-free electrolyte is universal to deposit dendritic Ni-compounds on many other types of substrates, versatile for different applications.

Design of Hierarchical NiCo@NiCo Layered Double Hydroxide Core–Shell Structured Nanotube Array for High‐Performance Flexible All‐Solid‐State Battery‐Type Supercapacitors

“…A novel 3D core/shell structured Co 3 O 4 @Ni(OH) 2 has to be fabricated by hydrothermal reaction, followed by a chemical bath deposition . Recently, we developed a simple and efficient electrodeposition in a source‐free electrolyte to fabricate Ni@NiO core/shell dendrites, which paved the way for the simple synthesis of metal@metal oxide or hydroxide core/shell structures.…”

Hierarchical Molybdenum Dioxide Microflowers Encapsulating Nickel Nanoparticles for High‐Performance Lithium‐Ion Battery Electrodes

“…Due to high intrinsic activity and abundant applications in electronics, catalysis and supercapacitors, the metallic atoms have received tremendous attention . Taking an example of nickel, as a good internal electronic conductor support, it can prompt the electron hopping and benefit the total conductivity when incorporated in the anode materials for LIBs .…”

Nanoflakes‐Assembled 3D Flower‐Like Nickel Oxide/Nickel Composites as Supercapacitor Electrode Materials

“…The high‐resolution Ni 2p spectrum in Figure d can be fitted with two spin–orbit doublets and two shakeup satellites by using a Gaussian fitting method. The peaks at 855.1 and 872.8 eV correspond to Ni 2p 3/2 and Ni 2p 1/2 , respectively, accompanied by satellite peaks at 860.6 and 879.1 eV . The difference in binding energy between Ni 2p 1/2 and Ni 2p 3/2 of 17.7 eV matches well with the electronic states of NiO .…”