Self-templated Synthesis of Nickel Silicate Hydroxide/Reduced Graphene Oxide Composite Hollow Microspheres as Highly Stable Supercapacitor Electrode Material

Table 1 Comparison of cycling stability between Ni₃Si₂O₅(OH)₄/RGO composite hollow microspheres and some of other reported nickel-based electrode materials. All these data were obtained in three-electrode systems

Electrode materials	Current density (A g^–1)	Number of cycles	Capacitance retention (%)	Ref.
Ni₃Si₂O₅(OH)₄/RGO composite hollow microspheres	6	5000	97.6	This work
NiO nanoparticles	2	1000	60.6	[35]
NiO nanosheet hollow spheres	3	1000	91	[36]
Nanoporous Ni(OH)₂	1	2000	92.3	[37]
Porous Ni(OH)₂/NiOOH composite film	2	1000	81	[38]
Doughnut-like Ni(OH)₂–Co(OH)₂ composites	5	1000	84.7	[39]
Ni(OH)₂–Ni nanohybrids	5	2000	98.4	[40]
Mesoporous NiCo₂O₄ nanosheets	2	2400	94	[41]
Urchin-like NiCo₂O₄ nanostructures	8	2000	90.8	[42]
Mesoporous Ni_0.3Co_2.7O₄ hierarchical structures	0.625	3000	98.1	[43]
RGO/NiCo₂O₄ nanoflake composites	4	2000	90.8	[44]
NiCo₂S₄ ball-in-ball hollow spheres	5	2000	87	[45]