Scalable, Binderless, and Carbonless Hierarchical Ni Nanodendrite Foam Decorated with Hydrous Ruthenium Dioxide for 1.6 V Symmetric Supercapacitors.

Herein, Ni nanodendrite (ND) with diameter ≈30-100 nm directly synthesized on Ni foam is utilized as an effective support for hydrous RuO₂ in symmetric supercapacitors operated at 1.6 V. Highest specific capacitance 678.57 F g⁻¹ can be achieved with energy density 60.32 Wh kg⁻¹. Even at large current density 100 A g⁻¹, high energy density 19.73 Wh kg⁻¹ can still be maintained with power density 40 kW kg⁻¹ owing to the pristine metal nanostructure without any carbon additive and resistive binder. Long lifespan is shown with marginal performance improvement (≈4%) over 10 000 cycles. More importantly, the template-less and self-assembled Ni ND synthesis requires only low temperature and eco-friendly chemicals, and can be simply dip-coated with RuO₂ nanoparticles. All of these render the RuO₂-Ni ND foam readily adapted into mass manufacturing without efforts. [ABSTRACT FROM AUTHOR]