Examining the charging behaviour of nickel hydroxide nanomaterials

To investigate the depth of charging at the material surface, batches of nickel hydroxide nanoparticles were hydrothermally synthesised in the range 3–450 nm. Any surfactant added was removed post synthesis using ozone. The capacity per gram (Cs) increased and the capacity per unit area (CA) was constant with decreasing particle size down to 20 nm. Further reduction in particle size resulted in a decrease in both CS and CA, suggesting the Ni(OH)2 is charged to a depth in the order of 10 nm at the charging rate studied. The results obtained have implications in the design of Ni(OH)2 electrodes in charge storage applications. [Display omitted] •Nanoplates of Ni(OH)2 with diameters 3–450 nm were synthesised hydrothermally.•Capacity/g was greatest for a particle size of 20 nm.•Capacity/area was constant for particle sizes >20 nm.•Capacity/area decreased with decreasing diameter for particles