Cyclability of binder-free β-Ni(OH)2 anodes shaped by EPD for Li-ion batteries

The electrochemical behaviour of β-Ni(OH)2 based anodes in Li-ion batteries (LIB) was analyzed. β-Ni(OH)2 nanoplatelests evidence an additional capacity ascribed to secondary reactions, while the high reversibility is related to the catalytic activity of the Ni nanoparticles within the nanostructure. In this manuscript we discuss the influence of the micro-architecture of the films shaped by electrophoretic deposition (EPD) in the electrochemical behaviour of the Li cell, when β-Ni(OH)2 has been considered as the active material. By EPD, the β-Ni(OH)2 nanoplatelets packed preferentially aligned parallel to their basal planes leading to a well-ordered and dense microstructure. Apart from the mesoporosity of the β-Ni(OH)2 nanoplatelets and its particular crystallography, the increase of packing density and connectivity are the key points affecting the electrochemical response of the anodes. A highly ordered and interconnected microstructure promotes the electrode stability during cycling and, although the additional capacity delivered due to the side reactions decreases, the electrolyte and the connectivity degradation are prevented. Microstructures of the densest structures maintain the delivered capacity of the anode at 600 mA h/g, close to the theoretical value, for more than 30 cycles.