Nickel-based layered double hydroxide from guest vanadium oxide anions

The layered double hydroxides (LDHs) are well known for ionic exchange properties to intercalate anionic compound in interlayer region. The Ni/V LDH composite was explored by co-precipitation method. The maximum capacitance of Ni/V LDH composite was 2612 F g^-1 at the scan rate 2 mV s ^-1. As-synthesized Ni/V LDH composite provides a three-dimensional conducting network frame for manifesting electrochemical capacitance. This is because the insertion of vanadium oxide anions (VO_x ^-) into nickel interlayer space between nickel layers is compensated for hydroxyl vacancies during synthesis of lower-pH condition. The network frame makes it possible to promote fast electron transfer for Ni/V LDH composite electrode material and consequently allows the improvement of the electronic conductivity for Ni/V LDH composite electrode material. Thus, the Ni/V LDH composite exhibits high capacitance than β-Ni(OH)₂ due to its unique properties, with vanadium oxide anions embedded in the turbostratic structure and shorter diffusion pathway.