Preparation of Nickel-Cobalt Layered Double Hydroxides for the Battery-like Electrodes in Rotor–Stator Reactor

Abstract

Nickel-cobalt layered double hydroxides (NiCo LDHs) with different Ni/Co ratios were prepared using rotor-stator reactor technology. The morphology, crystal structure, pore size distribution and electrochemical properties were characterized and the band structure was calculated with LDA+U method in CASTEP code based on density functional theory. The results show that the band gap value of Ni5Co3O16H16 decreases compared to that of Ni8O16H16. The pore size increases and the pore size distribution widens with the increasing cobalt content in the NiCo LDHs. The NiCo LDH with a Ni/Co ratio of 2: 1 has a surface area of 139.9 m(2) g(-1) and a specific capacity of 176.7 mA h g(-1) at a current density of 1 A g(-1) in 6 M KOH. The electrode also exhibits good cycling stability and the capacity retention still remains 98 % after 1000 cycles.