Novel application of CoAl-layered double hydroxide/reduced graphene oxide nanocomposite as a highly efficient cathode additive for nickel-based secondary batteries

A series of Co-Al layered double hydroxide (Co-Al LDHs)@reduced graphene oxide (rGO) nanocomposite are successfully synthesized through a hydrothermal method and applied as novel cathode additives for nickel-based secondary batteries for the first time. The obtained Co-Al LDHs@rGO nanocomposite is composed of many thin nanosheets, displaying laminated structure. The effects of various Co-Al LDHs@rGO on the properties of nickel cathodes were compared and its action mechanism was further investigated. Interestingly, the Ni(OH)(2) electrode added with Co-Al LDHs@rGO(10%) delivers best high-rate performances and more stable cycling stability as comparison with the pure Ni(OH)(2) and Ni(OH)(2)+CoO electrodes. Owing to its soft and flexible structure, Co-Al LDHs@rGO(10%) is conducive to modify the electronic conductivity, proton diffusion and electrochemical reversibility of the electrode by forming a more effective and stable conductive network. Especially, Co-Al LDHs@rGO(10%) with high electrochemical activity can contribute much higher discharge capacity than the commercial CoO. Owing to its high efficiency and low cobalt content, Co-Al LDHs@rGO(10%) can be applied as an effective, cheap, and promising cathode additive for nickel-based rechargeable batteries. (C) 2019 Elsevier Ltd. All rights reserved.