Porous CoC₂O₄/Graphene Oxide Nanocomposite for Advanced Potassium-Ion Storage.

Potassium-ion batteries (PIBs), as one of the alternatives to lithium-ion batteries (LIBs), have attracted considerable attention on account of the affluence and low-cost of potassium. Moreover, CoC₂O₄ and graphene oxide (GO) have been used very well in lithium-ion batteries. Hence, the hybrid CoC₂O₄/GO was investigated as a new anode material for PIBs. The hybrid CoC₂O₄/GO was synthesized by a facile and cheap method combined with supersonic dispersion. Electrochemical measurements reveal that the hybrid CoC₂O₄/GO delivered an excellent cycling stability of 166 mAh g at 50 mA g and a superior rate capability even at 1 A g. These results demonstrate although the cycle ability was insufficient for practical applications, transition-metal oxalates composites can still bring new hope to the development of PIBs.