2,2′-Bis(3-hydroxy-1,4-naphthoquinone)/CMK-3 nanocomposite as cathode material for lithium-ion batteries

Abstract

An inorganic–organic nanocomposite with the filling of 2,2′-bis(3-hydroxy-1,4-naphthoquinone) (H₂bhnq) in the pores of CMK-3 mesoporous carbon, which was synthesized by a simple impregnation method, was employed as a new cathode material for rechargeable lithium-ion batteries (LIBs). The characterization of the nanocomposite by wide-angle and low-angle X-ray diffraction, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the efficient loading of H₂bhnp within the nanosized pores of CMK-3 carbon. The nanocomposite delivered an initial discharge capacity of 308.6 mAh g⁻¹ at 0.1 C rate and a capacity retention of 202.6 mAh g⁻¹ after 50 cycles. The reversible capacities were 124.0 mAh g⁻¹ at a higher rate of 10 C. The enhanced cycling stability and high-rate capability is attributed to the fact that neat H₂bhnq was distributed in the nanochannels of the conductive carbon framework CMK-3. This constrains the dissolution of the embedded H₂bhnq. The results imply that the nanoconfinement with the pores of inorganic materials such as CMK-3 to fill organic active materials is important to improve the electrochemical performance of lithium-ion batteries.