Synthesis of Mesoporous Rod-Like MnC₂O₄/MWCNT Composite Anode Material for Lithium-Ion Batteries

MnC₂O₄ is a promising anode material for Li-ion batteries. However, MnC₂O₄ suffers from poor performance due to its low conductivity and volume change in cycles. Herein, a strategy based on the surface charge and flexibility of multiwalled carbon nanotubes (MWCNT) was developed to improve the performance of MnC₂O₄, and a rod-like mesoporous MnC₂O₄/MWCNT composite was prepared via simple precipitation in water. The [Mn(H₂O)_n]²⁺–MWCNT complex was formed through electrostatic attraction between [Mn(H₂O)_n]²⁺ and the surface charge of MWCNT, which acted as the nucleation site of the manganese oxalate rod. The flexibility of the MWCNT allowed it to curl and twine in the rod and wrap over the surface of the rod. Introducing MWCNT created abundant mesopores and a three-dimensional conductive network. This prepared composite delivered capacity of 1004 mA h/g and 983 mA h/g after 600 cycles at 2 A/g and 5 A/g, respectively. As a comparison, the capacity of the MnC₂O₄ rod without MWCNT was only 345 mA h/g and 270 mA h/g under the same conditions. The excellent performance of the MnC₂O₄/MWCNT composite can be ascribed to the abundant mesoporous structure and 3D conductivity network created by MWCNT, which enhance the conductivity, accelerate electrode kinetics, and alleviate the volume change in cycles.