Mesoporous multi-valence manganese oxides composite nanotubes boosting long-life lithium-ion batteries

Multi-component nano-oxide composite materials may present special synergistic effects as anode materials for lithium-ion batteries. Mesoporous β-MnO₂/Mn₃O₄ composite nanotubes are built here via controlling the deoxidation process of carbon-coating to induce a partial phase transition of high valence manganese dioxides. Compared to single β-MnO₂ nanotubes or Mn₃O₄@C nanotubes, the mesoporous β-MnO₂/Mn₃O₄@C composite nanotubes exhibit superior electrochemical properties. 679 mA h g^-1 of reversible specific capacity and 86% of capacity retention after 1000 cycles at 1 A g^-1 current density are obtained. The excellent performance is attributed to the unique multiple phase transitions regulation phenomena of manganese oxide occurring in the β-MnO₂/Mn₃O₄ composite material during the electrochemical processes, which significantly extends the cycle life of the β-MnO₂/Mn₃O₄ composite material.