Spinel-layered integrate structured nanorods with both high capacity and superior high-rate capability as cathode material for lithium-ion batteries

Spinel phase LiMn₂O₄ was successfully embedded into monoclinic phase layeredstructured Li₂MnO₃ nanorods, and these spinel-layered integrate structured nanorods showed both high capacities and superior high-rate capabilities as cathode material for lithium-ion batteries (LIBs). Pristine Li₂MnO₃ nanorods were synthesized by a simple rheological phase method using α-MnO₂ nanowires as precursors. The spinel-layered integrate structured nanorods were fabricated by a facile partial reduction reaction using stearic acid as the reductant. Both structural characterizations and electrochemical properties of the integrate structured nanorods verified that LiMn₂O₄ nanodomains were embedded inside the pristine Li₂MnO₃ nanorods. When used as cathode materials for LIBs, the spinel-layered integrate structured Li₂MnO₃ nanorods (SL-Li₂MnO₃) showed much better performances than the pristine layered-structured Li₂MnO₃ nanorods (L-Li₂MnO₃). When charge-discharged at 20 mA·g^-1 in a voltage window of 2.0-4.8 V, the SL-Li₂MnO₃ showed discharge capacities of 272.3 and 228.4 mAh·g^-1 in the first and the 60th cycles, respectively, with capacity retention of 83.8%. The SL-Li₂MnO₃ also showed superior high-rate performances. When cycled at rates of 1 C, 2 C, 5 C, and 10 C (1 C = 200 mA·g^-1) for hundreds of cycles, the discharge capacities of the SL-Li₂MnO₃ reached 218.9, 200.5, 147.1, and 123.9 mAh·g^-1, respectively. The superior performances of the SL-Li₂MnO₃ are ascribed to the spinel-layered integrated structures. With large capacities and superior high-rate performances, these spinel-layered integrate structured materials are good candidates for cathodes of next-generation high-power LIBs.