Three-dimensional architectures of spinel-type LiMn₂O ₄ prepared from biomimetic porous carbonates and their application to a cathode for lithium-ion batteries

We demonstrated nanostructural control of a functional material for electrochemical applications by using a biomimetic solution route. A nanoscopically ordered architecture of calcite-type MnCO₃ nanocrystals mimicking hierarchical structures of biological CaCO₃ was successfully produced in an organic gel matrix. A highly porous structure of spinel-type LiMn₂O₄ was produced as a cathode material for lithium-ion batteries from the ordered MnCO₃ architecture through nanocrystalline Mn₂O₃ as an intermediate phase. The rigid framework consisting of connected LiMn₂O₄ nanoparticles provided high durability in a lithium insertion/extraction process at a high current density due to a high porosity for the electrochemical reaction and three-dimensional channels for ion diffusion.