Controllable growth of LiMn₂O₄ by carbohydrate-assisted combustion synthesis for high performance Li-ion batteries

LiMn₂O₄ (LMO) spinels with diverse achievable morphologies are realized using solution processing techniques including sol-gel and cofuel-assisted combustion synthesis (CS). These LMOs are utilized as cathode materials in lithium ion batteries (LiBs), with LMO produced here by low-temperature, sorbitol-assisted combustion synthesis (SA-CS) yielding superior performance metrics. Morphological analysis by combined X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy demonstrates that these SA-CS LMO powders have optimum LiB grain (<500 nm) and crystallite (~30 nm) dimensions as well as spinel phase purity. Cathode mixtures having micron-scale, uniformly distributed LMO, conductive carbon, and a polymer binder provide effective electron and Li transport as assessed by electrochemical impedance spectroscopy and fabricated battery performance, showing high capacity (~120 mA h/g), good cycling stability (~95% capacity retention after 100 charge/discharge cycles), and high charge/discharge rates (up to 86 mA h/g at 10 C). SA-CS provides a simple, efficient, lower temperature, and scalable process for producing morphology-controlled high-performance LiB cathode oxides.