LithiumManganoxid

LithiumManganoxid, also known as lithium manganate, is a class of oxide compounds that contain lithium, manganese, and oxygen. The family includes stoichiometric and non-stoichiometric materials such as LiMnO2 and LiMn2O4, and related phases formed by varying lithium content and manganese oxidation states. These materials are of interest mainly as cathodes for lithium-ion batteries.

Structurally, lithium manganese oxides can adopt several motifs. The spinel LiMn2O4 features a three-dimensional lithium diffusion network and mixed-valence manganese (Mn3+/Mn4+), while layered LiMnO2 provides two-dimensional lithium layers with Mn in octahedral coordination. The exact phase composition influences voltage, capacity, and stability. Mn dissolution into the electrolyte is a common degradation mechanism that limits cycle life.

Synthesis methods include solid-state reactions from lithium and manganese precursors, sol-gel processes, and hydrothermal routes. Doping with metals such as nickel, cobalt, or aluminum and surface coatings improve structural stability, electronic conductivity, and resistance to dissolution. Particle size and morphology influence rate capability and cycle life.

Applications include use as cathodes in lithium-ion cells. They offer low cost and wide manganese availability but generally provide lower energy density and limited high-voltage stability compared to some alternatives. Research focuses on doping, nanostructuring, and composites to improve capacity retention and safety.

Environmental and safety considerations include abundant feedstocks and recycling challenges. Like other transition-metal oxides, manganese dissolution can affect performance, and electrolyte compatibility is important to ensure stability during cycling.