NaCoO2

Sodium cobalt oxide, with the chemical formula NaCoO2, is an inorganic compound belonging to the family of layered transition metal oxides. It is characterized by its layered structure, where layers of cobaltate (CoO2) are interleaved with sodium ions (Na+). This specific arrangement of atoms is crucial to its physical and chemical properties.

NaCoO2 exists in several crystallographic forms, most notably the alpha (α) and beta (β) phases. These phases differ in the arrangement of sodium ions and the stacking of cobalt-oxygen layers, leading to distinct electrochemical behaviors. The compound is typically synthesized through solid-state reactions at high temperatures or electrochemical methods.

The primary interest in NaCoO2 stems from its applications as a cathode material in rechargeable sodium-ion batteries. Its layered structure allows for the reversible insertion and extraction of sodium ions, which is the fundamental process in battery operation. The electrochemical performance, such as capacity and cycle life, is highly dependent on the specific phase and synthesis method of NaCoO2. While it offers potential as a cost-effective alternative to lithium-based battery materials, research continues to optimize its stability and energy density for practical applications. Beyond batteries, NaCoO2 has also been explored for its catalytic properties.