Well-crystallized Na_0.44MnO₂ is readily synthesized via a facile NaCl -flux reaction at 850°C for 5 h. The Na_0.44MnO₂ material exhibits a well-defined nanoribbon structure with dimension of 50–100 nm in thickness and 200–500 nm in width. Electrochemical properties of as-prepared Na_0.44MnO₂ are thoroughly investigated on assembled nonaqueous Na_0.44MnO₂ // Na cells using cyclic voltammetry, galvanostatic test, and electrochemical impedance spectroscopy. The results show that the Na_0.44MnO₂ nanoribbon material can deliver a high capacity of 106 mAh g^-1 with stable cycling performance over 40 cycles. In addition, it exhibits a favorable rate capability, delivering a capacity of 90 mAh g^-1 at a rate of 1 C. The high capacity retention combined with acceptable rate capability makes the Na_0.44MnO₂ a promising electrode material for advanced Na -ion batteries.