Single Crystalline Na0.7MnO2 Nanoplates as Cathode Materials for Sodium‐Ion Batteries with Enhanced Performance

Abstract Single crystalline rhombus‐shaped Na 0.7 MnO 2 nanoplates have been synthesized by a hydrothermal method. TEM and HRTEM analyses revealed that the Na 0.7 MnO 2 single crystals predominantly exposed their (100) crystal plane, which is active for Na + ‐ion insertion and extraction. When applied as cathode materials for sodium‐ion batteries, Na 0.7 MnO 2 nanoplates exhibited a high reversible capacity of 163 mA h g −1 , a satisfactory cyclability, and a high rate performance. The enhanced electrochemical performance could be ascribed to the predominantly exposed active (100) facet, which could facilitate fast Na + ‐ion insertion/extraction during the discharge and charge process.