Sodium substitution for partial lithium to significantly enhance the cycling stability of Li2MnO3 cathode material

Monoclinic layered Li2MnO3 has been extensively investigated due to its large discharge capacity. However, the poor cycling stability hinders its application as a cathode material of lithium-ion batteries. Herein we present a new strategy of sodium substitution for partial lithium to significantly enhance the cycling stability of Li2MnO3 through a conventional solid state reaction. In the electrochemical window of 2.0-4.6 V vs. Li/Li+, Li1.90Na0.10MnO3 delivers an initial discharge capacity of 181 mAh g−1 with an excellent capacity retention of 99.3% after 45 cycles at 1/10 C, and 161 mAh g−1 with a capacity retention of 98.6% after 100 cycles at 1/2 C. Sodium substitution for partial lithium is promising to make Li2MnO3 be practically applied at a low current density.