Performance Modulation through Synergetic Effect of Interstitial Water with Ti-substitution for Sodium Ion Battery Cathode

In this study, a novel P2-type sodium manganese oxide is presented using a facile preparation method. With the help of titanium doping, and introduction of interstitial water, the electrochemical performances of as-prepared nanosized material are greatly improved. Redox titration results indicate that a small amount substitution of Mn with Ti increases the manganese valance state, and an extended solid solution zone is observed in the initial charge-discharge curves. Electrochemical impedance spectroscopy results manifest that the charge transfer resistance is greatly reduced, and sodium ion diffusion is improved. The performance modulation in this work highlights the synergetic effect for the material design.