Expanded spinel ZnMnO induced by electrochemical activation of glucose - mediated manganese oxide for stable cycle performance in zinc - ion batteries.

Rechargeable aqueous Zn - MnO batteries show great potential for grid - scale storage due to cost - effectiveness and high safety. However, most of MnO cathodes suffer from irreversible phase transformation into spinel ZnMnO with reduced electrochemical activity after repeated charge/discharge cycles, leading to severe capacity decay. Herein, we reveal a strategic design utilizing glucose as the mediating agent to prepare nanostructured MnO/MnO material, which can be then transformed into lattice - expanded ZnMnO nanoparticles by electrochemical activation. The expanded structure of ZnMnO allows better accommodation of Zn and H ions and undergoes reversible lattice expansion/contraction during charge/discharge process. Therefore, the lattice - expanded ZnMnO retains 121 mAh g after 2000 cycles at 1 A g, exhibiting stable cycle performance in comparison with the parent MnO (63 mAh g) and well - crystalline ZnMnO (58 mAh g). Moreover, through the comparison of MnO/MnO, MnO/MnO, and pure MnO samples, MnO is found to play an important role in forming lattice - expanded spinel structure during the activation process.