Improved electrochemical performance of spinel LiMn2O4 derived from manganese-based metal–organic frameworks by organic ligands

Abstract

The spinel LiMn₂O₄ cathode has received substantial attention from researchers owing to its high voltage plateau, eco-friendliness, and cost-effectiveness. Nevertheless, its practical application has been impeded by severe capacity attenuation due to the Jahn–Teller effect and spontaneous disproportionation reaction. To overcome these issues, this study synthesized a series of manganese-based metal–organic frameworks with varying structures using aromatic carboxylic acids that contain different numbers of carboxyl groups as organic frameworks. These frameworks were then used as precursors for synthesizing spinel LiMn₂O₄ cathode materials. This approach aims to enhance capacity, cycle stability, and rate performance by reducing the diffusion resistance of lithium ions, exposing the (111) plane, and increasing the Mn³⁺ content. The LMO-PMA sample exhibited remarkable cycling stability (91.4% after 1000 cycles at 10C) and superior capacity (140.2 mA h g⁻¹ at 0.2C, 113.1 mA h g⁻¹ at 10C). This approach can be extended to the synthesis of other cathode materials.