Conductive MOF-Derived Coating for Suppressing the Mn Dissolution in LiMn 2 O 4 toward Long-Life Lithium-Ion Batteries

Spinel lithium manganese oxide (LiMn O , LMO) is a promising cathode material with nontoxicity, high operating voltage, and low cost. However, structural collapse during battery cycling ─ caused by Mn dissolution and the Jahn-Teller effect ─ is a critical disadvantage, reducing cycle retention, particularly at high temperatures. In this study, to solve these critical issues, we introduce Cu (HITP) (CuHITP; HITP = 2,3,6,7,10,11-hexaiminotriphenylene), a conductive two-dimensional (2D) metal-organic framework (MOF) as a surface coating material. The CuHITP-derived coating increases the electrical conductivity and suppresses Mn dissolution by enriching the LMO surface with Mn . By suppressing Mn dissolution, structural stability also improves, offsetting the inherent problems. As a result, at 60 °C, CuHITP-LMO exhibits an initial capacity of 95.8 mAh g at 100 mA g and achieves a capacity of 42.4 mAh g after 300 cycles. This research highlights the potential of conductive 2D MOFs to improve the electrochemical performances of LMO.