The heterogeneous structure facilitates the rapid transport of lithium ions in novel single-crystal CoMn-MOF derivatives

Abstract

Transition metal sulphides and oxides have been identified as potential cathode materials for lithium-ion batteries with high initial capacity and high selectivity. Nevertheless, the low ground conductivity and volume expansion have constituted significant obstacles to the advancement of this field of study. In this study, the heterostructure CoMn₂O₄/MnS₂@C1-2-2 of MnS₂ and CoMn₂O₄ was obtained through high-temperature (Ar. 450 °C) calcination of a novel red single crystal [CoMn(TDC)]_n precursor. The resulting structure exhibited excellent lithium-ion transport properties. The biphasic heterostructure with a porous carbon framework is capable of forming a multitude of phase interfaces and conductive pathways, which facilitate charge migration, enhance conductivity, and expand the contact area with the electrolyte, thereby augmenting the charge transfer capability. The CoMn₂O₄MnS₂@C1-2-2 composite displays remarkable lithium storage capabilities, with a specific capacity of 689 mA h g⁻¹ even after 400 cycles at 0.5 A g⁻¹.