Suppressing capacity fading and voltage attenuation by constructing organic interlayer in Li1.2Ti0.4Mn0.4O2 cation-disordered cathode

A typical cation-disordered rock-salt oxide, Li1.2Ti0.4Mn0.4O2, is considered as one of the most promising cathode candidate materials for the next generation of lithium-ion battery due to its high specific capacity, outstanding energy density, low cost and nature abundant resource. However, rapid capacity fading and voltage attenuation originated from severe oxygen release at the surface of Li1.2Ti0.4Mn0.4O2 seriously hindered its practical application. To date, carbon coating strategy has been proposed to suppress oxygen release. But the poor actual effect and accompanying capacity loss caused by onefold carbon layer herald carbon is not a suitable coating material for Li1.2Ti0.4Mn0.4O2. Herein, a specific organic interlayer is constructed via the polymerization of 3,4-ethylenedioxythiophene (EDOT), by which dense and conductive poly EDOT layer is adhered between Li1.2Ti0.4Mn0.4O2 core and carbon layer. The novel interlayer modification strategy can effectively restrain oxygen release and significantly improve the electrochemical performance of Li1.2Ti0.4Mn0.4O2. This work demonstrates the practicability and feasibility of carbon layer and EDOT interlayer cooperative coating strategy for optimizing the electrochemical performance of cation-disordered rock-salt oxides.