Control of Chemical Structure in Core–Shell Nanocrystals for the Stabilization of Battery Electrode/Electrolyte Interfaces

Undesired reactions at electrode/electrolyte interfaces impose challenges in the durability of Li-ion battery. Traditional strategies of interfacial stabilization involve coating with inactive oxide films on aggregated powders of active cathode oxides. Despite generating gains in electrode performance, the lack of control of film growth of existing methods limits the ability to design its chemical structure and enhance functionality. The complexity of these coated materials also complicates efforts to define the specific chemical and structural features that determine function. Core–shell heterostructures at the nanocrystal level offer opportunities for precise control of chemistry and homogeneity. This ability is demonstrated with the compositional and structural tailoring of passivating layers based on Al3+, grown conformally onto LiCoO2 nanoplates, using thermal treatments. They result in heterostructures from core–shell (LiCoO2 nanoplates@2 nm aluminum oxide) to LiCo1–xAlxO2 gradient structures compos...