The Effect of Interdiffusion on the Properties of Lithium-Rich Core-Shell Cathodes

Abstract

To obtain the highest energy density, lithium ion batteries based on layered Li-Ni-Mn-Co oxides need to be charged to above 4.5 V without sacrificing lifetime. Lithium-rich core-shell (CS) structured positive electrodes having a high energy density core material with poor stability against the electrolyte can be protected by a thin layer of a stable shell material. In this work, the effects of the initial shell thickness, sintering temperature and interdiffusion during sintering on the electrochemical performance of CS cathodes were studied for the first time to our knowledge. Full cell coin cells of selected CS samples with electrolyte additives showed good capacity retention. This work will help guide the design of next generation positive electrode materials using CS and coating strategies.