Aluminum-doped high-entropy oxide pyrochlore for enhanced lithium storage

High-entropy oxides (HEOs), composed of five or more distinct metal ions within a unified crystalline lattice, exhibit exceptional electrochemical capacity and catalytic properties. These characteristics make them highly valued materials for lithium-ion batteries (LIBs). However, their inherent low conductivities pose a significant challenge to further advancements in HEO development. Herein, a new kind of HEO, (Y_0.2La_0.2Ce_0.2Ca_0.2Mg_0.2)₂(Sn_1-xAl_x)₂O₇ is synthesized via a facile co-precipitation reaction, with various aluminum (Al) content doping (x = 0, 0.05, 0.1, 0.15). The optimized sample (x = 0.1) exhibits a superior initial discharge specific capacity of 1209.9 mAh g⁻¹ at 0.1 mA g⁻¹. This study provides clear evidence that incorporating metal doping into the structure of HEOs is an exceptionally effective strategy for enhancing its electrochemical performance as anode materials in LIBs.