Effect of crystallite size on lithium storage performance of high entropy oxide (Cr0.2Mn0.2Co0.2Ni0.2Zn0.2)3O4 nanoparticles

High-entropy oxides (HEOs), known for their high theoretical capacity and structural stability, are considered promising anode materials for next-generation lithium-ion batteries (LIBs). In this research, we synthesized a novel spinel-type HEO, (Cr0.2Mn0.2Co0.2Ni0.2Zn0.2)3O4, using a solution combustion method. By adjusting the quantity of the combustion agent, we produced samples with varying crystallite sizes. The crystallite size of the HEOs initially enlarges with an increased combustion agent, then diminishes. The enhancement of crystallite size correlates with improved electrochemical performance for lithium storage. Notably, the (Cr0.2Mn0.2Co0.2Ni0.2Zn0.2)3O4 nanoparticles, with the largest crystallite size of 36.3 nm, demonstrated a reversible capacity of 343 mA h g-1 after 100 cycles at 100 mA g-1, a capacity retention to 319 mA h g-1 after 1000 cycles at 1 A g-1, and a commendable rate capability of 260 mA h g-1 at 2 A g-1. This study underscores the pivotal role of crystallite size in LIB performance and presents a viable strategy to enhance the lithium storage capabilities of HEOs and other metal oxides. [Display omitted]