Photonic Synthesis and Coating of High‐Entropy Oxide on Layered Ni‐Rich Cathode Particles

High‐entropy materials have drawn much attention as battery materials due to their distinctive properties. Lithiated high‐entropy oxide (Li₀.₃₃(MgCoNiCuZn)₀.₆₇O, LiHEO) exhibits both high lithium‐ion and electronic conductivity, making it a potential coating material for layered Ni‐rich oxide cathodes (Li₁₊ₓ(Ni₁₋y₋zCoyMnz)₁₋ₓO₂, NCM or NMC) in conventional Li‐ion battery cells; however, high‐temperature synthesis limits its application. Therefore, a photonic curing strategy is used for synthesizing LiHEO and the non‐lithiated form (denoted as high‐entropy oxide [HEO]), and nanoscale coatings are successfully produced on LiNi₀.₈₅Co₀.₁Mn₀.₀₅O₂ (NCM851005) particles. To one's knowledge, this is the first report on particle coating with high‐entropy materials using photonic curing. NCM851005 with LiHEO‐modified surface shows good cycling stability, with a capacity retention of 97% at 1 C rate after 200 cycles. The improvement in electrochemical performance is attributed to the conformal coating that prevents structural changes caused by the reaction between cathode material and liquid electrolyte. Compared to bare NCM851005, the coated material shows a significantly reduced tendency for intergranular cracking, successfully preventing electrolyte penetration and suppressing side reactions. Overall, photonic curing presents a novel cost‐ and energy‐efficient synthesis and coating procedure that paves the way for surface modification of any heat‐sensitive material for a wide range of applications.