3D‐Printing of High‐Entropy Triple‐Phase Catalytic Micro‐Reactors toward Ultra‐High‐Rate Li‐O 2 Batteries

ABSTRACT Lithium‐oxygen (Li‐O 2 ) batteries possess an ultrahigh theoretical specific energy, rendering them promising candidates for next‐generation energy storage technologies. However, their practical application is critically hindered by sluggish redox kinetics and mass transport at the Li + /e − /O 2 triple‐phase boundary (TPB). Herein, we report the first design and fabrication of 3D‐printed high‐entropy La 0.8 Sr 0.2 (Cu 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Co 0.2 )O 3 triple‐phase catalytic microreactors (3DP@LSM5O) in Li‐O 2 batteries, achieving synergistic improvement in mass transport and redox kinetics. These microreactors constitute a hierarchical porous conductive network with vertically aligned macro‐micro channels that homogeneously encapsulate the LSM5O catalyst. This integrated architecture creates a harmonious TPB environment, enabling fast electronic conductivity, sufficient and instantaneous ion supply, and rapid oxygen diffusion highways without discharge products blocking the channels. In parallel, Sr 2 + doping introduces tensile strain into the LSM5O catalyst, fine‐tuning the Ni d‐band center and strengthening Ni 3d‐O 2p orbital hybridization, which collectively accelerates interfacial charge transfer and redox reversibility. Consequently, the 3DP@LSM5O electrodes deliver a record‐high areal capacity of 33.6 mAh cm −2 , outstanding cycling stability over 244 cycles, as well as an ultra‐high‐rate performance at a current density of 5 mA cm −2 , surpassing all previously reported 3D electrodes. This work offers a generalizable strategy for TPB microenvironment engineering, advancing metal‐air batteries toward practical implementation.