Ordering-Controlled Ultrafast Synthesis of High-Entropy Alloy Catalysts on Cellulose-Derived Boron-Doped Flash Graphene for Long-Life Neutral Zinc-Air Batteries

Developing robust electrocatalysts for neutral zinc-air batteries (ZABs) is critical for safe energy storage but is currently restricted by the trade-off between synthesis efficiency and structural stability. Herein, we report an ordering-controlled ultrafast synthesis strategy to transform renewable cellulose into boron-doped flash graphene-supported high-entropy alloy catalysts (PtFeCoNiMn/B-FG) via Flash Joule Heating (FJH). Unlike traditional long-duration annealing, the millisecond-scale thermal shock of FJH not only achieves instantaneous atomic diffusion and firm compositing with the conductive substrate in one step, but also uniquely induces a partial disorder-to-order phase transition by controlling the annealing conditions. Structural characterizations reveal that the presence of a thermodynamically stable ordered intermetallic phase provides structural stabilization, which suppresses metal dissolution. Concurrently, boron doping modulates the electronic structure of Pt and ensures robust anchoring of the alloy nanoparticles. Benefiting from this synergistic structural and electronic engineering, the PtFeCoNiMn/B-FG catalyst exhibits superior oxygen reduction performance with a half-wave potential of 0.69 V in neutral media. Consequently, the assembled neutral ZAB achieves a high open-circuit voltage of 1.41 V and a sustained cycling stability of 985 h at a current density of 2 mA·cm–2, markedly outperforming commercial Pt/C. This work demonstrates a simple, rapid, and environmentally friendly synthesis pathway for high-entropy alloy (HEA) composites, providing insights for the development of high-performance and durable neutral oxygen reduction reaction (ORR) catalysts.