Ultrafast In-Situ synthesis of flexible MoO3 anode in five seconds for High-Performance aqueous zinc ion hybrid capacitor

Abstract

The efficient synthesis of high-performance α-MoO3 on flexible conductive substrates is crucial for enhancing its value in the field of energy storage. However, traditional synthesis methods currently employed often suffer from slow heating rates, intricate reaction processes involving multiple steps, sluggish reaction kinetics, high energy consumption, and prolonged preparation times, thereby hindering efficient production. Presented herein is a facile, ultrafast, and versatile approach utilizing microwave carbon thermal shock, a one-step reaction synthesis of α-MoO3 on carbon substrates within 5 s. During microwave carbon thermal shock, the precursor salt experiences an extremely rapid heating rate, swiftly decomposing to form small-sized α-MoO3 crystals. Simultaneously, this process promotes the oxidation of adjacent carbon sites, thereby imparting multi-scale defects and oxygen-containing functional groups to the resulting carbon cloth (CC). The exceptionally low reaction energy barriers and superior Gibbs free energy (ΔG) further substantiate the advantages of the microwave carbon thermal shock strategy over traditional synthesis methods in terms of both kinetics and thermodynamics. The air-assisted transient microwave carbonthermal shock (AMCTS) process circumvents high energy requirements, multistep reactions, and extended preparation times, endowing AMCTS-CC@MoO3 with remarkable flexibility and processability. In demonstrating its practical utility within zinc-ion hybrid micro capacitors, it exhibits outstanding specific capacitance (up to 2300mF cm−2) and mechanical stability. This air-assisted transient microwave thermal shock process provides an efficient route for ultrafast and low-cost synthesis of flexible zinc-ion anode materials.