Scale‐Up Production of High‐Quality Reduced Graphene Oxide via Microwave Assistance

Abstract Microwave reduction of graphene oxide (GO) holds significant potential for producing high‐quality reduced graphene oxide (rGO). However, due to the undeciphered underlying mechanism of microwave‐assisted GO reduction, scalable batch preparation using this method has not yet been achieved. Here, high‐quality microwave‐reduced graphene oxide (MrGO) is prepared using a single‐mode cavity (SMC) microwave reactor by modulating the microwave responsiveness of GO precursors. The complete reaction pathway is elucidated via optical emission spectroscopy (OES), revealing that oxygen removal occurs simultaneously with the consumption of carbon radicals, effectively repairing vacancy defects within seconds. Furthermore, an automated microwave system is developed, enabling stable batch production of MrGO with a daily output exceeding 1 kg. LiFePO4 (LFP) cathode coating on the MrGO modified Al foil (LFP‐Al@MrGO) delivers high specific capacities of 188 mAh g ⁻¹ at 0.1C, far exceeding LFP‐Al at 25 °C. Even at −25 °C, it still shows a 95.2% capacity retention rate for 1000 cycles. Moreover, the resulting waterborne polyurethane (WPU)/MrGO composite film, with a thickness of 0.35 mm, demonstrates an electromagnetic interference (EMI) shielding effectiveness of 68.8 dB. This study presents a large‐scale, low‐cost, and sustainable MrGO production, providing an efficient potential application in lithium‐ion battery (LIBs) systems and EMI shielding.