Super heating/cooling rate enabled by microwave shock on polymeric graphene foam for high performance Lithium–Sulfur batteries

3D polymeric graphene foam (PGF) deposited with Mn₃O₄ nanocrystals are synthesized via a structural-enhanced microwave plasma technique as highly efficient electrocatalyst for lithium–sulfur battery. The uniform pore-structure of PGF enables high-temperature Ar plasma around 1536 K under microwave irradiation, which leads to super heating/cooling rate of >13700 K s⁻¹ forming Mn₃O₄ nanocrystals in 1.2 s. Interconnected PGF layers deposited with the Mn₃O₄ crystals around 8 nm in diameters can effectively promote the electron transport and anchoring/catalyzing the polysulfides conversion. The cathode exhibits a good capacity fading of 0.092% per cycle over 300 discharge/charge cycles at 0.2 C, indicating good reversibility. The high Mn₃O₄/graphene ratio and small particle size of the nanocomposite are hard to achieve by other methods within this short period. The instant and low-cost synthesis method is readily scalable and may provide a promising direction for the practical manufacturing of high-performance Li–S batteries.