A Designed High-Entropy Sulfide-Based Nanoporous Heterojunction for Fast, Durable, and High-Capacity Sodium Storage

As promising sodium ion battery (SIB) anodes, transition metal sulfide (TMS)-based heterojunctions still suffer from sluggish kinetics, low capacity, and structural instability. Herein, we design a nanoporous structured senary (AlCrCo)NiFeS 2 /MnS high-entropy heterojunction using dealloyed senary oxide as the starting materials. Owing to the high-entropy engineering-induced electronic structure regulation, the built-in electric field, the 3D nanoporous structure, and a hard carbon coating, the senary heterojunction exhibits a record high capacity of 885.5 mAh g –1 after 110 cycles at 0.1 A g –1 . Even at 40.0 A g –1, a high capacity of 331.5 mAh g –1 can be achieved after 4000 cycles. DFT calculations reveal the modified electronic structure (denser energy band structure) induced by multiple-metal ion mixing, which enhances the electronic conductivity and sodium ion adsorption when compared with those of the ternary NiFeS 2 /MnS heterojunction. This work highlights the potential of high-entropy engineering for developing SIB anodes with one of the best overall performances.