Super-aligned films of sub-1 nm Bi₂O₃-polyoxometalate nanowires as interlayers in lithium-sulfur batteries

Sub-1 nm nanowires (SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at sub-nanoscale. Herein, we synthesized Bi₂O₃-polyoxometalate heterostructure SNWs (PMB SNWs), and fabricated super-aligned PMB SNWs films (S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide (LPS) shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur (Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.[Figure not available: see fulltext.]