Fabrication of vulcanized hypercrosslinked polystyrene brushes with carbon nanotube substrates toward advanced lithium hosts

Uncontrolled lithium (Li) dendrites growth, severe volume fluctuations and fragile solid electrolyte interphase (SEI) have largely impeded the practical application of Li metal batteries (LMBs). In this work, a novel class of vulcanized hypercrosslinked polystyrene brushes with carbon nanotube substrates (CNT-g-sxPS) are successfully fabricated and utilized as advanced three-dimensionals (3D) Li hosts. On the one hand, hierarchical macro-, meso- and microporous structure of CNT-g-sxPS could accelerate Li ion transport, buffer volume fluctuation of Li anode, and provide high specific surface area to reduce local current density, which is beneficial for rapid and uniform Li plating/stripping. On the other hand, homogenously distributed sulfur groups in porous skeletons can react with Li to in-situ generate Li2S-containing SEI layer, contributing to a robust anode/electrolyte interface. Moreover, carbon nanotube substrates are able to offer conductive pathways for rapid transmission of electrons. As a result, Li|Li symmetric cell with CNT-g-sxPS@Cu/Li anode exhibits stable cycling performance of more than 500 h at a current density of 1 mA cm-2 and 1 mAh cm-2. When paired with LFP cathode, the full cell with CNT-g-sxPS@Cu/Li delivers a high discharge capacity of 101 mAh g-1 with a capacity retention ratio of 77% after 600 cycles at 1 C.