3D Printing of a V 8 C 7 –VO 2 Bifunctional Scaffold as an Effective Polysulfide Immobilizer and Lithium Stabilizer for Li–S Batteries

Lithium-sulfur (Li-S) batteries have heretofore attracted tremendous interest due to low cost and high energy density. In this realm, both the severe shuttling of polysulfide and the uncontrollable growth of dendritic lithium have greatly hindered their commercial viability. Recent years have witnessed the rapid development of rational approaches to simultaneously regulate polysulfide behaviors and restrain lithium dendritic growth. Nevertheless, the major obstacles for high-performance Li-S batteries still lie in little knowledge of bifunctional material candidates and inadequate explorations of advanced technologies for customizable devices. Herein, a "two-in-one" strategy is put forward to elaborate V8 C7 -VO2 heterostructure scaffolds via the 3D printing (3DP) technique as dual-effective polysulfide immobilizer and lithium dendrite inhibitor for Li-S batteries. A thus-derived 3DP-V8 C7 -VO2 /S electrode demostrates excellent rate capability (643.5 mAh g-1 at 6.0 C) and favorable cycling stability (a capacity decay of 0.061% per cycle at 4.0 C after 900 cycles). Importantly, the integrated Li-S battery harnessing both 3DP hosts realizes high areal capacity under high sulfur loadings (7.36 mAh cm-2 at a sulfur loading of 9.2 mg cm-2 ). This work offers insight into solving the concurrent challenges for both S cathode and Li anode throughout 3DP.