Aminomethyl‐functionalized carbon nanotube as a novel host of small sulfur clusters for high performance Li‐S batteries

Here we propose an effective strategy to stabilize the small sulfur species via the aminomethyl groups functionalized carbon nanotube (AM-CNT) without impairing the conductive channel of the carbon nanotube (CNT) cathode. The linear S n clusters can be strongly anchored with the AM-CNT via the favorable size of n = 5 and the maximum size of n = 6 in the production of cathode, thus effectively depressing the mass loss of active sulfur and completely eliminating the formation of high-order polysulfides during the discharging process. The most stable composite of three-dimensional cross-linked Inter-S 5 -AM-CNT network can endow a fast electron transfer redox reaction through the CNT skeleton, possessing a theoretical capacity of 1337 mA h g -1 (based on sulfur) or 592 mA h g -1 (based on cathode). The discharging products of linear S 5 cluster tend to form a hyper-branched tight structure via N...S...Li bridges, which is fully impregnated in the AM-CNT bundles, and thus stabilizing the entire system. More importantly, this study provides vital guidance into how to design the small sulfur clusters based cathode for Li-S batteries to intrinsically depress the shuttle effect during the charging-discharging cycles, which can be extended to the other small sulfur cluster based batteries.