fig2

Figure 2. Research on cathode for K-S batteries. (A) PANI@CMK-3/sulfur composite cathode (Reproduced with permission from^[23]. Copyright 2014, American Chemical Society). (B) Microporous carbon-confined small-molecule sulfur cathode (Reproduced with permission from^[26]. Copyright 2019, American Chemical Society). (C) SPAN cathode (Reproduced with permission from^[34]. Copyright 2018, The Royal Society of Chemistry).