Fig. 5. Morphological change of the sulfur cathode surface in coin cells CR2032 loaded with 0 and 0.5 wt% N-CDs electrolyte during the first discharge/charge process.

a–f SEM images of the sulfur cathode with 0.5 wt% N-CDs electrolyte. g–l SEM images of the sulfur cathode with 0 wt% N-CDs electrolyte. Scale bar: 10 μm.