context: The stretchability was also tested through stretching the developed spring ssZIBs. First, a spring solid-state battery was prepared by sealing the cathode, anode, and CNF–PAM hydrogel electrolyte in a spring-type plastic tube. As shown in Fig. 3i, a digital clock was powered by the developed blue spring solid-state battery. As shown by the figure in Fig. 3j and k and the video provided in ESI III and IV,† the spring solid-state battery still worked well under repeated tension and contraction. This demonstrates the robust stability, high stretchability and flexibility of our ssZIBs.