**Abstract:** A significant breakthrough in the development of high-strength, highly stretchable hydrogel materials has been achieved by a research team from the Department of Chemical Engineering at Tsinghua University, led by Professor Xueming Xie, in collaboration with Professor Chunyi Zhi from the Department of Physics and Materials Science at City University of Hong Kong. The team's innovative hydrogel, which exhibits exceptional mechanical properties, has been utilized as a solid electrolyte to fabricate a flexible supercapacitor that is not only highly stretchable but also self-healing. This advancement was published in the journal *Nature Communications*. The research, which involved Tsinghua University's PhD student Ming Zhong as a co-first author, introduces a hydrogel-based supercapacitor that can be stretched up to six times its original length and fully recover upon release. Moreover, the device can self-heal after being cut, maintaining its performance without degradation. The supercapacitor's design includes a nano-silica ball-polyacrylic acid gel as the electrolyte and polypyrrole-carbon nanotube paper as the electrode, providing a robust and flexible energy storage solution. Hydrogels, which are three-dimensional, hydrophilic polymer networks capable of retaining large amounts of water, have long been of interest in various fields, including healthcare, biomedical applications, drug delivery, and flexible sensing. However, the mechanical weakness and low strength of conventionally chemically synthesized hydrogels have limited their practical applications. To address this challenge, Professor Xie's team developed a novel method that leverages nanomaterials to create high-strength hydrogels. By using nanobrushes as gelators, they were able to construct a single-network nanocomposite hydrogel with multi-level crosslinking points in a simple one-step process. This hydrogel can dissipate energy through the sequential breaking of crosslinking bonds under tensile stress, followed by the reformation of reversible physical bonds, which results in a significant enhancement in tensile strength—up to tens to hundreds of times stronger than typical chemically crosslinked hydrogels. The material can be stretched to 40 times its original length and can self-heal at room temperature. The team's work has the potential to revolutionize the field of wearable electronics and electronic skin, where flexibility and durability are crucial. The high-strength, highly stretchable hydrogel supercapacitor could serve as a reliable power source for these applications, offering both mechanical robustness and the ability to recover from damage. This development is particularly significant as it overcomes the limitations of traditional hydrogels, which often fail under mechanical stress and cannot self-heal. The research has been supported by the National Natural Science Foundation of China and Tsinghua University's Independent Research Fund. The team's findings have also been published in other prestigious journals, including *Journal of Materials Chemistry B* and *Soft Matter*, highlighting the broad impact and potential applications of their work in the field of advanced materials and flexible electronics. **Key Events, People, and Locations:** - **Event:** Development of a high-strength, highly stretchable hydrogel material and its application in a flexible, self-healing supercapacitor. - **People:** Professor Xueming Xie (Tsinghua University), Professor Chunyi Zhi (City University of Hong Kong), and PhD student Ming Zhong (Tsinghua University). - **Location:** Tsinghua University, Beijing, China, and City University of Hong Kong, Hong Kong. - **Time:** The research and publication of the findings are recent, with the main results published in *Nature Communications*. **Technical Details:** - **Material Composition:** The hydrogel is composed of nano-silica balls and polyacrylic acid, while the supercapacitor's electrodes are made of polypyrrole and carbon nanotubes. - **Properties:** The hydrogel supercapacitor can be stretched up to six times its original length and fully recover, and it can self-heal after being cut, maintaining its performance. - **Applications:** Potential applications include wearable electronics and electronic skin, where the material's flexibility and self-healing capabilities are highly valuable. - **Support:** The project received funding from the National Natural Science Foundation of China and Tsinghua University's Independent Research Fund. This breakthrough represents a significant step forward in the development of materials for flexible and wearable electronics, opening up new possibilities for the integration of advanced energy storage solutions in these devices.