Puncture-Resistant Solid-State Lithium-Ion Batteries Based on Hydrogel Electrolytes and 3D Current Collectors

With the rapid growth of electric vehicles and portable electronics, the demand for safer energy-storage devices continues to increase. As key energy-storage units, lithium batteries face serious safety concerns, especially when subjected to external mechanical abuse such as puncture or impact, which can readily trigger internal short circuits and other hazardous failure events. Developing lithium batteries with high puncture resistance is therefore important for improving device safety and operational reliability. Herein, we report a design strategy for puncture-resistant solid-state lithium-ion batteries based on a polyacrylamide (PAM) hydrogel electrolyte and a stainless-steel mesh (SSM) current collector. In this system, the PAM hydrogel serves as the electrolyte framework and forms a gel electrolyte after swelling with a water-in-salt (WiS) electrolyte. The woven SSM current collector not only provides efficient electron-transport pathways for the active materials but also reinforces the structural stability of the battery. Experiments show that, under puncture conditions, the PAM-WiS hydrogel electrolyte can effectively mitigate direct contact between the cathode and anode active materials, thereby suppressing internal short circuits and improving battery safety. The resulting hydrogel-based battery delivers a specific capacity of approximately 120 mAh g −1 and retains about 114 mAh g −1 after puncture, demonstrating excellent capacity retention and puncture resistance. This design provides a practical strategy for developing energy-storage devices with both high safety and stable performance, and it shows promising potential for application in portable electronics, wearable devices, and smart-grid systems.