Gel alloy: One-step prepared stratified complementary hydrogel with multifunctions for deflagration substances packaging

Multifunctional hydrogels often face performance trade-offs inherent in homogeneous systems, while conventional methods for constructing stratified hydrogels struggle to reconcile simplicity, stability, and functionality. Herein, we introduce Gel Alloy, a three-layer hydrogel prepared via one-step self-assembly at room temperature, characterized by its alloy-like stratified complementary structure. This innovative design enables synergistic functionality, achieving combined properties that exceed the sum of individual layers. The resulting Gel Alloy exhibits exceptional integrated performance, including flame retardancy up to 1300 °C, high compressive strength (6.8 MPa), puncture resistance (111.3 MPa), and durability in saline-wet environments. These attributes effectively overcome classical functional trade-offs in protective materials, making it suitable for packaging deflagration-prone substances. This study offers fundamental insights into synergy-driven material enhancement and opens a new avenue for designing high-performance materials for critical applications. • A new lithium battery packaging material, Gel Alloy, with a three-layer stratified structure, utilizes an interlayer complementary effect similar to metal alloys. • Gel Alloy can be prepared in one step at room temperature, simplifying the process compared to traditional stratified gels. • Gel Alloy combines flame retardancy, heat insulation, compression resistance, puncture resistance, and salt-wet environment resistance, meeting safety requirements for the storage and transport of explosive and flammable substances.