Enhancing Thermal Protection in Lithium Batteries with Power Bank-Inspired Multi-Network Aerogel and Thermally Induced Flexible Composite Phase Change Material

• The Ge/SA biomass aerogel with multiple crosslinked networks exhibits excellent flame retardancy (V-0 rating) and thermal insulation (temperature difference ~120 °C across 1 cm). • The SAT/TPEE/EG composite phase change material (CPCM) achieves a high thermal storage density of 811.9 J g−1 and good flame retardancy. • Coupling CPCM with aerogel enables continuous heat absorption, delaying thermal saturation and maximizing insulation duration. • The Ge/SA-CPCM composite maintains top surface temperature at 89 °C after 100 min at 230 °C, offering a promising solution for lithium battery thermal runaway protection.