Fabrication of Porous Functional Monolithic Aerogels With High‐Temperature Insulating and EMI Shielding Properties From Spent Lead‐Acid Battery Anode

The safe disposal of lead‐acid batteries has emerged as a critical environmental challenge of global concern. The development of innovative treatment technologies is crucial for addressing the imminent surge in spent lead‐acid battery waste. This work presents an innovative strategy for fabricating porous functional monolithic aerogels (PFMA) derived from spent lead paste anode materials. PFMA was synthesized via a facile sol‐gel method by reacting spent lead paste anode material with AlCl 3 ·6H 2 O and C 8 H 12 O 8 Zr at a mild temperature (98 °C). Aluminum dihydrogen phosphate (AHP) was employed as an inorganic binder to enhance high‐temperature stability in the composite system. The as‐prepared PFMA exhibits a monolithic structure with excellent thermal insulation and good electromagnetic interference (EMI) shielding properties. The as‐synthesized PFMA exhibits a low thermal conductivity of 0.16 W/(m·k), demonstrating comparable thermal insulation performance to conventional refractory ceramic composites (Al 2 O 3 ‐ZrO 2 and Al 2 O 3 ‐Cr 2 O 3 ). When subjected to butane flame exposure (∼1300 °C) for 3 min, the 16 mm thick PFMA sample exhibited only a modest front surface temperature increase to 140 °C, demonstrating exceptional thermal insulation. Moreover, PFMA exhibits good EMI shielding performance in the range of 12–18 GHz, which corresponds to satellite and radar bands suggesting a promising potential application in this field.