Biomass-derived aerogels have received extensive attention as potential thermal management materials for energy-efficient buildings. However, it remains a huge challenge to fabricate a fully bio-based aerogel with excellent mechanical property, flame retardancy, and low thermal conductivity. Herein, we demonstrate a novel and facile strategy to manufacture a fully biomass-based aerogel from naturally abundant ammonium alginate (AL) and phytic acid (PA), in which PA acting as both flame retardant and cross-linking components constructs a strong network with AL matrix. Consequently, the resultant biomass aerogel with a low density of 0.052 g/cm³ exhibits ultrahigh mechanical modulus (25.1 ± 3.1 MPa) and specific modulus (440.4 ± 54.4 MPa cm³·g⁻¹), much superior to those of biomass aerogels ever reported. Due to the existence of the uniform three-dimensional porous network, the biomass aerogels exhibit low thermal conductivity (34–38 mW/m·K) and excellent thermal insulation performances. Further, the introduction of PA endows the aerogel with high flame retardancy (limiting oxygen index value of 57%, UL-94 V-0 rating, and extremely low heat release), while the biodegradability of the materials keeps at a high level with a biodegradation rate of 91.43%. Combining with the advantages of mechanically strong property, high flame retardancy, excellent thermal insulation, and biodegradation, the aerogel of this work provides a new strategy to fabricate thermal insulation materials with high environmental safety.

生物质气凝胶作为节能建筑的潜在热管理材料已受到广泛关注。然而，制备具有优异机械性能、阻燃性和低导热性的全生物基气凝胶仍然是一个巨大的挑战。在此，我们展示了一种新颖且简便的策略，可从天然丰富的海藻酸铵 (AL) 和植酸 (PA) 制造完全基于生物质的气凝胶，其中 PA 作为阻燃剂和交联组分构建了一个强大的网络AL 矩阵。因此，所得的具有 0.052 g/cm ³低密度的生物质气凝胶表现出超高的机械模量（25.1 ± 3.1 MPa）和比模量（440.4 ± 54.4 MPa cm ³ ·g ^-1)，远优于以往报道的生物质气凝胶。由于均匀的三维多孔网络的存在，生物质气凝胶表现出低热导率（34-38 mW/m·K）和优异的隔热性能。此外，PA的引入赋予气凝胶高阻燃性（极限氧指数值57%，UL-94 V-0等级，放热极低），同时材料的生物降解性保持在高水平，生物降解率为91.43%。该工作的气凝胶结合了机械强度高、阻燃性高、绝热性能好、可生物降解等优点，为制备具有高环境安全性的绝热材料提供了一种新策略。