Biomimetic Ceramic Fiber Papers for Security Thermal Management of Blade Batteries

Blade batteries have the advantage of high bulk energy density and can be arranged in a small space to achieve a longer driving range. However, the high heat production and lower heat dissipation avenues often induce a rapid temperature increase and irreversible thermal runaway of individual battery cells under abusive conditions. Previous research on thermal insulation materials indicates that they have large thicknesses (3–5 mm) and low strength and are difficult to apply to the gap of blade batteries (1 mm) for thermal protection. Here, we mimic the cocoon structure by developing a strategy. This approach combines compositional engineering and structural engineering. It controls macro- and micrometer building blocks while carefully designing geometric freedom in bonding networks. This enables the synchronous preparation of ceramic insulation papers (CFIPs). The resulting CFIPs are ultrathin and ultrastrong and exhibit ultralow thermal conductivity. Notably, the tensile strength of the resultant paper (1 mm) was as high as 1.88 MPa and exhibited a low thermal conductivity of 0.031 W/m·K. Even with calcination at 1000 °C, our CFIPs showed a tremendous retention of 80% of their tensile strength. These superior performances render the ceramic papers optimal for utilization as high-temperature insulation materials in the context of thermal runaway conditions associated with the blade battery.