Dual‐Functional Photonic Battery Enabling Dynamic Radiative Thermal Management and Power Supply

Dynamic thermal management materials are pivotal for advancing energy-efficient buildings and promoting global sustainability. However, existing materials typically offer only a single-function of temperature regulation, lacking the integrated power supply capability essential for sustaining indoor activities and building sustainability, particularly in the face of frequent power outages. A photonic battery that combines all-season dynamic radiative thermoregulation with electrical power supply in a single silicon-based unit is demonstrated. This device delivers dual functionality with high infrared emissivity regulation (0.53 at 8-13 µm) and superior energy storage performance, featuring a high specific capacity (≈3271 mAh g^-1), areal capacity (≈0.38 mAh cm^-2), and efficient energy recycling (71.6%). A reversible ion-interaction-induced phase change mechanism, enabling continuous and non-volatile electro-optical-thermal transformation and significant infrared tunability, is proposed. Our simulations indicate that the implementation of these dynamic materials into buildings could significantly reduce energy consumption by up to 18.4%, equating to 544.8 GJ, and achieve an annual reduction in CO₂ emissions of 124.1 tons. This work paves the way for the development of energy-saving electro-driven dynamic materials, marking a significant step forward in global sustainability initiatives.