Passive Cooling in the Era of Energy Crisis: Fundamentals, Materials, Applications, and Future Directions

Energy scarcity and climate change represent two of the most pressing challenges of the 21st century. Cooling technologies account for approximately 20% of worldwide electricity use, exacerbating greenhouse gas emissions and intensifying urban heat island effects. Passive cooling technologies have emerged as promising zero‐energy solutions to address these critical issues. These technologies show strong application potential in smart textiles, building energy efficiency, and energy systems. Notable advances in materials innovation, structural design, and system integration have markedly improved cooling performance. However, challenges persist in materials development, performance stability, and integration complexity. This review systematically presents the fundamental principles of passive cooling, summarizes recent advances in key materials and structural designs, and surveys practical applications across major fields. Potential solutions to the main challenges in innovative materials development, multi‐mechanism coupling, and the development of intelligent systems are discussed to provide a comprehensive and forward‐looking reference for researchers, and to offer insights into the development trajectory and recent advances in passive cooling. It seeks to stimulate innovation, foster interdisciplinary collaboration and technological integration, and accelerate scalable deployment across energy, architecture, electronics, and related sectors, ultimately supporting energy conservation, emissions reduction, and sustainable development.