Significance: The sun (∼6,000 K) and outer space (∼3 K) are two natural energy resources for humans. However, most of the approaches of energy harvesting from the sun and rejecting energy to outer space are achieved independently using absorbers and emitters with static spectral properties. Herein, a spectrally self-adaptive structure with strong solar absorption and switchable emissivity within the atmospheric window (i.e., 8 to 13 μm) is experimentally demonstrated to achieve diurnal solar thermal and nocturnal radiative cooling efficiently. The experiment shows that the proposed structure not only can be heated to 185°C in diurnal mode but also be cooled to −12°C in nocturnal mode. This work opens new possibilities for continuously efficient energy harvesting utilizing the sun and the universe.

Lithium-based batteries (LiBs) are integral components in operating electric vehicles to renewable energy systems and portable electronic devices, thanks to their unparalleled energy density, minimal self-discharge rates, and favorable cycle life. However, the inherent safety risks and performance degradation of LiB over time impose continuous monitoring facilitated by sophisticated battery management systems (BMS). This review comprehensively analyzes the current state of sensor technologies for smart LiBs, focusing on their advancements, opportunities, and potential challenges. Sensors are classified into two primary groups based on their application: safety monitoring and performance optimization. Safety monitoring sensors, including temperature, pressure, strain, gas, acoustic, and magnetic sensors, focus on detecting conditions that could lead to hazardous situations. Performance optimization sensors, such as optical-based and electrochemical-based, monitor factors such as state of charge and state of health, emphasizing operational efficiency and lifespan. The review also highlights the importance of integrating these sensors with advanced algorithms and control approaches to optimize charging and discharge cycles. Potential advancements driven by nanotechnology, wireless sensor networks, miniaturization, and machine learning algorithms are also discussed. However, challenges related to sensor miniaturization, power consumption, cost efficiency, and compatibility with existing BMS need to be addressed to fully realize the potential of LiB sensor technologies. This comprehensive review provides valuable insights into the current landscape and future directions of sensor innovations in smart LiBs, guiding further research and development efforts to enhance battery performance, reliability, and safety.

Photovoltaic/thermal (PV/T) utilization has been regarded as a promising technique to efficiently harvest solar energy, but its thermal efficiency highly degrades in cold seasons because of remarkable heat loss. Although various methods, such as using air or vacuum gap, have been used to reduce heat loss of the PV/T, heat radiative loss still exists. In addition, unlike selective solar absorbers, the current PV/T absorber behaves like an infrared blackbody, showing great radiative heat loss. To overcome this drawback, a novel aerogel PV/T (referred to as “A-PV/T” hereinafter) collector based on solar transparent and thermally insulated silica aerogel is proposed, which can reduce the heat loss from both the non-radiative and radiative heat transfer modes. Experimental testing demonstrates that the thermal efficiency improvement of 25.1%-348% can be achieved for PV/T within the collecting temperature range of 35–70 °C when silica aerogel is introduced, indicating a significant efficiency enhancement. Compared with traditional PV/T (referred to as “T-PV/T” hereinafter) collector, the stagnation temperatures of the A-PV/T collector are 96.7 °C and 103.1 °C in outdoor and indoor environments, which are 27.4 °C and 25.8 °C greater, respectively, indicating a heat loss suppression of the aerogel. Moreover, simulation reveals that useful heat can hardly be provided by the T-PV/T collector in cold seasons, but the A-PV/T still exists a high solar thermal performance, showing good seasonal and regional applicability.