Research Progress in Absorption Thermal Energy Storage

Energy storage technology can balance the mismatch between energy supply and demand, which is an important link between the use of renewable energy and waste heat. Absorption thermal energy storage has attracted considerable attention in recent years owing to its high energy-storage density, high energy-storage efficiency, low charging temperature, low heat loss, and flexible output. A state-of-the-art review of advanced cycles, working pairs, and experimental prototypes was conducted. The development of advanced cycles has further improved the energy storage density and efficiency and lowered the charging temperature. The screening of novel working pairs solved the crystallization problem of conventional salt solutions, increased the options of working fluids for different scenarios, and reduced costs. The successful development and operation of experimental prototypes have confirmed the excellent performance of absorption thermal energy storage and paved the way for its promotion and application. In conclusion, the challenges and opportunities of absorption thermal energy storage for the future are summarized, and the development direction is discussed.