Multi-physics modeling and full-cycle performance enhancement of Ca-based particle for calcium looping thermochemical energy storage

Calcium Looping (CaL) technology, utilizing CaCO₃/CaO as an energy carrier, is considered one of the most promising approaches for thermochemical energy storage (TCES) and CO₂ capture. Owing to the demand on enhancing the energy storage and multiple cycle performance of CaL, investigations on Ca-based energy carrier tend to involve highly-coupled calcination and carbonation process. However, available theoretical optimizations typically focus on characterizing individual energy storage (calcination) or release (carbonation) steps, neglecting the interactions within a full cycle and yielding insights that may not be applicable to practical systems. Herein, a full-cycle modeling of Ca-based energy carrier is developed by integrating multi-physics data. The behavior of energy carrier is further described, including heat-mass transfer, chemical reaction, energy conversion and thermal stress response. Based on the multi-physics characteristics, an operation strategy focusing on the released energy quality is proposed by enhancing the conversion rate of energy carrier, over 5-times higher than the conventional methods focusing on energy quantity. Subsequently, the efficiency and charge rate of energy carrier are defined and enhanced in terms of the suitable working conditions and materials properties. The efficiency of energy carrier is increased by 22.8 % associated with the appropriate charge rate and low risk of thermal stress failure. Furthermore, multi-cycle performance analysis reveals that incomplete conversion, despite high efficiency, leads to activation cycles and a significant decline in storage density. This work aids in evaluating and predicting the energy storage and cyclic performance of CaL and expands the potential of application.