We report many factors that affect the uptake and conduction of ions of triple conducting perovskites (TCPs) and the current research progress of TCPs by dividing TCPs into three categories.

With the strong advancement of the global carbon reduction strategy and the rapid development of renewable energy, compressed air energy storage (CAES) technology has received more and more attention for its key role in large-scale renewable energy access. This paper summarizes the coupling systems of CAES and wind, solar, and biomass energies from the perspective of system topology, and points out the advantages and limitations of each system. It is shown that the coupling of wind energy and CAES is mainly combined in series and in parallel, and sometimes part of the wind power can be converted into thermal energy when coupled to CAES. The coupling between solar heat and CAES is an important form of coupling between solar energy and CAES. Solar-heat-coupled CAES mainly uses solar energy to heat expander inlet air. The coupling forms of solar energy and CAES are based on various CAES forms, various heat heating sequences, reheating, bottom cycle, and other factors. The combination of biomass and CAES is generally based on biomass gasification power generation technology. In the future, a wind–solar–CAES multiple coupling system is expected to become a promising large-scale form for the utilization of renewable energy, and this integrated system has great potential as a system configuration, but has some technical challenges.

Seasonal solar thermal-energy storage systems used for space heating applications is a promising technology to reduce greenhouse gas emissions. A novel solar heating system with seasonal and cascade thermal-energy storage based on zeolite water is proposed in this study. The system’s efficiency is improved through cascade storage and the release of solar energy. The energy storage density is improved through the deep coupling of daily energy storage and cross-seasonal energy storage. A mathematical model of the system-performance analysis is established. The system performances in the non-heating and heating seasons and throughout the year are analyzed by considering the Chifeng City of China as an application case. The results indicate that the average collection efficiency of the proposed system is 2.88% higher in the non-heating season and 7.4% higher in the heating season than that of the reference system. Furthermore, the utilization efficiency of the proposed system is 37.16%, which is 3.26% higher than that of the reference system. Further, the proposed system has a supply heat of 2135 GJ in the heating season, which is 9.66% higher than the reference system. This study provides a solution for the highly efficient solar energy utilization for large-scale space-heating applications.

Symmetry analysis is a cutting-edge research approach in physics, yet its application in macroscopic energy systems remains limited. This study demonstrates its potential to provide valuable insights for a deeper understanding and development of thermodynamic cycles. This article first studies the symmetry of the proposed C- P diagrams and finds rich symmetries including reflection symmetry, translation symmetry, and rotational symmetry within Carnot cycles. Then, it emphasizes that one can use symmetry alone to prove that the highest efficiency for any cycle operating in a certain temperature range is the Carnot efficiency, without relying on the entropy concept in the second law of thermodynamics. Lastly, it is found that this symmetry analysis framework can also be used for thermal cycles with phase transitions, as exemplified by applying in Rankine cycles. This research not only contributes groundbreaking insights into unraveling the symmetry inherent in thermodynamic cycles, but also promotes symmetry analysis to be an alternative analysis mean.