Research Progress and Key Technical Barriers in CaO/Ca(OH)₂ Based Energy Storage: A Systematic Review

Abstract

The CaO/Ca(OH)₂ thermochemical energy storage system has garnered significant attention due to its cost-effectiveness, abundant raw material availability, optimal decomposition thermodynamics, high energy density, and recyclability as a promising candidate for large-scale renewable energy integration. Significant progress has been made in the research field of the CaO/Ca(OH)₂ energy storage system, while there are still key issues that require further investigation. This comprehensive review summarizes recent advancements in CaO/Ca(OH)₂ thermochemical energy storage systems, focusing on reaction mechanism and optimization through material engineering strategies, thermal-fluid dynamics in reactor configurations, cyclic degradation mechanisms under operational stresses, and scalability constraints in system integration. Persistent technical bottlenecks requiring resolution are discussed, particularly sintering-induced capacity decay and suboptimal heat transfer efficiency. The reactor design and optimization with advanced material modification techniques targeting enhanced stability are introduced as well. These discussions and derived suggestions provide a potential opportunity to bridge fundamental material science discoveries with engineering implementation for enabling deployment in stable utilization of renewable energy.

Keywords

CaO/Ca(OH)₂ energy storage system / Reactivity / Heat and mass transfer characteristics / Cyclic stability / Reactor and modification

Author Contributions

Conceptualization, Z.S. and F.L.; Methodology, Z.S. and D.W.; Software, J.W.; Validation, Y.G. (Yongchuan Gao), Y.D. and Q.L.; Formal Analysis, Z.S.; Investigation, J.W. and Y.G. (Yishi Gu); Resources, H.L.; Data Curation, D.Y. and Z.D.; Writing—Original Draft Preparation, J.W.; Writing—Review & Editing, J.W. and Z.S.; Visualization, Q.L.; Supervision, H.L.; Project Administration, H.L.; Funding Acquisition, F.L.

Ethics Statement

The study was “Not applicable” for studies not involving humans or animals.

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

Data will be made available on request.

Funding

This research was funded by the National Key R&D Program of China (2023YFB4104003-02) and National Natural Science Foundation of China (22378130 and U23B20170).

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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