Technologies are grouped into electrochemical, mechanical, chemical, and thermal storage, and evaluated using harmonized criteria (power and energy capability, response time, round-trip efficiency, lifetime, cost proxies, and maturity level). This paper systematically reviews the basic principles and research progress of current mainstream energy-storage technologies, providing an in-depth analysis of the characteristics and differences of various technologies. In 2025, 108 GW of new battery storage capacity was deployed worldwide, 40% more than in 2024. Lithium‑iron phosphate (LFP) batteries now account for around 90% of deployments;. The long-duration energy storage market is shifting from utility-led pilot validations to large-scale commercial offtake agreements, driven by new demand from power-intensive industries like artificial intelligence.
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