Renewable energy suffers some drawbacks such as instantaneity

instability

and the mismatch between supply and demand during the utilization. Thermochemical heat storage exhibits distinct advantages

including high heat storage density

elevated heat storage temperature

and negligible heat loss during the long-term storage.It has the capability to convert intermittent energy sources into stable moderate and high temperature heat energy to fulfill the needs of fluctuating output. The classification

basic mechanisms and characteristics of thermochemical heat storage within reaction temperature range of 400～1 100 ℃ are reviewed. Subsequently

the thermal storage performance of typical thermochemical heat storage materials

such as carbonates

hydroxides

oxides

metal hydrides

ammonia and methane are analyzed

and the structural targeted regulation and modification methods are investigated

alongside the introduction of typical demonstration projects. Following this

the reactor design and system integration of solid-gas and gas-gas reaction systems are discussed. In the last

the future research interests are deliberated and proposed in the development and industrial application of thermochemical energy storage materials.