Through physical modification methods such as washing

drying

and high-temperature calcination

sepiolite was treated to obtain modified sepiolite （ST）. Using the vacuum adsorption method

ST was used as the support to prepare a lauric acid （LA） and palmitic acid （PA） binary eutectic composite phase change materials

resulting in modified sepiolite-based lauric acid-palmitic acid composite phase change heat storage materials （LA-PA/ST）. The thermophysical properties

structural features

thermal conductivity and thermal reliability of the composite phase change materials （PCMs） were systematically investigated by testing methods such as differential scanning calorimeter （DSC）

Fourier transform infrared spectroscopy （FTIR）

scanning electron microscope （SEM） thermogravimetric analyzer （TG）

HotDisk analyzer and thermal cycling experiments. The results indicated that at an optimal adsorption mass ratio of LA-PA to ST of 1:5

LA-PA was uniformly distributed within the pores of ST and showed no leakage in the molten state. The thermal conductivity of pure LA-PA is 0.29 W/（m·K）

whereas that of LA-PA/ST increases significantly to 1.26 W/（m·K）. Additionally

the composite exhibited nearly no weight loss at 100 ℃

with initial 1% weight loss occurring at 128.36 ℃. After 200 thermal cycling experiments

the phase change temperature decreased by only 0.03 ℃. An experimental setup was constructed to evaluate the photothermal conversion performance

revealing a 461 s reduction in heat storage time and a 1711 s extension in heat release time. These experimental data demonstrate that LA-PA/ST possesses good thermal conductivity

thermal stability

and thermal cycling stability.