A sodium sulfate (Na

2

SO

4

)/silica (SiO

2

) composite was prepared as a shape-stabilized solid-liquid phase change material by a sol-gel procedure using Na

2

SiO

3

as the silica source. Na

2

SO

4

in the composite acts as a latent heat storage substance for solid-liquid phase change

while SiO

2

acts as a support material to provide structural strength and prevent leakage of melted Na

2

SO

4

. The microstructure and composition of the prepared composite were characterized by the N

2

adsorption

transmission electron microscope (TEM)

scanning electron microscope (SEM)

Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. The results show that the prepared Na

2

SO

4

/SiO

2

composite is a nanostructured hybrid of Na

2

SO

4

and SiO

2

without new substances produced during the phase change. The macroscopic shape of the Na

2

SO

4

/SiO

2

composite after the melting and freezing cycles does not change and there is no leakage of Na

2

SO

4

. Determined by differential scanning calorimeter (DSC) analysi

s

the values of phase change latent heat of melting and freezing of the prepared Na

2

SO

4

/SiO

2

(50%

by mass) composite are 82.3 kJ·kg

-1

and 83.7 kJ·kg

-1

and temperatures of melting and freezing are 886.0 ℃ and 880.6 ℃

respectively. Furthermore

the Na

2

SO

4

/SiO

2

composite maintains good thermal energy storage and release ability even after 100 cycles of melting and freezing. The satisfactory thermal storage performance renders this composite a versatile tool for high-temperature thermal energy storage.