Two new antimony (III) tellurite sulfates [Sb₂(TeO₄)](SO₄) (1) and [Sb₂(TeO₃)₂](SO₄) (2) were successfully synthesized through a conventional hydrothermal method and their crystal structures were determined by X-ray single crystal analysis. [Sb₂(TeO₄)](SO₄) crystallizes in the triclinic space group Pī (No. 2) with lattice parameters a=5.572(2), b=7.247(2), c=9.540(3) Å, V=358.5(2) ų, and Z=2, while [Sb₂(TeO₃)₂](SO₄) crystallizes in the orthorhombic space group Pbca (No. 61) with lattice parameters a=7.368(2), b=14.571(3), c=16.521(3) Å, V=1773.7(6) ų, and Z=8. The structure of [Sb₂(TeO₄)](SO₄) features a three-dimensional framework, composed of [SbO₄] trigonal bipyramids and [TeO₄] polyhedra to form a cationic ²∞[Sb₂(TeO₄)]²⁺ corrugated cationic layers along [100], linked by SO₄²⁻ anions. [Sb₂(TeO₃)₂](SO₄) forms a three-dimensional framework consisting of two dimensional wrinkled layers of ²∞[Sb₂(TeO₃)₂]²⁺ that are linked by SO₄²⁻ anions. The band gaps of 4.16 eV and 3.72 eV for [Sb₂(TeO₄)](SO₄) and [Sb₂(TeO₃)₂](SO₄) respectively are estimated from the solid state UV-vis-NIR diffuse reflectance spectra. Thermal analysis indicated that both compounds are thermally stable up to about 500 °C. The electrochemical specific capacity of [Sb₂(TeO₄)](SO₄) was determined to 245 mA h g⁻¹ on the first cycle in a Li-ion half-cell, the capacity remains at about 106 mA h g⁻¹ after 500 cycles.