Intercalation of Ce(III) and PANI in Interlayer Spacing of V ₂ O ₅ to Improve Electrochemical Salinity Gradient Energy Conversion

Salinity gradient energy is a promising marine renewable source that requires high-performance electrode materials for efficient harvesting. While polyaniline (PANI)-intercalated V₂O₅ enhances ion transport through an expanded interlayer spacing, its practical application is hampered by inherently low electrical conductivity and structural instability. In order to solve the structural stability problem, we co-intercalate Ce³⁺ and PANI into V₂O₅ layers Ce@PANI@V₂O₅ (CPVO), to stabilize the interlayer structure for improving the electrochemical conversion of salinity gradient energy. The results show that the Ce-N and Ce-O bonds formed by the co-intercalation of Ce³⁺ and PANI stabilized the interlayer structure, and brought a larger pore area, which improves the electrochemical performance of the electrode material. The CPVO has a specific capacitance of 238.0 F g^-1 at a current density of 0.2 A g^-1. After 1000 cycles, the capacity retention rate is 90.36%. The AC//(0.083 M Na₂SO₄, 0.5 M Na₂SO₄)//CPVO salinity gradient energy conversion device successfully converted an energy density of 9.10 J g^-1, paving the way for high-efficiency salinity gradient energy conversion systems.