High-temperature energy storage performance of PEI/PVDF blends enhanced by Al2O3 inorganic layer depositing

• Published in: Journal of energy storage 2025-02, Vol.109, p.115156, Article 115156
• Main Authors: Zhang, Tianran, Lv, Quanjiang, Zhang, Siyu, Song, Mengfan, Li, Siyuan, Zhang, Lixue, Wang, Jiping
• Format: Article
• Language: English
• Subjects: Atomic layer deposition; Dielectric polymer; Energy storage; High-temperature
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.115156

In polymer dielectric energy storage, even polymers with high glass transition temperatures suffer significant degradation in energy storage performance as temperature increases, primarily due to a sharp rise in electrical conduction loss. In this study, we employ atomic layer deposition to coat the surface of a PEI/PVDF blend film with an Al2O3 inorganic layer to enhance its energy storage performance at high temperatures. The influence of the inorganic layer's thickness on high-temperature energy storage performance is thoroughly analyzed. Experimental results and finite element simulations demonstrate that an ultra-thin Al2O3 inorganic layer with the thickness of 50 nm effectively reduces leakage current density and mitigates space charge accumulation within the PEI/PVDF blends, thereby improving the high-temperature energy storage performance of the blends. Notably, under an applied electric field of 500 MV/m at 150 °C, the PEI/PVDF blend film with 50 nm Al2O3 layer achieved a discharge energy density of 5.45 J/cm3 and a charge-discharge efficiency of 97.75 %. [Display omitted] •The Al2O3 nanolayer was coated on the PEI/PVDF blends using atomic layer deposition.•Both electrode-limited conduction and bulk-limited conduction in PEI were restricted.•The appropriate thickness of Al2O3 alleviates space charge aggregation in the polymer.•A high Ud of 5.45 J/cm3 and a high η of 97.75 % were achieved at 150 °C.