Enhanced energy-storage performance of an all-inorganic flexible bilayer-like antiferroelectric thin film via using electric field engineering

Abstract

A novel all-inorganic flexible bilayer-like Pb_0.99Nb_0.02(Zr_0.55Sn_0.40Ti_0.05)_0.98O₃ (PNZST_BL) thin film with the same chemical composition is designed to enhance its energy-storage performance. The PNZST_BL thin film that consists of a large polarization (PNZST_LP) top layer and a high electric breakdown field (PNZST_HE) bottom layer are deposited on flexible mica by controlling the sputtering pressure. The dislocations in such a bilayer-like film can be repressed effectively owing to the identical chemical composition. Most importantly, the PNZST_BL exhibits the complementary advantages of the PNZST_HE and PNZST_LP films based on the electric field amplifying effect and interlayer coupling. An enhanced recoverable energy-storage density (W_rec) of 39.35 J cm⁻³ is achieved in the PNZST_BL thin film, which is 70% higher than that of the single-layer PNZST_LP. Meanwhile, the flexible PNZST_BL thin film enjoys an outstanding stability in terms of frequency (10–5000 Hz) and temperature (30–170 °C). In addition, the flexible PNZST_BL thin film shows a favorable mechanical cycling endurance after repeated bending 1200 times for a 3.5 mm tensile radius. This work offers a fresh strategy to design prospective bilayer-like dielectric thin films for optimizing the energy-storage performances of materials.