Polymer dielectrics are preferred materials for high-energy-storage metalized film capacitors. However, the state-of-the-art commercial capacitor dielectrics represented by biaxially oriented polypropylene (BOPP) can hardly fulfill the practical requirements of the harsh operating environments of electronics and electrical-power equipment. In this work, a facile, high-efficiency strategy is proposed for fabricating polymeric films with excellent high-temperature capacitive performance. This strategy involves coating the surface of BOPP films with parylene polymers by chemical vapor deposition. The addition of a parylene polymer layer with deep trap energy levels and high melting temperatures significantly improves the temperature resistance of BOPP and effectively suppresses leakage current, resulting in excellent capacitive properties at elevated temperatures and high electric fields. The maximum discharged energy density (U_e) of the modified BOPP films is 10.10 J cm⁻³ with a charge–discharge efficiency (η) > 90% at 30 °C, and it reaches 5.52 J cm⁻³ with an η of over 90% at 120 °C. This method offers unprecedented opportunities for the development of scalable polymer dielectrics with high energy storage and low loss at high temperatures due to its non-damaging nature, precise thickness control, low temperature, and readily scaled-up conformal deposition.

This work presents a facile strategy to significantly boost the capacitive performance of aromatic polymer with simple preparation process. At 150 °C, the composite films exhibit remarkable comparative performance, U_e = 10.1 J cm⁻³ and η > 90%.

A dielectric polymer with high energy density is in high demand in modern electric and electronic systems. The current polymer dielectrics are facing the tradeoff between high energy density and low energy loss. Although many efforts have been devoted to solving the problem by modifying biaxially oriented polypropylene (BOPP), poly(vinylidene fluoride) (PVDF) and glassy polymers, limited success has been achieved. In the present work, we disperse the high polar nitrile units in a low polar polystyrene (PSt) matrix to avoid the strong coupling force among the adjacent polar groups and reduce the relaxation-induced high dielectric loss. In addition, the possible charge transportation offered by phenyl groups could be blocked by the enlarged bandgap. Notably, the induced polarization is established between the nitrile and phenyl groups, which may lead to the copolymer chain being more densely packed. As a result, excellent energy storage performances, including the high energy density and low loss, are achieved in the resultant poly(styrene-co-acrylonitrile) (AS). For instance, AS-4 exhibits a U_e of 11.4 J cm⁻³ and η of 91% at ambient temperature and 550 MV m⁻¹. Manipulating the dipole polarization in the low polar glassy polymer matrix is verified to be a facile strategy for the design of a high-energy storage dielectric polymer.

The laser semi-active seeker, crucial for miniaturizing guided munitions, offers high precision, anti-jamming, and rapid response. Current research focuses on system response, spot parameters, and angular velocity accuracy. With small-caliber munitions on the rise, further miniaturization and weight reduction are essential. This paper proposes a design for an optical system that balances dynamic imaging quality and miniaturized static structure. Using quadrant detector principles, factors affecting detection performance are analyzed to determine the optimal spot size and imaging range. Based on imaging requirements and the optical properties of a dual-reflector structure, we determine the design parameters of the system to achieve a combination of dynamic and static performance. Evaluations using ZEMAX and MATLAB confirm that the system achieves ±4^∘ linear and ±8^∘ full fields of view, 0.12% distortion, 4.52 mrad angular accuracy, a 15.72 mm axial length, and has the possibility of actual production. The system is compact, with excellent spot roundness, stability, and uniform energy distribution, providing a reference for future guided weapon research.