Electrostatic capacitors are critical components in the power system of electric vehicles (EVs). The current commercially available solutions are largely based on ferroelectric oxides of which the permittivity decrease with increasing electric field. Here, we propose a high entropy modulation design in a quantum paraelectric-ferroelectric/antiferroelectric matrix, which enables a stable and field-independent energy charge/discharge response across a wide voltage range. By effectively synergizing the high efficiency (η) of quantum paraelectrics and the high polarization of the ferroelectric/anti-ferroelectric matrix with the entropy regulator, a high recoverable energy density (W rec ) of 13.3 J cm − 3 with an η of 92.4% is achieved in the bulk state of the perovskite material, promising for device scale-up. Versatile polar regions as well as a defect-less microstructure is achieved by the optimized compositional design and material processing. On a mesoscopic level, the electrical microstructure of the material is engineered to provide a large breakdown strength ( E b ) of 750 kV/cm, which is confirmed by the resolved electrochemical information and finite-element simulation. The proposed strategy provides a new path for designing high performance next generation energy storage/power converting dielectrics. This demonstration of quantum paraelectrics for energy storage application is expected to stimulate extensive efforts in the area.
Liu Minmin,Yang Liting,Wu Zhengchen,Chen Guanyu,Wang Xiangyu,Yang Xiaofen,Liang Guisheng,Che Renchao
Periodically atomic displacement in two-dimensional (2D) ripple texturing offers a promising route for selective modulation of local potential, crucial for advanced electronic engineering. However, in 2D transition metal carbonitrides (MXenes), the construction and regulation of atomic ripples to control electronic properties meet substantial challenges due to the difficulty in tailoring homogeneous deformation. Here, we propose a competition strategy that leverages configurational entropy and surface termination to controllably modulate the atomic ripple structure within Nb 2 CTe x -based Mxenes. This chemical disorder releases the local in-plane strain induced by termination atoms with large ionic radii, thus enabling the regulation of out-of-plane atomic displacement. The deliberate design of the ripple structure regulates the dielectric relaxation time of the microscopic dipole in the electric field. Consequently, high-entropy MXenes deliver strong intensity of microwave absorption (−41.12 dB) and an absorption bandwidth of nearly 10 GHz, covering the S-, C-, and X-bands. This study establishes the relationship between atomic ripple structure, atomic strain, polarization relaxation, and dielectric properties, providing guidance for designing advanced MXenes materials for various applications.