Functional dielectric materials for high-performance solid-state batteries

In the development of advanced batteries, it is essential to achieve both high safety performance and energy density. One practical and effective approach is the use of solid-state batteries (SSBs). However, the intrinsic electrochemical performance of SSBs and the solid-solid contact between electrodes and solid electrolytes (SEs) lead to various problems such as dendrite growth and space charge layer (SCL) accumulation, resulting in safety hazards and limiting the transport of ions. Functional dielectric materials, including piezoelectric, ferroelectric, pyroelectric and other materials, can guide the orderly migration, diffusion, arrangement and uniform deposition of cations. They can also inhibit the SCL, thus increasing the transport flux of the cation and improving the rate and cycling performance of SSBs, due to their excellent dielectric properties, and piezoelectric and ferroelectric effects. In this review, the mechanism and classification of functional dielectric materials are introduced firstly, and then their applications in solid-state lithium batteries (SSLBs), sodium batteries and zinc batteries are reviewed. Finally, the application prospects of functional dielectric materials in SSBs are analyzed and anticipated. Functional dielectric materials can regulate the migration, diffusion and deposition of cations in solid-state batteries, leading to high performance.