Chinese Researchers Achieve Record Energy Density in Lead-Free Ceramics Using Polarizable Nanodomain Engineering

Chinese scientists develop BNT-based ceramics with 6.11 J/cm3 energy density, advancing next-gen capacitors for electric vehicles and renewable power.

By: AXL Media

Published: Apr 30, 2026, 9:36 AM EDT

Source: Information for this report was sourced from EurekAlert!

A Breakthrough in Sustainable Dielectric Energy Storage

The transition toward high-efficiency electronic systems has long been hindered by the limitations of dielectric ceramic capacitors, which often struggle to balance energy density with operational efficiency. In a study published in the Journal of Advanced Ceramics on March 24, 2026, a research group led by Pu Mao and Tianyu Li revealed a significant leap in material science. By engineering lead-free Bi0.5Na0.5TiO3-based ceramics, the team successfully addressed the traditional trade-off between polarization and breakdown strength, paving the way for more robust energy storage solutions in automotive and renewable sectors.

Engineering Nanoscale Domains for Superior Polar Stability

The technical foundation of this advancement lies in the deliberate manipulation of the material’s internal structure at the nanoscale. According to Prof. Pu Mao, the key innovation involves the formation of strongly polarizable nanodomains through multi-ion substitution, specifically incorporating Sm3+ doping. This chemical adjustment regulates the ratio between rhombohedral and tetragonal phases, effectively disrupting long-range ferroelectric order. By weakening the interactions between these domains, the researchers lowered the energy barriers required for polarization rotation, allowing the material to respond more dynamically to electric fields.

Quantifiable Performance Metrics Under Moderate Fields

The resulting ceramic composition, identified as 0.98(BNSB)0.985S0.01T-0.02CMN, demonstrated exceptional electrical characteristics during testing. At a moderate electric field of 330 kV/cm, the material reached a recoverable energy storage density of 6.11 J/cm3 alongside a discharge efficiency of 86 percent. These figures surpass most previously reported bulk dielectric ceramics under similar conditions. The researchers achieved an ultrahigh maximum polarization of 65.8 μC/cm2 while maintaining a remarkably low remnant polarization of 5.34 μC/cm2, which is critical for minimizing energy loss during rapid charge-discharge cycles.