Achieving high energy storage performance and efficiency in lead-free SrTiO₃ ceramics via neodymium and lithium co-doping technique

ABSTRACT

There is an immediate demand for eco-friendly, high-performance, and highly stable energy storage materials for pulse power systems. Ceramics based on SrTiO₃ have a high breakdown strength (BDS) and dielectric constant. In this work, we fabricated a polycrystalline of Sr_(1-x)(Nd, Li)xTiO₃ ceramics via microwave-assisted heating of the starting materials. X-ray diffraction analysis reveals a pure perovskite phase without any secondary phase. Scanning electron microscopy images exhibit dense grain morphology with a decrease in grain size as the dopant concentration increases. The frequency dependences of the dielectric properties were studied in the frequency range of 100 Hz-1 MHz at room temperature. The polarization-electric field hysteresis loops were examined to ascertain the effect of co-doping on the energy-storage capability of SrTiO₃ ceramics. After increasing the co-dopants from 0 to 8%, the energy density increased nine times (from 0.11 J/cm³ to 0.952 J/cm³), and the energy storage efficiency increased from 80.71% to 95.98%, respectively. In addition, the samples demonstrate excellent thermal stability, and their energy storage properties are stable up to 80°C. We may infer from this discovery that the bulk Nd³⁺ and Li⁺ co-doped SrTiO₃ materials are good candidates for high-energy-density capacitor applications.

GRAPHICAL ABSTRACT

The energy storage materials of SNLTx ceramics were effectively synthesized using the solid-state reaction method with microwave heating of the starting materials, resulting in small grain size and defect dipoles. A dense microstructure with a grain size enhanced the breakdown strength, resulting in a high energy storage density and energy storage efficiency exceeding 95%, superior to previously reported lead-free ceramics and a promising candidate for environment-friendly ceramics.

KEYWORDS:

• Strontium titanate
• co-doping
• dielectric properties
• energy storage density
• energy storage efficiency

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

All data generated or analyzed during this study are included in this article.

Authorship contribution statement

Mahmoud Alkathy: Writing, Correction, formal analysis, and original draft preparation.

Srinivas Pattipaka: Analysis and writing the original draft.

Mansour K. Gatasheh: Investigator.

H. Kassim: Synthetization, Methodology, and Formal Analysis.

Mohamed Saad Daoud: Investigator

Prof Eiras: Writing, Correction, supervision, and approval of the final version.

Additional information

Funding

The authors thank the Sao Paulo Research Foundation (FAPESP: Grant No. # 2017/13769-1 and Grant No # 2023/05716-6) for their financial support. Dr. Mansour is grateful to the Researchers Supporting Project number (RSP2023R393) at King Saud University in Riyadh, Saudi Arabia, for his financial support.