For many years, researchers have been trying to make a material more conductive than silver by incorporating carbon nanotubes or graphene into copper to form a composite material. However, after a decade-long effort, only a few groups reported successful results, raising concerns about the feasibility of this composite approach. Here, we report our effort to validate the multilayer graphene–copper composite approach for improving electrical conductivity. We demonstrate that, with an estimated 0.008 vol. % graphene addition, copper’s electrical conductivity was improved to 104.2% of International Annealed Copper Standard (IACS) at room temperature. If the copper substrate used to make the multilayer composite is discounted using the parallel resistance model, the conductivity is calculated to be 185% IACS. This result could be further improved if the thickness of the copper layers can be further reduced.

Antiferroelectric (Pb0.87Sr0.05Ba0.05La0.02)(Zr0.52Sn0.40Ti0.08)O3 thin film capacitors were fabricated for dielectric energy storage. Thin films with excellent crystal quality (FWHM 0.021°) were prepared on (100) SrRuO3/SrTiO3 substrates by pulsed laser deposition. The out-of-plane lattice constant of the thin film was 4.110 ± 0.001 Å. An average maximum recoverable energy storage density, 88 ± 17 J cm−3 with an efficiency of 85% ± 6% at 1 kHz and 80 ± 15 J cm−3 with an efficiency of 91% ± 4% at 10 kHz, was achieved at room temperature. The capacitor was fatigue resistant up to 106 cycles at an applied electric field of 2 MV cm−1. These properties are linked to a low level of hysteresis and slow polarization saturation. PbZrO3-derived oxide thin film capacitors are promising for high efficiency and low loss dielectric energy storage applications.

PbZrO₃-based antiferroelectric (AFE) ceramics are promising dielectrics for high-energy-density capacitors due to their reversible phase transitions during charge–discharge cycles. In this work, a new composition series, [Pb[ ]La[ ](Li[ ]Bi[ ]Sr[ ]][Zr[ ]Sn[ ]Ti[ ]]O₃, with Li[ ] and Bi[ ] substitution of Pb[ ] at [ ], 0.04, 0.08, 0.12, 0.16 is investigated for the microstructure evolution, ferroelectric (FE) and dielectric properties. It is found that Li[ ] and Bi[ ] substitution can significantly reduce the sintering temperature and simultaneously enhance the dielectric breakdown strength. An ultrahigh energy efficiency (94.0%) and a large energy density (3.22[ ]J/cm[ ] are achieved in the composition of [ ] with a low sintering temperature (1075^∘C).