Excellent energy storage density and superior discharge properties of NBT–NN–ST/xHfO₂ ceramics via 0–3 type heterogeneous structure designing

Abstract

We demonstrate 0–3 type heterogeneous NBT–NN–ST/HfO2 composites to achieve high Eb and Pmax. Some HfO2 are concentrated in grain boundaries to suppress local electric branches’ development for enhancing Eb while others diffuse into lattice to improve bonds’ polarity for maintaining high Pmax.

Optimization in the energy storage properties of Bi0.5Na0.5TiO3–SrTiO3 ceramics by introducing Bi(Mg0.5Zr0.5)O3

“…It is worth noting that the maximum electric field that the sample of x = 0.15 can withstand is moderate among various reports because of the electric field‐induced high polarization in BNT–ST– x BMZ ceramics. Table 1 shows the comparison in energy storage properties between x = 0.15 and other BNT‐based ceramics 11,15–17,22,23,28 . It is clear that the comprehensive energy storage properties of x = 0.15 are impressive, indicating great potential in energy storage applications.…”

“…A current waveform is observed for underdamped charge/discharge process under each electric field, as shown in Figure 6A. The peak current density ( C D ) and power density ( P D ) are generally calculated via the following equations 17 : $$$$\begin{equation}{C}_{\mathrm{D}} = \frac{{{I}_{{\mathrm{max}}}}}{S}\ \end{equation}$$$$ $$$$\begin{equation}{P}_{\mathrm{D}} = \frac{{E{I}_{{\mathrm{max}}}}}{{2S}}\ \end{equation}$$$$where I max is the first current peak value, and S is the sample's electrode area. The electric field‐dependent C D and P D values are plotted in Figure 6B, in which the C D and P D increase monotonically with rising electric field due to the positive relationship between polarization and electric field.…”

“…Yet, the W rec of pure BNT ceramics is limited by the low E b and high P r induced by the nonergodic ergodic relaxor state, which can be irreversibly transformed to the ferroelectric state under external electric field 14,15 . Currently, the chemical doping, grain refinement, domain engineering, microstructural design, and their collaborative effect are extensively employed to enhance the W rec of BNT‐based ceramics 11,15–19 . For example, the high‐entropy Sr(Zr 0.2 Sn 0.2 Hf 0.2 Ti 0.2 Nb 0.2 )O 3 was incorporated into BNT ceramics to enhance the dielectric thermal stability and W rec to 3.52 J/cm 3 11 .…”

“…On the other side, some Hf 4+ ions diffusing into the BNT–NN–ST lattice facilitated a maintaining of high P max . As a result, the BNT–NN–ST ceramics with 7 wt% HfO 2 exhibited an excellent W rec of 5.3 J/cm 3 17 . Although the energy storage performance of BNT‐based ceramics has made satisfactory progress, the W rec outperforming 8 J/cm 3 is still a severe challenge for most of the ceramics.…”

“…Although the energy storage performance of BNT‐based ceramics has made satisfactory progress, the W rec outperforming 8 J/cm 3 is still a severe challenge for most of the ceramics. One of the main reasons is the contradiction between high P max and small P r , which should be further addressed 5,17,20 …”