High strain with low hysteresis is crucial for commercial applications in high precision actuators. However, the clear conflict between the high strain and low hysteresis in BNT-based ceramics has long been an obstacle to actual precise actuating or positioning applications. To obtain piezoceramics with high strain and low hysteresis, it is necessary to enhance the electrostrictive effect and develop an ergodic relaxor (ER) and nonergodic relaxor (NR) phase boundary under ambient conditions. In this work, (Co_0.5Nb_0.5)⁴⁺ doped 76Bi_0.5Na_0.5TiO₃-24SrTiO₃ (BNST24) relaxors were fabricated using the conventional solid state reaction route. X-ray diffraction patterns revealed the B-site substitution in BNST24 ceramics. By adjusting the (Co_0.5Nb_0.5)⁴⁺ doping in BNST24, we effectively tuned the T_NR-ER and T_d close to ambient temperature, which contributed to the development of the ergodic relaxor phase and enhanced the electrostrictive effect at ambient temperature. The I-P-E loops and bipolar strain curves verified the gradual evolution from NR to ER states, while the enhanced electrostrictive effect was verified by the nearly linear S-P² curves and improved electrostrictive coefficient of the BNST24-xCN relaxors. An enhanced strain of 0.34% (d^*₃₃ = 483 pm/V) with low hysteresis of 8.9% was simultaneously achieved in the BNST24-0.02CN relaxors. The enhanced strain was mainly attributed to the proximity effect at the ER and NR phase boundary of BNST24-0.02CN, while the improved electrostrictive effect contributed to the reduced strain hysteresis. Our work demonstrates an effective strategy for balancing the paradox of high strain and low hysteresis in piezoceramics.

The laser beam mode affects the power density distribution on the irradiated target, directly influencing the product quality in laser processing, especially the hole quality in laser drilling. The Gaussian beam shape, Mexican-Hat beam shape, Double-Hump beam shape, and Top-Hat beam shape are four typical laser beam modes used as a laser heat source and introduced into our proficient laser-drilling model, which involves complex physical phenomena such as heat and mass transfer, solid/liquid/gas phase changes, and two-phase flow. Simulations were conducted on an aluminum target, and the accuracy was verified using experimental data. The results of the simulations for the fundamental understanding of this laser–material interaction are presented in this paper; in particular, the hole shape, including the depth–diameter ratio and the angle of the cone, as well as spatter phenomena and, thus, the formed recast layer, are compared and analyzed in detail in this paper. This study can provide a reference for the optimization of the laser-drilling process, especially the selection of laser beam mode.

Dielectric capacitors with a high density of recoverable energy storage are extremely desirable for a variety of uses. However, these capacitors often exhibit lower breakdown strengths and energy efficiency compared to other materials, which poses significant challenges for their practical use. We report on a novel antiferroelectric ceramic system in the present study, (1 − x){0.97[0.985(0.93Bi_0.5Na_0.5TiO₃–0.07BaTiO₃)–0.015Er)]–0.03AlN}–xNaNbO₃ (x = 0, 10 wt%, 20 wt%, 30 wt%, and 40 wt%), synthesized via a conventional solid-state reaction approach. Here, (Bi_0.5Na_0.5TiO₃–BaTiO₃) is denoted as BNT–BT. We observed that varying the NaNbO₃ (NN) content gradually refined the grain size of the ceramics, narrowed their hysteresis loops, and transformed their phase structure from antiferroelectric to relaxor ferroelectric. These changes enhanced breakdown strength (E_b), thus increasing the performance of energy storage. Specifically, the recoverable energy density (W_rec) and energy storage efficiency (η), respectively, reached 0.67–1.06 J/cm³ and 44–88% at electric fields of 110–155 kV/cm, with the highest performance observed at 30 wt% NN doping. Additionally, over a broad range of temperature and frequency, the 70 wt% {0.97[0.985(BNT–BT)–0.015Er]–0.03AlN}–30 wt% NN ceramic demonstrated exceptional stability in energy storage. These results demonstrate the significant potential of lead-free(1 − x)({0.97[0.985(BNT–BT)–0.015Er]–0.03AlN}–xNN ceramics for the applications of high-performance energy storage.

NaNbO₃-based ferroelectric composites are regarded as a highly promising typical energy storage material. In this work, 0.02xMnO₂−(1−x)NaNbO₃−xBi0.5Na_0.5TiO₃ composites were prepared by the solid-state sintering method and their microstructure, energy storage performance, and temperature stability were analyzed. As observed by the SEM images, the addition of Bi_0.5Na_0.5TiO₃ to NaNbO₃ in appropriate amounts can effectively suppress grain growth, which is beneficial for improving the breakdown field strength. When x = 0.3, an optimal value of 210 kV/cm is achieved. Meanwhile, as 2θ = 33.2°, the most intense XRD peak can be observed, indicating excellent solid solubility between the phase components. Consequently, 0.006MnO₂–0.7NaNbO₃–0.3Bi_0.5Na_0.5TiO₃ composites demonstrated an impressive discharging storage density of 2.464 J/cm³ and a considerable energy storage efficiency of 85.8%. In addition, within the temperature range of 30–80 °C, the fluctuation in energy storage density remains below 10%. All the above performances indicate that this type of material exhibits excellent practicality in the field of pulse power supply.

The tailored crystalline configuration coupled with submicron particles would be conducive to superior ionic conductivity, which could further improve the cycle life of lithium-ion batteries (LIBs). Here, manganese phosphide (Mn_5.64P₃) particles with hexagonal crystal structure embedded into nitrogen/phosphorus (N/P) co-doped carbon shells (Mn_5.64P₃-C) are successfully prepared by the self-template and recrystallization–self-assembly method. The electrochemical properties of as-synthesized Mn_5.64P₃-C as anode materials for LIBs are systematically investigated. The XRD and HRTEM combined with SAED indicate that the prepared Mn_5.64P₃-C hybrid with the ratio of 1:10 of Mn:C present a hexagonal crystal structure covered with a carbon layer. During charging/discharging at the current density of 0.5 A g⁻¹, the Mn_5.64P₃-C electrode exhibits the reversible capacity of 160 mAh g⁻¹ after 3000 cycles with high-capacity retention. The ex-situ XRD of initial discharge/charge process at different voltages implies that the Mn_5.64P₃ could be transformed to the amorphous Li_xMn_yP_z. The N/P co-doped carbon shells can provide high specific area for electrolyte infiltration, and act as the buffer matrix to suppress the loss of the Mn_5.64P₃ active material during cycling. The Mn_5.64P₃ with the hexagonal crystal structure and N/P co-doped carbon shells could promote the further optimization and development of manganese phosphide for high-performance LIBs.

The advancement of microelectromechanical systems (MEMS) drives the demand for multifunctional ferroelectrics that synergistically combine substantial strain with competitive energy storage capabilities. In this work, the simultaneous enhancement of electromechanical strain and energy storage properties is achieved in (1−x)(Bi_0.5Na_0.5)_0.94Ba_0.06(Ti_0.98Mn_0.02)O₃-xSrTiO₃ (0 ≤ x ≤ 0.3) ceramics by synergistically employing A-site defect engineering and the nonergodic/ergodic relaxor (NR/ER) phase boundary design. The incorporation of Sr²⁺ plays a dual role: it induces cationic disorder that expands the polarization difference (ΔP = P_max − P_r), thereby effectively boosting the recoverable energy density (W_rec). Concurrently, it stabilizes a critical NR/ER phase ratio near room temperature, which maximizes the strain while minimizing the strain hysteresis. Consequently, when x = 0.15, the optimized system delivers a large strain of 0.45% (d₃₃* = 562 pm/V) with low hysteresis (H = 10.8%). In addition, the x = 0.25 composition exhibits an enhanced W_rec of 1.06 J/cm³, a competitive energy-storage potential (W_rec/E) of 0.013 mC/cm², and a high efficiency (η) of 81% under 80 kV/cm. This work provides an effective strategy for developing multifunctional lead-free materials for integrated actuators and energy storage devices.