NaNbO₃(NN)具有价格低廉和密度小的优点，同时其兼具复杂的结构相变，被认为是一种极具潜力的无铅反铁电材料，但是NN陶瓷样品在高温烧时结容易引起晶粒尺寸粗大、Na元素挥发和大量的能源消耗等问题，除此之外，NN的铁电相在施加高电场时会使剩余极化强度增加，不利于储能性能提升。因此，如何降低NN基储能陶瓷烧结温度和进一步提升其储能性能成为当前NN基陶瓷的主要研究方向。因此本文首先将超快高温烧结技术引入到NN陶瓷的制备中并研究了NN陶瓷的快速致密化，除此通过B位工程法和构建弛豫体系，实现NN基陶瓷储能性能的提升。

在NN陶瓷的制备中引进超快高温烧结工艺技术，并结合有限元理论计算模拟了超快高温烧结NN陶瓷的温度场分布，优化了陶瓷样品与碳毡距离等的工艺参数。在1100 ℃保温60 s获得了相对密度为95%的NN陶瓷。对超快高温烧结的UHS60-1100陶瓷微观结构演化进行了研究，发现超快高温烧结的NN陶瓷Na元素的挥发和晶粒生长都得到了抑制，晶粒尺寸分布被扩展，在晶界处聚集着许多小的晶粒。超快高温烧结后的NN陶瓷电导率略高，激活能降低，这是因为超快高温烧结的NN陶瓷晶界占比提高，附着在晶界上的载流子的离子和电导性增加，导致电导率提高，然而由于极短的烧结时间也增加了NN陶瓷缺陷的数量，导致激活能降低。

通过引入低极化率的Ta⁵⁺取代B位的Nb⁵⁺制备了Na(Nb_1-xTa_x)O₃样品，研究了Ta⁵⁺掺杂对Na(Nb_1-xTa_x)O₃陶瓷结构、介电性能和铁电性能的影响。结果表明当x=0.1~0.6的时候，Ta⁵⁺取代B位的Nb⁵⁺，导致了晶格膨胀。随着Ta⁵⁺掺杂量的增加，当0.1≤x≤0.2的时候，Ta⁵⁺先进入NN基体的晶间处，当x>0.2的时候平均晶粒尺寸不断减小。当x=0.6的时，在E_b=260 kV/cm的时，储能密度为1.52 J/cm³，储能效率70.93%。表明当Ta⁵⁺掺杂量高时，可以抑制样品在高电场影响下Q相发挥的作用，以此实现对Na(Nb_1-xTa_x)O₃储能特性的优化。

通过采用弛豫策略，引入极性纳米微区(PNRs)，使得NN基体变成弛豫铁电体，制备了(1-x)NaNbO₃-xBa(Mg_1/3Ta_2/3)O₃陶瓷样品。结果表明随着BMT掺杂量增大，其物相结构从正交相渐渐变为对称性结构更高的伪立方相，且样品的平均晶粒尺寸在x<0.2的时候逐渐减小。当x=0.1的时候，陶瓷的介电峰宽化，且表现出强的的弥散相变行为。当x=0.2，其在180 kV/cm下，储能密度为1.24 J/cm³，储能效率为77.07%、电流密度为582.54 A/cm²、功率密度为40.78 MW/cm³、放电时间为0.04 μs，变温欠阻尼显示电流峰值和能量密度在30~130 ℃呈现良好的温度稳定性。表明0.8NN-0.2BMT陶瓷是脉冲功率电容器的优质备选材料。

NaNbO₃(NN) is regarded as a potential lead-free antiferroelectric material due to its low density, low cost and complex structural phase transition. However, high temperature sintering of NN ceramics is likely to cause coarse grain size, Na element volatilization and a large amount of energy loss. In addition, under high electric field, NN field-induced ferroelectric phase increases the residual polarization of the material and decreases the energy storage efficiency. Therefore, how to reduce the sintering temperature and further improve the energy storage density of NN ceramics has become a research hotspot. In this work, ultrafast high temperature sintering technology was introduced into the preparation of NN ceramics to study the rapid densification of NN ceramics, and then doping modification and relaxation system were further constructed to improve the energy storage performance of NN based ceramics.

Ultrafast and high temperature sintering technology was introduced in the preparation of NN ceramics, and the temperature field distribution of ultrafast and high temperature sintering NN ceramics was simulated by finite element theory, and the process parameters such as the distance between ceramic sample and carbon felt were optimized. NN ceramic with a relative density of 95% were obtained at 1100 ℃ for 60 s. The microstructure evolution of UHS60-1100 ceramics sintered using the UHS technology was studied. It was found that the volatilization of Na elements and grain growth were inhibited, the grain size distribution was expanded, and many small grains gathered at the grain boundaries. The electrical conductivity of NN ceramic using the UHS technology is slightly higher, and the activation energy is reduced. This is because the proportion of grain boundary of NN ceramics sintered using the UHS technology is increased, and the ion and conductivity of charge carriers attached to the grain boundary are increased, resulting in an increase in electrical conductivity. However, due to the short sintering time, the number of defects is also increased, resulting in a decrease in activation energy.

Na(Nb_1-xTa_x)O₃ ceramics were prepared by introducing low valence Ta⁵⁺ instead of B-site Nb⁵⁺.The effects of Ta⁵⁺ doping on the microstructure, dielectric properties and ferroelectric properties of Na(Nb_1-xTa_x)O₃ ceramics were studied. The results show that Ta⁵⁺ replaces Nb⁵⁺ at the B-position at 0.1~0.6, resulting in lattice expansion. With the increase of Ta⁵⁺ doping amount, when 0.1≤x≤0.2, Ta⁵⁺ first enters the intergranular NN, and when x>0.2, the grain size decreases continuously. When x=0.6, when E_b=260 kV/cm, W_rec~1.52 J/cm³, η~70.93 %. It shows that the introduction of high content of Ta is conducive to inhibiting the function of Q phase under high electric field, so as to achieve the purpose of optimizing energy storage characteristics.

(1-x)NaNbO₃-xBa(Mg_1/3Ta_2/3)O₃ ceramic samples were prepared by using relaxation strategy and introducing polar nanoscale (PNRs) to make the NN matrix become a relaxor ferroelectric. The results show that the introduction of BMT reduces the sintering temperature of ceramics, and the ceramic phase structure gradually changes from ortho-alternating phase to pseudo-cubic phase with higher symmetry structure, and the grain size decreases. At x=0.1, the dielectric peak of the ceramics widens and exhibits strong dispersion phase transition behavior. When x=0.2, at 180 kV/cm, the energy storage density is 1.24 J/cm³, the energy storage efficiency is 77.07%, the current density is 582.54 A/cm², the power density is 40.78 MW/cm³, and the discharge time is 0.04 μs. Variable temperature underdamping shows that the peak current and energy density show good temperature stability at 30~130 ℃. The results show that 0.8NN-0.2BMT ceramics are excellent candidate materials for pulsed power capacitors.