ABO₃-type high-entropy relaxor ferroelectric ceramics have rarely been studied in energy storage capacitor owing to easy formation of impurity phase. In this work, single phase (Bi_0.2Na_0.2Ba_0.2Sr_0.2Ca_0.2)TiO₃-xmol%PbO high-entropy ceramics are fabricated and investigated. The optimal composition of x = 2.0 shows a remarkable comprehensive energy storage performance with high recoverable energy density W_rec = 8.2 J cm^–3, ultrahigh efficiency η = 92.2%, excellent temperature stability (W_rec = 4.4 J cm^-3 ± 4%, η = 91% ± 3% within the range of 25–120 °C), and ultrafast discharge rate t_0.9 = 5.9 µs. Three key factors, low remnant polarization P_r originating from high-entropy enhanced relaxation degree, high maximum polarization P_m due to special electronic structure of Pb ion, and high electrical breakdown strength E_b stemming from small grain size, are responsible for the improved energy storage properties. These results provide a novel strategy of developing high-entropy ceramics to optimize electrical performances including energy storage property.

中文翻译：

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在细晶粒高熵弛豫铁电陶瓷中实现优异的储能性能

ABO ₃型高熵弛豫铁电陶瓷由于容易形成杂质相，在储能电容器中的研究很少。在这项工作中，制备并研究了单相(Bi _0.2 Na _0.2 Ba _0.2 Sr _0.2 Ca _0.2 )TiO ₃ - x mol%PbO 高熵陶瓷。x = 2.0的最佳组成 表现出显着的综合储能性能，具有高可回收能量密度W _rec  = 8.2 J cm ^–3，超高效率η = 92.2%，优异的温度稳定性（W _rec  = 4.4 J cm^-3  ± 4%，η = 91% ± 3% 在 25–120 °C 范围内），超快放电速率t _0.9  = 5.9 µs。三个关键因素，源自高熵增强弛豫度的_低剩余极化Pr ，由于_{Pb离子的特殊电子结构导致的高最大极化}Pm ，以及源自小晶粒尺寸的高电击穿强度 Eb，是改进_的原因。储能特性。这些结果提供了一种开发高熵陶瓷以优化包括储能性能在内的电气性能的新策略。