Xi Kaibiao, Hou Yudong, Yu Xiaole, Zheng Mupeng, Zhu Mankang
Key Laboratory of Advanced Functional Materials, Education Ministry of China, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.
ACS Appl Mater Interfaces. 2023 Oct 25. doi: 10.1021/acsami.3c10426.
It is an urgent need to develop lead-free piezoelectric energy harvesters (PEHs) to address the energy dilemma and meet environmental protection requirements. However, the low output power densities limit further promotion of lead-free PEHs for use in daily life. Here, an entropy-increasing strategy is proposed to achieve an increased output power density of 819 μW/cm in lead-free potassium sodium niobate (KNN)-based piezoceramics by increasing the configuration entropy and realizing nearly two times the growth compared with low-entropy counterparts. Evolution of the energy-harvesting performance with increasing configuration entropy is demonstrated systematically, and the excellent energy-harvesting properties achieved are attributed to the enhanced lattice distortion, the flexible polarization configuration, and the high-density randomly distributed nanodomains with the entropy-increasing effect. Moreover, excellent vibration fatigue resistance and variable temperature output power characteristics were also realized in the PEH prepared by the proposed entropy-increasing material. The significant enhancement of the comprehensive energy-harvesting performance demonstrates that the construction of KNN-based ceramics with high configuration entropy represents an effective and convenient strategy to enable design of high-performance piezoceramics and thus promotes the development of advanced PEHs.
开发无铅压电能量收集器（PEH）以解决能源困境并满足环境保护要求迫在眉睫。然而，低输出功率密度限制了无铅PEH在日常生活中的进一步推广。在此，提出了一种熵增策略，通过增加构型熵，在无铅铌酸钾钠（KNN）基压电陶瓷中实现了819 μW/cm的输出功率密度增加，与低熵对应物相比增长了近两倍。系统地展示了随着构型熵增加能量收集性能的演变，所实现的优异能量收集特性归因于增强的晶格畸变、灵活的极化构型以及具有熵增效应的高密度随机分布纳米畴。此外，在所提出的熵增材料制备的PEH中还实现了优异的抗振动疲劳性能和变温输出功率特性。综合能量收集性能的显著提高表明，构建具有高构型熵的KNN基陶瓷是设计高性能压电陶瓷的有效且便捷策略，从而推动了先进PEH的发展。
