Molecular antiferroelectric (AFE) materials, featuring antiparallel dipole configurations within neighboring lattices, have emerged as fascinating candidates for high-precision digital displacement sensors and energy-storage capacitors. Currently, the application of most molecular AFEs in energy storage confronts multiple key bottlenecks, including low maximum applied field amplitude and inadequate long-term cycling stability. However, it is challenging to rational design new molecular AFEs with superior breakdown resistance, owing to the lack of knowledge on the atomic-level origin regarding AFE orders.
In a study published in Angewandte Chemie International Edition, Prof. SUN Zhihua and Prof. LUO Junhua from Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, have conducted a pioneering study aimed at using cage-confined atomic displacement to regulate motif motion toward breakdown resistant energy storage AFEs.
For the first time, researchers presented ultra-stable breakdown resistance in 2D perovskite AFE, (2‑MBA)₂CsPb₂Br₇ (2‑MBA = 2‑methylbutylammonium), involved with the confinement-dependent atomic displacement.
The confinement-dependent atomic displacement is unlocked to exploit breakdown resistant AFE, which creates ultra-stable antifatigue merits including high electric breakdown field strength up to ~175 kV/cm and fatigue endurance over 106 cycles. These merits represent the highest level among molecular AFEs and even surpass those purely inorganic oxides.
Deep understanding of the displacive dynamics and its pivotal role in breakdown resistance is well established through combined energy barrier calculation and in situ solid-state Nuclear Magnetic Resonance(NMR) spectroscopy. Contrary to order-disordering dynamics, it is the high displacement energy barrier (Ea = 2.91 eV) of cage-confined Cs⁺ cations that leads to the increase in Curie temperature and forward coercive field.
This study provides a feasible principle of delicately manipulating cage-confined dynamics to design new electric-ordered candidates.
Illustration of the Research (Image by Prof. LUO’s group)
Contact:
Prof. SUN Zhihua
Fujian Institute of Research on the Structure of Matter
Chinese Academy of Sciences
Email: sunzhihua@fjirsm.ac.cn
