Record high-Tc and large practical utilization level of electric polarization in metal-free molecular antiferroelectric solid solutions

Metal-free antiferroelectric materials are holding a promise for energy storage application, owing to their unique merits of wearability, environmental friendliness, and structure tunability. Despite receiving great interests, metalfree antiferroelectrics are quite limited and it is a challenge to acquire new soft antiferroelectric candidates. Here, we have successfully exploited binary CMBr(x)l(1-x), and CMBrxCl1-x, solid solution as single crystals (0 <= x <= 1, where CM is cyclohexylmethylammonium). A molecule-level modification can effectively enhance Curie temperature. Emphatically, the binary CM-chloride salt shows the highest antiferroelectric-to-paraelectric Curie temperature of similar to 453 K among the known molecular antiferroelectrics. Its characteristic double electrical hysteresis loops provide a large electric polarization up to similar to 11.4 mu C/cm(2), which endows notable energy storage behaviors. To our best knowledge, this work provides an effective solid-solution methodology to the targeted design of new metal-free antiferroelectric candidates toward biocompatible energy storage devices.

Automated summary

Metal-free antiferroelectric materials have great potential for energy storage applications due to their wearability, environmental friendliness, and structure tunability. This study successfully synthesized binary CMBr(x)l(1-x) and CMBrxCl1-x solid solution single crystals, with a molecule-level modification to enhance the Curie temperature. Among the known molecular antiferroelectrics, the binary CM-chloride salt exhibits the highest antiferroelectric-to-paraelectric Curie temperature and provides a large electric polarization, enabling notable energy storage behaviors. This work introduces an effective solid-solution methodology for the targeted design of new metal-free antiferroelectric candidates towards biocompatible energy storage devices.