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, metal-free antiferroelectrics are quite limited and it is a challenge to acquire new soft antiferroelectric candidates. Here, we have successfully exploited binary CMBr_xI_1-x and CMBr_xCl_1-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 ~453 K among the known molecular antiferroelectrics. Its characteristic double electrical hysteresis loops provide a large electric polarization up to ~11.4 μC/cm², 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.

无金属反铁电材料由于其独特的耐磨性、环境友好性和结构可调性等优点，有望在储能应用中发挥作用。尽管受到了极大的关注，但无金属反铁电体仍然非常有限，获得新的软反铁电体候选物是一项挑战。在这里，我们成功地将二元 CMBr _x I _{1- x}和 CMBr _x Cl _{1- x}固溶体作为单晶（0 ≤  x ≤ 1，其中 CM 是环己基甲基铵）。分子水平的修饰可以有效提高居里温度。强调地，二元CM-氯化物盐在已知分子反铁电体中显示出最高的反铁电-顺电居里温度~453 K。其特有的双电滞回线提供高达~11.4 μC/cm ²的大电极化，这赋予了显着的能量存储行为。据我们所知，这项工作为针对生物相容性储能设备的新型无金属反铁电候选物的针对性设计提供了一种有效的固溶体方法。