The dispersion of nano-barium titanate(NBT) in polyvinylidene fluoride(PVDF) is one of the key issues in dielectric composites. Various NBT surface modification strategies which suffer from complex process and small-scale production have been reported. Herein, in-situ synthesized three-dimensional Ni(OH)₂ is introduced to improve NBT dispersion in PVDF. During hydrothermal reaction, NBT aggregates are dispersed on the petals of in-situ grown Ni(OH)₂ crystals as small aggregates. The three-dimensional structure of Ni(OH)₂ can act as physical barrier to prohibit secondary agglomeration in PVDF to allow rather uniform NBT dispersion. Meanwhile, these hydroxyl groups on Ni(OH)₂ ensures good interaction between filler and PVDF, and trigger β crystals. Comparing with NBT/PVDF containing the same amount of filler(2.5 wt%), the breakdown strength and maximum energy density containing mixed filler increases 14% and 70%, reach 282.6 KV/mm and 6.13 J cm⁻³, respectively. This study provides a new approach to uniformly disperse nanofillers in polymer for enhanced dielectric properties.

纳米钛酸钡（NBT）在聚偏二氟乙烯（PVDF）中的分散是介电复合材料的关键问题之一。已经报道了遭受复杂过程和小规模生产的各种NBT表面改性策略。在此，引入原位合成的三维Ni（OH）₂以改善NBT在PVDF中的分散。在水热反应过程中，NBT聚集体以小聚集体形式分散在原位生长的Ni（OH）₂晶体的花瓣上。Ni（OH）₂的三维结构可以充当物理屏障，以阻止PVDF中的二次附聚，从而实现相当均匀的NBT分散。同时，Ni（OH）₂上的这些羟基确保填料与PVDF之间的良好相互作用，并触发β晶体。与含相同量填料（2.5 wt％）的NBT / PVDF相比，含混合填料的击穿强度和最大能量密度分别提高了14％和70％，分别达到282.6 KV / mm和6.13 J cm ^-3。这项研究提供了一种将纳米填料均匀分散在聚合物中以增强介电性能的新方法。