选取SiO₂粒子为纳米添加剂，以超净交联聚乙烯（XLPE）作基体，分别按质量分数1%、2%和3%的掺杂比例制得3种SiO₂/XLPE复合材料。分析材料的结晶行为，包括材料的结晶度、结晶峰初始斜率、结晶峰温差以及半峰宽，研究材料在X射线衍射测试下的微晶尺寸，探究添加SiO₂粒子后材料击穿性能的变化。结果表明，粒子的添加可以在超净XLPE基体材料内部起到异相成核作用，均化晶粒尺寸分布，但这种效果随着粒子添加量的增加而减弱。添加质量分数1%的SiO₂粒子，材料（110）与（200）晶面微晶尺寸均提升至11%以上，晶粒生长较好，能够形成稳定晶区-非晶区界面，限制电子迁移，材料击穿性能上升了39.8%。SiO₂粒子掺杂质量分数提高到2%和3%时，由于团聚效应，材料结晶行为受限，结晶度分别下降约6%和13%，这会导致基体内部形成界面弱区，并增大自由体积、电子平均自由程，材料击穿性能分别降低6.5%与14.3%。

The SiO₂ particles were chosen as nano-additives, and ultra-clean crosslinked polyethylene (XLPE) was used as matrix. Three kinds of SiO₂/XLPE composites were prepared with doping ratios of 1%, 2% and 3% by mass fraction. The crystallization behavior of the materials was analyzed, including the degree of crystallinity, the initial slope of the crystallization peak, the temperature difference of the crystallization peak, and the half-peak width. The microcrystalline size of the materials under X-ray diffraction testing was studied, and the changes in the breakdown property of the materials after the addition of SiO₂ particles were investigated. The results show that the addition of particles can act as heterogeneous nucleation within the ultra-clean XLPE matrix material, homogenizing the grain size distribution, but this effect diminishes with increasing particle addition. With the addition of 1% mass fraction of SiO₂ particles, the microcrystalline size of the (110) and (200) crystal planes of the material both increase to over 11%, with good grain growth, forming a stable crystalline-amorphous interface, which restricts electron migration, and the breakdown property of the material increases by 39.8%. When the doping mass fraction of SiO₂ particles is increased to 2% and 3%, the crystallization behavior of the material is restricted due to aggregation effects, resulting in a decrease in crystallinity of approximately 6% and 13%, respectively, which leads to the formation of interfacial weak zones within the matrix and an increase in free volume and the average free path of electrons, decreasing the breakdown property of the material by 6.5% and 14.3%, respectively.