The present invention discloses a boron-containing plastic crystal polymer and a preparation method therefor and an application thereof. The described preparation method comprises the following step: curing a mixture containing a plastic crystal, a metal salt, a monomer and a photoinitiator. The plastic crystal polymer prepared by the present invention can be used as all-solid electrolyte, without any liquid additive being added therein. The obtained electrolyte has a room-temperature ionic conductivity up to 3.6104 S/cm, and shows a high sodium ion transference number and a wide electrochemical window up to 4.7V. The present invention further prepares composite positive and negative electrodes for positive and negative electrode modification of a sodium ion battery. A finally assembled all-solid sodium ion battery shows good rate performance and cycle stability at room temperature, achieving a specific discharge capacity up to 104.8 mAh/g at room temperature and a capacity retention ratio of 85.4% after 80 cycles.

Processes of polymerizing polyolefins and synthesis of activators. The polymerization processes include polymerizing one or more (C.sub.2-C.sub.12)-olefin monomers in the presence of at least one catalyst and at least one co-catalyst to produce a polyolefin. The co-catalyst includes a cation and an anion, in which the anion has a structure having a vinyl terminated alkene, one boron atom or more than one boron atoms, and at least four halogen atoms. The anion of the co-catalysts is incorporated into a polymer chain of the polyolefin.